Jun 22, 2019

Cuckoo

Cheating by Nature
by Nick Davies

I didn't know a lot about cuckoos, before. I was aware that they laid their eggs in another bird's nest, leaving the host parent to raise their chicks, and I've seen the astonishing video footage of the naked cuckoo chick pushing the other bird's chicks out of the nest to commandeer the resources all for itself. I didn't realize how intricate the depths of relationship goes, between cuckoos and their host birds. This book goes into all the details, while describing the fieldwork and experiments done to learn exactly how it all works out. Cuckoos in different areas (and not only cuckoos- honeyguides and a few other species also parasitize other birds' nests) use different host nests, and individual female cuckoos each specialize in using a certain host species. They not only match the host eggs in color and marking patterns, but the chicks match the host species' gape colors and begging calls in order to keep the host parents feeding them sufficiently. A big question the researchers had was: why are the host parents fooled? why don't they get rid of the foreign egg or abandon or evict the cuckoo chick. Sometimes they do. Sometimes the risk of guessing wrong and neglecting the own young is high, so they don't. It's all very complex and I was really intrigued by all the details, especially how the author and his colleagues figured some of it out. It's evolution happening real time, this constant friction between cuckoo and host birds- can they trick each other, will one get pushed out or the other. In certain areas host birds seem to have become wise to all the cuckoo's deceptions, and cuckoo numbers have actually fallen. But then another host species will be duped a few times, cuckoos that match that host enough to get away with it will thrive, and it starts all over again.

Borrowed from the public library.

Rating: 3/5                 289 pages, 2015

1 comment:

  1. I've always wondered how this relationship started in the first place...why cuckoos ever found it necessary to use this kind of trickery rather than just doing their own chick-raising. That the cuckoo chicks are so brutal right out of the egg is almost scary.

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