Document Type

Technical Report

Publication Date

12-2009

Subjects

Snowy plover -- Oregon -- Pacific Coast -- Geographical distribution, Snowy plover -- Oregon -- Pacific Coast -- Reproduction, Snowy plover -- Mortality -- Oregon -- Pacific Coast

Abstract

From 3 April – 23 September 2009 we monitored the distribution, abundance and productivity of the federally Threatened Western Snowy Plover (Charadrius alexandrinus nivosus) along the Oregon coast. From north to south, we surveyed and monitored plover activity at Sutton Beach, Siltcoos River estuary, the Dunes Overlook, North Tahkenitch Creek, Tenmile Creek, Coos Bay North Spit, Bandon Beach, New River, and Floras Lake. Our objectives for the Oregon coastal population in 2009 were to: 1) estimate the size of the adult Snowy Plover population, 2) locate plover nests, 3) continue selective use of mini-exclosures (MEs) to protect nests from predators and evaluate whether exclosure use can be reduced, 4) determine nest success, 5) determine fledgling success, 6) monitor brood movements, 7) collect general observational data about predators, and 8) evaluate the effectiveness of predator management.

We observed an estimated 199-206 adult Snowy Plovers; a minimum of 149-150 individuals was known to have nested. The adult plover population was the highest estimate recorded since monitoring began in 1990, and we found 236 nests in 2009. Overall Mayfield nest success was 23%. Exclosed nests (n = 34) had a 76% success rate, and unexclosed nests (n = 202) had a 25% success rate. Nest failures were attributed to unknown depredation (29%), rodent depredation (21%), unknown cause (17%), oneegg nests (12%), corvid depredation (8%), abandonment (7%), wave overwash (2%), infertility (1%), wind (1%), canine depredation (1%), and raccoon depredation (1%). We monitored 88 broods, including eight from unknown nests, and documented a minimum of 106 fledglings. Overall brood success was 73%, fledgling success was 50%, and 1.33 fledglings per male were produced.

Continued predator management, habitat improvement and maintenance, and management of recreational activities at all sites are recommended to achieve recovery goals.

Description

Part of the Oregon Bidiversity Information Center Report

Persistent Identifier

http://archives.pdx.edu/ds/psu/15746

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