Variable effects of a changing climate on lay dates and productivity across the range of the Red-cockaded Woodpecker

Many temperate bird species are breeding earlier in response to warming temperatures. We examined the effects of climate on breeding phenology and productivity in 19 populations across the range of the Red-cockaded Woodpecker (Picoides borealis), an endangered species endemic to pine (Pinus spp.) forests in the southeastern United States. Red-cockaded Woodpeckers nested earlier in warmer springs and delayed nesting in wetter springs. Earlier nesting and larger group sizes resulted in higher productivity. Spring temperatures have warmed over time across the range, but this has not led to range-wide advances in nesting date over time. Coastal and northern populations have exhibited a trend of earlier nesting over time, but the response of inland populations has been variable, including some populations in which nesting has become later over time. Geographic patterns included high and increasing productivity at higher latitudes, and declining productivity in the southwestern portion of th...