Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Larger female hyenas produce more offspring

24.03.2011
When it comes to producing more offspring, larger female hyenas outdo their smaller counterparts.

A new study by Michigan State University researchers, which appears in Proceedings of the Royal Society, revealed this as well as defined a new way to measure spotted hyenas’ size.

“This is the first study of its kind that provides an estimate of lifetime selection on a large carnivore,” said MSU graduate student Eli Swanson, who published the paper with MSU faculty members Ian Dworkin and Kay Holekamp, all members of the BEACON Center for the Study of Evolution in Action. “In short, we were able to document that larger female hyenas have more cubs over their lifetime than do smaller females as well as develop a novel approach for estimating body size.”

Size can be one of the most important traits affecting an animal’s life. It influences eating, getting eaten, speed and agility, and attractiveness to potential mates. However, overall height and weight measurements may not capture differences in more specific traits like leg length that might be more important in survival.

To identify the most-important traits, researchers sedated hyenas in Kenya and took 13 measurements on each subject, including total body length, skull size and leg length. They found that while overall size didn’t affect reproductive success, some clusters of traits did. They also learned that the length of the lower leg, the height at the shoulder and body length were all individually associated with more reproductive success.

“Our results highlight the importance of choosing appropriate measures when estimating animal body size,” Swanson said. “They also suggest researchers should take caution in interpreting selection on size-related traits as selection on size itself.”

Spotted hyenas are particularly interesting because females are larger than males, which is extremely unusual among mammals. In most mammals, the size difference is easy to explain. Larger males get more food and attract more females, but females are faced with a tradeoff between their own body size and the energy needed for pregnancy and lactation. As of yet, the size difference between the sexes is still unsolved.

However, researchers have been able to shed light on the reasons for the large females’ success. They found that larger females reproduce more often and live longer after beginning to reproduce, when compared to smaller females.

Estimating fitness — or success at surviving and reproducing — can be difficult with spotted hyenas, which can live at least 19 years in the wild. Since Holekamp’s field study of spotted hyenas has been ongoing for more than 20 years, the researchers were able to count the number of surviving offspring produced by a female in her lifetime, as well as the length of her total reproductive lifespan.

BEACON is an NSF-funded Science and Technology Center headquartered at MSU, with partners at North Carolina A&T State University, University of Idaho, University of Texas at Austin, and University of Washington.

Michigan State University has been working to advance the common good in uncommon ways for more than 150 years. One of the top research universities in the world, MSU focuses its vast resources on creating solutions to some of the world’s most pressing challenges, while providing life-changing opportunities to a diverse and inclusive academic community through more than 200 programs of study in 17 degree-granting colleges.

Layne Cameron | EurekAlert!
Further information:
http://www.msu.edu

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>