Theavutarda hubara macho(Chlamydotis undulata) haveornamental feathers that unfold with extravagancewhile running to attract her partner. However, this courtship comes at a significant cost. The birds that spend more time to “conquer” also moreage faster, according to a study published in the journalEcology Letters.
To reach this conclusion, the researchers analyzed data collected over a decade on thesexual behavior and fertility of more than 1,700 Houbara bustards, raised in a captive breeding program in Morocco. The main finding was that, when analyzing the semen, the scientists verified that thoseMales who had invested more time in displaying their gifts in front of females – some up to 18 hours a day – began to suffer earlier the decline in fertility associated with aging.
Specifically, after six years, the birds began to produce much smaller ejaculations, in many cases with immobile or abnormal sperm. And age was early in those males who had invested more time displaying their gifts ostentatiously to females. The specimens included in the study were between 1 and 24 years old.
“The logic indicates that the genes responsible for the deterioration should be gradually eliminated by natural selection, which is why these birds are an enigma for biologists”, explains Brian Preston, a researcher at the University of Burgundy (France) and one of the study authors. One of the theories to explain this anomaly is that animals have excessive behavior during their youth,expending enormous amounts of energy on sexual displays, which harms their bodies in the long run. “Living is risky,” Preston points out. Due to predators, parasites, and disease, the animals may not live long. “So it may be more important for them to spend their energy being young rather than worrying about the future,” he suggests.
