Broad-scale habitat use by fledgling Black-capped Vireo

Abstract

Knowledge of avian habitat associations during the postfledging stage is lacking for most songbirds, which limits the ability to develop and implement management plans that address the full life cycle of birds. The Black-capped Vireo (Vireo atricapilla; hereafter vireo) is a Neotropical migratory songbird that breeds in early to mid-successional vegetation but has been documented using late-successional vegetation. We used data collected in 2013 and 2014 to determine the spatial distribution of vireo fledglings in relation to the availability of woodland cover in central Texas. We found that woodland cover was used less often than it was available in the landscape. We used a model selection approach with generalized linear mixed models and generalized additive mixed models to determine which variables, i.e., age (days since fledging) or season (days since the first nest at the study site fledged young), best explained vireo fledgling use of woodland and distance from fledgling locations to woodland. The probability of woodland use by fledglings was best predicted by season, and fledglings were located closer to woodland vegetation as the season progressed and as fledglings aged. The lack of selection for woodland cover by vireo fledglings and their persistent use of shrub-dominated cover suggest that the shrubdominated cover provides analogous resources to those used by adults during the breeding season. Fledglings also use woodland cover where available and move toward the shrubland-woodland interface over time, suggestive of a possible function of woodland vegetation as postfledging habitat. Thus, land managers should consider the impact of land management practices in woodland and shrubland cover on the habitat availability for Black-capped Vireo throughout its life cycle, and on other migratory species.Utilisation à grande échelle de l'habitat par les oisillons deViréo à tête noire RÉSUMÉ. Les connaissances sur les associations d'habitats utilisés après l'envol du nid sont insuffisantes pour la plupart des oiseaux chanteurs, ce qui limite la capacité d'élaborer et de mettre en oeuvre des plans de gestion qui tiennent compte du cycle de vie complet des oiseaux. Le Viréo à tête noire (Vireo atricapilla; ci-après viréo) est un oiseau chanteur migrateur néotropical qui se reproduit dans la végétation de début à milieu de succession, mais dont la présence a été documentée dans la végétation de fin de succession. Nous avons utilisé les données collectées en 2013 et 2014 pour déterminer la distribution spatiale des oisillons de Viréo par rapport à la disponibilité du couvert forestier dans le centre du Texas. Nous avons constaté que le couvert forestier était moins utilisé que ce qui était disponible dans le paysage. Nous avons utilisé une approche de sélection de modèle avec des modèles mixtes linéaires généralisés et des modèles mixtes additifs généralisés pour déterminer quelles variables, c.-à-d. l'âge (jours depuis l'envol) ou la saison (jours depuis l'envol du premier nid sur le site étudié), expliquent le mie...

Fledgling Bachman’s Sparrows in a longleaf pine ecosystem: survival, movements, and habitat selection

“…The characteristics of high‐quality cover for fledglings vary among species and across land‐cover types, but fledglings in many species select habitat patches that maximize predator avoidance (Champlin et al 2009a,b, Vitz and Rodewald 2011, Streby and Andersen 2012) and food availability (Anders et al 1998, Kershner et al 2004, White et al 2005, Dittmar et al 2014, Streby et al 2015, Martinez et al 2019). For grassland‐dependent species, high‐quality cover for fledglings often consists of tall herbaceous vegetation, minimal amounts of litter, and moderate amounts of grass interspersed with bare ground (Jones and Bock 2005, Hovick et al 2011, Giovanni et al 2015, Small et al 2015).…”