Sooty Terns Establish Small Nesting Colony in Corpus Christi Bay, Marking a Rare Texas Find

Sooty terns are one of the world’s globally abundant birds in tropical zones, including having a large colony west of the Florida Keys. The open ocean birds, though, are a rare sight from land, particularly along the Gulf of Mexico coast and Texas.

Over the course of nearly half a century, bird watchers, scientists, and researchers in Texas had seen single digit pairs of the uniquely colored black and white birds on scattered islands along the Texas Gulf Coast. However, since 2021 researchers with the Conservation and Biodiversity program at the Harte Research Institute for Gulf of Mexico Studies at Texas A&M University-Corpus Christi (HRI) have documented a steady increase in numbers of nesting pairs in Corpus Christi Bay. This year they counted at least 32 pairs, more than quadruple the number of nesting pairs scientists have seen on one island along the Texas coast in more than 50 years. For a frame of reference, that same island had one pair in 2022 and five in 2023.

It’s a stunning find for a bird that has large colonies in places such as Hawaii, Samoa, New Zealand and other parts of the world. The species is considered threatened by the Texas Parks and Wildlife Department, which according to the Texas Administration Code is “any species that the department has determined is likely to become endangered in the future.”

The best part for researchers in Texas is when pairs nest successfully on an island, more tend to return to that island and researchers are hopeful it’s the beginning of a colony being established in Texas. And for bird watchers, it’s a chance to add one more rare bird to their “life” list.

“They usually start with one or two pairs, and next year more show up and in the following year even more show up,” said Liam Wolff, a research specialist with HRI’s Conservation and Biodiversity lab. “You have an exponential curve where there’s more and more until there’s a well-established colony of 10s of thousands. We are seeing that trend of exponentially more and it could be a colony established in Texas.”

Sooty Terns can be found in the Atlantic, Pacific and Indian Oceans, and spend most of their lives at sea only coming on land to breed on isolated tropical and subtropical islands.

They feed primarily on fish and squid and can travel great distances over the open ocean. They are known for their endurance, sometimes staying in the air for months at a time without touching land.

Sooty Terns usually lay one to two eggs in their nests, and their colonies are usually densely packed. Sooty terns have been spotted all along the Texas coast in small numbers, including as far north as Galveston Bay, but most have been spotted in the Lower Laguna Madre and Matagorda Bay. 

“This is a sought-after bird in Texas,” Wolff said.

Although it is unknown where the birds spotted in Texas may have come from, their presence indicates that something is right about the island in Corpus Christi Bay and the waters off its coast. Researchers are hopeful that the increase in nesting will increase so that they can study the link to important features of our local habitat.