Document Type

Technical Report

Publication Date

12-2007

Subjects

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

Abstract

From 3 April – 21 September 2007, 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, and New River. Our objectives for the Oregon coastal population in 2007 were to: 1) estimate the size of the adult Snowy Plover population, 2) locate plover nests, 3) continue selected 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 181-184 adult Snowy Plovers; a minimum of 162 individuals was known to have nested. The adult plover population was the highest estimate recorded since monitoring began in 1990, and we found the highest number of nests since monitoring began in 1990 (n = 202). Overall Mayfield nest success was 33%. Exclosed nests (n=38) had a 66% success rate, and unexclosed nests (n=164) had a 41% success rate. Nest failures were attributed to unknown depredation (20%), one-egg nests (20%), corvid depredation (17%), abandonment (16%), unknown cause (7%), unknown mammal depredation (7%), overwashed (3%), infertility (3%), coyote depredation (3%), wind/weather (3%), raccoon depredation (1%), and adult plover depredation (1%). We monitored 89 broods, including four from unknown nests, and documented a minimum of 123 fledglings; the highest number of fledglings since monitoring began in 1990. Overall brood success was 82%, fledgling success was 54%, and 1.60 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/15744

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