Menu Fermer

Articles sur Birds

Affichage de 241 à 260 de 511 articles

A male Olive-backed Euphonia (Euphonia gouldi), photographed in Costa Rica. Andy Morffew

Why do birds sing?

Birds spend a lot of time and energy singing, but they don’t do it the same way in every season of the year. And some can’t sing at all. What’s the purpose of birdsong?
Yolks are a great source of vitamins, minerals, fats and proteins packaged up by the female animal for an embryo. Emily Nunell/The Conversation CC-NY-BD

Curious Kids: why do eggs have a yolk?

A yolk allows a developing animal to stay in an egg longer, boosting its chance of survival. The downside is the mother has to work hard finding extra food so her body can create a nutritious yolk.
Chicken or rooster? This bird is both – female on the left (dark feathers), and male on the right (white feathers, with larger comb and physique). Mike Clinton (Roslin Institute)

How birds become male or female, and occasionally both

Birds have some of the most amazing sex differences of any animal. They can control the sex of offspring, and even produce rare half-male, half-females. And their sex genes and chromosomes are quite different from ours.
Generations of giraffes. Shutterstock.

Curious Kids: what is a species?

It can actually be very tricky to define a species, but in the 1900s, scientists found a pretty good way.

Les contributeurs les plus fréquents

Plus