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There's Room for Shorebirds, Too
To investigate this question, Kevin Lafferty, a marine ecologist with the USGS Western Ecological Research Center in Santa Barbara, CA, conducted a preliminary beach trial last summer at Coal Oil Point Reserve, a public beach in Santa Barbara. Kevin observed that human activity at the reserve often displaced shorebirds that were approached within 20 yards; 10 percent of humans and 40 percent of dogs disturbed shorebirds, most of which flew when disturbed. Unlike most other birds, threatened western snowy plovers hid from people up on the dry sand instead of moving. Still, each snowy plover was disturbed about 115 times per week, 16 times more than at remote or protected areas. Despite disturbance, the snowy plovers stayed faithful to their preferred habitat around a lagoon mouth, although they were less abundant near beach-access points. Kevin noted the types of disturbance snowy plovers were most sensitive to, measured the distance at which they reacted to disturbance, and determined the preferred habitat of plovers within a 3-km stretch of beach designated as critical habitat for the population. He then developed a mathematical model that predicted the optimal amount of habitat to set aside to maximize protection of plovers with minimal inconvenience to beach users.
The result? Disturbance to snowy plovers and other birds decreased dramatically, helping the plover chick successfully fledge. Snowy plover densities increased inside the fenced area. In addition, the number of least terns, an endangered species, increased sixfold. In total, the abundance of birds in the protected area increased nearly fourfold. Counts of birds outside the fence remained largely unchanged, suggesting that additional birds were entering the protected area. The fence, which is still in place, allows birds to sit in one spot without being forced away within a few minutes. In addition, other birds flying along the coast may notice a lot of birds sitting on the beach, realize the area must be a safe place to rest for a spell, and fly in. Most beach users walk along the wet sand near the water's edge and are not affected by the fence, which encloses only dry sand. During the preliminary trial, fewer than 5 percent of the people using the beach had to choose a different patch of dry sand to sit on. Interviews with beachgoers revealed that many people valued the increased opportunity to view wildlife, and even more said they were glad that the minor inconvenience was an alternative to beach closures used elsewhere to protect endangered birds.
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in this issue:
Gulf of Mexico Integrated Database Workshop Netherlands Visiting Scientist  |
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U. S. Department of the Interior | U.S. Geological Survey
cover story:
