Data to: Remotely sensed tree height and density explain global gliding vertebrate richness

In vertebrates, gliding evolved as a mode of energy-efficient locomotion
to move between trees. Gliding vertebrate richness is hypothesised to
increase with tree height and decrease with tree density but empirical
evidence for this is scarce, especially at a global scale. Here, we test
the ability of tree height and density to explain species richness of
gliding vertebrates globally compared to richness of all vertebrates,
while controlling for biogeographical and climatic factors. We compiled a
global database of 193 gliding amphibians, mammals and reptiles and
created maps of species richness from extent-of-occurrence range maps. We
paired species richness of gliding vertebrates with spatial estimates of
global tree height and density and biogeographical regions as covariates
to account for ecological differences among global regions. We used
univariate linear and multivariate generalised linear mixed-effect models
to evaluate relationships between species richness and tree height and
density and the interaction between both. We found that richness of all
gliding vertebrate species increased significantly with tree height, while
results for richness of amphibians, mammals and reptiles alone indicated
mixed responses, especially among different biogeographical regions.
Mixed-effect models mirrored these results for richness of all species
combined, while also revealing the mixed responses to tree height and
density of richness of amphibians, mammals and reptiles. Richness of all
vertebrate species – gliding and non-gliding – also increased with tree
height and density but at a lesser rate than richness of gliding
vertebrates indicating a greater influence of forest structure on richness
patterns of gliding vertebrates. Our results support hypotheses stating
that gliding in vertebrates globally evolved in tall forests as
energy-efficient locomotion between trees and provide further evidence for
the importance of forest structure to explain the distribution of gliding
vertebrates.