Word Press: Lek
In the Wall Street Journal (7/18/2013) was an article about the fate of an unusual bird called the Lesser Prairie Chicken, whose primary nesting territory is in the middle of the Oklahoma Panhandle. The small, brownish grouse is about the size of a football and it is competing against behemoth oil-drilling rigs for its home.
The battle has pitted the environmentalists against the Oil companies and we usually know how this is going to turn out. Only this time the ranchers, oil firms and environmentalists are suggesting a “habitat exchange” similar to some of the Cap and Trade ideas that have been floating around for years. Any proposal worth its salt has to satisfy all stakeholders, and this one, which would create a “stock exchange” of credits, seems to be taking wing in all of the five states impacted by the exchange (New Mexico, Colorado, Kansas, Oklahoma, and Texas).
From US Fish & Wildlife
The Lesser Prairie Chicken has been in decline for decades. Estimates are that there are only 37,000 Chickens left in the US. The threat of extinction is real, but environmentalists predict that it is a few decades off. The more immediate threat is that the Department of Fish and Wildlife might fast forward the Chicken to the “endangered species list” and cause havoc to all parties. Once on “the list,” as those of us in the Pacific Northwest know from the Northern Spotted Owl controversies, it stays there until the studies are completed, the population stabilized, and the chickens recover, which could take forever. Just as the owl has for the timber companies, such a listing would complicate oil companies’ efforts to develop large oil and gas deposits under the grasslands where the birds like to nest.
The line in the WSJ article that caught my attention was from a quotation by Alan Jett, a farmer in the Oklahoma Panhandle. Mr. Jett, who had parked his pick-up truck on a slight incline, with a gas pipeline behind him and an old oil well just ahead, said, “I’ve seen chickens lekking right around that pipeline.” Lekking. Now that is great word.
The word lekking is the present participle of the word LEK, which sounds like a word made up by Scrabble nuts; however, it refers to the dramatic dance that the Prairie Chickens do in their mating rituals. They have elaborate steps and noises and body parts that bulge … all in an effort for the males to attract the females and then mate. There are actually lots of species that perform the Lek, including the Great Prairie Chicken, American Turkey, Sage Grouse, and many more around the world. Even some insects, amphibians and mammals perform a lek.
I have seen some movies of the Lek dance, but I have never witnessed it in person. Mr. Jett feels it is nothing special, if the chickens are willing to do it with gas pipelines and lazy cattle in the vicinity. The birdwatchers of the five state region feel otherwise. For the birds themselves Lekking is a matter of genetic diversity and survival. There are some strict rules and a paradox to the practice of this behavior.
The word lek comes from the Swedish word for “play,” which is spelled the same. According to Wikipedia, lek is a noun that typically denotes pleasurable, less rule-bound children’s games. More specifically, the word refers to the area where “matrimonially affairs” were carried out by certain animals. The Swedish word lekställe translates as “mating ground.”
Greater Prairie Chicken
If we look at the typical bird species with lek behavior, such as the Prairie Chicken, there is always a ranking alpha-male, a beta-male, gamma-male, etc. who guard the territory of a few meters in diameter. In that area the dominant males can attract up to eight females. Common bird leks have up to 30 individual birds in the space, with the dominant male having the most prestigious central territory. Once the male’s territory has been established, the females come into these areas and choose their mates. The females then preferentially mate with their chosen male in the center of the territory.
One variation is called the “Exploded Lek,” where the territory becomes vast, and is bound by ear-shot and not sight. One species, the Kakapo, is known to have male territories many kilometers from each other.
The other rules appear to be around which birds are included in a lek (seeking genetic diversity), which birds mate more than once (seeking monogamy and fidelity), and what was the pecking order (following the Greek alphabet down from Alpha). The main benefit of the lek appears to be successful mating and expediency. The COST of the lek for the males is that they have to give up choosing — it is the Sadie Hawkins Dance of mating. Another cost is that sometime the females want to have a “male bake-off” or squawk-off. They want to listen for the loudest squawk or hear the fastest throat throttle or see the largest stomach display. Sometimes it comes to a fight, where to the victor goes the spoils.
The BENEFIT to the females is that the lekking process seriously reduces time it takes to search for a mate. They do not have to travel very far, they are in charge, and they receive immediate gratification. Pretty good deal.
The COST-BENEFIT to the species is survival. The males and females spend far less time preening on the fashion run-way and exposing the birds to predation. Just think of a week-long jamboree and all of the birds of prey who would flock nearby to pick up the wanderer or carrion. It is a numbers game: the faster lekking process allows for fewer casualties and more potential offspring.
The Lek Paradox
The conundrum of lekking behavior that intrigues naturalists and ornithologists is deciphering how the choice of particular male traits, over many generations, may help or hurt the genetic variability of a species. Will the right traits be present in the next generation to help the birds survive? The paradox may be alleviated by the presence of random mutations, naturally occurring in all species. Perhaps those mutations provide the differences that are crucial to survival. But does the constant choice by the female overwhelm the genome?
There appear to be several aspects to the Lek Paradox. One is that the males contribute only his genes. The second is that the female’s preferences do not affect her fertility. Female selection would naturally lead to a greater prevalence of offspring with the trait she chose as superior — size or color of grouse chest bubble, for example. The genetic variability of the species would decrease and, like any model on a fashion runway, the offspring would rush-off in one direction. Lekking, however, does not seem to lead to any, what is called, “runway selection.” Certain behavioral biologists have said that the females are more adept at finding the mate with the best overall characteristics than we might believe. They seem to have the ability to determine reproduction fitness better than we humans might imagine.
Rather than diving into the genetic variability of natural selection and arguments of condition-dependency, its worth noting that many species in the animal kingdom practice lekking. And those species have not only survived but thrived, which is pretty mating-amazing. Plus, the fact that animals as diverse as the Waterbuck, Fruit Bats, and Green Iguana practice lekking is even more amazing. Not to mention some species of fish, the midge insect, and the Ghost Moth all mate through lekking.
If lekking were a practice that reduced genetic variability, the lek rules would have died out thousands of years ago. In the mean time, go strut your stuff. Dash down that runway, let the females choose, and find your inner LEK. There are some Greater and Lesser Prairie Chickens who can show you the way.