He leks me, he leks me not…

The breeding behavior of animals is vastly diverse and has fascinated biologists for centuries. Birds sing elaborate songs and flash their colorful plumage, some mammals fight with each other for the right to breed with females, and some insects offer food as nuptial gifts to win their ladies’ hearts (who says romance is dead?). Among the mating behaviors, the lek-mating system  is particularly fascinating.

image1

Male Elephant Seals (Mirounga leonina) fighting with each other to gain access to a harem of females is just one example of diverse mating behaviors in the animal kingdom (Photo credit: Laëtitia Kernaléguen/BMCEcology, Flickr Creative Commons image)

So what is a “lek”, exactly?

The term “lek” came from the Swedish word “lekställe” which means “mating ground”. In lekking species, a lek is an area where males gather and defend mating territories during the breeding season. Often times, males perform courtship displays at the leks to attract females; these displays could involve an elaborate dance (in birds) or acoustic competition (in frogs). While the males are displaying, the females would check out different leks before deciding which male with whom she would mate, and that decision depends on many factors. For birds, degree of colorfulness in the male’s plumage and frequency of display at the lek are just two of many factors that contribute to his success at mating with a female.

image5

A greater sage-grouse lek on a mountain prairie in Wyoming with several males displaying (Photo credit: Jennifer Strickland/USFWS, Flickr Creative Commons image)

Who’s who in the lekking world

Many species across different taxonomic groups exhibit lekking behavior. The greater prairie-chicken (Tympanuchus cupido), for example, are known for their display during which males gather and strut around while inflating and showing off their brightly colored air sacs to the females. Lekking behavior doesn’t always involve complicated displays, however. For example, male topi (Damaliscus korrigum), an African antelope, exhibit lekking behavior by forming clusters of territories that they defend during the breeding season. Also, some  insect species such as the midge gather in swarms at hill tops that females visit to pick a mate (a.k.a. “hilltopping”).

image2

A male greater prairie-chicken inflating its air sacs during display at a lek. (Photo credit: Greg Kramos/USFWS, Flickr Creative Commons image)

image4

A topi standing on a dirt mound in Uganda (Flickr Creative Commons image)

When it comes to lekking display, though, manakins are the experts. The manakins (Family Pipridae) are a group of tropical birds whose lekking behavior biologists have obsessed over for decades. There are over 50 species of manakins, and each has its own particular lekking behavior. Readers are perhaps familiar with the “moonwalk” dance performed by red-capped manakins (Ceratopipra mentalis) that went viral a few years ago.

image6

A male red-capped manakin in Costa Rica (Photo credit: Greg Gilbert, Flickr Creative Commons image)

The long-tailed manakins (Chiroxiphia linearis) also perform elaborate display to impress potential mates. The male long-tailed manakins are almost entirely black with a red cap, sky-blue back, and two long tail feathers that earned the species its name. During display, two or more males gather at a lek: one is the “alpha”, and the rest are “betas”. The beta males act as wingmen for the alpha, and they collaborate to perform a carefully choreographed dance that would put the most skillful acrobats to shame accompanied by bizarre noises resembling a malfunctioning robotic cat. In most cases, only the alpha male get to mate with the female in the end.

Ladies’ choice

So why did so many species develop this behavior? What does lekking have over the good old-fashioned one-on-one courtship rituals performed by other animals? The fact of the matter is, lekking comes with its own costs, including increased predation risk for the males because they make themselves more noticeable by predators when they gather around and make a lot of noise. Also, lekking takes a lot of time and energy which the males could use for other activities such as foraging. So why go through all this trouble?

As it turns out, females are the driving force behind the evolution of lekking behavior. As with many other species, females get to be the choosy sex and males would adopt any strategies that would maximize their chance of encountering females and showing off their qualities. One hypothesis that scientists came up with to explain evolution of lekking behavior is the “hotspot” hypothesis, which states that it is advantageous for males to gather in an area where females visit frequently (“hotspots”) to increase mating opportunities. To put it in human perspective, a typical straight guy looking for a girlfriend will probably have better luck going to Salsa nights at a local bar than his urologist’s office (unless he likes the challenge).

The lek-mating system is just one of many different mating systems adapted by animals, and it is very diverse and complex in and of itself. Decades of studies in this behavior still leave many questions unanswered. For example, in cooperative lekking displays, why do beta males collaborate with the alpha male if they don’t get to mate with the female? Despite the unknowns, one thing is for sure: there seems to be no limit to the length at which males of a species will go to attract their mates, and that alone warms my cold, jaded heart.

About the author:

 

image3 Angela Hsiung is a PhD student in Warnell School of Forestry and Natural resources at UGA. She enjoys studying wildlife and fish ecology and conservation. Aspiring to be a master of none, when Angela is not at school, she can be found lagging behind a group of runners while gasping for breath, mis-identifying a bird, or failing spectacularly at playing “Sweet Home Alabama” on the guitar. You can contact her at solitaire.hsiung@gmail.com. More from Angela Hsiung.