tag:theconversation.com,2011:/us/topics/weasels-54189/articlesWeasels – The Conversation2022-12-05T13:25:26Ztag:theconversation.com,2011:article/1928952022-12-05T13:25:26Z2022-12-05T13:25:26ZWeasels, not pandas, should be the poster animal for biodiversity loss<figure><img src="https://images.theconversation.com/files/498335/original/file-20221130-20-3djrpi.jpg?ixlib=rb-1.1.0&rect=6%2C3%2C2037%2C1348&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A short-tailed weasel in Yellowstone National Park, Wyoming.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/2baqDL7">Jacob W. Frank, NPS/Flickr</a></span></figcaption></figure><p>At the <a href="https://www.unep.org/events/conference/un-biodiversity-conference-cop-15">United Nations biodiversity conference</a> that opens in Montreal on Dec. 7, 2022, nations aim to create a new global framework for transforming humanity’s relationship with nature. The <a href="https://www.cbd.int/conferences/2021-2022">conference logo</a> features a human reaching to embrace a panda – but from an ecological perspective, a weasel or badger would be a more appropriate choice.</p>
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<a href="https://images.theconversation.com/files/498319/original/file-20221130-8088-3h45m9.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic of a girl reaching to embrace a panda" src="https://images.theconversation.com/files/498319/original/file-20221130-8088-3h45m9.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/498319/original/file-20221130-8088-3h45m9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=925&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498319/original/file-20221130-8088-3h45m9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=925&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498319/original/file-20221130-8088-3h45m9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=925&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498319/original/file-20221130-8088-3h45m9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1162&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498319/original/file-20221130-8088-3h45m9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1162&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498319/original/file-20221130-8088-3h45m9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1162&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">Logo for the COP 15 conference in Montreal, which was delayed from its original 2020 date due to COVID-19.</span>
<span class="attribution"><a class="source" href="https://www.cop15news.com/en/index.htm">Convention on Biological Diversity</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>Large mammals with widespread appeal, also known as <a href="https://animals.howstuffworks.com/endangered-species/charismatic-megafauna.htm">charismatic megafauna</a>, often represent the highest achievement in biodiversity protection. As the logic goes, saving the tiger, polar bear, wolf or lion means saving an entire ecosystem, since these species often have large ranges and may sit at the top of food chains.</p>
<p>But research shows that, relatively speaking, many large charismatic species aren’t doing that badly in North America. Wolves are <a href="https://www.nytimes.com/2022/03/11/science/california-wolves-misinformation.html">repopulating California</a>, where their last wild ancestor was killed in 1924. Cougars could become <a href="https://doi.org/10.1016/j.ecolmodel.2015.09.026">reestablished across the Midwest</a> over the next several decades. Black bears have regained much of their range in the <a href="https://www.bearbiology.org/wp-content/uploads/2017/10/Scheick_and_McCown_2014_Ursus.pdf">eastern U.S</a>, to the point where many states have a <a href="https://www.outdoorlife.com/story/hunting/record-black-bear-hunting-harvest/">bear hunting season</a>. Similar stories are playing out across Europe, where even large carnivores like the lynx and wolverine are <a href="http://dx.doi.org/10.1126/science.1257553">recovering</a>. </p>
<p>For small carnivores like weasels, skunks and foxes, it’s a different story. These species and their relatives have equal or greater impacts on the ecosystems they inhabit than larger species like wolves. They even provide benefits for humans by preying on rodents that eat crops and infest our houses. Yet small carnivores are of increasing conservation concern because their populations are declining dramatically in many places.</p>
<h2>Many threats but no single cause</h2>
<p>While small carnivores don’t typically get as much public attention as larger species, conservation biologists have been trying to arrest their decline for decades. </p>
<p>For example, the black-footed ferret, a member of the same family as weasels and minks, has been <a href="https://www.fws.gov/species/black-footed-ferret-mustela-nigripes">on the U.S. endangered species list</a> since the list was created in 1973. As recently as the early 1900s there were thousands of black-footed ferrets across western prairies. Today scientists estimate there are <a href="https://blackfootedferret.org/">fewer than 400 left in the wild</a>. </p>
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<a href="https://images.theconversation.com/files/498333/original/file-20221130-22-dzg6n4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two ferrets with black feet and eye masks, one peeking out of a pipe" src="https://images.theconversation.com/files/498333/original/file-20221130-22-dzg6n4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/498333/original/file-20221130-22-dzg6n4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=410&fit=crop&dpr=1 600w, https://images.theconversation.com/files/498333/original/file-20221130-22-dzg6n4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=410&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/498333/original/file-20221130-22-dzg6n4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=410&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/498333/original/file-20221130-22-dzg6n4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=515&fit=crop&dpr=1 754w, https://images.theconversation.com/files/498333/original/file-20221130-22-dzg6n4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=515&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/498333/original/file-20221130-22-dzg6n4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=515&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">The U.S. Fish and Wildlife Service is breeding black-footed ferrets in captivity in northern Colorado. Restoring the endangered ferret is considered a key step in reviving prairie ecosystems.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/oct-29-there-are-48-outdoor-pre-conditioning-pens-that-news-photo/186801918">Kathryn Scott Osler/The Denver Post via Getty Images</a></span>
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<p>Recent evidence suggests that even the most common and widespread small carnivores are in decline. A 2005 study estimated that eastern spotted skunks, which are rarely seen today but historically occurred across much of the U.S. east of the Rocky Mountains, had <a href="https://doi.org/10.1017/S1367943005001964">declined in number by 90% over the preceding 50 years</a>. </p>
<p>I led an effort in 2021 to determine the status of the most widespread of small carnivores in North America – <a href="https://doi.org/10.1371/journal.pone.0254387">weasels</a>. We found range-wide decreases dating back to the 1960s that paralleled the decline of spotted skunks. </p>
<p>Scientists have a very poor understanding of what has caused losses of weasels and most other small carnivores. We suspect that many stresses may be involved, including changing farming practices, diseases and new carnivores like house cats, domestic dogs, raccoons and striped skunks that follow human development and outcompete or eat native small carnivores. </p>
<p>What we do know is that North America is not unique. Small carnivores are declining globally at an alarming rate. A 2021 review suggests that over the past couple of decades <a href="https://doi.org/10.1016/j.biocon.2021.109005">over half of all small carnivores have declined in number</a>, and a quarter are at risk of extinction. Proportionally, these are the same levels of decline and endangerment as the better-publicized threats to large carnivores. </p>
<h2>Short-legged ecosystem indicators</h2>
<p>We also know that compared with larger species, small carnivores have shorter lives and use smaller areas. This allows them to respond quickly to even minor fluctuations in temperature, habitat change and food availability. In my <a href="https://scholar.google.com/citations?user=CjwvzoIAAAAJ&hl=en&oi=sra">research over the past 23 years</a>, I have learned that these attributes make small carnivores sensitive indicators of even minor shifts in how well their ecosystems work. </p>
<p>A prime example comes from the Channel Islands off the coast of California, home to the diminutive <a href="https://www.nps.gov/chis/learn/nature/island-fox.htm">island fox</a>, a species found nowhere else on earth. In the late 1990s land and wildlife managers noticed a decline in island foxes, which coincided with the decline of bald eagles and arrival of golden eagles on the islands. Golden eagles preyed on the foxes, as well as on non-native wild pigs. At one point the fox population was reduced to fewer than 100 individuals. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/2AVRSGkartg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Saving California’s island foxes required reconstructing an ecosystem that human actions had drastically altered.</span></figcaption>
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<p>Restoring island foxes was a complex initiative that involved reintroducing bald eagles – which prey on fish, not mammals – to the islands to chase off golden eagles; eradicating introduced pigs, which served as food for the golden eagles and altered the vegetation where the foxes sheltered; restoring shrubs and grasses; and breeding foxes in captivity, then releasing them. This effort is one of the most prominent examples of biologists intervening to <a href="https://www.nps.gov/chis/learn/nature/island-fox.htm">reverse a species’ slide toward extinction</a>. </p>
<p>More broadly, the island fox story shows that small carnivores can provide unique insight into the structure of ecosystems, because they are at the centers of <a href="https://www.nature.com/scitable/knowledge/library/food-web-concept-and-applications-84077181/">food webs</a>. Look at the diet of a fox or weasel and you have a great snapshot of <a href="https://doi.org/10.1002/fee.2407">how many species are present in that ecosystem</a>. </p>
<p>Losing small carnivores can change ecosystems. Many small carnivores typically prey on small seed-eating rodents like mice and gophers. This reduces rodent impacts on plants and <a href="https://doi.org/10.1016/j.ecoser.2017.12.006">farm crops</a>. It also helps to reduce the <a href="https://doi.org/10.1016/j.ecoser.2017.12.006">spread of tick-borne diseases</a>, since small rodents can serve as <a href="https://doi.org/10.1186/s13071-020-3902-0">hosts for infected ticks</a>.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/Cld5PUMrvno/?utm_source=ig_web_copy_link","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>For these reasons, I and other ecologists argue that it makes sense to use small carnivores as <a href="https://doi.org/10.1111/mam.12300">barometers of ecosystem health</a>. This would mean replacing polar bears with weasels as global warming poster animals, and keying in on <a href="https://doi.org/10.1111/btp.12635">ocelots</a> rather than jaguars to understand how rainforest destruction is affecting wildlife. </p>
<p>While lions and polar bears are important, I believe ferrets, weasels and foxes deserve the same kind of protection and are a more precise tool for measuring how ecosystems are responding to a rapidly changing world.</p><img src="https://counter.theconversation.com/content/192895/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Jachowski 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>Polar bears and wolves may get the glory, but small predators like weasels, foxes and their cousins play outsized ecological roles. And many of these species are declining fast.David Jachowski, Associate Professor of Wildlife Ecology, Clemson UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1791512022-05-17T18:56:02Z2022-05-17T18:56:02ZConnecting fragmented wolverine habitat is essential for their conservation<figure><img src="https://images.theconversation.com/files/463082/original/file-20220514-16-891w4f.jpg?ixlib=rb-1.1.0&rect=57%2C0%2C5472%2C3514&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Wolverine numbers are declining globally due to heavy trapping and predator killing by humans, habitat loss, climate change and various other factors.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/connecting-fragmented-wolverine-habitat-is-essential-for-their-conservation" width="100%" height="400"></iframe>
<p>Present day wolverines, <a href="https://doi.org/10.1134/S1022795415090069">which emerged during the ice age</a>, have been declining globally despite their many adaptions to live in challenging, rugged environments. </p>
<p>These large land-dwelling weasels evolved to scramble up trees and climb steep, snowy mountains. Wolverines’ snowshoe-like paws, heavy frost-resistant fur and powerful muscles let them thrive in some of the coldest places on Earth. Their sharp claws and strong jaws allow them to <a href="https://doi.org/10.1002/ecs2.1407">feast on carcasses</a> and <a href="https://doi.org/10.22621/cfn.v132i3.1947">hunt species of all sizes</a> from ground squirrels to elk. </p>
<p>While wolverines have been <a href="https://www.youtube.com/watch?v=3SOjmJG73UI">filmed hunting caribou in Norway</a> and <a href="https://www.sciencedaily.com/releases/2003/05/030506073236.htm">observed battling black bears over food in Yellowstone</a>, they are extremely vulnerable, rarely seen and hard to study. <a href="https://doi.org/10.1016/j.gecco.2022.e02019">Wolverine numbers are declining</a> globally due to heavy trapping and predator killing by humans as well as habitat loss, climate change and various other factors. <a href="https://species-registry.canada.ca/index-en.html#/consultations/206">Scientists estimate there are more than 10,000 wolverines in Canada</a>, but population densities vary a lot and numbers are difficult to estimate. </p>
<p>Our <a href="https://doi.org/10.1016/j.gecco.2022.e02019">20 years of synthesized research about wolverines</a> shows that the best ways to protect remaining wolverine populations are to reduce trapping, minimize predator control pressures and connect the large blocks of intact habitat they need to survive.</p>
<h2>Not as resilient as you might think</h2>
<p>Wolverines are private, generally solitary, species. They are slow to reproduce and have an average of two cubs, or kits, every two to three years. </p>
<figure class="align-center ">
<img alt="A wolverine with her cub" src="https://images.theconversation.com/files/463083/original/file-20220514-8286-72ywkc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463083/original/file-20220514-8286-72ywkc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463083/original/file-20220514-8286-72ywkc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463083/original/file-20220514-8286-72ywkc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463083/original/file-20220514-8286-72ywkc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463083/original/file-20220514-8286-72ywkc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463083/original/file-20220514-8286-72ywkc.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">
<figcaption>
<span class="caption">Wolverines are slow to reproduce as they give birth to an average of two kits every two to three years.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>They are <a href="https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/cosewic-assessments-status-reports/wolverine-status-2014.html">naturally low in number</a> and defend territories as large as 500-1,000 square kilometres, or sometimes more. These traits make them vulnerable to human impacts around the world.</p>
<p>Since the Europeans colonized North America, fur trapping and landscape development <a href="https://species-registry.canada.ca/index-en.html#/consultations/206">shrank the wolverine range drastically</a>. South of the wide Arctic range, wolverines can be found only in the western boreal forest and mountains. But they used to live from coast to coast and as far south as New Mexico. </p>
<p>Today, in the United States, <a href="https://doi.org/10.2193/2006-548">only around 300 remain in the lower 48 states — mainly in the snowy strongholds</a> and high elevations of the mountain ranges. Wolverines are restricted to northern countries in Eurasia and are <a href="https://doi.org/10.1111/conl.12171">killed as predators of reindeer herds</a> in Fennoscandia.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/463518/original/file-20220517-20-nq8zp0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of the wolverine distribution in North America." src="https://images.theconversation.com/files/463518/original/file-20220517-20-nq8zp0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463518/original/file-20220517-20-nq8zp0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=513&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463518/original/file-20220517-20-nq8zp0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=513&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463518/original/file-20220517-20-nq8zp0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=513&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463518/original/file-20220517-20-nq8zp0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=644&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463518/original/file-20220517-20-nq8zp0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=644&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463518/original/file-20220517-20-nq8zp0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=644&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">Wolverine distribution in North America.</span>
<span class="attribution"><a class="source" href="https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/cosewic-assessments-status-reports/wolverine-status-2014.html#_fig03">(Environment Canada)</a></span>
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<p>As tough as they are, wolverines are sometimes <a href="https://doi.org/10.2193/0022-541X(2004)068%5b0493:SOSRAC%5d2.0.CO;2">eaten by other big predators</a>. As scavengers, taking food from a hungry bear or pack of wolves is a risky lifestyle. Their habitat is degraded by resource development, including <a href="https://doi.org/10.1016/j.foreco.2017.03.029">forestry</a>, <a href="https://doi.org/10.1002/ece3.3337">oil and gas</a> and <a href="https://doi.org/10.2981/wlb.00480">roads</a>. People still trap wolverines in Canada, often <a href="https://doi.org/10.1002/jwmg.21787">far too heavily</a>. They can also be <a href="https://doi.org/10.1002/ecs2.2611">sensitive to recreation</a>. </p>
<p>All this human activity makes life better for wolverines’ competitors — coyotes. Where coyotes exploit developed landscapes, they come into conflict with wolverines, <a href="https://doi.org/10.1016/j.biocon.2021.109435">and in these fights, wolverines lose</a>.</p>
<p>Piled on those problems is the impact of climate change on wolverine habitat. <a href="https://doi.org/10.1890/10-2206.1">The cold, snowy refuges</a> that wolverines have sought south of the Arctic are now thawing. Wolverines need snow to <a href="https://doi.org/10.1007/s00265-020-2823-4">cache food</a>, to raise their <a href="https://doi.org/10.2307/3801996">vulnerable kits safely</a> and to keep lowland competitors away. The one-two punch of landscape change and climate change are making matters worse for wolverines.</p>
<h2>Building blocks for wolverine conservation</h2>
<p>Wolverines need large, <a href="https://y2y.net/work/hot-projects/mapping-wolverine-way/">connected blocks of intact habitat to survive</a>. The only way to protect them in the long run is to help protect and connect their fragmented blocks of habitat. </p>
<figure class="align-center ">
<img alt="A scenic mountainous green landscape" src="https://images.theconversation.com/files/463084/original/file-20220514-12-32h47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463084/original/file-20220514-12-32h47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=297&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463084/original/file-20220514-12-32h47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=297&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463084/original/file-20220514-12-32h47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=297&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463084/original/file-20220514-12-32h47.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=373&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463084/original/file-20220514-12-32h47.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=373&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463084/original/file-20220514-12-32h47.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=373&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Prime wolverine habitat near Revelstoke, B.C. in summer. Wolverines need large areas of intact, connected habitat to survive.</span>
<span class="attribution"><span class="source">(Mirjam Barrueto/WolverineWatch.org)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Creating more protected areas and managing human activity within and next to them will help. Protecting “<a href="https://www.cbc.ca/radio/whatonearth/the-wolverine-s-world-is-shrinking-but-they-ve-found-a-safe-haven-in-b-c-mountains-1.6444665">climate refugia</a>” — the last bastions of cold wolverine habitat — is an important priority. Landscape planning to <a href="https://doi.org/10.1016/j.isci.2021.102840">connect mountain refuges</a> across busy degraded valley bottoms is sorely needed, especially in southern Canada and the United States </p>
<p>Work to maintain or improve ecological connectivity is happening in some places, such as <a href="https://theconversation.com/linking-protected-areas-from-yellowstone-to-the-yukon-shows-the-value-of-conserving-large-landscapes-not-just-isolated-parks-and-preserves-177501">from Yellowstone to Yukon</a> and <a href="https://portals.iucn.org/library/node/49061">other areas in the world</a>. </p>
<p>Roads and industrial development cut up major sections of prime habitat. We can fight habitat fragmentation by making better decisions about road-building, including when to decommission roads built for resource extraction and <a href="https://doi.org/10.1016/j.biocon.2019.06.030">mitigating the effects of traffic</a> on wolverines and other wildlife. Habitat protection, connectivity and restoration are critical for wolverines.</p>
<p>We also need transboundary co-ordination. We need to think across larger landscapes, especially regions that still support wolverines on both sides of a border — like between Canada and the United States or between Norway and Sweden.</p>
<h2>No longer ignorant nor blissful</h2>
<p>Globally, governments have insufficiently protected wolverines. </p>
<p>Sweden’s <a href="https://doi.org/10.1073/pnas.2011383117">predator stewardship program is an exception</a> and British Columbia has stopped wolverine trapping in small locales. </p>
<p>Otherwise, large-scale wolverine conservation has been on the back burner. In the U.S., a <a href="https://www.theguardian.com/environment/2020/oct/12/wolverines-endangered-species-act-us-fish-wildlife">petition to list wolverines on the federal Endangered Species Act was thwarted</a>. Canada lacks a federal management plan and British Columbia’s most recent wolverine plan is from 1989, while Alberta lists the species in the “data deficient” category.</p>
<figure class="align-center ">
<img alt="A wolverine in a camera trap surrounded by trees and a snow covered ground." src="https://images.theconversation.com/files/463085/original/file-20220514-23-lndoua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463085/original/file-20220514-23-lndoua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=442&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463085/original/file-20220514-23-lndoua.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=442&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463085/original/file-20220514-23-lndoua.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=442&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463085/original/file-20220514-23-lndoua.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=556&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463085/original/file-20220514-23-lndoua.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=556&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463085/original/file-20220514-23-lndoua.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=556&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A wolverine at a research station in southeastern British Columbia. We know a lot about wolverines. All we have to do is use the knowledge and act fast.</span>
<span class="attribution"><span class="source">(Mirjam Barrueto/WolverineWatch.org)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>For years it seemed like not much was known about wolverines, and policymakers have rested on wolverines’ mystery to excuse inaction. </p>
<p>The truth is, science knows a lot about wolverines. Research from around the world clearly shows what we need to do. </p>
<p>Wolverines may have evolved in the cold but the heat is on us to act now. We must <a href="https://doi.org/10.1016/j.gecco.2022.e02019">use the research compiled over the past two decades</a> to make the changes needed to conserve wolverines.</p><img src="https://counter.theconversation.com/content/179151/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jason T Fisher receives funding from Oil Sands Monitoring Program, Government of Alberta (Environment and Parks), Yellowstone to Yukon Conservation Initiative, and Urban Wildlife Stewardship Society.</span></em></p><p class="fine-print"><em><span>Aerin Jacob works for the Yellowstone to Yukon Conservation Initiative (Y2Y), an environmental non-government organization and charity in Canada and the United States. Y2Y receives funding from foundations, corporations, and government bodies further described at <a href="https://y2y.net/about/partners/supporters">https://y2y.net/about/partners/supporters</a>.</span></em></p>The key to protecting wolverines around the world is to reduce trapping, minimize predator control pressures, and to protect and connect large blocks of intact habitat they need to survive.Jason T Fisher, Adjunct Professor; Head, Applied Conservation Macro Ecology Lab, University of VictoriaAerin Jacob, Adjunct professor, Department of Ecosystem Science and Management, University of Northern British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1035452018-09-20T09:34:33Z2018-09-20T09:34:33Z‘Penis bones’ – an evolutionary puzzle explained using innovative 3D scanning<figure><img src="https://images.theconversation.com/files/237119/original/file-20180919-158237-1kk1e7m.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A 3D model of the skeleton of a European polecat. Penis bone (baculum) is highlighted in pink. </span> <span class="attribution"><span class="source">Charlotte A. Brassey</span>, <span class="license">Author provided</span></span></figcaption></figure><p>For ferrets, sex is a prolonged affair. In total, the act of mating might last up to three hours. Fortunately for the males of the species, they are packing a secret weapon to help them through this daunting task. Some modern mammals (including <a href="https://academic.oup.com/icb/article/56/4/644/2198249">ferrets, mice, dogs and even apes</a>) have a bone inside their penis, called <a href="https://theconversation.com/how-penis-bones-help-primates-win-the-mating-game-and-why-humans-might-have-lost-theirs-70312">the baculum</a>. </p>
<p>The bones have evolved different shapes and sizes, from the ice-cream scoop form of the honey badger to the long thin osseous bone of a black bear. It has always been a bit of mystery as to why some species of male mammals evolved bones in their penises. Humans are actually unusual in this respect, as our species has lost the mineralised bone in place of <a href="https://onlinelibrary.wiley.com/doi/abs/10.2164/jandrol.04145">a small ligament</a> in the tip of the penis. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/237281/original/file-20180920-129859-uijwub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/237281/original/file-20180920-129859-uijwub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=320&fit=crop&dpr=1 600w, https://images.theconversation.com/files/237281/original/file-20180920-129859-uijwub.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=320&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/237281/original/file-20180920-129859-uijwub.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=320&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/237281/original/file-20180920-129859-uijwub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=402&fit=crop&dpr=1 754w, https://images.theconversation.com/files/237281/original/file-20180920-129859-uijwub.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=402&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/237281/original/file-20180920-129859-uijwub.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=402&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ferrets are one of the mammals which have a baculum.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ferret-outdoor-portrait-field-flowers-773851156?src=5S3Enyz0e2WtzghVGyswWg-1-7">Everydoghasastory/Shutterstock</a></span>
</figcaption>
</figure>
<p>In animals possessing a baculum, males with wider penis bones have been shown to <a href="https://bmcbiol.biomedcentral.com/articles/10.1186/1741-7007-11-66">father a larger number of offspring</a>. Yet exactly how the penis bone impacts on male fertility has remained a puzzle. </p>
<h2>Protecting the urethra</h2>
<p>However, <a href="http://rspb.royalsocietypublishing.org/content/285/1887/20181473">our new research</a> – which used innovative 3D scanning and engineering-inspired computer simulations – has revealed that in carnivores (the group including cats, bears, dogs and weasels), the baculum may help males breed for extended periods of time. The “prolonged intromission” hypothesis suggests that the penis bone has evolved to protect the urethra (the tube responsible for delivering sperm) when sex becomes a lengthy endeavour. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/237116/original/file-20180919-158234-16e98kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/237116/original/file-20180919-158234-16e98kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/237116/original/file-20180919-158234-16e98kn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/237116/original/file-20180919-158234-16e98kn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/237116/original/file-20180919-158234-16e98kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/237116/original/file-20180919-158234-16e98kn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/237116/original/file-20180919-158234-16e98kn.png?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">A museum drawer containing sea otter bacula at the Smithsonian National Museum of Natural History.</span>
<span class="attribution"><span class="source">Charlotte A Brassey</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Other studies have found mixed evidence in support of this idea, some <a href="http://rspb.royalsocietypublishing.org/content/283/1844/20161736">in favour</a> and some <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2907.2002.00112.x">against</a>. In part, this might be due to important features of the baculum previously being ignored. Penis bones are notable for being extremely diverse in shape, with species being distinguished by possessing bizarre tips, ridges and grooves. Yet in the past, biologists have only included the most basic metrics (bone length and diameter) into their models of baculum function. </p>
<h2>Virtually ‘crash-testing’ the penis bone</h2>
<p>To address this oversight, we used a digital modelling technique more familiar to engineers and physicists. In “finite element analysis” (FEA), a 3D computer model is virtually “crash-tested” in order to calculate how strong the object is. The method is more commonly applied to structures such as <a href="https://www.sciencedirect.com/science/article/pii/S1359836814003588">bridges</a> or <a href="https://dspace.lib.cranfield.ac.uk/handle/1826/7258">race cars</a>, as a way of predicting their performance without physically damaging the object. </p>
<p>The major benefit of FEA is that the whole 3D shape of the baculum can be incorporated into our estimates of bone strength. Our results suggest that animals breeding for very long durations typically have penis bones that are much stronger than their fast-mating relatives.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/237133/original/file-20180919-158228-iannoa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/237133/original/file-20180919-158228-iannoa.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=551&fit=crop&dpr=1 600w, https://images.theconversation.com/files/237133/original/file-20180919-158228-iannoa.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=551&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/237133/original/file-20180919-158228-iannoa.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=551&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/237133/original/file-20180919-158228-iannoa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=693&fit=crop&dpr=1 754w, https://images.theconversation.com/files/237133/original/file-20180919-158228-iannoa.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=693&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/237133/original/file-20180919-158228-iannoa.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=693&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">3D finite element models of carnivore penis bones - from top to bottom: tiger, brown bear, wolf, polecat. Not to scale. Hot colours indicate regions bone areas that are highly stressed. Cool colours indicate bones that are less stressed (more robust).</span>
<span class="attribution"><span class="source">Charlotte A. Brassey</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Where are all the females?</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/237124/original/file-20180919-158213-13wfc2m.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/237124/original/file-20180919-158213-13wfc2m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/237124/original/file-20180919-158213-13wfc2m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/237124/original/file-20180919-158213-13wfc2m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/237124/original/file-20180919-158213-13wfc2m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/237124/original/file-20180919-158213-13wfc2m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/237124/original/file-20180919-158213-13wfc2m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">X-ray image of live mating ferrets.</span>
<span class="attribution"><span class="source">Charlotte A. Brassey</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Previous research, including our own study, has tended to focus heavily on male anatomy, to the exclusion of females. In mammals, <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001851">less than a quarter</a> of all studies investigating the evolution of genitals have included both sexes. This bias may partly stem from practical issues – male genitals are often made up of rigid hard parts sitting outside the body, making them easier for scientists to study. But it may also reflect a historic misconception of the female reproductive system as being a “passive” vessel, compared to more “active” male structures. </p>
<p>This means we have potentially overlooked important interactions between the sexes. Thankfully, with the application of new X-ray imaging techniques and computer modelling, our awareness of female genital anatomy is beginning to catch up. We are now extending our study to also include the size and shape of the vaginal tract and to capture the live motion of the genitals during mating, as a more holistic approach to studying animal reproduction.</p><img src="https://counter.theconversation.com/content/103545/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Charlotte Brassey receives funding via a BBSRC Future Leader Fellowship (BB/N010957/1)</span></em></p><p class="fine-print"><em><span>James Gardiner 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>Our study used innovative 3D scanning and engineering-inspired computer simulations to understand the evolution of the penis bone in some mammals.Charlotte Brassey, Research Fellow in Animal Biology, Manchester Metropolitan UniversityJames Gardiner, Research Associate in Musculoskeletal Biology, University of LiverpoolLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/971382018-05-24T14:36:32Z2018-05-24T14:36:32ZClimate change has left some weasels with mismatched camouflage<figure><img src="https://images.theconversation.com/files/220291/original/file-20180524-90281-1qovmkh.jpg?ixlib=rb-1.1.0&rect=0%2C177%2C3567%2C2101&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.nature.com/articles/s41598-018-26057-5">Karol Zub</a></span></figcaption></figure><p>Finding oneself improperly dressed for the weather can have fatal consequences – just ask a white-coated weasel.</p>
<p>Animals that live in areas that usually have a lot of snow in the winter often change their coats to match their surroundings. Some weasels have evolved so that in the autumn they moult their brown summer coat and change to a white version. In spring they reverse the process and return to the brown version.</p>
<p>A new study published in Nature <a href="https://www.nature.com/articles/s41598-018-26057-5">Scientific Reports</a> suggests that there is a strong relationship between the quantity and duration of snow in a forest in Poland during the winter and the number of weasels wearing white the following winter. Clearly this is not a fashion decision on the part of the local weasel population. </p>
<p>The scientists behind the study looked at two subspecies of the rather charmingly named “least weasel”, <em>Mustela nivalis nivalis</em>, which does change its colour in the winter, and <em>Mustela nivalis vulgaris</em>, which does not. Both species live in Białowieża, an ancient relic of the <a href="https://theconversation.com/europes-oldest-forest-is-threatened-by-a-beetle-infestation-let-nature-take-its-course-57079">vast primeval forest</a> that once covered most of Europe, and both compete for similar resources. Yet the authors determined that when there is no snow cover the white-coated weasels were more likely to be eaten by the foxes, wolves and buzzards that see them as prey. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/220299/original/file-20180524-51102-1beg0iv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/220299/original/file-20180524-51102-1beg0iv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/220299/original/file-20180524-51102-1beg0iv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/220299/original/file-20180524-51102-1beg0iv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/220299/original/file-20180524-51102-1beg0iv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/220299/original/file-20180524-51102-1beg0iv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/220299/original/file-20180524-51102-1beg0iv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/220299/original/file-20180524-51102-1beg0iv.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"><em>Mustela nivalis</em> nicely camouflaged in a brown summer coat.</span>
<span class="attribution"><span class="source">Karol Zub</span></span>
</figcaption>
</figure>
<p>When there is deep snow, weasels of both colours tend to hunt underneath it, which, after all, is where the small rodents are, so the predation rates for both species are reduced. In periods of winter without snow, however, white weasels are much more conspicuous than brown ones. In recent years, because of climate change, there have been more days without snow, and the date when snow disappears in the spring has become progressively earlier.</p>
<p>The conclusion of the study is that the proportion of white weasels in the population is influenced by predation rates due to lack of camouflage during the previous winter.</p>
<h2>Survival risk?</h2>
<p>The question for the future seems to be how long <em>M. n. nivalis</em> as a subspecies can survive, given the milder, largely snow-free winters that are becoming more frequent as climate change takes hold. One of the important factors in this is likely to be its ability to change the time when it moults its coat, both in the autumn and the spring. Though the weasels are already showing signs of moulting into their brown summer coats earlier in the spring, they have not yet changed the time of their autumn moult. This is thought to be because autumn temperatures have remained relatively stable while springs have been getting warmer.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/220300/original/file-20180524-51095-130lidt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/220300/original/file-20180524-51095-130lidt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/220300/original/file-20180524-51095-130lidt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/220300/original/file-20180524-51095-130lidt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/220300/original/file-20180524-51095-130lidt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/220300/original/file-20180524-51095-130lidt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/220300/original/file-20180524-51095-130lidt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/220300/original/file-20180524-51095-130lidt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">How the camouflage is meant to work.</span>
<span class="attribution"><span class="source">Victor Tyakht / shutterstock</span></span>
</figcaption>
</figure>
<p>Another problem for the weasel is that, even when it can shed its winter coat earlier, that will not be helpful in the increasing periods during the winter when there is no snow. Since moulting and growing a new coat is a serious business, chopping and changing during the season is not possible. In addition to ambient temperature, moulting and therefore coat colour change is triggered by day length, the change in which affects the weasel’s hormonal state. So starting a new moult is only possible during spring and autumn when the days reach the appropriate length as well as the right temperature.</p>
<h2>Wrong winter wardrobe</h2>
<p>The issue of having the wrong coat for the weather is not confined to weasels. At least 22 species <a href="https://repositorio-aberto.up.pt/bitstream/10216/110927/2/255363.pdf">change their coat colour</a> in winter including <a href="http://www.pnas.org/content/pnas/110/18/7360.full.pdf">snowshoe hares</a>, <a href="https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.1722">mountain hares</a> and Arctic foxes. The various hare species face similar problems to weasels and arctic foxes, in so far as they are more vulnerable to predation when they are not camouflaged. However, as plant eaters, they don’t have to worry about also being more visible to their prey.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/220306/original/file-20180524-51130-1cn0x11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/220306/original/file-20180524-51130-1cn0x11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/220306/original/file-20180524-51130-1cn0x11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/220306/original/file-20180524-51130-1cn0x11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/220306/original/file-20180524-51130-1cn0x11.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/220306/original/file-20180524-51130-1cn0x11.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/220306/original/file-20180524-51130-1cn0x11.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/220306/original/file-20180524-51130-1cn0x11.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">This Arctic fox will turn brown and grey for the summer.</span>
<span class="attribution"><span class="source">Neil Burton / shutterstock</span></span>
</figcaption>
</figure>
<p>For some animals, such as the Arctic fox, the changes in the timing of seasonal events, known as phenological changes, are not the only problems brought on by climate change. Because of the warming climate and the spread of their prey species northwards, red foxes, which are larger, bolder and more robust than their Arctic cousins, have been able to extend their range northwards, too, and are now threatening to <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1472-4642.2011.00876.x">out-compete Arctic foxes</a>. </p>
<p>The situation with the weasels is not quite the same, as it is greater visibility to predators that is threatening the white colour morph, rather than direct physical competition with another species. However, unpublished data from the authors of the study suggest that <em>M. n. vulgaris</em> (the one that stays brown) has a higher resting metabolic rate that <em>M. n. nivalis</em>, which means they will require more calories just to stay alive. This may just give the white form of the weasel the edge in the winter when calories are scarce, which may help to redress the balance. </p>
<p>If not then the potential loss of this beautiful and unique subspecies of the least weasel because of anthropogenic climate change will be one more crime to be laid at the door of humanity.</p><img src="https://counter.theconversation.com/content/97138/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jan Hoole 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>With less snow on the ground, weasels that turn white for winter are easier prey for foxes and wolves.Jan Hoole, Lecturer in Biology, Keele UniversityLicensed as Creative Commons – attribution, no derivatives.