Re: Bobwhite

[Clyde Sorenson <clyde_sorenson@ncsu.edu>]

All,

Actually, we have pretty compelling evidence that habitat is the culprit
in bobwhite decline. I have been involved in a research project for the
last 4 years investigating the impacts of herbaceous field borders
around agricultural fields and small mammal predator control on
populations of bobwhites and other early successional birds usually
associated with agricultural lands. Quail populations (based on a very
well documented call-based survey technique) are as much as 4 times
higher on areas with 10-20 ft herbaceous borders around all agricultural
fields than on areas without such borders. Small mammal predator control
appears to result in only incremental improvements in quail populations.
On one survey I recently participated in, one of our observers heard 6
coveys (at the dawn calling period) from one point in a habitat
improvement treatment area.

These borders also may offer water quality and soil conservation
benefits and may qualify for some of the conservation incentive
programs.

The landscape scale habitat changes that have led to quail decline are
complex and hard to understand. Most are related to how crops get grown
now compared to twenty, thirty, or fifty years ago. perhaps one of the
biggest players is the advent of extremely effective agricultural
herbicides which reduce in-field plant diversity (and hence insect
biomass and diversity) foraging cover, and weed seed food reserves;
another is the continuing consolidation of agricultural fields to meet
the demands of machinery economies-of-scale which reduce field edge area
(and quail are edge birds). Quail populations will in all likelihood
never be what they were in the 1930s and 40s, but concerted effort on
fairly large blocks of land may give us glimpses of the old days in some
areas. This approach was recently adopted by the NCWRC.

Take care,

Clyde Sorenson
NCSU Dept. of Entomology
Clayton and Raleigh