Seasonal and annual survival of adult Pacific brant

Journal of Wildlife Management
By: , and 

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Abstract

Declining mid-winter counts of Pacific brant (Branta bernicla nigricans) and reduced numbers of nesting birds on their main breeding grounds prompted us to assess factors that may be limiting recovery of this population. We estimated seasonal and annual survival rates of adult brant in 1986-93 from resightings of leg-banded birds. Brant were banded at a major colony on the Yukon-Kuskokwim Delta, Alaska (Y-K Delta) in 1986-92, and resighted there in 1987-93 as well as at major fall and spring migration and wintering areas in 1990-93. Seasonal survival was the same for males and females. Mean monthly survival rate was lowest (P ≤ 0.05) in late spring migration (15 Apr-1 Jun), the period of greatest subsistence harvest on the breeding grounds, and highest in winter (1 Jan-1 Mar), the period of greatest sport harvest. Annual survival rate did not vary among years (F = 0.51; 5, 718 df; P = 0.91) and averaged 0.840 (SE = 0.031) from 1986 to 1993. Subsistence harvest has contributed to low population levels of Pacific brant.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Seasonal and annual survival of adult Pacific brant
Series title Journal of Wildlife Management
DOI 10.2307/3802184
Volume 61
Issue 3
Year Published 1997
Language English
Publisher Wiley
Contributing office(s) Alaska Science Center
Description 9 p.
First page 773
Last page 781
Country United States
State Alaska
Other Geospatial Yukon-Kuskokwim Delta