By Andrea Sanchez
I recently accompanied GCBO biologist Carol Jones to St. Mary’s Island in Scott Bay (near the Houston Ship Channel) to census the nesting population of birds on the island. St. Mary’s Island was restored by ExxonMobil in response to the Houston Ship Channel widening and deepening project. The island is twelve acres and the species observed there have changed dramatically over time. It’s gone from being a bare-ground nesting location with birds like Black Skimmers and various terns to being overgrown with vegetation. Now, there are more species of a greater variety that nest on this island. There were thousands of birds of fifteen different species including various herons and egrets, Brown Pelicans, White Ibis, Neotropic Cormorants, Roseate Spoonbills, and Black-Bellied Whistling Ducks. The most abundant species on the island was Laughing Gull though. There were over a thousand of these black-capped birds nesting on this one island.
All these different species nesting in one place is gorgeous, but add to it that all of these birds were parading around in their fantastic breeding plumage and you have yourself a breathtaking view that you never want to leave. Breeding plumage is of course the plumage many birds acquire right before the breeding season to try to attract a mate. Birds dress up to impress each other too! This plumage may include bright colors or unusual feather shapes (such as plumes and streamers).
Among the species we saw were one of my favorites, the Roseate Spoonbill. This already brightly colored bird becomes even more brilliant pink during the breeding season. The color deepens so much that you’d think you were in a tropical paradise. Another bird whose color makes it feel like you’re in paradise is the Tricolored Heron. As this bird’s name suggests, it is three beautiful colors. The most brilliant color during the breeding season is the bright blue of its bill. It becomes so bright; it’s amazing to think that nature is able to produce such fantastic colors.
Snowy Egrets were also prominent on this island. This distinctive bird becomes even more distinctive during the breeding season. Their head, neck, and back become adorned with long, lacy plumes giving them a delicate look and their feet and skin around the eyes become red. Great Egrets and Cattle Egrets are also embellished with these delicate plumes during the breeding season.
The most common species on this island, and probably the most well known, was Laughing Gulls. Most people recognize this species as the pesky seagulls that eat any food you happen to bring to the beach or even the Walmart parking lot. This bird is readily recognizable by the black cap it wears during breeding season; I’ve found that many people don’t know that they lose their cap during the winter.
Of course there were many more breeding species on this island. Words could never do these beauties justice. Whether breeding or not these birds are remarkable, but that extra boost of breeding plumage only adds to the wonder of these amazing creatures. It was an amazing experience and if you ever get the chance to see a heron rookery you should definitely go!