Document Type

Technical Report

Publication Date

12-2010

Subjects

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

Abstract

From 8 April – 27 September 2010 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 2010 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 fledging success, 6) monitor brood movements, 7) collect general observational information about predators, and 8) evaluate the effectiveness of predator management.

We observed an estimated 232-236 adult Snowy Plovers; a minimum of 175 individuals was known to have nested. The adult plover population was the highest estimate recorded since monitoring began in 1990. We monitored 261 nests in 2010, the highest number of nests since monitoring began in 1990. Overall Mayfield nest success was 25%. Exclosed nests (n = 67) had a 72% apparent nest success rate, and unexclosed nests (n = 194) had a 23% apparent nest success rate. Nest failures were attributed to unknown depredation (24%), unknown cause (17%), one-egg nests (15%), rodent depredation (14%), abandonment (12%), wind/weather (5%), corvid depredation (5%), mammalian depredation (4%), wave overwash (2%), infertility (2%), and adult depredation (1%). We monitored 94 broods, including two from unknown nests, and documented a minimum of 80 fledglings. Overall brood success was 55%, fledging success was 33%, and 0.90 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/15737

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