Latitudinal gradients in body size and sexual size dimorphism in fleas:males drive Bergmann’s pattern

We tested for the effects of latitude and geographic range size(GRS)on body size,leg length,and sexual size dimorphism(SSD)across 103 species offleas,taking into account phylogenetic between-species relationships.When the data on body size were combined for males and females,the positive correlation between body size and latitude,but not GRS,was revealed.When the analysis was restricted to one sex only,the effect of latitude appeared to be non-significant for females,whereas male body size increased with an increase in latitude.Intraspecific body size variation was not associated with either the latitude or the latitudinal span of the geographic range,independently of which data subset was analyzed.No evidence of association between size-independent tibia length and latitude was found for either females,males,or both sexes combined.The degree of SSD decreased with a decrease in latitude but was not affected by GRS.We conclude that macroecological patterns might be manifested differently in males and females.This should be kept in mind while searching for these patterns.

Phylogeography of the common hamster(Cricetus cricetus):paleoclimatic reconstructions of Late Pleistocene colonization

INTRODUCTION Anthropogenic activities and associated factors such as climate change and habitat destruction are causing the ongoing sixth mass extinction on Earth,which is a major characteristic of the Anthropocene.Collectively,these factors pose the most serious environmental threat to the existence of civilization because it is irreversible.More than 500 species of mammals were found to be on the brink of extinction and likely to be lost within 20 years(Ceballos et al.2020).One example is the common hamster Cricetus cricetus(Linnaeus,1758).In 2020,this species was classified as Critically Endangered across its global range by the IUCN Red List(Banaszek et al.2020).The protection status of the common hamster was elevated by 4 levels at once—from Least Concern to Critically Endangered.Although the causes behind the dramatic decline of the species are not fully understood,one may suppose it stems from the negative impact of habitat degradation and even climate change(Banaszek et al.2020).