Male golden-collared manakins (the bird shown in the photo above), have to jump through a lot of hoops to get a mate. First, they set up a “court” on the forest floor, clearing a small area with little saplings. Then, they start doing acrobatics, all in the hopes that a passing female will be impressed enough to mate with him.
Scientists have now found evidence that subtle differences in the performance of a male can make or break his chances of successfully enticing a female to mate with him.
Researchers Julia Barske, Barney Schlinger, Martin Wikelski, and Leonida Fusani took high speed videos of males during courtship display and measured different aspects of the display. They then measured how successful each male was (i.e. how many times did he interest and/or mate with a female?). The research was published online April 20, 2011, in the Proceedings of the Royal Society: Biological Sciences. You can see the abstract here.
The courtship display of these birds is intense. They have to jump from sapling to sapling and, mid-flight, snap their wings together hard enough to make a loud noise. Once they land, they have to quickly spin around to face the center of the court, get themselves situated, and then show their sexy yellow beards off to the ladies before quickly jumping off again. Check out the video to see this in action.
Not all males are successful at getting mates. In fact, only a small number of males will get to mate with most of the females. What are these males doing so right?
By measuring different aspects of the courtship display, the researchers found that females were able to see very subtle differences between males. Females really liked males that snapped their wings more often and spent less time between jumps. Females of this species are very hard to impress: males that were slower by just a few tens of milliseconds were not as attractive.
So why the harsh judgement, ladies?
During their acrobatic jumps and beard display movements, males have to use a lot of energy. They use so much energy that their hearts have to beat twice as hard as normal, especially when snapping their wings. In order to have a top-notch courtship display, males have to be extremely fit. Not only do they have to have good nutrition and excellent health, they also have to have been born with good coordination and a generally good nervous system.
This means females can use the male’s acrobatic abilities to judge whether he is likely to have good genes. Since these genes gave the male his excellent muscle coordination and strength, they would probably be good for escaping predators, too. By picking the best male, she has a better chance of having babies with the same good genes.
Filed under: Sexual selection Tagged: Female choice, Male courtship, manakins, Scientific literature