Habitat niches of bird species along a recovery gradient in the Chocó tropical forest

• Published in: Ecological indicators 2024-09, Vol.166, p.112260, Article 112260
• Main Authors: Falconí-López, Ana, Mitesser, Oliver, Martin Schaefer, H., Blüthgen, Nico, Busse, Annika, Feldhaar, Heike, Freile, Juan, Gelis, Rudy, Grella, Nina, Heibl, Christoph, Kortmann, Mareike, Newell, Felicity L., Rabl, Dominik, Schleuning, Matthias, Seibold, Sebastian, Şekercioğlu, Çağan H., Tinoco, Boris A., Tremlett, Constance J., Müller, Jörg, Donoso, David A.
• Format: Article
• Language: English
• Subjects: Canandé; Chronosequence; Conservation; Niche Breadth; Niche Position; Ornithology; Restoration; Tropical Biology
• ISSN: 1470-160X
• DOI: 10.1016/j.ecolind.2024.112260

[Display omitted] •We sampled 323 bird species in the Chocó forest in northwestern Ecuador.•We calculated niche position and breadth for bird species in a restoration gradient.•Niche metrics offered a assessment of bird distributions along the recovery gradient.•Niche metrics recovered associated changes in morphology, diet and distribution.•Policymakers can use our niche metrics to evaluate forest recovery in tropical regions. Conservation programs need improved tools to measure the recovery of animal diversity across restoration gradients. We used soundscapes and expert identifications of bird species to calculate niche position (i.e., mean of environmental conditions across all areas a species occupies) and niche breadth (i.e., the standard deviation of the species distribution) along a recovery gradient; from agriculture to early (up to 20 yrs) and late (up to 38 yrs) recovery, to old-growth forests. Our survey included 323 bird species and was conducted in 66 plots in the lowland Chocoan tropical rainforest in Ecuador where less than 11% of the forest remains intact, and large areas are currently undergoing regeneration post-abandonment. First, we validated our niche metrics by contrasting them against independent global categories of forest density dependency. We then explained the niche metrics of the bird species with different ecological traits, gathered from the literature, reflecting species-specific primary diet, morphology and distribution, and accounting for the phylogenetic relatedness of species. Finally, we explored the phylogenetic signal present in bird species’ ecological traits and recovery niche metrics. Niche position and breadth across the recovery gradient closely followed global categories of forest density dependency. However, our approach provided a more fine-scaled sorting of bird species in forest plots categorized as late recovery and old-growth. Granivorous birds occupied niche positions in active cacao and pasture plots and were replaced by frugivorous birds in older regeneration plots. Along the recovery gradient, tail length and handwing index decreased with niche position, supporting previous observations that birds in old-growth forests are less mobile. Birds in old-growth forests had smaller global distribution ranges than birds in agricultural plots. Finally, the latitudinal distribution of birds in the study area averaged south of the equator, with birds in old-growth plots averaging latitudinal centroids in wet fore