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!
Developing a digital holography-based multimodal imaging system to visualize living cells
03.06.2020 | Kobe University
Possible physical trace of short-term memory found
03.06.2020 | Institute of Science and Technology Austria
An analysis of more than 200,000 spiral galaxies has revealed unexpected links between spin directions of galaxies, and the structure formed by these links...
Two prominent X-ray emission lines of highly charged iron have puzzled astrophysicists for decades: their measured and calculated brightness ratios always disagree. This hinders good determinations of plasma temperatures and densities. New, careful high-precision measurements, together with top-level calculations now exclude all hitherto proposed explanations for this discrepancy, and thus deepen the problem.
Hot astrophysical plasmas fill the intergalactic space, and brightly shine in stellar coronae, active galactic nuclei, and supernova remnants. They contain...
In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".
Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...
Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.
researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...
Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.
When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...
19.05.2020 | Event News
07.04.2020 | Event News
06.04.2020 | Event News
03.06.2020 | Medical Engineering
03.06.2020 | Physics and Astronomy
03.06.2020 | Physics and Astronomy