Importance of private working lands for the conservation of neotropical birds on an urban-wilderness gradient

Abstract

Global biodiversity and land conservation initiatives rely on an accurate understanding of the spatial distribution of species populations and communities. Identifying the spatial habitat use of wildlife communities across land uses and levels of human modification provides the opportunity to produce more efficient and effectual conservation plans. Our goal was to model breeding bird community occupancy across a complete spectrum of human land use modification to determine the habitat characteristics that best maximized the conservation of bird diversity. We used repeat-visit point counts on private and public lands to record the detection/non-detection of breeding bird species across the land use gradient. We modeled multiple proportional land cover and landscape structure covariates and employed a hierarchical multi-species occupancy model to analyze the habitat use of each species and to estimate guild-level species richness dynamics across the study area. We detected a total of 70 breeding bird species and our model estimated a total of 78 species within the total metacommunity. We found that insectivorous species richness was lowest in urban and suburban areas (xˆ = 7), but highest on multiple use working lands with low to moderate levels of human modification (xˆ = 22), not in the fully preserved protected areas (xˆ = 16). In contrast, the richness of the predominately human commensal omnivorous species was highest in urban and suburban areas (xˆ = 10) and across much of the more human modified landscape and lowest in the preserved lands (xˆ = 3). Moderately disturbed working lands, which primarily consisted of a mixture of rotating silvicultural tracts, agriculture, low density housing, and riparian corridors, supported the most species (xˆ = 36) and were especially important for the occupancy of breeding neotropical insectivores. These findings highlight the potential conservation benefits for incorporating private working lands with multiple land uses and land covers into future conservation planning scenarios, both for their wildlife conservation potential and as buffers around traditional protected areas.