Virginia Coastal Program: 2003 Coastal Grant Project Description and Final Summary
Project Task:
FY2003 Task 12.10
Grantee:
Virginia Museum of Natural History
Project Title:
Seaside Heritage Program: Avian Habitat Restoration on the Virginia Barrier Islands
Project Description as Proposed:
We propose to continue
testing and refining our plan for the restoration of nesting habitat
for beach-nesting shorebirds and colonial waterbirds through mammalian
predation management on the Virginia barrier islands. Final analyses
of the 2003 avian nesting data are not yet available, but other
lines of evidence continue to produce encouraging support for the
efficacy of predation management: (1) The abundances of raccoons
and red foxes remained relatively low on treated islands (i.e.,
islands from which these mammalian predators had been removed) between
summer 2002 and 2003. (2) We observed no inter-island movement of
radiocollared raccoons between 2002 and 2003, suggesting relatively
low rates of long-distance movement between islands. (3) In an August
2003 pilot experiment using artificial nest scrapes containing 1
quail egg and 1 clay egg, raccoons and red foxes depredated 99%
of the scrapes on an untreated island (Parramore) and 0% on a treated
island (Metompkin). In collaboration with the Virginia Coast Reserve
of The Nature Conservancy and Utah State University, we propose
to continue experimental predation management and the related avian
and predator population studies during 2004, including a full-fledged
artificial-nest experiment incorporating multiple treatment and
control islands.
Five new and continuing tasks are planned for 2004:
(1) Continue to monitor mammalian predator distribution and abundance
on the Virginia barrier islands.
VMNH will continue to collaborate with The Nature Conservancy, the
College of William and Mary, the Virginia Department of Game and
Inland Fisheries, the Virginia Natural Heritage Program, and the
U.S. Fish and Wildlife Service to conduct seasonal, systematic predator
track surveys on all islands from Metompkin southward through Fishermans,
including Chimney Pole Marsh and Sandy Island, using the methods
of Keiss (2001) (February, June, November). These surveys have proven
to be very effective at detecting the presence of specific mammalian
predator species on selected islands. For example, these surveys
have detected the periodic occurrence of raccoons on Ship Shoal
Island since 1998, the apparent colonization of Cobb Island by the
red fox in 2001, and the transient occurrence of the coyote on Sandy
Island in February 2002.
(2) Continue to monitor the effects of experimental habitat restoration
through predation management, in terms of the diversity, abundance
and nesting success of shorebirds and colonial waterbirds on a series
of treatment and control islands.
The Nature Conservancy implemented systematic predation management
(i.e., intensive trapping and removal of raccoons and red foxes)
on Metompkin and North Cedar Islands in 2000 and on Wreck, Ship
Shoal and Myrtle Islands in 2001. The U.S. Fish and Wildlife Service
implemented similar management on Assawoman Island in 2000 and Fishermans
Island in 2003. (Note: No raccoons or red foxes were captured on
Wreck Island in 2000, and no sign of mammalian predators has been
observed since 1998. Wreck is now considered to be a control island,
along with Parramore, Hog and Cobb.)
VMNH will continue to collaborate with The Nature Conservancy, the
College of William and Mary, the Virginia Department of Game and
Inland Fisheries, the Virginia Natural Heritage Program, and the
U.S. Fish and Wildlife Service to monitor avian nesting success
on the six “treatment” islands (Assawoman, Metompkin,
North Cedar, Ship Shoal, Myrtle, Fishermans), to further test the
influence of predator removal and/or predator absence on the diversity,
abundance and nesting success of shorebirds and colonial waterbirds.
Although analysis of the 2003 avian nesting data remains incomplete
at this time, the results observed through 2002 strongly support
the use of predation management as a means of avian habitat restoration.
The results for 2003 are expected to be confounded by the protracted
cold, wet Spring and early Summer.
(3) Analyze additional raccoon tissue samples from locations strategically
selected to further refine the patterns of genetic connectivity
among populations.
VMNH will extend the genetic analyses of mainland and island raccoons.
Tissues were collected from ~100 additional raccoons during 2003,
including ~25 in the vicinity of Folley Creek on the mainland and
Metompkin and North Cedar Islands. VMNH will analyze these 25 additional
samples in 2004 using the same mitochondrial DNA (mtDNA) analysis
performed in 2002.VMNH will follow up the mtDNA analyses with microsatellite
analyses of tissue samples selected to resolve any remaining uncertainties
in the interpretation of population structure.
(4) Initiate a search for physical evidence of natural corridors
of mainland-to-island movement by raccoons and red foxes
VMNH will conduct a low-level aerial survey of the extensive tidal
marsh between the mainland in the vicinity of Folley Creek and Metompkin
and North Cedar Islands during winter 2004, to look for game trails
across the marsh. If such trails are observed, an extensive ground
reconnaissance will be undertaken in spring 2004 to look for raccoon
or fox sign in association with these trails. Depending on the results
of these surveys, an extensive trapping and tagging program may
be undertaken on Folley Creek during Summer 2004, to look for natural
predator movement between the mainland and the adjacent islands.
This task represents a new approach to the search for movement corridors.
(5) Refine and expand a 2003 pilot study of predation on artificial
(i.e., undefended) nest scrapes, to quantify the intensity of predation
and the composition of the predator community.
VMNH conducted a pilot study in Summer 2003 in which 100 artificial
nest scrapes were created on the beaches of Parramore (control)
and Metompkin (treatment) Islands. Each scrape contained a “clutch”
of one quail egg and one clay egg, and was monitored and restocked
daily for four days. Predators were identified by a combination
of animal tracks in the nest and tooth/beak marks on the clay eggs.
Raccoon and red fox predation rates on these unattended nests were
vastly higher on Parramore (~99% per day) than on Metompkin (~0%
per day). Nevertheless, gulls and ghost crabs depredated ~19% of
the nests per day on Metompkin in the absence of mammalian predators.
VMNH will repeat this experiment Summer 2004 with technical refinements
to the procedures, at least one additional control island (probably
Hog) and one additional treatment island (North Cedar). A TrailMaster
activity-activated camera system will be used to document specific
predation events (June through August).
Tasks 1-5 will provide vital new information for the development
of an overall predation management plan for the islands, facilitate
the implementation of predation management on selected islands,
and provide leverage in the pursuit of additional funding. The Nature
Conservancy will provide supplemental funding for each of these
tasks.
Federal Funding:
$23,475
Project Contact:
Nancy D. Moncrief, 276/ 666-8614, moncrief@mail.evsc.virginia.edu
Project Status:
Grant Closed
Final Product Received:
Project Summary Provided by Grantee:
The recent spread of the raccoon (Procyon lotor) and red fox (Vulpes vulpes) on the Virginia barrier islands (VBIs) has greatly reduced habitat suitability for beach-nesting and colonial waterbirds on the islands (Erwin et al. 2001). We have been working since 1998 to develop, test and refine a plan for predation management in order to restore avian nesting habitat on the VBIs. Our 2004 activities, results, and observations can be summarized as follows: (1) Track surveys detected raccoons on 15 of the 26 islands and red fox on 6. Wildlife Services removed red foxes and raccoons from Metompkin, raccoons from North Cedar, Smith and Fisherman during spring 2004. U.S. Fish and Wildlife Service personnel removed red foxes from Assawoman. (2) We monitored avian nesting on 6 islands (Assawoman, Metompkin, North Cedar, Wreck, Ship Shoal and Myrtle) from June through August. (3)We analyzed additional raccoon tissue samples to further describe the patterns of genetic connectivity among mainland and island populations and to identify travel pathways from the mainland to the islands. Analysis of our data indicate that there may be frequent movement of raccoons among the northern islands and the adjacent Delmarva Peninsula, whereas movement of raccoons among the southern islands and the southern portion of the Delmarva Peninsula is less frequent and more restricted. (4) We searched for physical evidence of natural corridors of mainland-to-island and island-to-island movement by raccoons. We observed many trails in the marshes from the air, but these trails were difficult to find and follow on the ground. (5) We ran a study in which we used artificial nest scrapes stocked with a clutch of 2 Japanese quail eggs to determine the rate of predation and the species composition of the nest predator community. Raccoon and red fox predation rates were higher on Parramore than on Metompkin. On Metompkin, gulls and ghost crabs depredated more nests than did raccoon and red foxes. Predation management remains a useful method to enhance and restore avian nesting habitat on the Virginia barrier islands.
Form C end
Disclaimer: This project summary provides the federal dollars initially awarded to the grantee. Due to underexpenditure or reprogramming of grant funds, this figure may change. For more information on the allocation of coastal grant funds, please contact Laura McKay, Virginia Coastal Program Manager, at 804.698.4323 or email: Laura.McKay@deq.virginia.gov
A more detailed Scope of Work for this project is available. Please direct your request for a copy to Virginia.Witmer@deq.virginia.gov
