Genetic and environmental factors associated with survival of a rare songbird in a fragmented urban landscape

Conservation Science and Practice
By: , and 

Links

Abstract

The coastal Cactus Wren (Campylorhynchus brunneicapillus) persists in small and fragmented populations throughout southern California that are subject to genetic drift and inbreeding. We combined individual banding and resighting data and genotyped individuals at 22 microsatellite loci to assess whether heterozygosity was associated with survival across three regional Cactus Wren populations on conserved lands in Orange and San Diego Counties between 2009 and 2020. Using Cormack-Jolly-Seber models (CJS) to analyze the 5-year capture histories of 528 individual wrens, we found that age class (hatch year or after hatch year) was the strongest predictor of survival. Individual heterozygosity and precipitation also had positive effects on survival, with survival up to 2 times higher in the most heterozygous individuals compared to the least and up to 1.5 times higher in high precipitation years versus drought years. Multi-locus heterozygosity was significantly correlated across loci, suggesting that inbreeding depression is likely driving the association between survival and heterozygosity. Study results support that genetic rescue efforts that reduce inbreeding have the potential to improve fitness and mitigate further loss of genetic variation in managed populations.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Genetic and environmental factors associated with survival of a rare songbird in a fragmented urban landscape
Series title Conservation Science and Practice
DOI 10.1111/csp2.70155
Edition Online First
Publication Date October 08, 2025
Year Published 2025
Language English
Publisher Society for Conservation Biology
Contributing office(s) Western Ecological Research Center
Description e70155, 14 p.
Country United States
State California
County Orange County, San Diego County
Additional publication details