Hi tweets:

Somebody wrote in a week or so ago, wondering about the life spans of birds.
As I get tweeters in digest form and can only read about once
a week, this response is late, but hopefully still useful.

The original query was about chickadees and crows and was answered, but
if you're interested in raptors too, there is a beautiful book called,
"Raptors - The Birds Of Prey", written by Scott Weidensaul (sp?). One
chapter is devoted entirely to the subject of life spans of raptors and
includes the oldest known, as well as the average life span, of many species
from all over the world. The information is even divided up into regions and
it's quite amazing how different the average life span of a bird is from
one place to another. There are also charts on survival
rates of young birds divided up into what percentages survive through
their first winter, second...and so on.

I don't have the book with me so I can't give any more details at the
moment, but if anyone is interested in knowing more about it, mail me
directly, or I will eventually respond to a post to tweeters.

Ingrid Lae
ilae at scienceworld.bc.ca