The evolution of sociality in small,carnivorous marsupials: the lek hypothesis revisited

One of the few mammal species reported to have a mating system of lek promiscuity is the tree-hollow nesting marsupial, the agile antechinus, Antechinus agilis. Past conclusions about its mating system have been based on seasonal changes in social group size, sex-specific nest switching and space use. Thermoregulation has also been suggested as an explanation for variation in social behaviour in this species and its relatives. We tested predictions of the lekking and thermoregulation hypotheses to explain sociality in cavity nesting antechinuses using published data, and new data on brown and subtropical antechinuses. We found that across four species, social group size is negatively correlated with daily minimum temperature, but not with timing of breeding. Females have a matrilineal fission–fusion social system, which continues during the brief mating season, and males range increasingly further throughout their lives, contacting as many females as possible in nests. Males show no indication of fission–fusion sociality. All evidence in species other than A. agilis, and some data on A. agilis, indicate a mating system of scramble polygyny, and not lek promiscuity. We conclude that across species, thermoregulation is the main reason for seasonal variation in nesting group size in both sexes.     

Trophic structure of fish communities in mangrove systems subject to different levels of anthropogenic intervention,Tropical Eastern Pacific,Colombia

Environmental Science and Pollution Research - Mangroves are important ecosystems of tropical and subtropical shorelines. Anthropogenic activity decreases their habitat quality, affecting...     

Silicon nanoparticles decrease arsenic translocation and mitigate phytotoxicity in tomato plants

Environmental Science and Pollution Research - In this study, we simulate the irrigation of tomato plants with arsenic (As)-contaminated water (from 0 to 3.2 mg L?1) and investigate...     

Current controversies in prenatal diagnosis 1: NIPT for chromosome abnormalities should be offered to women with low a priori risk

In its successful annual cycle of controversies and debates, the International Society of Prenatal Diagnosis and Therapy once again addressed non-invasive prenatal testing (NIPT) by following up on the 2013 controversy, ‘Should non-invasive DNA testing be the standard screening test for Down syndrome in all pregnant women’? with the proposition, ‘NIPT for chromosomel abnormalities should be offered to women with low a priori risk’. © 2014 John Wiley & Sons, Ltd.