Sunday, May 30, 2010

Nesting Terns at Bolsa Chica Ecological Reserve

Sterna antillarum browni
Bolsa Chica Ecological Reserve
Huntington Beach, California
May 29th, 2010

This weekend I went birding at one of my favorite Southern California locations, Bolsa Chica Ecological Reserve. The reserve is located just east of PCH and is bordered to the north by Warner Avenue and to the south by Seapoint Avenue. The reserve consists of approximately 1,200 acres of wetlands and several miles of trails. It is an amazing place to bird. Historically over 320 species of birds have been spotted here, with many, including terns, plovers, and herons nesting in the reserve. I have personally observed over 50 species between the months of February and May this year alone. If you would like to learn more about the ecological reserve or plan your own birding trip click here.

The California Least Tern (Sterna antillarum browni) is one of three least tern subspecies that breed in North America. All three of which are listed as endangered under the Federal Endangered Species Act. One of the reasons they are endangered is that they nest along the sandy shoreline and have to compete with humans for territory. As their preferred nesting locations disappear, they have been forced to nest on  flat gravel roofs of building, or in mudflats. Unfortunately these nesting locations are not ideal, a roof can heat up causing tar to seep through the gravel sticking to fledgling birds, and mudflats can make the birds more prone to predation. Additionally, over-crowding of ideal nesting locations can also make the birds more vulnerable to predation. 

Since 1970, when the California Least Tern was listed as an endangered species, conservations efforts have been somewhat successful. The population has grown from 225 nesting pairs to over 6,561 pairs recorded in 2004. Biologists though, are still worried that the distribution of the species is limited and without future management may not be viable. With an increase in public awareness and future conservation efforts maybe these little terns will have a better chance. 

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