We traveled to the cloud forests of Milpe Bird Sanctuary where we came across an extraordinary species that, despite its small size and ordinary looks, is a fascinating example of evolution.
In the brief video below of a male Club-winged Manakin (Machaeropterus deliciosus) located at its ‘lek’ (or display site) at Milpe Bird Sanctuary, in northwestern Ecuador, we can see the bird engaging in a courtship ritual to hopefully (be worthy enough to) attract a mate.
The video shows the male manakin making (‘Tik Tik WANNNG’) sounds as it extends its legs and lifts its wings conspicuously over its back. The concept (and the evidence seen) seems simple enough, but this species shines a light on a series of concepts most of us have probably never thought about, which go against many ‘facts’ we were taught in school, and may even hold as truths.
1) We know that birds sing with the help of a special organ in their throat (the syrinx);
2) We know that many bird species are dimorphic, whereby males are often more colorful than females;
3) We also know, based on what we understand as the survival of the fittest, that those beautiful males are living proof that they are competing to demonstrate just how fit they are, to ‘wow’ the girls… a MACHO thing
Well, yes, many species are dimorphic, with males being more brightly colored or more highly adorned than their female counterparts. But, the male Club-winged Manakin (seriously throwing points 1 and 3 into question) courts females by grating his sort-of disheveled-looking wings together at a most mind-boggling 107 times/second, creating its metallically musical serenade (no syrinx needed).
Females of this species, for some reason, decided that that really turns them on, if done just right! So this species has evolved in a way that has allowed males to make that enticing sound. BUT… in order to do so effectively, the male Club-wing must have solid wing-bones!
‘Is that what you really want, my love?’
Remember… birds evolved hollow bones over many, many millions of years. They did so explicitly to facilitate flight. Wouldn’t you think that having some solid bones in your wings would make flying more difficult? More clumsy? And that that could maybe even endanger your entire species?
Well, the Club-winged Manakin certainly fits that description. In fact, this cool little bird survives in spite of that serious disadvantage. And what’s even more inexplicable is that these solid wing-bones develop while the birds are still inside the egg, as embryos (prior to becoming male or female), which means that both sexes suffer this disadvantage just because the ladies like the ‘song & dance’. And… females can’t even ‘sing’ with their wings!
This phenomenon is known as “decadence”, whereby females of this species actually choose beauty that endangers the survival prospects of their own young, their potential male mates, and even themselves! This counters the basic principle of evolution that we’ve been taught: survival of the fittest. This is, rather, about sexual selection… or the survival of the most beautiful.