Area and distance from mainland affect in different ways richness and phylogenetic diversity of snakes in Atlantic Forest coastal islands

Authors

José Thales da Motta Portillo, Universidade Estadual Paulista “Júlio de Mesquita Filho”
Lilian Sayuri Ouchi-Melo, CUNY City College
Lucas Batista Crivellari, Universidade Federal do Paraná
Thiago Alves Lopes de Oliveira, Universidade Federal do ABC
Ricardo J. Sawaya, Universidade Federal do ABC
Leonardo da Silva Duarte, Universidade Federal do Rio Grande do Sul

Document Type

Article

Publication Date

3-14-2019

Abstract

Aim: The Theory of Island Biogeography posits that ecological and evolutionary processes regulate species richness of isolated areas. We assessed the influences of an island area and distance from the mainland on species richness, phylogenetic diversity, and phylogenetic composition of snakes on coastal islands.

Location: Coastal islands of the megadiverse Atlantic Forest in southeastern Brazil.

Methods: We compiled the species composition of 17 coastal islands in southeastern Brazil. Species richness and phylogenetic diversity were calculated for each island. Phylogenetic composition was measured using principal coordinates of phylogenetic structure. We then employed generalized linear models to test the influence of area and distance from the mainland on the diversity metrics.

Results: We found a prominent influence of area on species richness, whereas phylogenetic diversity was more affected by distance from the mainland. Snake clades were distinctly associated with area and distance. The Boidae family was associated with nearer and larger islands, whereas Elapidae was broadly distributed. Distance from the mainland was associated with the distribution of Dipsadidae, whereas Colubridae was influenced by both the area and distance. The Viperidae family attained higher values of phylogenetic diversity in smaller and more remote islands.

Main Conclusions: This island system conserved a considerable piece of snake richness from southeastern Brazil, including island endemic species. Area and distance from the mainland were important drivers of snake diversity in the Atlantic Forest coastal islands. However, these predictors affected the different components of diversity in different ways. Phylogenetic composition analysis enables us to understand how basal nodes contributed to high levels of phylogenetic diversity on smaller and farther islands regardless of the decrease in species richness.

Comments

This article was originally published in Ecology and Evolution, available at DOI: 10.1002/ece3.5019.

This is an open access article under the terms of the Creative Commons Attribution License (CC BY 4.0)