[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Blackpolls and other landscape effects on migrants



Van Horne wrote an excellent paper in 1983 on density
being a misleading indicator of habitat quality, a
standard reference and consideration for study design
and data analysis in current landscape scale
ornithological research.  This is probably exactly
what is happening not only with Balckpoll Warblers but
also other migrants. Who here has a favorite migrant
spot that happens to be a relatively small island of
habitat in an urban area?

Kendrick Weeks
Fuquay Varina

Josh wrote:

The consensus seems to be that Blackpolls migrate
across the landscape 
in
a more-or-less uniform front. Upon encountering a
developed area, all
Blackpolls that would normally be spread across that
area get 
concentrated
into the few trees available, those being typically
the big streetside
oaks. A few folks have noted that large oaks tend to
host a large 
variety
of inchworms and other lep larvae, and that oaks in
town are more 
stressed
by heat, pollution, pavement covering their roots,
etc. and so less 
able
to resist infestations, thus constituting a very
long-term and indirect
sort of bird feeder for insectivorous species.



__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com