Cuckoo Plumage Morphs Giving Them an Edge for Reproduction.

This article discusses the color morphisms seen in female cuckoos. Cuckoo birds are known for their brood parasitic; That is they lay the eggs in the nests of other species of birds and trick those birds into raising their young. A very different strategy, is parenting really that hard?? 

   

Besides the cuckoos having mimicry abilities with the color of their eggs resembling the hosts species eggs, the females also have a color morphism in their plumage. Some are grey, as seen in the picture above on the left, and others are rofous (reddish). As you can you see, the grey morphs closely resemble sparrowhawks, which prey on smaller birds. This "hawk costume" allows the cuckoo to spook other birds out of their nest and come in and lay their eggs. Some birds have picked up on the grey morphs tricks, and can identify it is a non threat when approaching, complicating the cuckoos parasitic plan.

The rufous variety does not have this mimicry advantage, but perhaps it benefits by being less familiar. The chromose containing these plumage variants is on the W chromosome, a sex chromosome only found in female birds. So only females can have these color varients. The males are also grey, this gives the rufous morphs a advantage in being rarer and less recognizable by other birds.The bottom line, species having different color morphs, with one having a mimicry aspect and one does not, may benefit the species as a whole. This gives scientist a point of interest to study selection and how it oscillates under unique conditions.

Mimicry has always fascinated me, and this is no exception. The cuckoo bird has such a unique reproduction strategy, how can you not marvel? Maybe the birds that raise cuckoos unknowingly, actually are just super excited to have a cuckoo foster. 

https://www.sciencedaily.com/releases/2024/04/240424160236.htm

https://phys.org/news/2024-04-evolutionary-biologists-variants-female-cuckoos.html

Posted by Michael Breslin