Featured Research

from universities, journals, and other organizations

Cannibalism Among Rattlesnakes Helps Females To Recover After Birth

Date:
February 22, 2009
Source:
Plataforma SINC
Summary:
Researchers have produced the first quantitative description of cannibalism among female rattlesnakes (Crotalus polystictus) after monitoring 190 reptiles. The study has shown that these animals ingest on average 11% of their postpartum mass (in particular eggs and dead offspring) in order to recover energy for subsequent reproduction.

Rattlesnake in Mexico (Crotalus polystictus).
Credit: Estrella Mociño / SINC

Spanish, American and Mexican researchers have produced the first quantitative description of cannibalism among female rattlesnakes (Crotalus polystictus) after monitoring 190 reptiles. The study has shown that these animals ingest on average 11% of their postpartum mass (in particular eggs and dead offspring) in order to recover energy for subsequent reproduction.

Related Articles


The lack of information about cannibalism in rattlesnakes (Crotalus polystictus) led researchers to start a study in 2004, which they continued for three years in central Mexico, where this species is endemic. They measured "cannibalistic behaviour" among 190 females, which had 239 clutches of eggs, and determined that this phenomenon is justified by "enabling the mother to recover and regain strength".

"A cannibal rattlesnake female can recover lost energy for reproduction without having to hunt for food, a dangerous activity that requires time and expends a great deal of energy," Estrella Mociño and Kirk Setser, lead authors of the study and researchers at the University of Granada, along with Juan Manuel Pleguezuelos, tell SINC.

The study, published in the latest issue of the journal Animal Behaviour, shows that cannibalism in this species is an evolutionary result of its feeding behaviour, since its prey is dead for some time before being eaten by the snake. "Viperids in general are prepared to eat carrion, and for this reason it is not so strange that they consume the non-viable sections of their clutches after going through the great energy expenditure caused by reproduction," says Mociño.

The research team say this behaviour can be explained by four biological factors - the day of the birth (females that give birth at the end of July are more likely to be cannibals, since they have less time to feed and prepare themselves to reproduce again), the proportion of dead babies per clutch, the level of maternal investment (the larger the brood, the greater the chance that it will contain non-viable elements, which she will eat), and stress caused by being in captivity (the researchers maintained the females in captivity for an average of 21 days).

Of all the females, 68% consumed part or all of their dead offspring, and 83% of these ate them all, and waited little time to do so (around 16 hours), although some ate them "immediately after giving birth", adds Mociño. The rest (40%) of the females "did not display cannibalistic behaviour".

According to the scientists, cannibalism is "not an aberrant behaviour, and is not an attack on the progeny", since it is not the same as parricide or infanticide as it does not involve live elements. It simply recovers some of what the snake invested in the reproduction process, and prepares it to reproduce once again.

Snakes can distinguish between dead and live offspring

The scientists showed there was a low risk of the snakes eating healthy offspring, which look very similar to dead ones for the first two hours after emerging from their membranes. During the study, only one female ate live babies.

"In comparison with mammals or birds, snakes are not as maternal, but the study shows that they also display behaviour that has evolved, and that helps the female and her offspring to reproduce and grow successfully," say Mociño and Setser.

Crotalus polystictus is categorised as a "threatened species" according to the Official Mexican Regulations on protection of native species of wild flora and fauna in Mexico. Limited habitat, urban expansion and the growth of agriculture are the main threats to the snake.

To date, the scientists have marked more than 2,000 individuals of this species, which range in length on average from 50cm to 90 cm, and which display different survival strategies from many other rattlesnakes in the north of Mexico and the United States.

This reptile has a very rapid reproduction rate, suggesting that it is experiencing a high death rate caused by external factors. As well as contributing to scientific knowledge about animal cannibalism from an evolutionary perspective, the scientists hope that publicising these results will "lead to human beings being less aggressive towards these snakes".


Story Source:

The above story is based on materials provided by Plataforma SINC. Note: Materials may be edited for content and length.


Journal Reference:

  1. Mocinodeloya et al. Cannibalism of nonviable offspring by postparturient Mexican lance-headed rattlesnakes, Crotalus polystictus. Animal Behaviour, 2009; 77 (1): 145 DOI: 10.1016/j.anbehav.2008.09.020

Cite This Page:

Plataforma SINC. "Cannibalism Among Rattlesnakes Helps Females To Recover After Birth." ScienceDaily. ScienceDaily, 22 February 2009. <www.sciencedaily.com/releases/2009/02/090219095533.htm>.
Plataforma SINC. (2009, February 22). Cannibalism Among Rattlesnakes Helps Females To Recover After Birth. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/2009/02/090219095533.htm
Plataforma SINC. "Cannibalism Among Rattlesnakes Helps Females To Recover After Birth." ScienceDaily. www.sciencedaily.com/releases/2009/02/090219095533.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Water Fleas Prepare for Space Voyage

Water Fleas Prepare for Space Voyage

Reuters - Innovations Video Online (Jan. 26, 2015) — Scientists are preparing a group of water fleas for a unique voyage into space. The aquatic crustaceans, known as Daphnia, can be used as a miniature model for biomedical research, and their reproductive and swimming behaviour will be tested for signs of stress while on board the International Space Station. Jim Drury went to meet the team. Video provided by Reuters
Powered by NewsLook.com
Florida Might Legalize Black Bear Hunting

Florida Might Legalize Black Bear Hunting

Newsy (Jan. 24, 2015) — A string of black bear attacks has Florida officials considering lifting the ban on hunting the animals to control their population. Video provided by Newsy
Powered by NewsLook.com
Ebola Killing Large Portion Of Ape Population

Ebola Killing Large Portion Of Ape Population

Newsy (Jan. 23, 2015) — Experts estimate Ebola has wiped out one-third of the world&apos;s gorillas and chimpanzees. Video provided by Newsy
Powered by NewsLook.com
Controversy Shrouds Captive Killer Whale in Miami

Controversy Shrouds Captive Killer Whale in Miami

Reuters - Light News Video Online (Jan. 23, 2015) — Activists hope the National Oceanic and Atmospheric Agency (NOAA) will label killer whales endangered, allowing lawyers to sue a Miami aquarium to release an orca into the wild after 44 years. Jillian Kitchener 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