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FW: effects of winter storm on kinglet populations & parting shots



This message may be long and many may want to skip it. Especially with 
warblers, swallows, and martins beginning to make their way northward.

To echo Marylin, I am not trying to be contentious. But I believe c-birds 
is a proper place to discuss differences in opinion regarding avian 
ethology. The possibility of an unusual mortality event regarding kinglets 
in the Piedmont, due to unusual weather is simply one possibility.

Some, such as myself may lean to other possibilities, like the one espoused 
below.

Robert Prisig noted in one of his novels that the difference between 
science and religion was that science comes with an eraser. If someone can 
present data or steer me to data that would outweigh the logic posited 
below, I would be happy to use my well-worn eraser.

Namaste`

Don Hendershot
Waynesville, NC


-----Original Message-----
From:	Bruce Peterjohn [SMTP:Bruce_Peterjohn@usgs.gov]
Sent:	Monday, March 06, 2000 1:26 PM
To:	donh@asap-com.com
Cc:	Jeff Hatfield
Subject:	Re: effects of winter storm on kinglet populations



Don:
I have a few comments to add to the earlier message from Jeff Hatfield.
Even if your winter counts of kinglet numbers show a sharp decline after 
the storm, it may not be the result of mortality. Some of our wintering 
species, such as juncos, kinglets, and yellow-rumped warblers, are known to 
be facultative migrants during the winter period. Hence, they have the 
ability to migrate away from areas where food is no longer available to 
other locations where (hopefully) they can find some food. Lower counts 
could reflect these factultative movements, rather than mortality. You 
might have to wait until this summer and look at breeding population levels 
to have a better idea of whether the current shortage of kinglets may have 
resulted from mortality rather than migration. Breeding Bird Survey (BBS) 
data may provide an insight into this question, but unfortunately, the 
breeding range of both kinglets extends well into the boreal forests of 
Canada where there are few BBS routes to indicate breeding population 
trends.
Since kinglets glean their food from the branches of trees, I doubt that 
the large accumulation of snow would bother them too much. On the other 
hand, ice storms, especially persistent ice, could pose some major problems 
for wintering kinglets and other gleaners (creepers, woodpeckers, etc...) 
Golden-crowneds seem to be more tolerant of cold temperatures than 
Ruby-crowneds (based on their winter ranges). By themselves, single digit 
temperatures should not bother Golden-crowneds much but could be a problem 
for Ruby-crowneds. A combination of prolonged ice and cold temperatures 
could be potentially lethal for both species, however.
Hopefully this breeding season will provide some answers. Kinglets have a 
high reproductive output, so even if their numbers were decimated by the 
winter storms, their populations should recover fairly quickly.


Bruce Peterjohn
USGS Patuxent Wildlife Research Center