Variable Weather Patterns Affect Annual Survival of Northern Flickers More than Phenotype in the Hybrid Zone

• Published in: The Condor
• Main Authors: D. T Tyler Flockhart, Karen L. Wiebe
• Format: Text
• Language: English
• Published: American Ornithological Society 2008
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: https://doi.org/10.1525/cond.2008.8613

Fitness in a hybrid zone is determined both by the reproductive success and the survival of phenotypes. The hybrid zone of Northern Flickers (Colaptes auratus), a common woodpecker, is one of the largest and most well-known hybrid zones in North America. Bounded-hybrid superiority, the most widely accepted hypothesis for the persistence of the zone, suggests hybrids should have equal or higher reproduction or survival than parental types in the zone, but the latter life history trait has never been examined. We analyzed the apparent survival of 1117 flickers over nine years using capture-recapture models and found no evidence that the phenotypic hybrid index influenced survival. Instead, annual adult apparent survival was best modeled according to large-scale weather patterns such as the North Atlantic Oscillation (NAO). During warm phases of the NAO, adult flickers had lower survival compared to cooler phases of NAO. There was no evidence that phenotype influenced the local recruitment of yearling flickers to the study area and no effect of NAO on this relationship. These results suggest survival in the flicker hybrid zone is largely influenced by annually variable weather patterns and that if there are differences in survival according to phenotype, they are extremely small for the flicker hybrid zone in the north.