Correlates of species richness in North American bat families

Abstract Aim A near universal truth in North America is that species richness increases from the Arctic Circle to the Central American tropics. Latitude is regarded as a major explanatory variable in species density, although it is only a surrogate for underlying ecological variables. I aimed to elu...

Full description

Bibliographic Details
Published in:Journal of Biogeography
Main Author: Patten, Michael A.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2004
Subjects:
Online Access:http://dx.doi.org/10.1111/j.1365-2699.2004.01087.x
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2699.2004.01087.x
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2699.2004.01087.x
Description
Summary:Abstract Aim A near universal truth in North America is that species richness increases from the Arctic Circle to the Central American tropics. Latitude is regarded as a major explanatory variable in species density, although it is only a surrogate for underlying ecological variables. I aimed to elucidate those underlying ecological variables that are associated with variation in bat species richness across the entire North American continent, providing a portrait of the macroecology of the order Chiroptera and its familial components. Methods I determined the number of bat species recorded for every state in Mexico and the United States, every province or territory in Canada, and every country in Central America. For each of these entities ( n = 99), I also gathered basic data on mean annual precipitation, variation across the year (July vs. January) in mean temperature, mean January temperature, range in elevation (topographic relief), per cent vegetative cover and median latitude. Using a variety of linear regression and model‐fitting techniques, I analysed the strength and direction of the relationship between species richness and environmental variables for the order Chiroptera as a whole and separately for each of four familial groups: Molossidae (free‐tailed bats), Phyllostomidae (New World leaf‐nosed bats), Vespertilionidae (evening bats), and a set of six families (the Desmodontidae, Emballonuridae, Furipteridae, Natalidae, Noctilionidae, and Thyropteridae) represented in North America relatively poorly. Results and main conclusions Save for the Vespertilionidae, species richness of bats increased towards the Panamanian Isthmus. The Phyllostomidae and the set of miscellaneous families are particularly speciose in tropical Central America, with many fewer species occurring through subtropical Mexico into (in some cases) the southernmost United States. The Molossidae extends farther north, sparingly into the middle of the United States. Species density of the Vespertilionidae peaks in central and western ...