tag:theconversation.com,2011:/au/topics/human-effect-on-habitat-2468/articlesHuman effect on habitat – The Conversation2018-06-14T18:01:03Ztag:theconversation.com,2011:article/981352018-06-14T18:01:03Z2018-06-14T18:01:03ZTo avoid humans, more wildlife now work the night shift<figure><img src="https://images.theconversation.com/files/223236/original/file-20180614-32319-1rmbjtk.jpg?ixlib=rb-1.1.0&rect=557%2C393%2C3830%2C2787&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Red fox under cover of darkness in London</span> <span class="attribution"><a class="source" href="https://www.jamiehallphotography.co.uk/index">Jamie Hall. For use only with this article.</a></span></figcaption></figure><p>For their first 100 million years on planet Earth, our mammal ancestors relied on the cover of darkness to escape their dinosaur predators and competitors. Only <a href="https://doi.org/10.1038/s41559-017-0366-5">after the meteor-induced mass extinction of dinosaurs</a> 66 million years ago could these nocturnal mammals explore the many wondrous opportunities available in the light of day.</p>
<p>Fast forward to the present, and the honeymoon in the sun may be over for mammals. They’re increasingly returning to the protection of night to avoid the Earth’s current terrifying super-predator: <em>Homo sapiens</em>.</p>
<p>My colleagues <a href="https://scholar.google.com/citations?user=L_vGm14AAAAJ&hl=en&oi=ao">and I</a> have made the first effort to measure the global effects of human disturbance on the daily activity patterns of wildlife. <a href="https://doi.org/10.1126/science.aar7121">In our new study</a> in the journal Science, we documented a powerful and widespread process by which mammals alter their behavior alongside people: Human disturbance is creating a more nocturnal natural world. </p>
<p>Many catastrophic effects of humans on wildlife communities have been well-documented: We are responsible for habitat destruction and overexploitation that have <a href="https://doi.org/10.1126/science.1251817">imperiled animal populations</a> around the world. However, just our presence alone can have important behavioral impacts on wildlife, even if these effects aren’t immediately apparent or easy to quantify. Many animals fear humans: We can be large, noisy, novel and dangerous. Animals often go out of their way to avoid encountering us. But it’s becoming more and more challenging for wildlife to seek out human-free spaces, as the human population grows and our footprint expands across the planet.</p>
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<a href="https://images.theconversation.com/files/223060/original/file-20180613-32313-kcwiu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/223060/original/file-20180613-32313-kcwiu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/223060/original/file-20180613-32313-kcwiu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223060/original/file-20180613-32313-kcwiu6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223060/original/file-20180613-32313-kcwiu6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223060/original/file-20180613-32313-kcwiu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223060/original/file-20180613-32313-kcwiu6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223060/original/file-20180613-32313-kcwiu6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A badger explores a South London cemetery at night.</span>
<span class="attribution"><span class="source">Laurent Geslin. For use only with this article.</span></span>
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<h2>Global increase in nocturnality</h2>
<p>My collaborators and I noticed a striking pattern in some of our own data from research in Tanzania, Nepal and Canada: animals from impala to tigers to grizzly bears seemed to be more active at night when they were around people. Once the idea was on our radar, we began to see it throughout the published scientific literature.</p>
<p>It appeared to be a common global phenomenon; we set out to see just how widespread this effect was. Might animals all over the world be adjusting their daily activity patterns to avoid humans in time, given that it is becoming harder to avoid us in space? </p>
<p>To explore this question, we conducted a <a href="https://doi.org/10.1038/nature25753">meta-analysis</a>, or a study of studies. We systematically scoured the published literature for peer-reviewed journal articles, reports and theses that documented the 24-hour activity patterns of large mammals. We focused on mammals because their need for plenty of space often brings them into contact with humans, and they possess traits that allow for some flexibility in their activity.</p>
<p>We needed to find examples that provided data for areas or seasons of low human disturbance – that is, more natural conditions – and high human disturbance. For example, studies compared deer activity in and out of the hunting season, grizzly bear activity in areas with and without hiking, and elephant activity inside protected areas and outside among rural settlement.</p>
<p>Based on reported data from remote camera traps, radio collars or observations, we determined each species’ nocturnality, which we defined as the percentage of the animal’s total activity that occurred between sunset and sunrise. We then quantified the difference in nocturnality between low and high disturbance to understand how animals changed their activity patterns in response to people.</p>
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<a href="https://images.theconversation.com/files/223249/original/file-20180614-32310-1xo577y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/223249/original/file-20180614-32310-1xo577y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/223249/original/file-20180614-32310-1xo577y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=612&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223249/original/file-20180614-32310-1xo577y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=612&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223249/original/file-20180614-32310-1xo577y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=612&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223249/original/file-20180614-32310-1xo577y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=769&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223249/original/file-20180614-32310-1xo577y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=769&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223249/original/file-20180614-32310-1xo577y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=769&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">For each species, researchers compared the animals’ active periods when people are nearby to when people aren’t around. The distance between the grey and red dot pair for each animal shows how extreme the shift in nocturnality.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1126/science.aar7121">Reprinted with permission from Gaynor et al., Science 360:1232 (2018). For use only with this article.</a></span>
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<p>Overall, for the 62 species in our study, mammals were <a href="https://doi.org/10.1126/science.aar7121">1.36 times as nocturnal in response to human disturbance</a>. An animal that naturally split its activity evenly between the day and night, for example, would increase its nighttime activity to 68 percent around people.</p>
<p>While we expected to find a trend toward increased wildlife nocturnality around people, we were surprised by the consistency of the results around the world. Eighty-three percent of the case studies we examined showed some increase in nocturnal activity in response to disturbance. Our finding was consistent across species, continents and habitat types. Antelope on the savanna of Zimbabwe, tapir in the Ecuadorian rainforests, bobcats in the American southwest deserts – all seemed to be doing what they could to shift their activity to the cover of darkness.</p>
<p>Perhaps most surprisingly, the pattern also held across different types of human disturbance, including activities such as hunting, hiking, mountain biking, and infrastructure such as roads, residential settlement and agriculture. Animals responded strongly to all activities, regardless of whether people actually posed a direct threat. It seems human presence alone is enough to disrupt their natural patterns of behavior. People may think our outdoor recreation leaves no trace, but our mere presence can have lasting consequences. </p>
<h2>Future of human-wildlife coexistence</h2>
<p>We don’t yet understand the consequences of this dramatic behavioral shift for individual animals or populations. Over millions of years, many of the animals included in our study have evolved adaptations to living in the daylight.</p>
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<a href="https://images.theconversation.com/files/223243/original/file-20180614-32327-i3eot0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/223243/original/file-20180614-32327-i3eot0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/223243/original/file-20180614-32327-i3eot0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=778&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223243/original/file-20180614-32327-i3eot0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=778&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223243/original/file-20180614-32327-i3eot0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=778&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223243/original/file-20180614-32327-i3eot0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=977&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223243/original/file-20180614-32327-i3eot0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=977&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223243/original/file-20180614-32327-i3eot0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=977&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Sun bears retreat from the sunny hours when people are nearby.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sun-bear-495966712">Hakumakuma/Shutterstock</a></span>
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<p><a href="http://eol.org/pages/328074/details">Sun bears</a>, for example, are typically diurnal and sun-loving creatures; in undisturbed areas less than 20 percent of their activity occurred at the night. But they <a href="https://doi.org/10.1046/j.1523-1739.1993.07030623.x">increased their nocturnality to 90 percent</a> in areas of the Sumatran forest where intensive forest research activity created a disturbance.</p>
<p>Such diurnally adapted animals may not be as successful at finding food, avoiding predators or communicating in the darkness, which could even reduce their survival or reproduction. </p>
<p>However, because our mammalian ancestors evolved under the cover of darkness in the time of the dinosaurs, most mammal species possess traits that allow for some flexibility in their activity patterns. As long as animals are able to meet their needs during the night, they may actually thrive in human-dominated landscapes by avoiding daytime direct encounters with people that could potentially be dangerous for both parties. In Nepal, for example, <a href="https://doi.org/10.1073/pnas.1210490109">tigers and people share the exact same trails</a> in the forest at different times of day, reducing direct conflict between humans and these large carnivores. Dividing up the day, through what researchers call temporal partitioning, may be a mechanism by which people and wildlife can coexist on an ever more crowded planet.</p>
<p>An increase in nocturnality among certain species may also have far-reaching consequences for ecosystems, reshaping species interactions and cascading through food webs. In California’s Santa Cruz Mountains, <a href="https://doi.org/10.1016/j.biocon.2015.05.007">coyotes are becoming more nocturnal</a> in areas with human recreation. By analyzing coyote scat, scientists have linked this behavioral change to <a href="https://doi.org/10.1111/oik.04592">dietary shifts from diurnal to nocturnal prey</a>, with implications for small mammal communities and for competition with other predators.</p>
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<a href="https://images.theconversation.com/files/223055/original/file-20180613-32347-18lcrdn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/223055/original/file-20180613-32347-18lcrdn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/223055/original/file-20180613-32347-18lcrdn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223055/original/file-20180613-32347-18lcrdn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223055/original/file-20180613-32347-18lcrdn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223055/original/file-20180613-32347-18lcrdn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223055/original/file-20180613-32347-18lcrdn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223055/original/file-20180613-32347-18lcrdn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">European beaver active at night in Orléans, France.</span>
<span class="attribution"><a class="source" href="https://www.eurekalert.org/jrnls/sci/pages/gaynor-06-15-18.html">Laurent Geslin. For use only with this article.</a></span>
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<p>Working on this study reminded me that people aren’t alone on the planet. Even if we don’t see large mammals while we’re out and about during the day, they may still be living alongside us, asleep while we are awake and vice versa. In areas where threatened species live, managers may consider restricting human activity to certain times of the day, leaving some daylight just for wildlife.</p>
<p>And it is likely that we need to preserve wilderness areas entirely free of human disturbance to conserve the most vulnerable and sensitive mammal species. Not all animals are willing or able to just switch to a nocturnal lifestyle around people. Those that try to avoid human disturbance entirely may be most vulnerable to the consequences of the expanding human footprint.</p><img src="https://counter.theconversation.com/content/98135/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kaitlyn Gaynor receives funding from the National Science Foundation. </span></em></p>It’s becoming harder and harder for animals to find human-free spaces on the planet. New research suggests that to try to avoid people, mammals are shifting activity from the day to the nighttime.Kaitlyn Gaynor, Ph.D. Candidate in Environmental Science, Policy and Management, University of California, BerkeleyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/575052016-04-11T03:45:54Z2016-04-11T03:45:54ZThe future for frogs looks bleak, unless humans change their habits<figure><img src="https://images.theconversation.com/files/117973/original/image-20160408-23649-1qxbogn.jpg?ixlib=rb-1.1.0&rect=0%2C516%2C2537%2C1652&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Frogs in the Western Cape area of South Africa are susceptible to climate change.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Amphibians, the oldest group of land vertebrates, are regarded as the <a href="http://science.sciencemag.org/content/306/5702/1783">most threatened across the globe</a>. From Brazil’s tropical rain forests, to Canada’s temperate boreal forests, from fresh streams in the Alps to Australia’s temporary ponds, most populations are declining. Contributing factors include habitat destruction, invasive species, disease spread and rapid climate change. Most are human induced.</p>
<p>Frogs are ectotherms: they generate their heat from the environment around them. When the temperature changes in their native areas, frogs need to change their behaviour or habitat to stay at their preferred temperature. </p>
<p>Frogs are also generally regarded as poor dispersers among land vertebrates. This means that, unlike birds or large mammals, they find it difficult to move – or they move slowly – across landscapes. As a result, it has been suggested that they will not be able to keep track of rapid climate change because they cannot cover the distances required to match the particular climate they require. </p>
<p>South Africa’s Cape region, comprising both succulent semi-desert and <a href="http://www.fynboshub.co.za/fynbos-conservation/what-is-fynbos/">fynbos</a> vegetation, has a unique amphibian fauna that has been <a href="http://science.sciencemag.org/content/339/6115/74">recognised globally</a>. It consists of more than 50 species of frogs, 37 of which are endemic (they occur nowhere else in the world). Cape frogs are important because of their global uniqueness.</p>
<p>But their future may be under threat, and the climate of the future looks to be changing faster than the steady climate they evolved into in the past. How can we target conservation interventions to pinpoint which species or sub-populations need particular help? </p>
<h2>Confined to smaller and smaller areas</h2>
<p>Biologists have already observed that species use different methods to keep up with changes in climate. These methods broadly involve species shifting their distribution to track suitable climate, and changes in behaviour and genetic make-up to enable them to survive new climate regimes.</p>
<p>In a recently published <a href="http://www.sajs.co.za/assessing-effects-climate-change-distributions-cape-floristic-region-amphibians/mohlamatsane-m-mokhatla-dennis-r%C3%B6dder-g-john-measey">study</a>, we looked at how changes in global climate have affected the spread of the endemic Cape frog community during two key periods in recent history: the <a href="http://science.sciencemag.org/content/325/5941/710">Last Glacial Maximum</a> about 21,000 years ago; and the <a href="http://link.springer.com/article/10.1007/s00382-007-0231-3">Holocene Glacial Minimum</a> about 6,000 years ago.</p>
<p>We then projected the distributions forward into two possible future scenarios using two emission scenarios. This allowed us to ask whether the forecasted climates would significantly change the distribution of Cape frogs. By predicting these future distributions, we were able to assess whether these species are likely to move in specific directions, like north or south, or whether their distributions are likely to become fragmented. It also established which particular group of frogs is likely to be more negatively affected.</p>
<p>The results were startling. Our models suggested that the area occupied by Cape frogs today is just a fraction of the area of suitable climate space they would have had available at the Last Glacial Maximum. But comparing the current distribution with that at the Holocene Glacial Minimum provided very little evidence for change. The biggest surprise was the massive loss in suitable climate space between current distributions and future forecast scenarios in 2080. </p>
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<a href="https://images.theconversation.com/files/117974/original/image-20160408-23645-gaxjo7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/117974/original/image-20160408-23645-gaxjo7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/117974/original/image-20160408-23645-gaxjo7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/117974/original/image-20160408-23645-gaxjo7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/117974/original/image-20160408-23645-gaxjo7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/117974/original/image-20160408-23645-gaxjo7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/117974/original/image-20160408-23645-gaxjo7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/117974/original/image-20160408-23645-gaxjo7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Cape frogs are likely to be confined to a smaller space due to climate change.</span>
<span class="attribution"><span class="source">Reuters</span></span>
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<p>Not only are Cape frogs likely to be confined to a much smaller area, but the rate at which they will be forced to move is faster than anything that they have experienced in a very long time. This would mean that many of the species would experience a fragmentation effect: their sub-populations would be separated beyond what they’re likely to be able to bridge through their own hopping abilities. In other words, sub-populations would become isolated from each other – and too far apart to reach each other to breed. This effectively makes each small sub-population more vulnerable to extinction.</p>
<p>Our models predict that the suitable climate space is likely to shift Cape frog distributions to the north. Based on the estimates, this has been a trend since the Last Glacial Maximum. But in the past this would have seen a movement rate equivalent to 1km per 1,000 years. The movement between the present and the worst emission scenario in 2080 is more than 500 times faster.</p>
<h2>Is there any hope?</h2>
<p>Our interest is in the trends that the data show, and asking how these potential scenarios could be mitigated by conservation actions today. For example, in the future lowland species are expected to be more fragmented than highland species. This shows the need to establish corridors of suitable habitat between existing sites for many species. </p>
<p>These areas need to be made up of both terrestrial and aquatic habitats, allowing animals to track suitable climate space as they move. Where possible, corridors should not only move between lowland sites, but link lowland to upland sites. </p>
<p>By making predictions of what may happen to the Cape community of frogs, we are providing information that may be typical for any animal with limited dispersal ability, including lizards and flightless insects. </p>
<p>The comparative datasets for many smaller invertebrates are absent. But our results could be generalised to a much larger group of ectothermic animals that are limited in their ability to move.</p>
<p>Our study has shown that despite major changes in climate, as well as available habitat in the Cape, the frogs continue to survive. Their resilience is likely to require our help in the future through conservation actions that not only preserve their current breeding and foraging sites but also enable them to move into areas with suitable climate conditions.</p>
<p>There is hope. If the global community can stick to the recent <a href="https://unfccc.int/resource/docs/2015/cop21/eng/l09r01.pdf">Paris Agreement</a>, our scenario suggests that the biotic velocity – the distance and/or time to move between the point where a population is and the nearest climatically suitable space – of the Cape frog community will be roughly double that of historical rates. </p>
<p>Many conservation agencies have started <a href="http://sourcetosea.org.za/">taking specific actions</a> that would see many coastal and upland areas linked through areas of continuous reserves. </p>
<p>The study has also helped identify areas where the frogs can be monitored to assess whether climate change is likely to affect them. These include lowland areas that are already very heavily affected by humans for agriculture and living space. These areas won’t be changed back to their original state, but they could be made more tolerant of the flora and fauna that could be used as corridors. Today, frogs are reliant on the spaces that we humans make for them.</p><img src="https://counter.theconversation.com/content/57505/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Measey receives funding from the Centre of Excellence for Invasion Biology and the National Research Foundation of South Africa. </span></em></p><p class="fine-print"><em><span>Mohlamatsane is funded by the National Research Foundation (NRF) PhD Innovation bursary and the Nelson Mandela Metropolitan University (NMMU).</span></em></p>Climate change may threaten the survival of the Cape frog. The solution could lie in creating corridors for them to move to new habitats and more suitable climate spaces.John Measey, Senior Researcher at the CIB based in the Department of Botany and Zoology, Stellenbosch UniversityMohlamatsane Mokhatla, Scientist at South African National Parks & PhD student at the CIB, Department of Botany and Zoology, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/550422016-02-29T04:25:16Z2016-02-29T04:25:16ZWhy southern Africa’s iconic baboon is on the decline<figure><img src="https://images.theconversation.com/files/112893/original/image-20160225-15165-smkc8g.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The core habitat of the notorious chacma baboon is becoming smaller due to human takeover.</span> <span class="attribution"><span class="source">Olivia Stone</span></span></figcaption></figure><p>Southern Africans have a love-hate relationship with chacma baboons. They have an unmistakable presence on the landscape, but their reputation as notorious troublemakers makes them unpopular. Lethal removal is common throughout their range; humans are the principal cause of the population decline.</p>
<p>The people of southern Africa associate the infamous primates with home, even though they are are seen as pests. They are as much a part of southern African heritage as the big five (elephant, rhinoceros, buffalo, lion and leopard), rich cultural diversity, and the magnificent vista. Baboons are an African icon.</p>
<p>Humans have actually taken over most of the key areas where baboons traditionally live. These key areas include many major cities where baboons are seemingly abundant. In reality, baboon numbers are dropping.</p>
<p>Human versus baboon competition and conflict probably always existed due to the close association between our species, as seen in fossil records. But baboons have never before encountered the human population expansion and vast land transformations that are permanently altering the modern landscape. </p>
<p>Now more than ever, it appears that baboons are losing the ability to access large amounts of land that has historically been central to their survival. Their core habitat is diminishing.</p>
<p>The general perception is that baboons are abundant, despite <a href="http://link.springer.com/article/10.1007/s10329-012-0303-9">evidence of population decline</a>. This belief exists, in part, because in many cities and populated areas we can still see baboons daily. But <a href="http://dx.doi.org/10.17159/sajs.2015/20140279">new research</a> suggests these same areas are the very regions that offer the best environmental conditions for baboon survival; it is their core habitat. So, baboons will inevitably attempt to inhabit these areas in preference to areas that outwardly appear more suitable, with less human population and disturbance. </p>
<p>The impression of abundance may relate to the baboons’ continuing proximity to human populated areas. Effectively, it is a fight over prime real estate.</p>
<p>This prime real estate, or <a href="http://dx.doi.org/10.17159/sajs.2015/20140279">baboon environmental core habitat</a>, is approximately 10% of the entire range for the baboon. It includes or is adjacent to more than 30 major southern African cities. These cities included Harare, Johannesburg, Pretoria, Soweto, Bulawayo, Port Elizabeth and one of the fastest-growing cities in Africa, Botswana’s Gaborone, to name a few.</p>
<p>To put it simply, the baboon populations are intertwined with human settlements because we are living in their core habitat. Instinctively these animals want to be there too.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/112895/original/image-20160225-15145-bxgm86.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/112895/original/image-20160225-15145-bxgm86.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/112895/original/image-20160225-15145-bxgm86.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=605&fit=crop&dpr=1 600w, https://images.theconversation.com/files/112895/original/image-20160225-15145-bxgm86.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=605&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/112895/original/image-20160225-15145-bxgm86.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=605&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/112895/original/image-20160225-15145-bxgm86.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=760&fit=crop&dpr=1 754w, https://images.theconversation.com/files/112895/original/image-20160225-15145-bxgm86.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=760&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/112895/original/image-20160225-15145-bxgm86.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=760&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Much of the natural core habitat of the chacma baboon is in areas where humans are now living.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Gaborone</h2>
<p>According to the IUCN Red List of Threatened Species’ chacma baboon distribution <a href="http://www.iucnredlist.org/details/16022/0">map</a>, there is a large uninhabited area of land – that also happens to be core habitat – in eastern Botswana. </p>
<p>This area also happens to include or be adjacent to seven of Botswana’s major centres, including Gaborone and the close (100km) surrounds that by 1991 contained 50% of the human population of <a href="https://www.google.co.nz/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjvyYqV9OvKAhUBG5QKHVyNAp8QFggfMAA&url=http%3A%2F%2Fwww.ibrarian.net%2Fnavon%2Fpaper%2FPatterns_and_Trends_of_Urbanization_in_Botswana__.pdf%3Fpaperid%3D2572503&usg=AFQjCNGpKE_5NcaIye0r_IA92WfS2rLCSQ&sig2=TT3dLdUfljEPEa66CMwPJg">Botswana</a>. </p>
<p>Gaborone itself has a human population density of <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0031743">1 160 people per km2</a> and that particular region of core habitat has a higher human population density than the majority – three-quarters – of southern African baboon core habitat. All of this, combined with the extensive growth of Botswana’s urban satellite <a href="http://ecastats.uneca.org/aicmd/Portals/0/Census%202011%20Preliminary%20%20Brief%20Sept%2029%202011.pdf">villages</a>, means that the land transformation and deterioration in this region is likely to be widespread and pervasive. So, the absence of baboons may not be surprising.</p>
<p>The problem is not limited to Botswana – it is southern-Africa-wide. For example, the status of baboons in Lesotho is unknown and likely poor. The <a href="http://dx.doi.org/10.17159/sajs.2015/20140279">limited core habitat in Lesotho</a> is in close proximity to seven out of ten district capitals. </p>
<p>The core habitat in South Africa – which is more than half of the total core habitat of southern Africa – also contains at least 62 settlements or cities of more than 20,000 people. This includes the major cities mentioned above, in addition to many smaller settlements. In the South African province of KwaZulu-Natal, <a href="http://dx.doi.org/10.17159/sajs.2015/20140279">less than 5%</a> of baboon core habitat contains baboons</p>
<h2>What does this mean?</h2>
<p>We need to consider that baboons are highly resilient adaptable animals, so if we begin to detect a decline in their population, we must consider that the less resilient animals are potentially already in a worse condition.</p>
<p>Think of it like an ecological alarm system. When this species starts to falter, we have problems.</p>
<p>Second, more than half of the world’s primates that have known conservation status are classified as <a href="http://www.iucn.org/?11259/Primates-in-peril--conservationists-reveal-the-worlds-25-most-endangered-primates">threatened</a>. The baboon is one of the few primate species that has survived thus far without failing. </p>
<p>Despite all of the baboons’ perceived misgivings, can we really afford to sit back and let the chacma baboon become part of those statistics?</p>
<h2>What can we do?</h2>
<p>Start teaching respect for nature, including understanding that wild animals will be wild. We need to raise awareness that baboons are trying to live in their natural habitat and are not necessarily problem animals, therefore alternative, non-lethal strategies may have potential.</p>
<p>General conservation efforts need to aim to preserve areas of land that have the lower population and less degradation and are within these core habitat areas. Baboons are not necessarily protected in “protected” areas. </p>
<p>Private reserves and game parks, along with government land areas, should consider protecting these animals. If nothing else, we should acknowledge this loss of habitat and currently reported population decline, and that alone should motive us to do regional reassessments to confirm population status over the wider southern African region.</p>
<p>We need to make a start and stop burying our heads in the sand. Or it will be a sad day when the iconic symbol – the baboon silhouettes on a hill, in the setting African sun – is no longer visible.</p><img src="https://counter.theconversation.com/content/55042/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Olivia Stone does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The iconic southern African Chacma baboon is in danger. The species is facing a population decline.Olivia Stone, Researcher at the Evolution & Ecology Research Centre, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/497282016-02-04T13:40:27Z2016-02-04T13:40:27ZHow humans threaten pumas just by being nearby<figure><img src="https://images.theconversation.com/files/99742/original/image-20151026-18440-1t7gp1v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A puma and her two kittens look out over San Jose, California.</span> <span class="attribution"><span class="source">Cchristopher Fust</span>, <span class="license">Author provided</span></span></figcaption></figure><p>You are wandering in the forest where you live, thinking about what you are going to have for dinner. Among the familiar calls of chickadees, you hear a foreign sound. You crouch in hiding, frightened for yourself and your family. Not until nightfall does the noise abate, allowing you to move again under the cloak of darkness. Soon you learn that the sounds come from unfamiliar beings taking over your homeland. You learn to live in hiding, believing that as soon as you let your guard down you may pay the ultimate price.</p>
<p>This is not the premise of a zombie apocalypse movie. It is the story of human expansion into wild places, where the wildlife that coexists with us often lives in chronic fear of humans. </p>
<p>Disturbance by humans changes the behavior of animals near towns, along roads and in areas that we use for mining, energy development and recreation. Although conservationists are starting to consider how the presence of humans affects the behavior of some species, they rarely analyze how these changes in animals’ behavior affects entire ecosystems. In my research examining pumas, or mountain lions, in California, I’ve found that our presence alters how they hunt for deer, which can have a significant effect on the ecosystem overall.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/99746/original/image-20151026-18443-1bbbnkg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/99746/original/image-20151026-18443-1bbbnkg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/99746/original/image-20151026-18443-1bbbnkg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=803&fit=crop&dpr=1 600w, https://images.theconversation.com/files/99746/original/image-20151026-18443-1bbbnkg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=803&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/99746/original/image-20151026-18443-1bbbnkg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=803&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/99746/original/image-20151026-18443-1bbbnkg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1009&fit=crop&dpr=1 754w, https://images.theconversation.com/files/99746/original/image-20151026-18443-1bbbnkg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1009&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/99746/original/image-20151026-18443-1bbbnkg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1009&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Deer killed by puma in a residential area of the Santa Cruz Mountains.</span>
<span class="attribution"><span class="source">Justine A. Smith</span></span>
</figcaption>
</figure>
<h2>Fear factor</h2>
<p>Fear is a powerful force in ecosystems. For decades, ecologists have acknowledged that fear can dictate when, where, and what animals eat, what habitats they use and how they communicate with one another. These behavioral changes in animals are ecologically important because they can change interactions among species. Although many animals are known to respond fearfully to their predators, we are only beginning to understand how humans elicit the same responses in wildlife.</p>
<p>In the Santa Cruz Mountains of California, I am studying how fear of humans in a top predator, the puma, resonates throughout the ecosystem. The Santa Cruz Mountains are isolated from other natural areas, bordered by the Pacific Ocean on the west, the San Francisco Bay metropolitan area on the north, and a major highway on the east. Like many places across the country, this region is dotted with residential developments and land utilized for mining and logging. However, it also contains open space preserves and state and county parks that provide important high-quality habitat for wildlife. </p>
<p>This kind of multi-use and fragmented landscape is increasingly becoming the norm in places where humans encroach on wild lands. To keep developing areas as wild as possible, we need to conserve natural animal behaviors and relationships.</p>
<h2>Scaredy cats</h2>
<p>With my colleagues at the <a href="http://santacruzpumas.org/">Santa Cruz Puma Project</a>, I am studying how human disturbances indirectly affect the behavior of pumas, the last remaining large carnivores in our region that roam the ravines between ridges lined with houses. We have <a href="https://doi.org/10.1371/journal.pone.0060590">found</a> that pumas attempt to avoid people, but their sensitivity to disturbance depends on what the cats are doing. Although pumas consistently travel and kill prey relatively close to human developments, they make their dens and communicate with each other through scent marking in areas far from zones that humans have altered. </p>
<p>In many types of ecosystems, researchers have observed that animals will <a href="https://doi.org/10.1139/z90-092">avoid feeding opportunities</a> when they fear a predator. To see whether the presence of humans was having this effect on pumas, I examined behavioral changes at kill sites in areas of the Santa Cruz Mountains with varying levels of human activity. To find these kill sites, our team tracked GPS-collared pumas using their locations and searched for prey remains. I then used data from the GPS collars to learn how behavior at these kill changed near human development. </p>
<p>Surprisingly, I <a href="https://doi.org/10.1098/rspb.2014.2711">found</a> that pumas often kill deer near human residences. However, unlike in wild areas where pumas stay close to their kills for a few days while they feed, pumas in developed areas leave their kills and move away from humans to rest, returning to feed only after dark. This causes pumas to waste energy by spending more time on the move, while losing opportunities to feed on their kills. Moreover, pumas that hunt in the most disturbed areas kill 36 percent more deer than pumas in the most rural areas. We believe that pumas ranging near developed areas kill more deer because they cannot fully consume their prey while also avoiding interactions with humans. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/110183/original/image-20160203-5822-3q2wz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/110183/original/image-20160203-5822-3q2wz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=188&fit=crop&dpr=1 600w, https://images.theconversation.com/files/110183/original/image-20160203-5822-3q2wz2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=188&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/110183/original/image-20160203-5822-3q2wz2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=188&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/110183/original/image-20160203-5822-3q2wz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=236&fit=crop&dpr=1 754w, https://images.theconversation.com/files/110183/original/image-20160203-5822-3q2wz2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=236&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/110183/original/image-20160203-5822-3q2wz2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=236&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Warning sign at Los Trancos Open Space Reserve, San Mateo County, California.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/kmanohar/3242740400/in/gallery-26760199@N06-72157635300877547/">kmanohar/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Our study provides evidence that the presence of humans not only changes the way top carnivores behave, but also indirectly impacts other species. Pumas that are afraid of humans but still hunt in residential areas alter their relationship with deer, their primary prey. Greater pressure on deer could possibly provide more food for scavengers or reduce deer browsing near developed areas. </p>
<p>Our work provides just one example of the cascading effects that human disturbance can cause in wild ecosystems. Human presence can fundamentally alter the ways in which species interact, which changes the function and composition of the animal community. By considering how humans impact the behavior of important species, we can develop conservation solutions that preserve entire functioning ecosystems.</p><img src="https://counter.theconversation.com/content/49728/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Justine Smith receives funding from the National Science Foundation, The Gordon and Betty Moore Foundation, The Nature Conservancy, Midpeninsula Regional Open Space District, UC Santa Cruz and the Felidae Conservation Fund.</span></em></p>Many Americans move to rural areas to live near nature. But the mere presence of humans changes wildlife behavior in ways that may have ripple effects.Justine Smith, Ph.D. Candidate in Conservation Biology, University of California, Santa CruzLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/398972015-05-07T09:51:53Z2015-05-07T09:51:53ZApes under pressure show their ingenuity – and hint at our own evolutionary past<figure><img src="https://images.theconversation.com/files/80533/original/image-20150505-966-bzjnni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Chimpanzees are wily enough to adapt in some ways when people encroach on their turf.</span> <span class="attribution"><span class="source">Kimberley Hockings</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>In the mid 20th century, when paleoanthropologist Louis Leakey sent three pioneering women to study great apes in their natural habitats, the Earth’s wilderness was still untouched in many places. <a href="http://www.janegoodall.org/janes-story">Jane Goodall</a> went to Gombe in Tanzania to study chimpanzees; at first she could only study them with binoculars from far away because the chimps would not let her approach. In those days, Gombe was not the tiny island of forest surrounded by villages and crop fields it is today. In the neighboring country of Rwanda, <a href="http://gorillafund.org/about_dian_fossey">Dian Fossey</a> became the first researcher to be accepted by wild mountain gorillas. In the 1960s, her “gorillas in the mist” had not yet suffered the severe impact of war and refugees. The third of “<a href="http://dx.doi.org/10.1126/science.260.5106.420">Leakey’s Angels</a>,” Birutė Galdikas, arrived in Borneo to study the red apes, orangutans. When she started her work in 1971, oil-palm plantations and loggers were just beginning to force orangutans into increasingly small patches of rain forest.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/80566/original/image-20150505-943-1wqsgnj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/80566/original/image-20150505-943-1wqsgnj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/80566/original/image-20150505-943-1wqsgnj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/80566/original/image-20150505-943-1wqsgnj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/80566/original/image-20150505-943-1wqsgnj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/80566/original/image-20150505-943-1wqsgnj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/80566/original/image-20150505-943-1wqsgnj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/80566/original/image-20150505-943-1wqsgnj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A baby mountain gorilla born today has never known a pristine environment free of threat from people.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/duplisea/4294912776">Bradford Duplisea</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>When these pioneering women started studying great apes in their pristine forests, the Earth had just entered a time characterized by the tremendous impact of humans on every ecosystem of our planet, what many scientists call a new epoch: the <a href="http://www.anthropocene.info/en/anthropocene">Anthropocene</a>. Hunting, poaching and logging was taking place in the 1960s and 1970s, but the scale of the problem has dramatically increased since then. </p>
<p>As researchers studying great apes in the wild, we’re fully aware that there are few, if any, untouched forests left in tropical Africa and Southeast Asia. Chimpanzee sites across equatorial Africa are suffering <a href="http://dx.doi.org/10.1038/nature13727">human disturbance</a>, but little is known about the ways in which these apes are surviving alongside their human neighbors. The unfortunate situation of declining habitat provides an interesting opportunity for science: we can study these apes in novel situations they’ve never had to deal with before and we can look for clues about our own evolutionary past.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/2uuB8VLUEfY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Bossou chimpanzees employ an old mechanism to adapt to a more recent dangerous situation.</span></figcaption>
</figure>
<h2>Responding to new pressures</h2>
<p>Is the behavior of our closest evolutionary cousins changing as <a href="http://dx.doi.org/10.1016/j.cub.2006.08.019">human settlements and roads</a> push into their habitats? We’ve observed that the chimpanzees of Bossou (Guinea), a field site under severe human pressure, increase their waiting time when they have to cross a large road with heavy human and vehicle traffic and wait less time before crossing a narrow, quieter road. Adult male chimpanzees are more likely to lead and bring up the rear when crossing the larger, more dangerous road with a group, in an attempt to protect vulnerable individuals in the road-crossing party, such as infants.</p>
<p>Apes now also need to cope with increased competition from human beings for resources such as fruits. Chimpanzees are developing new strategies to access resources that are shared with people. Adult males are more likely to take the risk to enter the village to raid human crops than females and younger individuals are; sometimes they bring these crops back to the safety of the forest to share with females. Researchers in Uganda have recorded <a href="http://dx.doi.org/10.1371/journal.pone.0109925">nocturnal crop-raiding</a> by chimpanzees. Typically, they haven’t previously been observed in activities after dark and this suggests that they are aware that the risks are lower under the cover of darkness.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/80558/original/image-20150505-969-mnmn82.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/80558/original/image-20150505-969-mnmn82.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/80558/original/image-20150505-969-mnmn82.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=406&fit=crop&dpr=1 600w, https://images.theconversation.com/files/80558/original/image-20150505-969-mnmn82.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=406&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/80558/original/image-20150505-969-mnmn82.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=406&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/80558/original/image-20150505-969-mnmn82.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=510&fit=crop&dpr=1 754w, https://images.theconversation.com/files/80558/original/image-20150505-969-mnmn82.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=510&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/80558/original/image-20150505-969-mnmn82.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=510&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Chimpanzee in Bossou demonstrates how to carry nuts and stone tools with just two feet on the ground.</span>
<span class="attribution"><span class="source">Jules Dore</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Novel situations appear to trigger novel behaviors on the part of great apes. For example, we’ve recently reported how chimpanzees in Bossou <a href="http://dx.doi.org/10.1016/j.cub.2012.01.052">exhibit bipedal behavior</a> when they need to transport unpredictable and valuable resources, including fruits. Normally chimpanzees move around on four legs. When chimpanzees go to a village to crop-raid papayas, it’s a risky behavior since frequently the fruits grow very close to people’s houses. To minimize their exposure, chimpanzees try to carry as much as possible at once, sometimes as many as three large papayas. By running on two feet, they can carry more of a resource that might not even be available next time they return.</p>
<p>When apes are confronted with new human-induced challenges, we’re able to study the flexibility of ape cognition. Can they figure out how to solve problems they would never encounter if people weren’t a part of their lives? Bossou chimpanzees, for example, have been seen <a href="http://dx.doi.org/10.1007/s10329-010-0212-8">deactivating snares</a> that hunters place in the forest to catch animals that will be eaten as bush meat. They’ve figured out how to free themselves from these traps, and even more amazingly it appears that they transmit the knowledge throughout their group. It’s a surprising and intelligent way of solving the problem, and something researchers haven’t observed in many other animals.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/80559/original/image-20150505-946-1miab9s.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/80559/original/image-20150505-946-1miab9s.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/80559/original/image-20150505-946-1miab9s.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/80559/original/image-20150505-946-1miab9s.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/80559/original/image-20150505-946-1miab9s.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/80559/original/image-20150505-946-1miab9s.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/80559/original/image-20150505-946-1miab9s.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/80559/original/image-20150505-946-1miab9s.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Villagers in Bossou watch chimps carrying out a papaya raid mission.</span>
<span class="attribution"><span class="source">Susana Carvalho</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Different apes living side by side</h2>
<p>The study of how these apes face new challenges may also teach us about our own evolutionary past. Researchers René Bobe and Bernard Wood, at George Washington University’s <a href="http://cashp.columbian.gwu.edu">Center for the Advanced Study of Human Paleobiology</a>, are focused on understanding living primates and ancient human fossils to learn about our origins and evolution. They work closely with us and our colleagues studying <a href="http://dx.doi.org/10.1016/j.tree.2015.02.002">ape responses to modern-day threats</a> to learn about our own evolution.</p>
<p>For example, how do modern ape species living in the same habitats at the same time interact with one another? During the course of our evolution over many millennia, we know that human ancestors faced severe climatic and environmental changes. Some species survived and continued to evolve. Others went extinct. At various times human ancestors and close evolutionary cousins shared the same environments, much like chimpanzees and gorillas do today in parts of Africa. But we know little about how some of these ancient species competed for space and resources.</p>
<p>Our own species survived these challenges to become the only ape able to colonize the entire planet, and to have in its hands the survival of all other remaining apes. By looking at how great apes coexist now, we might find clues into our own evolutionary past. For instance, the chimpanzees who choose to run on two feet when rushing back to the forest with village crops hint at which pressures may have contributed to our ancestors becoming bipedal.</p>
<p>Human beings and chimpanzees currently share the same habitats, as do human beings and orangutans. Studies of modern sympatric apes – that is, different ape species that live in the same area and encounter one another frequently – can help us answer crucial evolutionary questions: which apes can adapt to rapid environmental change? What characteristics help them do that? How do apes avoid conflict when they must share resources with other apes?</p>
<p>Researchers are interested in whether a more or less specialized diet could be a barrier for adapting to a changing habitat. We also wonder about how apes avoid conflict when facing the need to share resources with other apes. One study in Congo reported <a href="http://www.congo-apes.org/2013/wp-content/uploads/2013/08/Morgan-Sanz-2006-Feeding-Ecology-of-Chimpanzees-and-Gorillas-in-the-Goualougo-Triangle.pdf">interesting cases</a> of chimpanzees and gorillas eating in the same tree at the same time. What is their way of avoiding conflict and sharing resources and space? They feed at different heights of the tree and eat different parts of the plants!</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/80560/original/image-20150505-966-1o0wber.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/80560/original/image-20150505-966-1o0wber.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/80560/original/image-20150505-966-1o0wber.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=653&fit=crop&dpr=1 600w, https://images.theconversation.com/files/80560/original/image-20150505-966-1o0wber.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=653&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/80560/original/image-20150505-966-1o0wber.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=653&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/80560/original/image-20150505-966-1o0wber.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=821&fit=crop&dpr=1 754w, https://images.theconversation.com/files/80560/original/image-20150505-966-1o0wber.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=821&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/80560/original/image-20150505-966-1o0wber.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=821&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Eating and sharing papaya after crop raiding.</span>
<span class="attribution"><span class="source">Susana Carvalho</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Apes’ ability to adapt doesn’t mean they should have to</h2>
<p>The problem of apes adapting to human-dominated ecosystems has to be approached carefully. We dedicate our lives to trying to save these fascinating animals, and the last thing we want is to misuse the ability of apes to survive as a justification to continue the destruction of their remaining habitats. Some might argue that if wildlife can survive in highly human-influenced areas, then why put so much effort into conservation? </p>
<p>However, for apes to survive this new epoch, the Anthropocene, we need to understand how apes modify their behavior under human impact. We need to understand the limits of ape adaptability. Apes cannot adapt to urban areas, unlike some monkeys such as baboons and macaques. They do not survive in cities and towns. It’s imperative to understand the limits beyond which they cannot survive.</p><img src="https://counter.theconversation.com/content/39897/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Apes and people are sharing habitat more than ever. As apes are pushed into novel situations, we can see how they adapt and maybe find clues into early human evolution.Susana Carvalho, Postdoctoral Scientist in Human Paleobiology, George Washington UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/399752015-04-09T18:05:41Z2015-04-09T18:05:41ZGenome sequencing mountain gorillas reveals the genetic impact of inbreeding<figure><img src="https://images.theconversation.com/files/77550/original/image-20150409-15244-1rx6xcl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Not a happy cousin. </span> <span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Gorillas_in_Uganda-2,_by_Fiver_Löcker.jpg">Gorilla Tracking </a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Our genetic cousins, mountain gorillas, have been the subject of ongoing conservation efforts for decades. Despite this there are fewer than 900 left in the wild because of poaching and habitat destruction. Now, genetic sequencing has revealed the toll these constant threats have taken on their genome.</p>
<p>Our research, published in <em>Science</em>, reveals a striking loss of genetic diversity, but also finds more to be optimistic about than expected. </p>
<h2>Man-made threats</h2>
<p>Gorillas are classified into two species: one in West Africa (<em>Gorilla gorilla</em>) and one to the east (<em>Gorilla beringei</em>) in the centre of the continent. Mountain gorillas are a subspecies of the eastern gorilla species, and differ from the others in that their habitat ranges to high altitudes. This has consequences for their diet and physiology – for example, they have thicker and longer fur, which helps them survive the colder temperatures and the wetter, mistier environment.</p>
<p>The number of mountain gorillas living in the Virunga volcanic mountain range (on the borders of <a href="http://www.livescience.com/27337-gorilla-facts.html">Rwanda, Uganda and the Democratic Republic of Congo</a>) dropped to around 253 in 1981. Since then, conservation efforts have bolstered numbers there to approximately 480. There is another colony of about 400 of mountain gorillas about 30 km to the north. This adds up to only around <a href="http://www.awf.org/wildlife-conservation/mountain-gorilla">880 mountain gorillas</a> surviving in the wild. </p>
<p>Our new research is based on blood samples collected from wild-born gorillas and is the first whole genome study; previous studies have used DNA from fecal samples or looked at much smaller sequences.</p>
<h2>Chronic decline</h2>
<p>Analysis of the genome data revealed that as well as suffering a dramatic collapse in numbers during the last century, mountain gorillas had already experienced a long decline going back many thousands of years. These events have resulted in a very substantial loss of genetic diversity and more inbreeding than expected: it turns out that two mountain gorillas are typically identical at more than a third of their genetic sequence – the comparable number for most humans is only a few percent.</p>
<p>Inbreeding increases the threat from disease and environmental change by reducing mountain gorillas’ ability to adapt. It also means they carry a larger burden of harmful mutation than other gorilla species.</p>
<h2>Silver lining</h2>
<p>However there is a silver lining: many of the most severely harmful mutations are less common in mountain gorillas than in other gorilla subspecies, and appear to have been purged. These are mutations that disrupt the operation of a gene by prematurely terminating the protein it produces. Such mutations are expected to be more problematic than other others which may only alter the protein slightly, and some of them will be very harmful or even lethal if the protein is doing an essential job in the body.</p>
<p>To see why severely harmful mutations can be reduced as a result of inbreeding, consider that in a large population someone carrying such a mutation is less likely to meet and have children with another carrier. The mutation is able to persist because we have two copies of every gene, meaning it is usually only present in one copy in offspring. The lethal effect is masked by a working copy and can be passed on. However in an inbred population, carriers are more likely to meet others with the same mutation, meaning their children are more likely to have two copies, with lethal consequences for the children and preventing the mutation from being passed on.</p>
<p>As great apes, mountain gorillas are <a href="http://news.nationalgeographic.com/news/2012/03/120306-gorilla-genome-apes-humans-evolution-science/">close evolutionary cousins</a> of humans, so understanding their evolution also provides some insights into our own. For example, it is believed that our own ancestors also experienced severe reductions in population size at least once during human evolution, and other close relatives such as the Neanderthals went extinct in this way. Mountain gorillas thus provide an opportunity to study how humans might have adapted genetically to this condition.</p>
<h2>Justice for poachers</h2>
<p>It is also hoped that the detailed, whole-genome sequence data gathered through this research will aid conservation efforts in a practical way. Now that a genome-wide map of genetic differences between populations is available, it will be possible to identify the origins of gorillas that have been illegally captured or killed. This will enable more gorillas to be returned to the wild and will make it easier to bring prosecutions against those who poach gorillas for souvenirs and bush meat. </p>
<p>So, despite the threats they face, there are reasons to be optimistic about the future for mountain gorillas, if conservation efforts can be sustained and further encroachment on their habitat resisted. This research suggests that although low in genetic diversity, they have not yet crossed a point of no return. They can continue to survive and will return to larger numbers if we help them.</p><img src="https://counter.theconversation.com/content/39975/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aylwyn Scally receives funding from The Royal Society.</span></em></p>Poaching, habitat destruction and disease have reduced mountain gorilla numbers for decades, but how have these threats affected their genomes?Aylwyn Scally, Group Leader , University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/376882015-03-04T16:07:36Z2015-03-04T16:07:36ZCoral reefs’ physical conditions set biological rules of nature – until people show up<figure><img src="https://images.theconversation.com/files/72644/original/image-20150220-21899-1f9ggr3.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coral reefs, the rain forests of the sea.</span> <span class="attribution"><span class="source">Brian Zgliczynski</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Much ecological literature focuses on the effects that human actions have on species, habitats or ecosystems. Unfortunately, human effects on the natural world are often negative. Whether it’s <a href="http://www.sciencemag.org/content/222/4628/1081.short">deforestation</a>, <a href="http://www.pnas.org/content/104/24/10288.short">carbon emissions</a>, <a href="http://classic.rstb.royalsocietypublishing.org/content/364/1526/1985.short">plastic pollution</a> or <a href="http://www.nature.com/nature/journal/v423/n6937/full/nature01610.html">industrialized fishing</a> to name a few, humans are having a tremendous impact on the planet.</p>
<p>In the marine world, coral reef ecosystems have received particular attention. Beautiful in color, shape and the diversity of species they harbor, corals have been called the <a href="http://rainforests.mongabay.com/09reefs.htm">rainforests of the oceans</a>. Corals have also earned the nickname <a href="http://www.nature.com/scitable/knowledge/library/coral-reefs-canaries-of-the-sea-rainforests-97879685">“canaries of the sea”</a> because, like the canaries miners carried underground to warn of noxious gas leaks, they readily respond to changes in environmental conditions, including <a href="http://www.sciencemag.org/content/301/5635/929.short">temperature</a> and <a href="http://onlinelibrary.wiley.com/doi/10.4319/lo.2007.52.2.0716/abstract">light</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/72654/original/image-20150220-21891-6zda8e.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/72654/original/image-20150220-21891-6zda8e.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/72654/original/image-20150220-21891-6zda8e.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/72654/original/image-20150220-21891-6zda8e.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/72654/original/image-20150220-21891-6zda8e.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/72654/original/image-20150220-21891-6zda8e.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/72654/original/image-20150220-21891-6zda8e.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/72654/original/image-20150220-21891-6zda8e.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Picture perfect, a healthy reef showing high diversity.</span>
<span class="attribution"><span class="source">Brian Zgliczynski</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Many scientific investigations have documented direct causal effects of human behaviors on coral reef systems: for example, <a href="http://www.sciencedirect.com/science/article/pii/0025326X78902758">aggregate mining</a>, <a href="http://www.sciencedirect.com/science/article/pii/S0025326X04004497">land runoff</a> of excessive nutrients, and <a href="http://link.springer.com/article/10.1007%2Fs002679900006?LI=true">destructive fishing practices</a>. Few, however, have taken a step back to look at how the presence of humans can affect the natural functioning of coral reef systems as a whole. </p>
<p>What we haven’t known much about is the way environmental factors affect coral reefs in the absence of people. Presumably there are certain physical drivers for how a healthy reef community grows. What natural physical conditions lead to healthy reefs in environments untouched by human beings? What are the natural biophysical relationships in these ecosystems?</p>
<p>A <a href="http://dx.doi.org/10.1111/ecog.01353">recent study</a> published in the journal <a href="http://www.ecography.org/accepted-article/local-human-impacts-decouple-natural-biophysical-relationships-pacific-coral-reefs">Ecography</a> takes a wider view. Rather than identifying a particular negative effect of a certain human activity, the researchers investigated what the natural drivers are for a healthy coral reef ecosystem. With that knowledge, they could then describe how humans alter the way nature works in tropical coral systems. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/72671/original/image-20150220-21891-cn8zqj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/72671/original/image-20150220-21891-cn8zqj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/72671/original/image-20150220-21891-cn8zqj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/72671/original/image-20150220-21891-cn8zqj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/72671/original/image-20150220-21891-cn8zqj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/72671/original/image-20150220-21891-cn8zqj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/72671/original/image-20150220-21891-cn8zqj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/72671/original/image-20150220-21891-cn8zqj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Research vessel moored off a Pacific island survey site.</span>
<span class="attribution"><span class="source">Brian Zgliczynski</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Pristine vs populated</h2>
<p>The <a href="https://scripps.ucsd.edu">Scripps Institution of Oceanography</a>-based <a href="http://sandinlab.ucsd.edu">research team</a>, in collaboration with the <a href="http://www.pifsc.noaa.gov/cred/">Coral Reef Ecosystem Division</a> of NOAA in Hawaii, analyzed data from 39 different US-affiliated Pacific islands. Fifteen islands that are home to local human populations served as “impact” test sites. Twenty-four remote and unpopulated islands served as low human impact controls.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/72651/original/image-20150220-21904-1d6ohdk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/72651/original/image-20150220-21904-1d6ohdk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/72651/original/image-20150220-21904-1d6ohdk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/72651/original/image-20150220-21904-1d6ohdk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/72651/original/image-20150220-21904-1d6ohdk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/72651/original/image-20150220-21904-1d6ohdk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/72651/original/image-20150220-21904-1d6ohdk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/72651/original/image-20150220-21904-1d6ohdk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Lead author Gareth Williams surveying one of the 39 Pacific island reef sites.</span>
<span class="attribution"><span class="source">Brian Zgliczynski</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Using SCUBA and towing specialized camera gear around the circumference of each island, the team documented the corals and algae living on each reef – their so-called benthic communities. In addition, at each island they visited, the team used satellite data to tell them the sea surface temperature, irradiance (a measure of the sun’s brightness), wave energy and level of chlorophyll-a (how productive the water is).</p>
<p>Few, if any, previous studies have been able to document the “natural drivers” of benthic communities on coral reefs because study sites are too often confounded by human impacts. This study is among the first. The team found that a coral community’s composition was determined by the environmental parameters they measured at each site. But this connection held only for the unpopulated, low human-impact sites. Around the people-free islands, environmental measurements explained the benthic cover the team saw. For instance, coral cover peaked in warmer, more productive waters where the magnitude of anomalous wave events was low. </p>
<p>At populated islands, however, the story was quite different. The benthic communities there were not determined by the same natural environmental parameters. At these human-affected islands, the team either saw novel relationships emerge between the benthic communities and the background environment or the ability to explain variation in benthic communities between islands was lost.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/72653/original/image-20150220-21928-wieb5f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/72653/original/image-20150220-21928-wieb5f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/72653/original/image-20150220-21928-wieb5f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/72653/original/image-20150220-21928-wieb5f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/72653/original/image-20150220-21928-wieb5f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/72653/original/image-20150220-21928-wieb5f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/72653/original/image-20150220-21928-wieb5f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/72653/original/image-20150220-21928-wieb5f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A degraded reef at a populated island. The stark reality of human presence… and impact.</span>
<span class="attribution"><span class="source">Jamison M Gove</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Decoupling the biological from the physical</h2>
<p>At populated islands, benthic communities no longer reflected the natural physical regimes in which they were found. Study leader <a href="http://sandinlab.ucsd.edu/members/garethw/">Gareth Williams</a> and his team termed this “biophysical decoupling” – the natural links between the biological (in this case the benthic cover made up of corals and algae) and the physical (temperature, light, productivity and wave energy) becoming disrupted in the presence of human impacts. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/72672/original/image-20150220-21887-1noe201.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/72672/original/image-20150220-21887-1noe201.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/72672/original/image-20150220-21887-1noe201.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/72672/original/image-20150220-21887-1noe201.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/72672/original/image-20150220-21887-1noe201.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/72672/original/image-20150220-21887-1noe201.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/72672/original/image-20150220-21887-1noe201.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/72672/original/image-20150220-21887-1noe201.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Lifting anchor on the dive vessel after a round-island survey.</span>
<span class="attribution"><span class="source">Gareth Williams</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Williams et al. present crucial baselines to identify the drivers of natural variability in coral reef benthic communities across the Pacific in the absence of local human impacts. Such work gives us a glimpse into the forces that structure ecological communities in a world without humans. It also highlights the fact that not all reefs look the same; management targets for coral reef ecosystems therefore must be context specific. Importantly, this research suggests that at populated islands, coral reef benthic communities are not determined by the natural surrounding environment, but by something else: human presence, or at least impacts associated with human presence.</p><img src="https://counter.theconversation.com/content/37688/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Frederick Johnson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A new ecology study doesn’t focus on how people degrade the environment. Instead, it untangles the way physical factors in a pristine ecosystem drive the biology of what lives there.Andrew Frederick Johnson, Postdoctoral Researcher of Marine Biology at Scripps Insitution of Oceanography, University of California, San DiegoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/56532012-03-04T19:33:24Z2012-03-04T19:33:24ZGrim reaper cuts swathes through the Little Penguins of Perth<figure><img src="https://images.theconversation.com/files/8299/original/gbrqs7c6-1330659517.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">For whom the bell tolls: a Little Penguin.</span> <span class="attribution"><span class="source">Belinda Cannell</span></span></figcaption></figure><p>Little Penguins off the coast of Perth are being found dead - starved, battered, and in some cases almost completely beheaded - as elements both natural and manmade conspire against them.</p>
<p>Penguin Island, 50 kilometres south of Perth and just 600 metres offshore from a rapidly growing urban area, is home for a very special colony of Little Penguins, which are the smallest of the penguins with an average height of 33 centimetres. Penguin island is not only the largest colony in Western Australia, but it also has the highest conservation status of all major colonies in Australia. In addition, there are no Little Penguin colonies further west in the world. </p>
<p>In the Perth region, a smaller colony is also found on Garden Island, just seven kilometres north. It lies at the western edge of Cockburn Sound, the busiest bay in Western Australia. The two colonies together are regarded as one “metapopulation”.</p>
<p>This metapopulation of Little Penguins is the most northern in WA. It is facing an increasing range of natural, anthropogenic and climate-change threats. </p>
<p>From August-December 2011, the number of penguins found dead increased four-fold. Forty-nine penguin corpses were found on the foreshore between Safety Bay and the mouth of the Donnelly River, some 400 kilometres around the coast from Penguin Island, as well as on Penguin Island. The penguins were mostly banded or microchipped, so I know that most of them came from Penguin Island.</p>
<figure>
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<br><small><a href="http://maps.google.com/maps?f=q&source=embed&hl=en&geocode=&q=Penguin+Island,+Western+Australia,+Australia&aq=3&oq=penguin+island&sll=-37.813187,144.96298&sspn=0.147685,0.211487&ie=UTF8&hq=&hnear=Penguin+Island&t=m&ll=-32.289019,115.712986&spn=0.063851,0.075359&z=13">View Larger Map</a></small></figure>
<p>With the support of the Department of Environment and Conservation, autopsies were performed on many of the penguins, and the major cause of death was starvation. This is most likely to be linked to high sea surface temperatures and other oceanographic changes associated with a strong La Nina and a very strong Leeuwin Current (a warm current that flows south along the WA coast). </p>
<p>This “marine heat wave”, as it has been labelled by the Department of Fisheries, is suspected of causing a decline in stocks of fish that the Little Penguins rely on for food. Indeed, sandy sprat, usually their major prey item while raising chicks, were not found in the penguins’ diet in 2011. The species of fish the penguins were feeding on was determined by analysing the DNA in their faeces.</p>
<p>The penguins also had the worst breeding season since monitoring of this colony began in 1986, with many fewer penguins even attempting to breed. The penguins must remain close to the colony while raising chicks, so they can return each night or two to feed them, so it is likely that the nearby fish resources were much less abundant than normal.</p>
<p>If this wasn’t bad enough, the lack of fish has most likely contributed to more penguins being found dead during their annual two-week moult. Penguins cannot go to sea and catch fish while they are moulting, so they must build up enough fat and protein before moulting to “feed” this very energetically demanding process of making new feathers. If the fish are less abundant, and the penguins have to travel further to catch them, then they can’t build up enough reserves to last the fasting stage of moult.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/8298/original/c8dvsfns-1330659422.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/8298/original/c8dvsfns-1330659422.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/8298/original/c8dvsfns-1330659422.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/8298/original/c8dvsfns-1330659422.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/8298/original/c8dvsfns-1330659422.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/8298/original/c8dvsfns-1330659422.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/8298/original/c8dvsfns-1330659422.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It tolls for thee: Little Penguin found with a broken wing and dead.</span>
<span class="attribution"><span class="source">Belinda Cannell</span></span>
</figcaption>
</figure>
<p>Sadly, we have also found quite a few penguins with injuries from watercraft. These injuries include deep cuts across their backs or feet, bleeding under the skin with no external wounds, broken necks and even completely severed necks. </p>
<p>A boat ramp has recently been constructed seven kilometres south of the colony. We don’t yet know if a potential increase in watercraft used in the area has caused this increase in deaths from injuries. The penguins could be weaker due to starvation and unable to get out of the way of the watercraft, or it could be a combination of both. We need to know more about the seasonality of dead penguins, where they are found and their causes of death, to know what effect the boat ramp is having.</p>
<p>Perth has just experienced its hottest summer on record. This also contributed to a number of deaths, particularly in moulting penguins. They are unable to leave the island until their new feathers have become waterproof, so some penguins died from overheating. </p>
<p>It was probably lucky that there were very few chicks that hatched this year. Otherwise they could have died from overheating too, as I have witnessed in past years. The predictions for the changes associated with climate change - warming temperatures and less rain in the south-west of Australia - do not bode well for this colony of penguins.</p>
<p>It’s hard to know how the mortality and low breeding observed in 2011 will affect the overall survival of the colony. Certainly, a population estimate I undertook in 2011 showed that there were fewer adults on the island compared to the estimate of 2369 penguins in 2007. However, this is likely to be an indication that there were fewer penguins breeding, as was certainly identified from the monitoring of nest sites. </p>
<p>Seabirds are long lived, the adults usually have a high survival rate, and young penguins don’t join the breeding population until they are two to three years old. Therefore, marked changes in the population are likely to occur over the macro-scale. </p>
<p>However, it is likely that the survival rate of the adults in 2011 was much lower than normal. Also, very few chicks were raised, and those that did leave the nest would have a slim chance of surviving if fish weren’t available close by. </p>
<p>It is likely that we will see a real decline in the population over a shorter time scale, especially if La Nina conditions continue.</p>
<p>But all is not lost for the Perth penguins; not yet, anyway. The colony on Garden Island did not appear to fare so badly. Their breeding participation and success was much better than that at Penguin Island - it usually is. This is probably because they feed in Cockburn Sound: just a short trip out the back door for these penguins. And for whatever reasons still to be identified, the fish stocks the penguins feed on in Cockburn Sound were apparently not affected by these high sea temperatures. </p>
<p>These penguins also nest in lovely cool limestone, unlike the penguins on Penguin Island who nest under bushes or in nesting boxes. So they are unlikely to be affected to the same extent by high air temperatures.</p>
<p>So this colony of penguins might be the saviour for penguin presence in Perth if we are unable to manage all the threats the penguins on Penguin Island are exposed to. We just need to maintain all the things that are responsible for them doing so well. We just don’t know what all of those are yet! </p>
<p><em><a href="http://bcove.me/nmyx2lv7">Watch a video</a> about the Little Penguins.</em></p><img src="https://counter.theconversation.com/content/5653/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Belinda Cannell received funding from the DEC to undertake the population estimate and diet composition studies in 2010 and 2011.
She also received funding from an ARC Linkage for her Postdoctoral fellowship in 2006-2009. The Linkage partners were ARC, Department of Environment and Conservation, Department of Defence, Fremantle Ports, Tiwest, and The Winifred Violett Scott Trust Fund. </span></em></p>Little Penguins off the coast of Perth are being found dead - starved, battered, and in some cases almost completely beheaded - as elements both natural and manmade conspire against them. Penguin Island…Belinda Cannell, Research Associate, Murdoch UniversityLicensed as Creative Commons – attribution, no derivatives.