California Least Tern Chicks Banded at Lengueta Arenosa
In late June of 2024, the California Least Tern chicks began hatching! And Pro Esteros biologists have been banding them as part of a crucial monitoring program for this endangered species.
The sandy beaches and dunes at the tip of Lengueta Arenosa (“The Spit”) provides essential nesting habitat for California Least Terns, offering a relatively safe place away from human traffic for these birds to lay their eggs and raise their chicks. However, monitoring their population is crucial to ensure their survival. Here’s how scientists and conservationists are doing just that:
Nest Surveys: Biologists regularly visit Lengueta Arenosa during the breeding season to count nests. They carefully mark nest locations to track changes over time.
Chick Banding: One of the most effective methods for studying Least Terns is chick banding. Here’s how it works:
Shortly after chicks hatch, they are gently captured.
Each chick receives a unique metal or plastic leg band with an identification number.
The band allows researchers to track individual birds throughout their lives.
By monitoring banded chicks, biologists can learn about survival rates, migration patterns, and breeding success.
Predator Control: To protect nests and chicks, conservationists implement predator control measures. These include installing fences, using decoys to deter predators, and monitoring for signs of disturbance.
Unlike the precocial snowy plover chicks, that are able to run around on their own after hatching, California Least Tern are altricial, meaning they are very dependent on the parents after hatching and not very mobile. California Least Terns aren’t like most altricial chicks in that they can move about shortly after hatching – but not nearly as rapidly as the plover chicks.
The California Least Tern colony is very vulnerable to disturbance, as the nest is simply an indentation in the sand and the eggs and chicks are camouflaged and easily trampled. Please use caution when visiting this area and do not cross the fencing or allow dogs to enter the area. Thank you!
