Hi Tweets,

I just thought of an indicator species for climatic change that is immune
to many of the problems that Stuart MacKay and others have outlined:

the thermometer.

Seriously, if the goal is to diagnose global warning, there are more
straightforward methods than watching birds. If, on the other hand, the
goal is to discover what effects global warming has on bird populations,
one would still want to know if global warming were happening before one
looked for its effects, wouldn't one? I'm not denying that bird
populations change as the climate varies, nor that the changes are
uninteresting. But I don't think that looking for indicator species of
climate change is a subsitute for studying the weather records.

Chris Hill
Seattle, WA
cehill at u.washington.edu