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Leks. Hotspot Female preference Male aggregations Hotshots Kin selection The lek paradox. Leks. Swedish for mating arena No male parental care No resource on territory Males aggregate and display at traditional sites. Leks occur when females are not defensible. Leks ->. antelope.
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Leks • Hotspot • Female preference • Male aggregations • Hotshots • Kin selection • The lek paradox
Leks • Swedish for mating arena • No male parental care • No resource on territory • Males aggregate and display at traditional sites
Leks occur when females are not defensible Leks -> antelope grouse & ptarmigan
Males defend tiny territories on a lek Bat video
Male mating success on leks Sage grouse video
Lekking and frugivory in birds Lek Exploded lek Territory
New World lekking birds Cock-of-the-rock Manakins Bell birds
Hypotheses for male clustering • Hotspot • males aggregate to maximize female encounter rate • Female preference • Females prefer to select mates in aggregations • Females prefer central male • Females prefer attractive male (hotshot) and other males aggregate around him • Kin selection • Males aggregate around relatives
Leks of leks suggest hotspots Hermit hummingbird Ochre-bellied flycatcher Red-capped manakin Blue-crowned manakin
Lek location Female nest density Sage grouse leks and hotspots
Best-of-n expectation Std dev units Number of males Possible reasons for female preference to mate at a lek • Reduce predation • No evidence in sage grouse • More efficient comparison of males • Reduce mate searching costs • But, assuming male quality is normally distributed, advantage of choosing best male is greatest in small, not large, leks • Can copy choice of others
Mate choice copying in sage grouse Green = observed, orange = predicted w/out copying
No! Do leks recruit more females/male in kob?
Do leks recruit more females/male in ruff? Sometimes!
Are black grouse hotshots? Yearly shift suggests male attractiveness, not position, is important
Shorey et al. 2000 Nature 408:352-353 Also in peacock, black grouse, satin bowerbirds, wild turkeys Related manakins on leks
The lek paradox • In lekking species, males only pass sperm. Therefore, only indirect benefits are possible. • If males differ in genetic quality, then females should always prefer the male of highest quality. • Over time, such intense selection will deplete and possibly eliminate genetic variation. • What then do females gain by choosing?
Solution to the lek paradox • Genetic variation must persist for ornamental traits and genetic quality • Ornament expression depends on condition. • Only males in good condition are able to fully express ornament • Condition is likely influenced by many genes. Consequently, deleterious mutations constantly replenish genetic variation.
