h as the Athi/Kapiti Plains and beyond. According to the researchers, in environments like Tsavo that have especially high minimum temperatures throughout the year, lions in their reproductive prime--from the approximate ages of five thru seven years old--usually possess only very marginally developed manes, while most of the more thoroughly maned lions in those same territories were already well past their breeding prime.

Furthermore, the researchers found compelling evidence indicating that manes of lions from all populations continue to develop long after a lion has achieved sexual maturity, such that the best-maned lions in any region are typically of an older age class. "Usually lions are well past their breeding prime when they carry the most extensive and often darkest manes of their lives," explains Kerbis Peterhans Adjunct curator of Mammals at The Field Museum, Professor at Roosevelt University, and co-author of the study.

This finding stands in contrast to recent studies arguing that female-driven sexual selection in the species Panthera leo is focused on males with more extensively developed and darker manes. "Up until now, it has been incorrectly assumed that lions typically achieve the full extent of mane development by the time they reach four to five years of age," Kerbis Peterhans adds. "This phenomenon carries across the board to all African lion populations, including recently extinct ones, based on the data from our rigorous review of museum specimens."

The team found no evidence that rainfall, season, habitat, soil nutrients, nutrition, lion density, prey density or biomass were correlated with mane-growth patterns, but established that increased humidity appears to have a negative impact on mane growth in especially warm environments. Recent theories, linking manelessness in Tsavo's lions to male pattern baldness (due to excessive testosterone and aggression), are not support
'"/>

Contact: Greg Borzo
gborzo@fieldmuseum.org
312-665-7106
Field Museum
25-Sep-2006

Page: 1 2 3 4
Related biology news :

1. Kaiser Permanente Unveils Groundbreaking Genetic Research Program
2. Kaiser Permanente Unveils Groundbreaking Genetic Research Program
3. Groundbreaking research highlights myriad health benefits of flavanol-rich cocoa
4. Groundbreaking study shows adult stem cells have same ability to self-renew as embryonic
5. New study warns limited carbon market puts 20 percent of tropical forest at risk
6. Clones on task serve greater good, evolutionary study shows
7. Pollution causes 40 percent of deaths worldwide, study finds
8. A study by the MUHC and McGill University opens a new door to understanding cancer
9. New study suggests Concord grape juice may provide protection against breast cancer
10. Preclinical study links gene to brain aneurysm formation
11. In limiting life span, study finds booming bacteria innocent