Monday, February 20, 2012

Love gifts in the animal kingdom

On Valentine's day, what beau could possibly resist a hand-picked gift, wrapped in perfumed silk?
Certainly not female Paratrechalea ornata spiders, according to research by Dr Luiz Costa-Schmidt, an arachnid expert studying in Brazil.
Male spiders of this south-American species incorporate a chemical known as a pheromone into their silk gift wrap. This encourages females to accept them as mates.
Using a present, or "nuptial gift", to ensure a sexual engagement is a practice found throughout the animal kingdom but it can be startlingly different from our human perception of courtship.
Here are some of the weird array of presents that animals give to potential mates.
Perfumed package
P. ornata are not the only spiders to give gifts to their intended: the male nursery web spider (Pisaura mirabilis), commonly found in European grass meadows, also wraps offerings in silk.
With this presentation, however, all is not as it seems. The males do not always wrap up enticing morsels of prey for their mates.
Instead, beguiling packaging can disguise a multitude of disappointing items - from dried-out ant husks to worthless bits of plant.
"If a male finds a receptive female, but [he] doesn't have prey at that moment, any object could be easily be wrapped in silk to be offered," explains Pedro Ere Disconzi Brum, another member of the Brazilian research team.
"This may be a crucial step for this male to be chosen by the female in the early steps of the courtship process."
Moreover, Mr Brum explains, if the male is in poor condition, he can catch prey for himself and wrap up the leftovers to gain the attention of a mate.

No comments:

Post a Comment