CWF Wildlife Biologist Emmy Casper handling an oystercatcher chick captured for banding. Picture courtesy of Northside Jim
Those who have followed CWF’s work throughout the years know how important bird banding can be for wildlife biologists and conservationists. The practice, which involves placing metal and/or color bands on a bird’s legs, can provide useful information about that bird’s life history, site fidelity, and movement. Typically, banded shorebirds are equipped with a unique alphanumeric code or color combination (kind of like a name tag), which enables scientists to track an individual bird throughout its lifetime. For those monitoring New Jersey’s beach-nesting bird populations, bird banding greatly enhances the quality and accuracy of our productivity data, which allows us to make better-informed decisions regarding management.
CWF has played a major role in helping monitor breeding American oystercatchers in New Jersey ever since surveys were initiated in the state just over two decades ago in the early 2000’s. Most of the statewide effort, conducted by a variety of partners, has been focused on pairs nesting on the sandy barrier beaches of the Atlantic Coast, in conjunction with efforts there to monitor and manage other beach nesting birds, such as piping plovers and least terns. These sites are often those beaches that are highly recreated and most used by beachgoers, public beaches where these species need added protection to hatch nests and raise their young chicks.
When CWF began monitoring American oystercatchers nesting on the Delaware Bay this past spring, we also set out to place field-readable bands on as many oystercatcher adults and chicks as logistically possible. Band resights allow biologists to collect a wealth of information about site fidelity, habitat use, dispersal, and migration, especially when data is collected over many years. Since the Delaware Bay population of oystercatchers was previously unmonitored, we have a lot to learn about their life histories and how they may differ from other oystercatchers in the state, if at all. Where are these birds staging and wintering? Do breeding adults return to the same mates and nesting locations each year? Where do fledged chicks disperse, and will they return to their natal grounds on the Delaware Bay to breed upon reaching sexual maturity? Banding efforts, combined with resight data reported by biologists, dedicated volunteers, and the general public will help answer these questions (and more) as we increase the number of marked individuals on the Bayshore.
Orange C41 (aka “Crouton”) being equipped with a metal federal band on the lower leg. The color of the field-reable bands on the upper legs represents which state the bird was banded in (New Jersey and New York use orange), while the alphanumeric code on the band is unique to the individual bird. All handling of birds is conducted by trained individuals under proper permits.
This past winter, CWF announced a new project designed to study and monitor the population of American oystercatchers breeding along the New Jersey side of the Delaware Bay. In addition to locating nesting pairs and tracking their success, our goal is to better understand how oystercatchers utilize the bayshore habitats and what factors threaten their productivity. The data we gather with our partners at The Wetlands Institute and U.S. Fish and Wildlife Service will be used to inform future management decisions. We spent the past few months working hard to conduct the project’s first season of monitoring, and we are happy to say that we have made significant progress in beginning to unravel the mysteries surrounding this understudied population.
Delaware Bay American oystercatcher study area. Most oystercatcher pairs this season were concentrated in the bay beaches between Stipson Island and Heislerville WMA.
Since so little is known about this subpopulation of oystercatchers, we had a lot of ground to cover in our first season of fieldwork. First, we had to locate any breeding oystercatcher pairs across 35 sites spanning approximately 45 miles of bayshore from Cape May Point to Sea Breeze. Luckily, we had a head-start based on a preliminary census survey from 2021 that documented some already existing pairs as well as some sites with potentially suitable nesting habitat. We were also fortunate to have a dedicated seasonal technician assisting with the heavy workload. That said, figuring out how to access many of these sites was definitely a learning curve. We quickly discovered that many beaches were only reachable by boat or kayak and only during a narrow window of tide and wind conditions. Other sites were walkable, but only at peak low tides, which meant our surveys couldn’t take too long without risking becoming stranded by the rising tide.
CWFNJ’s 2022 Edwin B. Forsythe NWR Beach Nesting Bird Field Crew. L to R: Jacob Miranda, Lexie Lawson, Amy Kopec, Erin Foley, (missing Dakota Bell).
For the past eight years, CWF has been contracted by the U.S. Fish and Wildlife Service through a cooperative agreement to provide monitoring and management of beach nesting birds at the Edwin B. Forsythe National Wildlife Refuge. The Refuge nesting sites – both the Holgate and Little Beach Island Units – provide some of the only habitat in the state closed to the public and free of human disturbance and detrimental beach management practices. The habitat at the sites is especially suitable for the state endangered piping plover as a result of optimal nesting conditions created by Superstorm Sandy and largely sustained since then through winter storms. As of the 2021 season, the Refuge sites had the highest concentration of piping plovers in the state, with Holgate having by far the most pairs (46). Furthermore, on average in recent years, Holgate has produced a higher fledgling rate than many sites in the state.
Most people are surprised to hear that American oystercatchers are present in New Jersey in the winter. They usually associate the charismatic shorebird as a breeding species here. Our state’s wintering oystercatchers, a combination of breeders from further north and our own, are at the northern extent of the Atlantic coast wintering range.
American oystercatcher foraging for oysters along the Delaware Bay. Photo credit: Meghan Kolk.
The Delaware Bay is well known for the spectacular phenomenon of spawning horseshoe crabs and migrating red knots every May, but in recent years the American oystercatchers (Haematopus palliatus) have also discovered the allure of the Bayshore and made it their home. American oystercatchers, a State Species of Special Concern, have been monitored and managed by CWF and the NJDFW’s Endangered and Non-game Species Program along the Atlantic coast beaches for nearly two decades, resulting in a steady population increase. However, the population that breeds along the Bayshore, first documented in 2016, has not received the same attention and had never been fully surveyed until this year.
CWF’s interest in this newly discovered population led to a small pilot study of a few known breeding pairs in 2018. Then this past May, we launched a bay-wide survey of the sandy beaches of the New Jersey side of the Bay from Cape May Point up to Seabreeze, the northernmost beach in Cumberland County. The purpose of the bay-wide survey is to determine a baseline of the number and distribution of breeding pairs along the Bayshore. The data gathered from this survey will add to the Statewide population estimate and help determine the amount of time and funding needed to fully monitor and manage the Bay’s population. More monitoring will be necessary to assess risk factors and reproductive success. Reproductive success can then be maximized by managing for risk factors such human disturbance, predation and tidal flooding.
This survey was made possible due to the efforts of dedicated volunteers and could not have been completed without their help. Unlike the Atlantic coast, the Bayshore beaches are often difficult to access, and many can only be reached by boat, making this survey more challenging. In fact, two sites that we planned to survey proved to be too difficult to reach and were skipped for this year. Each of the 33 remaining sites were surveyed just once within a specific timeframe, giving only a snapshot of the breeding season. We hope to be able to collect much more information in the future when more funding for this project is available. Based on the survey that was conducted, 13 pairs were documented at 8 different sites and 8 nests were documented at 5 different sites.
In addition to the formal survey, I was able to collect some observations as I spent every day in May on the Bay working with red knots. I took notice of the prey items that the oystercatchers were choosing. I often observed them feasting on oysters, which were plucked off exposed rubble at low tide. They also spent time at the man-made oyster reefs that were constructed at several beaches to act as breakwaters to slow the erosion of beaches. They also favored ribbed mussel beds, which become exposed as the tide recedes. The most interesting foraging behavior I witnessed was an oystercatcher plucking a fresh slipper shell off a horseshoe crab as it came to shore to spawn. It seems the Bay offers a variety of good food sources for a bird that mainly preys on bivalve mollusks.
I also noticed that flocks of up to 11 oystercatchers were traveling together up and down the Bayshore. This is a peculiar behavior since oystercatchers are highly territorial during the breeding season and are typically only seen in flocks once the breeding season is over. Could it be that the Bayshore is a popular spot for non-breeding young adults to hang out?
So much more research is needed to answer the many questions we have about the mysterious Bayshore oystercatchers.
CWF biologists Todd Pover, Meghan Kolk, Ben Wurst, and Erin Foley have delivered a series of hands-on lessons – on the beach and in the classroom – in Asbury Park this summer. So far, students have learned about owls, beach nesting birds, and ospreys.
Conserve Wildlife Foundation is proud to partner with Asbury Park School District and New Jersey Natural Gas to teach students about Asbury Park’s rare wildlife, and how to protect and preserve the environment the kids – and the wildlife – call home.
Check out photos of this summer’s fun!
Students took to the beach to learn about beach nesting birds with Todd Pover and Erin Foley:
Meghan Kolk dissected barn owl pellets with students to learn more about their diet:
And Ben Wurst met students at the local football field to view an active osprey nest atop a light pole:
Update May 30, 2019: Another example of the dangers of fishing (or this time crabbing) line unfolded in dramatic fashion in Tuckahoe Wildlife Management Area. CWF biologist Ben Wurst was called upon to put his climbing skills to the test to help an osprey dangling high above the ground. Thankfully Ben was able to get to the bird in time, and our friends at Tri-State Bird Rescue and Research nursed the osprey back to health and were able to re-release him near where he was found. Read more about the daring rescue on our Facebook page.
Ben Wurst puts his climbing skills to the test to rescue and entangled osprey
As thousands of people plan their trips to the Jersey shore for Memorial Day weekend, it is a good time think about how to help out shore and sea birds. Enjoy the holiday weekend!
The 141 miles of seashore in New Jersey are home – or at least part-time host – to many of the birds Conserve Wildlife Foundation protects and nurtures. Osprey, oystercatchers, black skimmers, piping plovers, red knots, and many others rely on a healthy coast to thrive.
Many piping plover and American oystercatcher pairs have been busy laying their eggs over the last few weeks. As beach nesting bird biologists, we invest a lot of time into every pair at our sites. We revel in their successes and feel defeated at their losses. Unfortunately, many nests did not fare well in the April 25th Nor’easter that was coupled with new moon tides. Luckily, it is early enough in the season that all of them have begun, or will soon begin, attempting new nests.
The breeding habitat of the American oystercatcher in New Jersey consists of coastal beaches, inlet systems, and salt marshes. Population estimates in New Jersey suggest 350-400 breeding pairs can be found here from March through August. Much of the monitoring and research done with American oystercatchers in New Jersey takes place on the coastal beaches where other beach nesting birds, such as piping plovers, least terns and black skimmers, are found. In 2016, more than 120 breeding pairs of beach nesting American oystercatchers successfully fledged 83 chicks. This was an especially productive year for those pairs and productivity levels were well above the target goal of .5 chicks per pair.
Photo courtesy of Sam Galick.
Oystercatchers arrive back on their breeding grounds here in New Jersey in early March to set up breeding territories and begin nesting. Once paired up, adults typically lay one to three eggs. Both the male and female will take turns incubating the nest for 28 days. Once chicks hatch, they are semi-precocial, which means they are born in an advanced state, but are still reliant on adults for food and protection. Oystercatcher chicks are fledged (or able to fly) 35 days after hatching. After fledging, most Oystercatchers migrate to the southeast, but a wintering population does remain here in New Jersey.
American oystercatchers are listed as a Species of Special Concern in New Jersey. A “Species of Special Concern” is a status determined by the New Jersey Division of Fish & Wildlife and applies to species that have an inherent threat to their population or have evidence of recent population declines. Since American oystercatchers share the same habitat as other endangered or threatened beach nesting birds (piping plovers, least terns, and black skimmers), they also share the same threats to their nests and young. Human disturbance, a host of predators, and flooding events, such as the one that took place last week, are just some of the many threats beach nesting birds face daily.
The Conserve Wildlife Foundation of New Jersey has long partnered with the New Jersey Division of Fish and Wildlife’s Endangered and Nongame Species program in the monitoring and management of New Jersey’s endangered beach nesting birds. Fencing and signage are placed in nesting areas to alert beachgoers to the presence of nesting American oystercatchers and other beach nesting birds. Throughout the summer, CWFNJ and partners will be out on the beaches monitoring and collecting data that will be used to track population trends and identify threats to oystercatchers and their young.
Emily Heiser is a wildlife biologist for Conserve Wildlife Foundation of New Jersey.
