Survival of a native mammalian carnivore, the leopard cat <i>Prionailurus bengalensis</i> Kerr, 1792 (Carnivora: Felidae), in an agricultural landscape on an oceanic Philippine island

Concerns about vulnerability of mammalian carnivores to extinction, especially on small islands, appear to conflict with prior reports of endemic populations of leopard cat Prionailurus bengalensis (Kerr, 1792) surviving in agricultural landscapes on oceanic islands. We investigated the persistence of the Visayan leopard cat (P. b. rabori) in the sugarcane fields on Negros, an oceanic island in central Philippines. A population remained throughout the year at our study site on a sugarcane farm, and reproduction was noted. Non-native rodents form the bulk of the cat diet, followed by reptiles, birds, amphibians, and insects. Prey species identified from the samples commonly occur in agricultural areas in the Philippines. Prey composition did not vary significantly with respect to wet and dry season, or sugarcane harvest cycle. This study provides evidence that an intensively managed agricultural landscape on this oceanic island supports a native obligate carnivore that subsists primarily on exotic rats. This study supports a prior prediction that leopard cats will show flexibility in prey selection on islands with few or no native small mammal prey species, but in this case they do so not by switching to other vertebrates and invertebrates, but rather to exotic pest species of rodents

Testing the island rule: primates as a case study

The island rule states that after island colonization, larger animals tend to evolve reduced body sizes and smaller animals increased sizes. Recently, there has been disagreement about how often, if ever, this rule applies in nature, and much of this disagreement stems from differences in the statistical tests employed. This study shows, how different tests of the island rule assume different null hypotheses, and that these rely on quite different biological assumptions. Analysis and simulation are then used to quantify the biases in the tests. Many widely used tests are shown to yield false support for the island rule when island and mainland evolution are indistinguishable, and so a Monte Carlo permutation test is introduced that avoids this problem. It is further shown that tests based on independent contrasts lack power to detect the island rule under certain conditions. Finally, a complete reanalysis is presented of recent data from primates. When head–body length is used as the measure of body size, reports of the island rule are shown to stem from methodological artefacts. But when skull length or body mass are used, all tests agree that the island rule does hold in primates

Relational contexts in adjustment to pregnancy of HIV-positive women: relationships, social support and personal adjustment

Relational contexts are a central issue in most people's lives, and people usually rely on the support of others in everyday circumstances. Social support, as a relational context, could have a positive influence on personal adjustment, and is particularly relevant in the psychological well-being of HIV patients. Guided by the Convoy Model of social networks, in a sample of 31 HIV-positive pregnant women we try to assess the role of social support and social network in the adjustment to pregnancy. Profile analysis suggests a greater importance of social support provided by the partner and both parents, especially the support provided by the mother. At the same time, it seems to highlight the buffering hypothesis of social support, which could be understood as a protection factor in the adjustment of HIV-infected women' to pregnancy

The island rule: made to be broken?

The island rule is a hypothesis whereby small mammals evolve larger size on islands while large insular mammals dwarf. The rule is believed to emanate from small mammals growing larger to control more resources and enhance metabolic efficiency, while large mammals evolve smaller size to reduce resource requirements and increase reproductive output. We show that there is no evidence for the existence of the island rule when phylogenetic comparative methods are applied to a large, high-quality dataset. Rather, there are just a few clade-specific patterns: carnivores; heteromyid rodents; and artiodactyls typically evolve smaller size on islands whereas murid rodents usually grow larger. The island rule is probably an artefact of comparing distantly related groups showing clade-specific responses to insularity. Instead of a rule, size evolution on islands is likely to be governed by the biotic and abiotic characteristics of different islands, the biology of the species in question and contingency