Article by Taylor Bennett
The Gull-billed Tern is a medium sized tern that breeds along the beaches and bays of Texas Coast from May to August. It is a species of high concern here, meaning that it is at risk of becoming threatened or endangered. Gulf Coast Bird Observatory helps monitor the local colony that breeds along with the Black Skimmer colony at Dow Plant A in Freeport, TX.
Like other tern species, there is a difference between the breeding and wintering plumage of Gull-billed Terns. We often observe them in their breeding plumage in Texas. They have a white body with broad wings, black legs, a black cap, and a rather thick black bill like a gull, hence the name.
Like other tern species, Gull-billed Terns tend to nest in large groups called colonies. They often nest with other tern species and Black Skimmers. They do this for safety from predators, but also so that they can have the occasional free meal by stealing from the other birds. They nest along beaches, but prefer to nest on oyster shell like Black Skimmers.
Gull-billed Terns are ground nesters. To nest, they create shallow bowls in the sand or shell called scrapes. They lay 2 to 3 buff-speckled eggs in the nest bowl. Both the parents help incubate the eggs until they hatch which is usually within 23 days. The chicks are partially precocial, so they hatch covered in down, and can usually walk and move around within hours after hatching. But they still rely on the parents on food and shelter for about 4 to 5 weeks until they can fly.
Gull-billed terns differ from other terns in the way they feed and what they eat. Usually, you can easily identify terns by the way they hunt by hovering in the air and then plunging into the water to catch a fish. Not this tern. The Gull-billed Tern mainly feeds on insects, so it feeds by flying slowly into the wind similar to a swallow or by simply plucking things from the ground.
This tern has a rather broad and peculiar diet. It eats what it wants It can feed on pretty much anything from insects, crabs, lizards, frogs, mammals, and, yes, even other birds. Believe it or not, Gull-billed terns are a common predator of Least Tern and Plover chicks. Oh, and if they so happen to want a fish they will just simply pluck it from their neighbor. This is the type of neighbor who wouldn’t just borrow a cup of sugar, but would steal the whole bag from right under your nose!
Even though the Gull-billed Tern is a voracious predator, its population is in decline and is considered a species of high concern. They are highly vulnerable to people, vehicles, and dogs. So, like other shorebirds and waterbirds please remember to swim, fish, and play from 50 yards away. On behalf of Gulf Coast Bird Observatory, thanks for reading and we wish you safe and well.
Gull-Billed Tern: Gull-billed Tern observed feeding on a dragonfly in a marsh on Follet’s Island. Photo by Morgan Barnes.