Spider love: Little guys get lots more

Dec 08, 2008

Big males outperform smaller ones in head-to-head mating contests but diminutive males make ten times better lovers because they're quicker to mature and faster on their feet, a new study of redback spiders reveals.

Published in the current online issue of Journal of Evolutionary Biology, the study shows the importance of maturation in defining mating and paternity success. In field enclosures, researchers simulated two competitive contexts favouring the development of differently sized male redbacks (Latrodectus hasselti).

The larger males were more successful at mating with and impregnating females when they competed directly with smaller males. However, when faster maturing smaller males were given a one-day head start, reflecting their earlier maturation in nature, they had a ten-times higher paternity rate than larger males.

Courtship between redbacks lasts an average of 50 minutes when males are competing and 4.5 hours for single, non-competing males. Copulation lasts from 6 to 31 minutes, and males are usually injured or killed during the process.

"The results reveal that big males don't get it all their own way," says lead author, UNSW postdoctoral fellow, Dr Michael Kasumovic, who co-authored the paper with Maydianne Andrade of the University of Toronto. "Nature favours larger and smaller males under different circumstances. Larger males experienced a longer maturation process so they are unable to search for and mate with females and produce offspring at the same rate as smaller redback spiders.

"Large size and weaponry are strong predictors of a male's competitive strengths because those traits help them dominate smaller males when they compete for food and mating rights. However, evidence from studies of midges, dung flies and seed beetles reveals that smaller males develop sooner than larger males and often mate before larger competing males arrive on the scene. Size isn't the only ruler by which we can measure a male's quality. Many other factors, including maturation time, are critical in that definition."

Source: University of New South Wales

Explore further: Study shows how epigenetic memory is passed across generations

add to favorites email to friend print save as pdf

Related Stories

Taking the 'sting' out of reproduction

23 hours ago

(Phys.org) —Female parasitic wasps have more reproductive success when working together with other females, which can also explain sex biased reproduction, according to new research.

Size doesn't matter if you're a sex sneak

Sep 10, 2014

Research into the mating behaviour of one of New Zealand's most unusual insects shows it doesn't always pay to be brave – sneaking sex can be just as effective.

Lady baboons with guy pals live longer

Sep 10, 2014

Numerous studies have linked social interaction to improved health and survival in humans, and new research confirms that the same is true for baboons.

Whale sex: It's all in the hips

Sep 08, 2014

(Phys.org) —Both whales and dolphins have pelvic (hip) bones, evolutionary remnants from when their ancestors walked on land more than 40 million years ago. Common wisdom has long held that those bones ...

Recommended for you

Stem cells use 'first aid kits' to repair damage

2 hours ago

Stem cells hold great promise as a means of repairing cells in conditions such as multiple sclerosis, stroke or injuries of the spinal cord because they have the ability to develop into almost any cell type. ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

morpheus2012
1 / 5 (4) Dec 08, 2008
spider love is this the gay news for kids?

spider in iss or some?

or waht?


eww tired of tthi fake fox news
Nartoon
1 / 5 (1) Dec 08, 2008
Size isn't the only ruler by which we can measure a male's quality.

Sounds like the female redback spiders don't discriminate based on male size.