The Voyeur Biologist

Sharp-tailed Grouse Lek - Arrowwood National Wildlife Refuge

Male hummingbirds, while courting females, produce a sound with their tail feathers, produced by rapidly spreading and closing them while in a downward dive by a female.  These sounds are unique to individual species, varying based on the location, size, shape, mass and stiffness of feathers. 

The motivation behind these sounds is unknown, but two hypotheses posit that it may reflect females’ preference for better fliers (as flying proficiency indirectly reflects general fitness), or that the sounds developed incidentally to flying, with no unique purpose. 

(Source: laboratoryequipment.com)

jestcomedy:

Planet Earth: Just the Sex

David Attenborough narrating leopard slugs mating.

(Source: charlesherbertbest)

Being Glamourous in the bird world - Battle of the Animal Sexes - BBC

Green Porno - Deer

Bizarre Parents - Battle of the Animal Sexes - BBC

Goat Mating is Weird 

Hedgehog Mating Rituals - David Attenborough (Life of Mammals - BBC)