Influence of Landscape Structure on Toucans and Parrots in the Fragmented Landscape of Los Tuxtlas, Mexico

Background and Research Aims: Habitat amount plays an important role in determining the presence and abundance of bird species in modified landscapes, whereas habitat fragmentation has shown little effects. Toucans (Ramphastidae) and parrots (Psittacidae) are large-bodied primary consumers and among the most representative birds in Neotropical forests. They are highly sensitive to habitat loss; nevertheless, their response to fragmentation has been poorly assessed leading to contradictory results. Here, we evaluate the influence of landscape structure on toucans and parrots in the tropical forest of Los Tuxtlas, Mexico. Methods: We censused birds in 12 landscapes of Los Tuxtlas and used a multi-scale landscape approach to assess the influence of landscape composition and configuration on the number of individuals of toucans and parrots. Results: We found that the most important and positive predictor of toucans and parrots was the amount of primary forest cover in the landscape. Forest fragmentation had positive effects on the number of toucan individuals, whereas parrots had negative responses to patch density but positive responses to edge density in the landscape. Conclusion: Our results suggest that primary forest loss is the main threat for toucans and parrots in Los Tuxtlas. Implications for conservation: Future conservation and land management must consider the protection of large and small remnants of primary forest and avoid additional forest loss in order to preserve toucan and parrots and their functional roles in human-modified Neotropical landscapes.