Two years’ worth of photographing and trapping raccoons, feral hogs and other predators at American oystercatcher nest sites is providing needed insight into how and when controlling predators can help these rare red-beaked shorebirds.
The project, supported by a National Fish and Wildlife Foundation grant through Southern Company’s Power of Flight program, explored the role of managing predators at key nesting areas for American oystercatchers. Southern Company is the parent company of Georgia Power.
Once common along the Atlantic and Gulf coasts, oystercatchers numbered only about 10,200 birds as of 2008. The good news, however, is that National Fish and Wildlife Foundation estimates indicate the population is growing again and expected to top 13,200 by 2019.
Researchers in Georgia had predators trapped in some oystercatcher nest sites, set trail cameras at those and areas that weren’t trapped to assess predator pressure, and monitored nests. Sites varied from state-protected Little Egg Island Bar in the Altamaha River delta in Glynn County to Little St. Simons and St. Catherines islands. Partners included the Georgia Department of Natural Resources, the University of Georgia, St. Catherines, Little St. Simons and the U.S. Fish and Wildlife Service.
Project leader Tim Keyes, a wildlife biologist with DNR’s Nongame Conservation Section, said results are still being sifted following the completion of fieldwork this summer. But some take-homes are clear.
“We were documenting higher nesting success and higher fledgling rates when we did some trapping,” Keyes said. “… Generally, I think it confirms that a trapping program is necessary in some areas.”
From 121 American oystercatcher pairs documented this year on Georgia’s coast, researchers counted 32 chicks, the most ever recorded and production boosted in part by fewer high tides, which can wash over and destroy nests. Biologists banded 28 of the chicks for future monitoring.
“Basically, sites we trapped had chicks survive to fledging,” Keyes wrote. “Sites we did not trap had no checks fledge.”
Analysis of study data could help resource managers determine where and when shooting or trapping predators – which is time-consuming, costly and sometimes contentious – will most benefit oystercatchers. For example, findings suggest that raccoon activity at some sites seemed to increase near the start of nesting season. Raccoons were the primary predator at nest sites.
Keyes said the project also underscores the importance of nesting areas where there are no raccoons, hogs or coyotes, such as on isolated sandbars like Pelican Spit, St. Catherines Island Bar and the spit at Gould’s Inlet.
Unfortunately, these places are usually very low in elevation, ephemeral – lasting only a short time – and prone to overwash. The impact of human and pet disturbance on oystercatchers, which shy from such contact, is another challenge for conserving this and other beach-nesting species.
“Some of these non-predator sites are used by boaters, some of whom let their dogs roam,” Keyes said.
In July, a domestic dog killed an oystercatcher chick on Williamson Island, near Little Tybee Island. Pets are prohibited at Williamson, which is designated a “bird island” by DNR and protected as critical habitat for shorebirds and seabirds.
Keyes said about one oystercatcher pair in three must fledge chicks each year to stabilize Georgia’s population. While even the increased success rate this summer fell short, the hope is that continued conservation efforts, boosted by the new details on controlling predators, puts that goal within reach.
DNR’s Nongame Conservation Section works to conserve American oystercatchers and Georgia’s other rare and endangered animals and native plants. Yet the agency receives no state general funds, depending instead on fundraisers, grants and donations.
Help by purchasing the new nongame wildlife license plate – a bald eagle in flight! – or renew your older eagle or ruby-throated hummingbird plates. Thanks to a law change this year, you can upgrade to a DNR wildlife plates for only $25 more than a standard tag, and more of those fees will be dedicated to conserving Georgia wildlife.
Supporters can also contribute directly to the Georgia Nongame Wildlife Conservation Fund. These programs support conservation of wildlife not legally fished for, hunted or collected. Learn more at www.georgiawildlife.com/conservation/support.
The National Fish and Wildlife Foundation protects and restores America’s wildlife and habitats. Created by Congress in 1984, the foundation directs public conservation dollars to pressing environmental needs and matches those investments with private contributions. The organization works with individuals, foundations, government agencies, nonprofits and corporations.
In 26 years, the National Fish and Wildlife Foundation has funded 3,700 organizations and leveraged $490 million in federal funds into $1.6 billion for conservation. Learn more at www.nfwf.org.