Fascinating fact #2
August 30th, 2010
I love this book.
August 30th, 2010
I love this book.
It has taken decades for ornithologists to figure out what's up with Ruffs [link mine]. First, Ruffs breed on what are known as leks--display courts where females come to choose a mate and copulate. [...] Male Ruffs follow one of three distinct reproductive strategies: a dominant and aggressive strategy, a subordinate and passive strategy, and a "sneaker" strategy. Males with dark ruffs or dark head tufts are the dominant males. Males with white ruffs and white or rusty head tufts are satellites. Males in female-like plumage and with small body size are sneakers. These plumage types and associated strategies are genetically determined, fixed at the moment of conception.
[...] The aggressive strategy of males with dark ruffs constitutes the most common reproductive strategy. These males fight vigorously among themselves for the best positions on the lek, and females tend to mate with the males that hold these favored lekking positions. [...] Males with white ruffs and head tufts play the role of satellites, meaning that they do not attempt to defend a particular spot on the lek. White-morph males are not aggressive and always submit to dark-morph males. White-morph males actually form mutualistic displays with dominant males. Many dominant, dark-morph males tolerate a white-morph male on their territories--often right in the heart of the lek--and the two males will display together with ritualized satellite-dominant displays. Studies show that dark-morph males with white-morph males on their territories are more attractive to females than dominant males without satellites. Despite their passive behavior and subordinate role, white-morph males are about as successful at fertilizing females as dark-morph males.
[...] Perhaps the most fascinating reproductive strategy employed by male Ruffs is the sneaker strategy. Sneaker males lack a ruff and have plumage coloration that is exactly like the plumage of Reeves [female Ruffs]. As a matter of fact, these sneaker males are so cryptic that they were overlooked by ornithologists through nearly 90 years of studies on Ruffs. The sneaker strategy was described only in 2006. Sneaker males not only look like females but act like females. They are smaller than ornamented males and their cryptic appearance and behavior deceive dominant males most of the time and allow sneaker males to penetrate unchallenged right to the heart of the lek.
Sneaker males do whatever it takes to keep dark-morph males from copulating with females and to gain mating opportunities for themselves. When a dominant male approaches a receptive female, a sneaker male tries to insert itself between the pair or will crouch like a female to entice the dominant to mount him rather than the female. Following such a ruse, females will sometimes copulate with the sneaker.
- National Geographic Bird Coloration
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