Monday 7 April 2014

Crows feed cuckoo chicks, get stinky defense against predators

Science Focus

original post »
Vittorio Baglione

If you come across a young cuckoo in a bird’s nest this summer, you’ll be witness to one of the most bizarre sights in nature. Cuckoo chicks are interlopers in the nests of other species, and they can be seen being frantically fed by their unwitting foster parents even though they’re often many times larger than their hosts.

It makes you wonder: why on earth does this bird expend so much energy raising such clearly unrelated offspring? Or, more accurately, why haven’t all the species victimized by the cuckoo evolved some form of defense against this nest parasitism? The clue comes from thinking about this puzzle in terms of costs and benefits.

Raising a cuckoo chick often comes at an obvious cost. Common cuckoo chicks, for example, famously remove any host eggs or young from the nest within days of hatching. Chicks of some other cuckoo species will grow up alongside their host’s own offspring, yet they still remove competition. Magpie chicks often die of starvation when sharing a nest with great spotted cuckoo chicks, because the cuckoos beg to be fed more intensely.

Read 12 remaining paragraphs | Comments


#science
original post...
See Zazzle gifts tagged with 'science'

No comments:

Post a Comment