Documenting Bird Life in Delaware Bay Salt Marshes

by Harrison Hepding, CWF Biological Technician

The remote coastal salt marshes of the Delaware Bayshore harbor a unique and seldom observed ecosystem, boasting a rich natural history and diverse wildlife. To help prevent the loss of these valuable habitats and their inhabitants, CWF is participating in a partner-driven, multi-year project led by Ducks Unlimited and the U.S. Fish & Wildlife Service to enhance habitat quality and restore natural hydrology to salt marshes in Delaware and New Jersey. CWF is actively involved in the second season of biological monitoring at select Bayshore salt marshes targeted for restoration efforts designed to revegetate mudflats existing on old salt hay farms (read more about salt hay farming impacts here). At this stage of the project, our role is to gather important pre-restoration data to evaluate the anticipated impact and effectiveness of restoration techniques.

A view from one of our survey points at Dix Wildlife Management Area.
Photo courtesy of Emmy Casper, CWF Wildlife Biologist.
Continue reading “Documenting Bird Life in Delaware Bay Salt Marshes”

Band Resighting Sheds New Light on Delaware Bay Oystercatcher Population

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.
Continue reading “Band Resighting Sheds New Light on Delaware Bay Oystercatcher Population”

The Complicated History of Our Marshes and an Update on Restoration Progress

by Caroline Abramowitz, CWF Biological Technician

When looking at the expansive mudflats along the marshes of the Delaware Bay, it is hard to imagine that the area was once densely vegetated and home to a variety of bird species. This spring, CWF began work on a new marsh restoration project funded by the National Fish and Wildlife Foundation and led by Ducks Unlimited and the U.S. Fish and Wildlife Service (USFWS). CWF was contracted to assist with biological monitoring at sites targeted for marsh restoration along New Jersey’s side of the Delaware Bay. Restoration efforts for our sites are being directed toward mudflats that exist due to significant physical alterations made to the marsh in the past. The story of how these mudflats came to be lies in the area’s history and roots in salt hay farming.

As early as 1675, settlers arriving on the Delaware Bay built dikes in salt marshes to protect land from saltwater inflow and create an environment more conducive to salt hay farming and development. One of the most important types of salt hay harvested along the Delaware Bay was Spartina patens, a crop that was widely used as bedding and feed for livestock due to its high nutritional value. By the mid-1800s, at least 14,000 acres of marsh were impounded in Salem County alone with comparable areas altered in both Cumberland and Cape May counties (Cook, 1870). Impoundments restricted tidal flow within the marsh, which stopped the natural process of marsh accretion in which sediment is consistently added to the marsh to increase its elevation. Additionally, drier conditions exposed marsh soil to too much air, resulting in the breakdown of soil and further loss of elevation.

Salt hay farming circa 1940’s.
Photo retrieved from”From Marsh to Farm: The Landscape Transformation of Coastal New Jersey,” by Kimberly R. Sebold.
Retrieved through https://www.nps.gov/parkhistory/online_books/nj3/contents.htm
Continue reading “The Complicated History of Our Marshes and an Update on Restoration Progress”

It’s a Wrap! First Season of Delaware Bay American Oystercatcher Monitoring is a Success

by Emmy Casper, Wildlife Biologist

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.

Continue reading “It’s a Wrap! First Season of Delaware Bay American Oystercatcher Monitoring is a Success”

A Day in the Life of a Shorebird Steward

By: Cara Franceschini, CWF Summer 2023 Intern

In the May 16th blog, Shorebird Stewards On the Bay in May, it’s mentioned that some beaches along the Delaware Bay have restricted access every year from May 7th to June 7th. This is due to the migratory shorebirds that travel thousands of miles and need a place to stop to feed. Our beaches contain excellent food sources to help birds gain weight to continue their journey- horseshoe crab eggs. They are filled
with fat and protein. The Delaware Bay is the largest spawning area for horseshoe crabs in the world!

Now what do the Shorebird Stewards, such as myself, do all day? We monitor our assigned
beaches and educate the public about this incredible phenomenon! My favorite beaches are
Roosevelt Blvd. beach and Cook’s Beach because I see the most active flocks of shorebirds at
these locations.


A group of the infamous Red Knots: Calidris canutus, Semipalmated Sandpipers: Calidrus pusilla,
and Ruddy Turnstones: Arenaria interpres, at the beach on Roosevelt Blvd., photo: C. Franceschini

On a quiet day with not many people to educate, there are many things for us Stewards to do.
Some Stewards read their books, watch movies, listen to music/podcasts, color/paint, take
walks, research, etc. I do all of the above! Since we have a love for these special shorebirds,
most Stewards also birdwatch! It’s a must to bring your binoculars or scope to observe these
beautiful birds. Sometimes, you observe other interesting animals, too!

Another activity to do in the down-time is to flip the spawning Atlantic Horseshoe crabs, Limulus
polyphemus
, back onto their legs so they can crawl back into the bay. When the tide rise, these
crabs get overturned by the waves and have no way of returning back to their feet! Personally,
this is my favorite activity to do. When you return after your “crab walk”, you get to see the
tracks of their feet traveling back into the bay where they belong. Below on the left is a picture of
flipped and rescued crabs: the one on the left is a male who decided to bury himself in the sand
to preserve water until the tide comes back in, and the one on the right is a male who decided to
make the trek back into the bay. When the tide comes in, the horseshoe crabs come up
and begin spawning. Pictured below in the middle is an example of how crowded the beaches
get with these creatures! On the right, is a photo of a tagged crab I found, and reported it to
the US Fish and Wildlife Service so that they can collect data on the tagged crabs.

You can also get involved with helping these critters! “Return the Favor” is an organization
dedicated to conducting beach walks to flip overturned horseshoe crabs on the NJ beaches of the Delaware Bay. You can join public walks that are held by walk leaders or sign up to be a volunteer
and conduct your own walk (until July 15th, 2023 or next year). I am a volunteer and walk leader
and it is one of my favorite things to do. Flipping horseshoe crabs is such a special event
because that means you’re saving those crabs so they can continue to spawn and produce eggs
for the shorebirds. With your help, you could help save hundreds of crabs just by flipping
them over! Of course I had to capture this special moment of me flipping a crab (picture below)!

On these walks, you experience much more than just crabs. You get to see other wildlife that
emerges during dusk or dawn. You can also go on the closed beaches to save the crabs that
can’t be rescued during the day. During my walk, I got to see thousands of horseshoe crab
eggs!

In the News: WHYY Article Highlights New Delaware Bay Marsh Restoration Project

by Emmy Casper, Wildlife Biologist

Over the winter, biologists from CWF, Ducks Unlimited, USFWS, and Partnership for the Delaware Estuary visited sites like this marsh in Dix Wildlife Management Area to assess their restoration potential and strategize monitoring plans.  

This spring, CWF will begin fieldwork for a new marsh restoration project along the Delaware Bay. The ambitious project, funded by the National Fish and Wildlife Foundation and co-led by Ducks Unlimited and the U.S. Fish and Wildlife Service, aims to implement cost effective and low-tech marsh restoration techniques in New Jersey and Delaware salt marshes. Restoration plans will be designed to create, protect, and/or enhance habitat for multiple marsh-dependent species including black rails and saltmarsh sparrows. As a project partner, CWF will provide two seasons of biological monitoring assistance at the New Jersey sites. This week, WHYY published an article about the project, featuring representatives from CWF and other project partners. Click the link below to read the piece and learn more about some of the important work being done by the Delaware Bay! 

Announcing New NFWF Funded Project to Study and Monitor American Oystercatchers along the Delaware Bay

by Emmy Casper, Wildlife Biologist

CWF is excited to announce a new project funded by the National Fish and Wildlife Foundation’s Delaware Watershed Conservation Fund designed to develop and execute management strategies for American oystercatchers along the Delaware Bay. Breeding populations of American oystercatchers (State Species of Special Concern) have been well studied and monitored along New Jersey’s Atlantic Coast since 2003, but very little is known about the oystercatchers that nest on the sandy beaches along the Delaware Bay. In 2021, CWF conducted a near bay-wide window census survey to establish a baseline estimate of the Bayshore population. Thirteen oystercatcher pairs were documented across approximately 35 sites from Cape May Point to Sea Breeze, prompting a need for further research and management. This new project seeks to shed light on this understudied population and add to our scientific understanding of their management needs.

American oystercatcher. Photo courtesy of Daniel Irons
Continue reading “Announcing New NFWF Funded Project to Study and Monitor American Oystercatchers along the Delaware Bay”

Red knot decline confirmed by CWF research highlighted in NY Times

Photo by Hans Hillewaert

Conserve Wildlife Foundation’s research with scientist Dr. Larry Niles was highlighted in today’s New York Times feature detailing the 80 percent decline in red knots in New Jersey’s Delaware Bay this spring.


by Jon Hurdle, The New York Times

A sudden drop in the number of red knots visiting the beaches of Delaware Bay during migration this spring has renewed concern among scientists about the survival of the threatened shore bird’s Atlantic Coast population.

According to biologists, the number of knots that stayed to feed at the bay in May declined by about 80 percent from the same time last year. The Delaware Bay is one of the world’s most important sites for shorebird migration.

Continue reading at nytimes.com.

Close to the Finish Line

by: Dr. Larry Niles of Wildlife Restoration Partnerships. Dr. Niles is working in Delaware Bay on behalf of Conserve Wildlife Foundation. He has helped lead the efforts to protect at-risk shorebirds and horseshoe crabs for over two decades.

Read part one of this update on the 2020 Delaware Bay migration stop over, “Ecological Lockdown for Horseshoe Crabs”.

Direct Flight to the Arctic or Stopover?

A migratory stopover for arctic nesting shorebirds must provide each bird the energy necessary to get to the next stopover or to the ultimate destination, the wintering or breeding area. Delaware Bay stands out among these shorebird refueling stops because it delivers fuel in the form of horseshoe crab eggs giving birds options. Our telemetry has shown that Red knots, the species we best understand, may leave Delaware Bay and go directly to their Arctic breeding areas, or stopover on Hudson Bay. The choice of going straight to the breeding area or stop at another stopover may be critical to understanding the ecological dramas now underway on Delaware Bay.

Continue reading “Close to the Finish Line”

Ecological Lockdown for Horseshoe Crabs – A Delaware Bay 2020 Update

Guest post by: Dr. Larry Niles

When asked to describe the ecological conditions of any one year of our 23 years of work on Delaware Bay, Humphrey Sitters, one of the first biologists to understand the value of Delaware Bay to shorebirds would respond “every year is unprecedented”. And so it seemed until this year.

Continue reading “Ecological Lockdown for Horseshoe Crabs – A Delaware Bay 2020 Update”