Living Fast and Dangerously: Hormones Influence the 'Pace of Life' of Songbirds
Sunday, June 20 2010 @ 01:00 AM EDT
Contributed by: jkr
ScienceDaily (June 17, 2010) — Human beings, fish, reptiles and birds have the same hormones in their blood with very similar functions. But why does one find hormone values in some species that are ten times higher than in others?
A team of international scientists headed by Dr. Michaela Hau from the Max Planck Institute for Ornithology in Radolfzell has now discovered that the differing concentrations in birds of the stress hormone, corticosterone, and the reproductive hormone, testosterone, are correlated with the "pace of life." They control whether energy is invested into reproduction, i.e. the number of eggs laid and the breeding attempts in a given season, or more into longevity, i.e. immune function or the flight response in times of danger.
The results show that the hormone titres vary with the animal's life history.
To continue article www.sciencedaily.com/releases/2010/06/100617075157.htm