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Wildlife Cameras as a Wetland Monitoring Tool: Birds in the Marsh

Written on: May 25th, 2022 in Beneficial UseWetland Restorations

By Kayla Clauson, DNREC’s Watershed Assessment and Management Section

Wildlife cameras are a tool scientists can use to collect wildlife field data. Often, scientists go out in the field and conduct monitoring that gather similar data but are restricted because they only get a small snapshot of their target observations. For example, a field crew will observe all birds using a salt marsh during marsh bird surveys, which are conducted early morning at sunrise when there is low tide. This typically gets done three times a year, when birds are likely to be most active. Using wildlife cameras allows scientists to capture birds that are using the project area during the entire year, all hours of the day and night. Although wildlife cameras are not a perfect tool, they allow scientists to actively capture data with minimal disturbance to the animals as well as gather data over a longer period.

The target of this monitoring is to better understand wildlife habitat utilization at both our reference (salt marsh) and project (mudflat) sites. The goal is to see how animal usage may compare long-term between the two sites before marsh recreation occurs (current), during the reconstruction and afterwards. To get a better understanding of the entire project and other current monitoring, check out this previous blog post.

Images from the wildlife cameras at both the reference and project site.

Our wildlife cameras have captured a variety of both mammals and birds. Let’s take a look at the birds we’ve captured for now.

Duck, Duck, Goose…

Family: Anatidae – Ducks, Geese, Swans.

Although waterfowl aren’t the primary targets of this study, we capture a lot of interactions of birds in the Anatidae family. Some of the common Anatidae family we’ve captured are Canada Geese (Branta canadensis), Mallard (Anas platyrhynchos), Green-Winged Teal (Anas crecca), and Hooded Merganser (Lophodytes cucullatus). These birds can be seen mostly around high tide, while swimming or eating.

Figure 2. Honk (goose) and Tonk (gander) are nesting in front of this camera. Notice how Honk is the assumed primary aggressor/protector during mating season.
Figure 1. Green-winged Teal (top left), Mallard (top right), Canada Geese (bottom left), and Hooded Merganser (bottom right).

Anatidae Highlight

There has been a Canada goose pair nesting at our reference site. They have been named Honk and Tonk. Honk is the male goose (gander) and can be distinguished in most of the photos as he is a fierce protector of his female partner, Tonk. While she is incubating, she won’t be leaving her nest often until her eggs hatch. Since they are nesting in front of the camera, many of the captures at this site will be of them and can skew our data. However, scientists can use their best judgement on data recording of these two individuals.

What’re you laughing at?

Family: Laridae – Gulls, Terns, Skimmers.

The second most common birds we see a lot of are gulls and terns. Gulls can be seen in the project area mostly at low tide foraging on the mudflat. Gulls can be challenging to identify due to similar morphology, coloration, and juvenile plumage. For data collection gulls were identified down to their family name (Laridae), except for Laughing Gulls (Leucophaeus atricilla). Named for their laugh-like call, Laughing Gulls are easily distinguished from other gulls because of their black head. In addition to Laughing Gulls, some common gulls and terns include Herring Gulls (Larus argentatus), Ring-billed Gulls (Larus delawarensis), Forster’s Tern (Sterna forsteri), and Common Terns (Sterna hirundo).

Laridae Highlight

Terns are known for their aerial dives when foraging for fish below the waters surface. Although terns are not typically found walking around the mudflat like gulls, we’ve been fortunate enough to capture some of their aerial dives on camera with a big splash!

Heron Paparazzi

Family: Ardeidae – Herons, Egrets, Bitterns

The third most common family we observe are herons and egrets in the Ardeidae family. One of our most seen birds during our monitoring are Great Blue Herons (Ardea herodias). We’ve also captured Great Egrets and Snowy Egrets- but with a lot less captures. We hope as the cameras remain out, we will capture more secretive marsh birds, such as the Least Bittern or American Bittern.

Figure 5. From left to right we see Great Blue Heron, Snowy Egret, and Great Egret at both sites.
Figure 6. Great Blue Heron observing the camera and seemingly showing off.

Ardeidae Highlight

Standing about four-feet tall with a six-foot wingspan, Great Blue Herons are quite the impressive bird. Known for their huge size and stalking behavior alongside coastlines and waterways, they also turn out to be quite photogenic. Many photos captured include Great Blue Herons observing the cameras closely, seemingly posing, or showing off the large fish they can catch.

Talon-ted birds

Family: Accipitridae- Hawks, Eagles, Kites

The last birds to discuss that are often captured in our project are hawks and eagles. We are fortunate enough to have captured Northern Harriers (Circus hudsonius) and Bald Eagles (Haliaeetus leucocephalus). We see Northern Harriers flying low along the marsh looking for prey, such as small mammals, in the grasses. Bald Eagles can be spotted soaring with fish or showing off their talons.

Figure 7. Bald Eagle with fish (top) and Northern Harrier soaring with distinguishable white patch on back (bottom).
Figure 8. Bald Eagle Adults (top left and right) and juvenile (bottom left and right). Notice the wing and head feather differences between adults and juveniles.

Accipitridae Highlight

Best known for their patriotic symbolism for the United States of America, Bald Eagles are a frequent capture at our reference and project sites. We can distinguish both adult and juvenile Bald Eagles from each other based on the coloration of the feathers. Adult bald eagles are dark brown with a white head and tail, whereas juveniles are fully brown in coloration and do not have a fully white head until about 5 years of age.

Birds of a Feather

Some other birds we capture are Yellow Legs (Tringa melanoleuca), Clapper Rails (Rallus crepitans), Turkey Vultures (Cathartes aura), and Cormorants (Nannopterum auritum). Yellow legs belong to the family Scolopacidae, while Clapper Rails belong to Rallidae. These are both birds that directly utilize the marsh for hiding and foraging. Cormorants in the family Phalacrocoracidae are seen swimming at high tide and Turkey Vultures in the family Cathartidae are seen scavenging for food.

Figure 9. Turkey Vulture (top left), Cormorant (top right), Yellow Legs (bottom left) and a pair of Clapper Rails (bottom right).

Stay tuned to learn more about what we capture on our wildlife cameras next time when we explore mammals on the marsh!

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