Estimating ecological metrics for holistic conservation management in a biodiverse but information-poor tropical region

Abstract

Conservation ecologists face the dual challenge of working with difficult-to-study species and providing ecological metrics that support conservation management at global, regional, and local levels. We present metrics identifying distributions, site-level and global abundance, site-contextualized habitat requirements, and threats for seven dry forest endemic birds (two threatened, one Near Threatened) in the globally important Tumbes region of Peru. Extents of occurrence ranged from 36,000 to 152,000 km2, and while broad distributions were generally congruent, nearly half of species overlapped <50% of their range with other species. Population sizes ranged from the low thousands in the threatened/Near Threatened taxa to >150,000. Site-level population estimates varied hugely, reflecting size of site and extreme variation in local abundances. Large tree girths and dense low cover generally promoted bird abundance, but stem density acted in opposite directions for different species, implying the need for site- and species-specific habitat management. Habitat quality varied across sites, further complicating management options at the local level (e.g., reduced grazing). We highlight the suitability of our methods in providing useful conservation metrics for data-poor regions, and demonstrate their application. Importantly, we propose key sites and priority actions for the region, including extensions of existing protected areas.