Abundance models of endemic birds of the Sierra Nevada de Santa Marta, northern South America, suggest small population sizes and dependence on montane elevations

Abundance measures are almost non-existent for several bird species threatened with extinction, particularly range-restricted Neotropical taxa, for which estimating population sizes can be challenging. Here we use data collected over nine years to explore the abundance of 11 endemic birds from the Sierra Nevada de Santa Marta (SNSM), one of Earth’s most irreplaceable ecosystems. We established 99 transects in the “Cuchilla de San Lorenzo” Important Bird Area within native forest, early successional vegetation, and areas of transformed vegetation by human activities. A total of 763 bird counts were carried out covering the entire elevation range in the study area (~175–2650 m). We applied hierarchical distance-sampling models to assess elevation- and habitat-related variation in local abundance and obtain values of population density and total and effective population size. Most species were more abundant in the montane elevational range (1800–2650 m). Habitat-related differences in abun..., , , # Data from: Abundance models of endemic birds of the Sierra Nevada de Santa Marta, northern South America, suggest small population sizes and dependence on montane elevations

MS Reference Number: ORNITH-APP-23-061R2
Dataset name: Abundance_models_priority_endemics_SNSM.xlsx

The whole dataset contains data for fitting hierarchical distance-sampling models for priority, endemic bird species from the Sierra Nevada de Santa Marta, northern Colombia. Models were used to assess elevation- and habitat-related variation in local abundance and obtain values of population density and total and effective population size for the study species. Details on other methods used for estimating extent of presence (EOP) and area of occupancy (AOO), and for generating abundance maps are provided in the manuscript and the supplementary material file that accompanies it. Abundance maps will be uploaded as distribution hypothesis for each species to the BioModelos online platform (Velásquez-Tibatá et al. ...