Tuesday, April 19, 2005

Watson adds info about inbreeding and a tiny [but hopeful] note about Lilly

In a post yesterday, John Blakeman brings up the problems of inbreeding if some of the several redtails trying to nest around Central Park are Pale Male's progeny. Steve Watson responds with the note below:

In regards to the question about the CP red-tails being related and the concomitant possibility of inbreeding depression: there's a fascinating case of an isolated population undergoing inbreeding, that has been exceptionally well studied by some of the very best wildlife biologists.

The wolves on Isle Royale National Park arrived via travel on the ice in the 1950's, probably as a single pair. ALL wolves on the island today are descended from those original wolves, and so the population is genetically isolated, and undergoing inbreeding and loss of heterozygosity. The effects are starting to be seen as evidenced by bone abnormalities, including extra vertebrae, asymmetrical vertebrae, etc. Nevertheless, the population is not undergoing any dramatic losses. There are currently 3 packs and 30 wolves, about average for the population over time.

This population has been the subject of nearly a half-century of continuous research, one of the longest-running studies of a single population of carnivores ever. It forms a fascinating (essentially closed) ecosystem with perhaps as simple a predator-prey relationship as to be found anywhere in nature. More on this can be found at


Despite the inbreeding and abnormalities that are now showing up, "..the wolf population on Isle Royale continues to reproduce at normal levels. Furthermore, breeding wolves, at least, survive to old age. The continued success of this small, isolated population is presently one of our most interesting and important scientific issues. It has been impossible to accurately predict year-to-year developments in this protected population, and the wolves themselves are clearly defining what is possible." (2004-2005 Ecological Studies of Wolves on Isle Royale).

Isle Royale just came to mind when I read the Q & A regarding possible inbreeding in the CP red-tails!


P.S. Lilly had an interesting interaction with another kestrel today...we don't know what it means. Details at the website.