For the second year in a row, the nesting success of western snowy plovers on Oregon beaches set a record, according to state and federal agencies. This year 107 young birds survived long enough to learn to fly and become independent of their parents. This number is almost three times the average of 37 young produced annually since monitoring began in 1990, and nearly twice last year's then-record results of 60.
Washington's beaches enjoyed similar increases, with 45 successful nests this year producing 27 fledglings. At Leadbetter Spit, the only area where protection from predators was provided, a fourfold increase in nest success was observed.
Snowy plovers are small, pale-colored shorebirds with dark patches on either side of the upper breast. The coastal population breeds along the Pacific coast from southern Washington to southern Baja, California in Mexico. This population was listed by the U.S. Fish and Wildlife Service as ?threatened? in 1993 under the federal Endangered Species Act. The inland and coastal populations are listed collectively by the State of Oregon as a threatened species. They are considered a species of concern by the State of California, and a threatened species by the State of Washington.
Biologists attribute the higher number of fledglings this year to a combination of factors, including:
- increased habitat quality from long-term restoration projects;
- increased chick survival from selective predator management;
- more separation of beach users from plover nesting areas through beach management techniques;
- general cooperation from beach users in avoiding plover nesting areas, and
- good weather, without much rain during the plover's nesting season.
"As is almost always the case, it takes a number of factors working together to improve something as complex as nesting success for a shorebird," said Kerrie Palermo, a Bureau of Land Management senior wildlife biologist in Coos Bay. "There's rarely one single thing you could point to in a given year, just as it took a combination of factors to reduce plover numbers historically.?
Habitat restoration projects include sites at Leadbetter Spit in Washington, Sutton Beach, Siltcoos Estuary, Oregon Dunes Overlook; Tenmile Estuary (northern Coos County), the North Spit of Coos Bay; Bandon Beach State Natural Area and New River area beaches in Oregon.
Carefully targeted predator control took place at all active nesting sites on Oregon beaches this year, and the data indicate that predator control is helping plover numbers climb toward recovery goals. Hatching success was also dramatically increased in Washington where several nests were protected with predator exclusions (wire cages).
"Beach users were generally positive in their responses to our beach monitors," said Palermo. "Once people understood that beach restrictions were in place to protect a threatened shorebird; that only 17 miles of the whole Oregon coast have such restrictions, and that the restrictions don't apply to the wet sand portions of the beach - most folks were very cooperative.?
The estimated 136 to 142 plovers populating the Oregon coast this year is the highest number since 1996-1997, and equal to the highest population estimate since 1990. The 120 breeding plovers in 2004 were the most since 1990. Excellent chick production in 2003 helped contribute to the increase in plover numbers in 2004, and biologists hope that this year's production will result in further increases to the overall population next season.
Oregons plover population went from 72 in 1993, when it was listed as threatened, to 141 in 1997, but the effects of El Nino weather patterns in the winters of 1997 and 1998 caused plover numbers to decline along the Pacific coast.
The birds prefer coastal sand spits, dune-backed beaches, beaches at creek and river mouths and salt pans at lagoons and estuaries. The breeding season in Oregon extends from 15 March through 15 September. Biologists attribute the decline of the species to loss of nesting habitat due to development of dune areas, the encroachment of European beach grass into former open dune areas, human disturbance of nest sites, and nest predation by raccoons, ravens and non-native red foxes.
