Abstract

Aim:  Ecological niches are complex and the product of interactions with biotic and abiotic environments across the entire geographic range of species.  One recent distinction is between Grinnellian niche characteristics that reflect influences at large spatial scales such as climate and Eltonian niche characteristics that reflect influences at the local level such as distribution of resources and how they are shared among species.  Aims of this research were to estimate Grinnellian and Eltonian niche characteristics of phyllostomid bats distributed throughout the Atlantic Forest, examine degree of phylogenetic non-independence of distribution and niche characteristics, and estimate relative contribution of niche characteristics to distribution of bats across this large Neotropical region.\

Location:  The Atlantic Forest

Taxon: Phyllostomid bats

Methods:  Canonical correlation analysis was used to characterize association between Grinnellian and Eltonian niche characteristics.  Phylogenetic non-independence was estimated with phylogenetic eigenvector regression.  Variation partitioning was used to distinguish relative contributions of different niche characteristics to distribution of bats.

Results:  Grinnellian and Eltonian niche characteristics were strongly and significantly associated.  Phylogenetic signal was weak for Grinnellian and strong for Eltonian niche characteristics.  Both suites accounted for significant unique variation in distribution of phyllostomid bats in the Atlantic Forest.  Grinnellian niche characteristics accounted for more than five times the variation in distribution than Eltonian characteristics.

Main Conclusions:  Distinct Grinnellian and Eltonian perspectives on the niche provide valuable insights into the distribution of species.  The degree to which these two different set of characteristics account for distribution is likely scale dependent with Grinnellian characteristics more important at geographic spatial scales and Eltonian characteristics more important at local spatial scales.  Grinnellian and Eltonian niches are important corollaries of α- and β- niches and their associated traits and similarities and differences in the two distinct concepts should be better explored across different taxa and geographic domains.

To construct a database on dietary patterns of bats across a number of communities in the Atlantic Forest, I began with a Web of Science search using the terms “Atlantic Forest and Bat and Diet”.  This search was conducted on 3 August 2020.  Based on the studies identified, I examined the literature cited sections of each to obtain additional records.  I also queried each library of each state and national university in the states of Brazil that overlapped the Atlantic Forest.  I examined all theses and dissertations related to bats and perused the literature cited sections of these documents to obtain additional records.  I also included literature discovered serendipitously during this search.  Dietary data from these literature sources resulted from substantive sampling effort, were obtained in all seasons, and were presented in the form of a bat species by dietary item matrix for each of the 35 sites generated from fecal analysis of bats at each site.