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Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ecologists often seek to infer patterns of species occurrence or community structure from survey data. Hierarchical models, including multi‐species occupancy models (MSOMs), can improve inference by pooling information across multiple species via random effects. Originally developed for local‐scale survey data, MSOMs are increasingly applied to larger spatial scales that transcend major abiotic gradients and dispersal barriers. At biogeographic scales, the benefits of partial pooling in MSOMs trade off against the difficulty of incorporating sufficiently complex spatial effects to account for biogeographic variation in occupancy across multiple species simultaneously. We show how this challenge can be overcome by incorporating preexisting range information into MSOMs, yielding a "biogeographic multi‐species occupancy model" (bMSOM). We illustrate the bMSOM using two published datasets: Parulid warblers in the United States Breeding Bird Survey and entire avian communities in forests and pastures of Colombia's West Andes. Compared with traditional MSOMs, the bMSOM provides dramatically better predictive performance at lower computational cost. The bMSOM avoids severe spatial biases in predictions of the traditional MSOM and provides principled species‐specific inference even for never‐observed species. Incorporating preexisting range data enables principled partial pooling of information across species in large‐scale MSOMs. Our biogeographic framework for multi‐species modeling should be broadly applicable in hierarchical models that predict species occurrences, whether or not false absences are modeled in an occupancy framework. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Páramos are high-elevation grassland-dominated ecosystems of the northern Andes that harbour large numbers of small-ranged and endemic species and provide important ecosystem services. Though páramos are increasingly managed with a conservation focus, they remain ecologically threatened, in part due to overgrazing. Here, we assess the impacts of grazing on bird communities using data collected from three páramo complexes in the Eastern Andes of Colombia. We (1) assess how densities of shrubs and frailejones—a keystone group of plants in the páramo—are impacted by grazing, (2) determine the influence of these vegetation features on bird occupancy, and (3) examine how bird species richness and community composition are impacted by páramo grazing. We find that grazing status strongly influences the vegetation characteristics of the páramo, resulting in large reductions in the abundance of shrubs and frailejones. These vegetation changes have significant impacts on páramo bird communities, with reduced shrub abundance resulting in lower occupancy for most species (4 out of 48). As a consequence, grazed páramo communities contain fewer bird species and vary in composition relative to those of natural páramo. However, the magnitudes of these differences are modest and it is possible that low-intensity grazing remains compatible with conservation management. We suggest that it is important to consider how páramo conservation may interact with management of adjacent montane forests and the potential for leakage effects resulting in increased deforestation outside of protected areas. [ABSTRACT FROM AUTHOR]