Is green the new black? Black-backed Woodpecker vital rates do not differ between unburned and burned forests within a pyrodiverse landscape

ABSTRACT Woodpeckers often reflect rapid changes to forest health and serve as indicator species to help guide forest management decisions. The Black-backed Woodpecker (Picoides arcticus) is known for its strong association with recently burned forests and is a species of conservation concern due to habitat loss stemming from post-fire management of burned forest. Several studies have found the Black-backed Woodpecker occupying extensive areas of unburned (i.e., green) forests in the western part of its range during the breeding season, raising questions about whether green forests can support viable nesting populations in this region. We studied breeding Black-backed Woodpeckers in southern Oregon, USA to evaluate whether 2 vital rates critical to population recruitment—nest survival and post-fledging survival—differed between green and burned forests. During 2018, 2019, and 2021, we monitored 91 Black-backed Woodpecker nests (n = 34 in green forest, n = 57 in burned forest) and found that neither daily nest survival rate nor reproductive output (i.e., the number of fledglings per successful nest) differed between nests located in green and burned forest; however, nestling body condition was slightly enhanced in green forest. We also quantified survival of recently fledged individuals using VHF radio telemetry and found that the survival rate of birds in green forest was nearly identical to those in burned forest, with most mortalities occurring within 4 weeks of fledging. Our results indicate that Black-backed Woodpeckers in green forests were equally successful at breeding as conspecifics in recently burned forest, although densities of nesting pairs in green forest were lower than those in burned forest. Our findings indicate certain types of green forest, particularly mature lodgepole pine, can support viable populations of the Black-backed Woodpecker in the western portion of its range. This finding has conservation implications given that green forest occupies much of the forested landscape in this region and is often juxtaposed to areas subjected to high severity fire. Therefore, practices that promote pyrodiversity—landscape-level spatial and temporal variability in fire effects—as well as connectivity between green and burned forest within fire-prone landscapes are likely to provide the greatest conservation benefit for this species. How to Cite Kerstens, M. E., and J. W. Rivers (2023). Is green the new black? Black-backed Woodpecker vital rates do not differ between unburned and burned forests within a pyrodiverse landscape. Ornithological Applications 125:duad010. LAY SUMMARY • The Black-backed Woodpecker (Picoides arcticus) is typically found breeding within recently burned forests in the western United States. • Two recent studies found this species in unburned, green forests during the breeding season, suggesting such forests might hold self-sustaining populations. • Our research found that two components of breeding success—nest survival and the survival of young after fledging from the nest—did not differ between birds nesting in green forests and burned forests of southern Oregon, USA. • Our results indicate that certain green forests, such as mature lodgepole pine, are suitable areas for Black-backed Woodpeckers to rear offspring, and they may play an important role for conservation efforts aimed at maintaining Black-backed Woodpecker populations in the western portion of its range. RESUMEN Los pájaros carpinteros a menudo reflejan cambios rápidos en la salud del bosque y sirven como especies indicadoras para ayudar a guiar las decisiones de manejo forestal. La especie Picoides arcticus es conocida por su fuerte asociación con los bosques recientemente quemados y es de interés para la conservación debido a la pérdida de hábitat derivada del manejo de los bosques quemados después de los incendios. Varios estudios han encontrado que P. arcticus ocupa extensas áreas de bosques no quemados (i.e., verdes) en la parte occidental de su área de distribución durante la temporada reproductiva, lo que genera dudas sobre si los bosques verdes pueden albergar poblaciones de anidación viables en esta región. Estudiamos la reproducción de P. arcticus en el sur de Oregón, EEUU, para evaluar si dos índices vitales críticos para el reclutamiento poblacional (supervivencia del nido y supervivencia posterior al emplumamiento) diferían entre los bosques verdes y los quemados. Durante 2018, 2019 y 2021, monitoreamos 91 nidos de P. arcticus (n = 34 en bosque verde, n = 57 en bosque quemado) y encontramos que ni la tasa de supervivencia diaria del nido ni el rendimiento reproductivo (i.e., el número de volantones por nido exitoso) difirió entre nidos ubicados en bosque verde y quemado; sin embargo, la condición corporal de los polluelos mejoró ligeramente en el bosque verde. También cuantificamos la supervivencia de individuos recién emplumados utilizando radio-telemetría VHF y encontramos que la tasa de supervivencia de las aves en el bosque verde fue casi idéntica a la de los bosques quemados, con la mayoría de las muertes ocurriendo dentro de las cuatro semanas del emplumamiento. Nuestros resultados indican que los individuos de P. arcticus en bosques verdes tuvieron el mismo éxito en la reproducción que sus congéneres en bosques quemados recientemente, aunque las densidades de parejas anidando en bosques verdes fueron menores que en bosques quemados. Nuestros hallazgos indican que ciertos tipos de bosques verdes, particularmente los pinos maduros de Pinus contorta, pueden sustentar poblaciones viables de P. arcticus en la parte occidental de su área de distribución. Este hallazgo tiene implicaciones para la conservación dado que el bosque verde ocupa gran parte del paisaje boscoso en esta región y, a menudo, se yuxtapone a áreas sujetas a incendios de alta severidad. Por lo tanto, las prácticas que promueven la pirodiversidad (variabilidad espacial y temporal a nivel del paisaje en los efectos del fuego), así como la conectividad entre el bosque verde y el quemado dentro de los paisajes propensos a incendios, probablemente proporcionen el mayor beneficio de conservación para esta especie.