Featured Research

from universities, journals, and other organizations

Assertiveness is the best form of defense, at least for hyena pups

Date:
June 21, 2012
Source:
Forschungsverbund Berlin e.V. (FVB)
Summary:
A new scientific study shows for the first time in spotted hyena (Crocuta crocuta) twin litters, that success in sibling competition for maternal milk is influenced by training effects, sex and hunger, and that dominant siblings exert incomplete control over their littermate’s access to the resource.

Spotted Hyena (Crocuta crocuta).
Credit: Marion L East; IZW

A new scientific study shows for the first time in spotted hyena (Crocuta crocuta) twin litters, that success in sibling competition for maternal milk is influenced by training effects, sex and hunger, and that dominant siblings exert incomplete control over their littermate's access to the resource.

These findings challenge the general expectation that in species with intense and potentially fatal sibling rivalry -- as the spotted hyena -, the dominant sibling has complete control over the share of food received by its sibling(s). The expectation derives from extensive theoretical and empirical research on sibling rivalry in birds. It was not known whether dominant siblings in mammalian litters exert such a despotic control over their siblings' access to the resource until this question was investigated for the first time in this study in the spotted hyena by researchers from the German Leibniz Institute for Zoo and Wildlife Research (IZW).

The authors studied sibling tactics during competition for access to maternal milk. The results, recently published in the scientific journal Proceedings of the Royal Society B, demonstrate that by using aggression, dominant siblings monopolise access to maternal milk and thereby benefit from higher growth rates than their subordinate littermate. However, subordinate siblings adjust their behavior according to their hunger level and increase their assertiveness when hungry. As a result, subordinate siblings enhance their own access to milk, suggesting that they can effectively adjust their submissiveness according to their likelihood of starvation.

But why does one offspring show submission to its sibling anyway? In contrast to bird species with asynchronous hatching, in the spotted hyena dominance does not depend on differences in body size or fighting ability. The study shows that young subordinates are intensively trained as 'losers' by their dominant sibling, and as a consequence, respect dominance conventions as they become older.

The authors then tested the effect of the sex of the littermate on sibling success during competition for milk. Interestingly, in a species where adult females socially dominate adult males, the researchers found that sisters were more effective than brothers during competition for maternal milk. This result is in contrast to many studies according to which females were weaker competitors than males during conflicts.

These new insights into how the fundamental dynamics of sibling rivalry is modified by litter sex composition and hunger state offer opportunities for future research. One such topic could be how mothers affect sibling rivalry by chosing to intervene or not to intervene.


Story Source:

The above story is based on materials provided by Forschungsverbund Berlin e.V. (FVB). Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Benhaiem, H. Hofer, S. Kramer-Schadt, E. Brunner, M. L. East. Sibling rivalry: training effects, emergence of dominance and incomplete control. Proceedings of the Royal Society B: Biological Sciences, 2012; DOI: 10.1098/rspb.2012.0925

Cite This Page:

Forschungsverbund Berlin e.V. (FVB). "Assertiveness is the best form of defense, at least for hyena pups." ScienceDaily. ScienceDaily, 21 June 2012. <www.sciencedaily.com/releases/2012/06/120621112616.htm>.
Forschungsverbund Berlin e.V. (FVB). (2012, June 21). Assertiveness is the best form of defense, at least for hyena pups. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2012/06/120621112616.htm
Forschungsverbund Berlin e.V. (FVB). "Assertiveness is the best form of defense, at least for hyena pups." ScienceDaily. www.sciencedaily.com/releases/2012/06/120621112616.htm (accessed October 23, 2014).

Share This



More Plants & Animals News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Working Mother DIY: Pumpkin Pom-Pom

Working Mother DIY: Pumpkin Pom-Pom

Working Mother (Oct. 22, 2014) How to make a pumpkin pom-pom. Video provided by Working Mother
Powered by NewsLook.com
San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Bear Cub Strolls Through Oregon Drug Store

Raw: Bear Cub Strolls Through Oregon Drug Store

AP (Oct. 22, 2014) Shoppers at an Oregon drug store were surprised by a bear cub scurrying down the aisles this past weekend. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Family Pleads for Pet Pig to Stay at Home

Family Pleads for Pet Pig to Stay at Home

AP (Oct. 22, 2014) The Johnson family lost their battle with the Chesterfield County, Virginia Planning Commission to allow Tucker, their pet pig, to stay in their home, but refuse to let the board keep Tucker away. (Oct. 22) Video provided by AP
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