Featured Research

from universities, journals, and other organizations

Female Spiders Eat Small Males When They Mate

Date:
September 11, 2008
Source:
University of Chicago Press Journals
Summary:
A number of hypotheses have been proposed for why females eat males before or after mating. After looking at a wide range of data, researchers found that sexual cannibalism may not be a complex evolutionary balancing act of costs and benefits but rather a case of a hungry female eating a male when he is small enough to catch.

A female wolf spider, Hogna helluo, consuming a male.
Credit: Shawn M. Wilder

Female spiders are voracious predators and consume a wide range of prey, which sometimes includes their mates. A number of hypotheses have been proposed for why females eat males before or after mating.

Related Articles


Researchers Shawn Wilder and Ann Rypstra from Miami University in Ohio found that the answer may be simpler than previously thought.

Males are more likely to be eaten if they are much smaller than females, which likely affects how easy they are to catch. In one species of spider, Hogna helluo, large males were never consumed while small males were consumed 80% of the time. This result was also confirmed when Wilder and Rypstra examined published data from a wide range of spider species. Males are more likely to be eaten in species where males are small relative to females.

Much research on sexual cannibalism has focused on a few extreme cases involving sexual selection and sperm competition. However, by looking at data on a wide range of spiders, Wilder and Rypstra discovered that the size of the male relative to the female (often referred to as sexual size dimorphism) determines how often sexual cannibalism occurs in a species.

"We were surprised to find that such a simple characteristic such as how small males are relative to females has such a large effect on the frequency of sexual cannibalism," states Shawn Wilder. In many cases, sexual cannibalism may not be a complex balancing act of costs and benefits for males and females but rather a case of a hungry female eating a male when he is small enough to catch.

In an interesting twist, evolution does not appear to be driving this relationship. For example, females would not become larger to consume more males because each male would then be a smaller meal to the larger female and males would not become smaller to be eaten more often because they would not get to mate as often.

Rather, sexual cannibalism may be a byproduct of the evolution of large females and small males in a predatory species.


Story Source:

The above story is based on materials provided by University of Chicago Press Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. Wilder et al. Sexual Size Dimorphism Predicts the Frequency of Sexual Cannibalism Within and Among Species of Spiders.. The American Naturalist, 2008; 172 (3): 431 DOI: 10.1086/589518

Cite This Page:

University of Chicago Press Journals. "Female Spiders Eat Small Males When They Mate." ScienceDaily. ScienceDaily, 11 September 2008. <www.sciencedaily.com/releases/2008/09/080910165846.htm>.
University of Chicago Press Journals. (2008, September 11). Female Spiders Eat Small Males When They Mate. ScienceDaily. Retrieved April 1, 2015 from www.sciencedaily.com/releases/2008/09/080910165846.htm
University of Chicago Press Journals. "Female Spiders Eat Small Males When They Mate." ScienceDaily. www.sciencedaily.com/releases/2008/09/080910165846.htm (accessed April 1, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, April 1, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gorilla Falls Into Zoo Moat

Gorilla Falls Into Zoo Moat

Reuters - Light News Video Online (Mar. 31, 2015) A gorilla comes to the rescue of her sister who fell into a moat in Israel&apos;s Safari zoo. Rough cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
California on Alert Over Surge in Sea Lion Strandings

California on Alert Over Surge in Sea Lion Strandings

AFP (Mar. 31, 2015) Since the start of the year, thousands of baby sea lions have washed up on beaches along the west coast of the United States. Marine animal care centers are working around the clock to save the stranded creatures. Duration: 02:06 Video provided by AFP
Powered by NewsLook.com
Giant Amphibian Fossils Found in Portugal

Giant Amphibian Fossils Found in Portugal

Reuters - Light News Video Online (Mar. 31, 2015) Scientists discover a new species of giant amphibian that was one of the largest predators on earth about 220 million year ago. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Rhino Goes on Deadly Rampage in Nepal

Rhino Goes on Deadly Rampage in Nepal

Reuters - News Video Online (Mar. 31, 2015) A rhino runs rampant down a bustling city street, killing one woman and injuring several others, before security personnel chase it back into the forest. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins