Big love costs spider an arm and a few legs

Big is beautiful for female jumping spiders, which risk being cannibalised for sex with large males.

A team of Kiwi scientists travelled to Kenya to study the spiders.

They tempted females with an array of different-sized dead males and, despite the gamble of being devoured, virgin females were attracted to bigger males - but then chose smaller, safer males as long-term mates.

"It's worth the risk, because their offspring will be bigger, and they in turn will be more attractive to females," Simon Pollard of Canterbury Museum said.

The spiders' culinary habits were the opposite of other species such as the black widow, where males make a light snack for the bigger females.

Dr Pollard, Canterbury University's Robert Jackson and doctorate student Fiona Cross are trying to unravel the mysteries of the spiders with the help of the Marsden Fund.

Despite having a brain smaller than a pinhead, the spiders displayed complex behaviour, Dr Pollard said.

Unusually for spiders, both males and females played a part in courtship. The males might put on a dazzling dancing display, while sometimes the female made the first move by coyly approaching her suitor.

Ms Cross spent hours observing the little spiders in a lab. Part of her job was to protect the females from hungry males to make sure the study did not run out of spiders.

"I was armed with a little paintbrush to stop them. If they just mated, that was okay."

The jumping spiders' bedroom antics were also odd, she said - males transfer sperm to females via leg-like appendages in front of their face.

"I have to say, watching these animals mate is one of the strangest things I have ever seen."

 

The Dominion Post