Mountain caves of the central region of Veracruz: A vertebrate biodiversity reservoir in a Neotropical hotspot

similarity in species richness is directly related to the distance between karts (r = 0.15, p = 0.11) and volcanic (r = 0.42, p = 0.33) caves. Discussion The land region of central Veracruz is considered a biodiversity hotspot, but its cave diversity and ecosystems are underexplored. We found a high vertebrate diversity (i.e., 184 bird species, 30 mammal species, 15 reptile species, 12 amphibian species, and 1 fish species) in karst and volcanic caves. To our knowledge, this is the first study focusing on the diversity of all verte- brate classes in karst and volcanic caves along an altitudinal gradient in Eastern Mexico. Thus, the knowledge generated in this study contributes to filling the information gap on the diver- sity of vertebrates that inhabit the subterranean ecosystems of this region and can help to design conservation actions for vertebrate diversity and cave ecosystems. Effective number of species in caves We hypothesized that karst caves would contain a higher diversity of individuals of all verte- brate classes than volcanic caves. Vertebrate species showed a clear pattern in both cave types: high species richness and a few common, dominant, and very dominant species. These results agree with different studies carried out in China [3], Colombia [44], and the south of Veracruz (Mexico), where the presence (but not diversity) of all vertebrate classes has been recorded [45,46]. Therefore, our results confirm that karst caves provide natural habitats for all verte- brate classes and play a significant role in the maintenance of cave vertebrate diversity.

The effective number of species in karst caves indicates that bird and mammal species have a higher richness (q0) but lower evenness due to the high presence of common (q1), dominant (q2), and very dominant species (q3). Reptiles and amphibians showed a relatively similar Fig 7. β-diversity values of four vertebrate classes calculated between the environments of karst and volcanic caves. The total height represents the overall β-diversity. Overall β-diversity is partitioned into replacement (repl. In yellow) and richness (rich in red) components. https://doi.org/10.1371/journal.pone.0306105.g007 PLOS ONE Vertebrates in caves of Neotropical hotspot PLOS ONE | https://doi.org/10.1371/journal.pone.0306105 August 9, 2024 11 / 19