A complete report of the systematic survey of cliff surfaces conducted by the
Center for Conservation Biology in cooperation with the Fish and Wildlife
Service and the National Park Service has been completed. The survey covered a
significant portion of the southern Appalachian Mountains including nearly all
of the mountains of Virginia a small portion of Kentucky, and the spine of the
Appalachians in West Virginia. During the course of helicopter flights, 242
exposed rock surfaces were mapped, characterized, and surveyed for bird use.
Cliffs had a combined length of 122.4 km and a combined area of 470 ha. More
than 25% (118 ha) of the collective rock surface that was mapped was occluded
by vegetation.
Eleven bird species were observed using cliff faces during aerial surveys.
Birds were either roosting/loafing or nesting. Cliffs appear to represent
prominent roosting sites within the landscape for several bird species.
Vultures were observed roosting on 124 (51.2%) of the 242 cliffs surveyed with
an additional 54 (22.3%) cliffs with characteristic whitewash. Nests of 5
species were detected on cliffs including Common Ravens (35), Turkey Vulture
(2), Peregrine Falcon (1), Red-tailed Hawk (1), and Great Horned Owl (1).
Common Ravens and Red-tailed Hawks built stick nests on the cliff surface or
within overhangs while Turkey Vultures, Peregrine Falcons and Great Horned Owls
were nesting within crevices or overhangs.
Given the distribution of historic breeding sites, the release of nearly 250
young falcons in the mountains, the growth of the population in coastal
Virginia, and the recovery of breeding populations within the northern
Appalachians, the near absence of Peregrines from the study area was
surprising. Close examination of historic eyries suggests that the re-growth
of vegetation around cliffs may have played a role in the lack of activity.
Intense recreational use of the most prominent formations may have also played
a role. It is also possible that the previous approach to hacking in the study
area may have been inadequate to establish breeding pairs within this landscape.
One of the benefits of the systematic approach used in this survey is the
documentation that exposed rock surfaces are not evenly or randomly distributed
throughout the study area. The survey allowed for the delineation of 6
geographic areas that contain dominant rock formations that will not be
degraded over time by vegetation and multiple surfaces that appear appropriate
for nesting. Because of their qualities, these areas should represent
priorities in the reintroduction, management, and monitoring of the Peregrine
Falcon population. Over the next decade, efforts should be made to
re-establish nesting pairs within all 6 of these sites so that they may serve
as "nuclei" for re-colonization of this portion of the southern Appalachians.
CCB is interested in any sightings of adult Peregrines in the mountains from
March through July and young-of-the-year during June and July. To learn more
about Peregrines in Virginia visit the VAFALCONS page at http://www.ccb-wm.org.
The complete report can be viewed at:
http://ccb-wm.org/publications/pdf_techreports/ccbtr0614CliffSurvey.pdf
Bryan Watts
posted for Bryan Watts by Bart Paxton
