Testing Bergmann's rule and the resource seasonality hypothesis in Malagasy primates using GIS‐based climate data

Abstract

We tested four major hypotheses on the ecological aspects of body mass variation in extant Malagasy strepsirrhines: thermoregulation, resource seasonality/scarcity, resource quality, and primary productivity. These biogeographic hypotheses focus on the ecological aspects of body mass variation, largely ignoring the role of phylogeny for explaining body mass variation within lineages. We tested the independent effects of climate and resource-related variables on variation in body mass among Malagasy primates using recently developed comparative methods that account for phylogenetic history and spatial autocorrelation. We extracted data on lemur body mass and climate variables for a total of 43 species from 39 sites. Climatic data were obtained from the WorldClim database, which is based on climate data from weather stations compiled around the world. Using generalized linear models that incorporate parameters to account for phylogenetic and spatial autocorrelation, we found that diet and climate variables were weak predictors of lemur body mass. Moreover, there was a strong phylogenetic effect relative to the effects of space on lemur body mass in all models. Thus, we failed to find support for any of the four hypotheses on patterns of geography and body mass in extant strepsirrhines. Our results indicate that body mass has been conserved since early in the evolutionary history of each genus, while species diversified into different environmental niches. Our findings are in contrast to some previous studies that have suggested resource and climate related effects on body mass, though these studies have examined this question at different taxonomic and/or geographic scales.

Phylogenetic signal in primate behaviour, ecology and life history

“…Generally, high phylogenetic signal in morphological traits is attributed to their strong correlation with body mass; however, K-values for both male and female body mass were lower than for brain size (male mass: K ¼ 0.707; female mass: K ¼ 0.670). Similarly, a recent study of Malagasy primate body mass found levels of phylogenetic signal that do not differ from the Brownian expectation [38]. Thus, the high phylogenetic signal in brain size cannot be entirely explained by allometry alone.…”

Nocturnal light environments and species ecology: implications for nocturnal color vision in forests

“…Trees used for each analysis are presented in supplementary material Fig.S1. For each comparison, we also calculated Pagel's lambda, which measures the effect of phylogeny in the data, where 0 reflects no phylogenetic influence and 1 reflects a strong phylogenetic signal (Pagel, 1999;Kamilar et al, 2012). We excluded one species (Phodopus sungorus) because it has SWS and LWS pigment co-expression (both pigments present in a single cone) in all cones and no functional color vision (Lukáts et al, 2002).…”

Edge Effects on Morphometrics and Body Mass in Two Sympatric Species of Mouse Lemurs in Madagascar

“…These hypotheses are typically applied to ecological data that operate at the regional or continental scales. For example, Kamilar et al [2012] tested well-known ecological and phylogenetic hypotheses on body mass variations in 43 species of Malagasy strepsirhines. They documented a strong phylogenetic effect, but no ecological effects, on interspecific variations in body mass of the lemurs.…”