The Center for Conservation Biology and The Nature Conservancy (TNC) just
completed the annual winter survey of Red-Cockaded Woodpeckers (RCWs) at the
TNC Piney Grove Preserve. We recorded a record high of 41 woodpeckers
within 8 clusters this season. The term cluster refers to a unit of closely
spaced cavity trees that supports a group of cooperatively breeding RCWs
that also spend the winter months together for foraging and roosting. This
marks another season of growth for the Piney Grove population. We had 31
birds within 7 clusters in the winter of 2008.
This record high count follows a banner reproductive season of 2009 when
RCWs in six clusters fledged a total of 15 young birds. We detected 13 of
these 15 hatch year birds during the winter survey marking one of the higher
rates of juvenile retention in recent years. However, we generally lose a
greater proportion of young birds between their first winter and the
following spring. Birds missed during the survey may be due to mortality,
dispersal, or simply individuals that avoided detection because they are not
associated with other birds of a cluster but rather floating solo in the
area.
The continued growth of the Piney Grove population of RCWs would not be
possible without proper habitat and cavity management. The addition of 1
more occupied cluster this winter is a result of birds dispersing to new
areas of the Piney Grove Preserve. The newly occupied cluster is actually
composed of artificial cavity trees installed by The Nature Conservancy.
Artificial cavities are used to manage RCWs throughout their southeastern
range and are basically composed of a wooden box with a properly sized
entrance hole that is inserted into a living pine tree. The artificial
cavity does not kill the pine tree and RCWs use them regularly. In cases
where this technique is successful in supporting birds over a longer term
(including Piney Grove), the woodpeckers drawn in by artificial cavities
begin excavating their own cavities nearby. At Piney Grove, 5 of the 8
existing RCW clusters were established by the aid of artificial cavities.
The other 3 clusters at Piney Grove were all naturally occurring groups of
birds. The legacy of these natural clusters is special because back in 2000
they were the last remaining breeding groups of RCWs in Virginia.
It is our hope that the newly established cluster will follow the track of
the other artificial cavity clusters with RCWs attempting to breed this
coming
spring.
Michael Wilson
Center for Conservation Biology
College of William and Mary & Virginia Commonwealth University
PO Box 8795
Williamsburg, VA 23187-8795
phone: 757-221-1649
fax: 757-221-1650
email: mdwils@xxxxxx
