Status of Large Terrestrial Vertebrates in the Monteverde-Arenal Bioregion, Northwestern Costa Rica

Abstract

Protected areas have been important in reducing tropical forest biodiversity loss. Costa Rica has been a model country in protecting forests and promoting conservation. However, many Costa Rican protected areas are surrounded by highly modified habitat and may be losing species, either because they are too small to support viable populations or are too isolated to allow for population connectivity. We used camera traps to study terrestrial mammal and terrestrial bird populations in the Monteverde-Arenal Bioregion of northwestern Costa Rica. We sampled core protected areas and nearby unprotected, fragmented habitats. Of 33 species historically found in the region, we detected 25. However, most species were rarely detected, and only five were found more than once per 30 days of camera time. The most commonly detected species represented major feeding groups, including obligate herbivores, omnivores, and obligate carnivores. Most ungulates were rare and may not have viable population sizes. However, a top predator, the puma (Puma concolor), was commonly detected. Fragmented areas had lower abundance and fewer species detected; a few species were not detected at all, even though some of them were abundant in the core protected areas. We suggest that conservation efforts are protecting some terrestrial mammals and birds, and there is a functioning food web. However, many species are either rare or extirpated, indicating the Monteverde-Arenal Bioregion is a partially defaunated landscape.