Complementarity in Allen's and Bergmann's rules among birds.

Biologists have long noted that endotherms tend to have larger bodies (Bergmann's rule) and shorter appendages (Allen's rule) in colder environments. Nevertheless, many taxonomic groups appear not to conform to these 'rules', and general explanations for these frequent exceptions are currently lacking. Here we note that by combining complementary changes in body and extremity size, lineages could theoretically respond to thermal gradients with smaller changes in either trait than those predicted by either Bergmann's or Allen's rule alone.

Ecological drivers and consequences of torpor in Andean hummingbirds.

Daily torpor allows endotherms to save energy during energetically stressful (e.g. cold) conditions.

Perinatal oxycodone exposure causes long-term sex-dependent changes in weight trajectory and sensory processing in adult mice.

Rationale: In utero opioid exposure is associated with lower weight and a neonatal opioid withdrawal syndrome (NOWS) at birth, along with longer-term adverse neurodevelopmental outcomes and mood disorders. While NOWS is sometimes treated with continued opioids, clinical studies have not addressed if long-term neurobehavioral outcomes are worsened with continued postnatal exposure to opioids. In addition, pre-clinical studies comparing in utero only opioid exposure to continued post-natal opioid administration for withdrawal mitigation are lacking.

Phenotypic responses to climate change are significantly dampened in big-brained birds.

Anthropogenic climate change is rapidly altering local environments and threatening biodiversity throughout the world. Although many wildlife responses to this phenomenon appear largely idiosyncratic, a wealth of basic research on this topic is enabling the identification of general patterns across taxa. Here, we expand those efforts by investigating how avian responses to climate change are affected by the ability to cope with ecological variation through behavioural flexibility (as measured by relative brain size).

Mid-Cenozoic climate change, extinction, and faunal turnover in Madagascar, and their bearing on the evolution of lemurs.

Background: Was there a mid-Cenozoic vertebrate extinction and recovery event in Madagascar and, if so, what are its implications for the evolution of lemurs? The near lack of an early and mid-Cenozoic fossil record on Madagascar has inhibited direct testing of any such hypotheses. We compare the terrestrial vertebrate fauna of Madagascar in the Holocene to that of early Cenozoic continental Africa to shed light on the probability of a major mid-Cenozoic lemur extinction event, followed by an "adaptive radiation" or recovery. We also use multiple analytic approaches to test competing models of lemur diversification and the null hypothesis that no unusual mid-Cenozoic extinction of lemurs occurred.

Defensive fruit metabolites obstruct seed dispersal by altering bat behavior and physiology at multiple temporal scales.

The paradoxical presence of toxic chemical compounds in ripe fruits represents a balance between plant enemies and allies: chemical traits can defend seeds against antagonistic herbivores, seed predators, or fungal pathogens, but also can impose costs by repelling mutualistic seed dispersers, although the costs are often difficult to quantify. Seeds gain fitness benefits from traveling far from the parent plant, as they can escape from parental competition and elude specialized herbivores as well as pathogens that accumulate on adult plants. However, seeds are difficult to follow from their parent plant to their final destination.

Common Noctule Bats Are Sexually Dimorphic in Migratory Behaviour and Body Size but Not Wing Shape.

Within the large order of bats, sexual size dimorphism measured by forearm length and body mass is often female-biased. Several studies have explained this through the effects on load carrying during pregnancy, intrasexual competition, as well as the fecundity and thermoregulation advantages of increased female body size. We hypothesized that wing shape should differ along with size and be under variable selection pressure in a species where there are large differences in flight behaviour.

Fruit secondary compounds mediate the retention time of seeds in the guts of Neotropical fruit bats.

Plants often recruit frugivorous animals to transport their seeds; however, gut passage can have varying effects on plant fitness depending on the physical and chemical treatment of the seed, the distance seeds are transported, and the specific site of deposition. One way in which plants can mediate the effects of gut passage on fitness is by producing fruit secondary compounds that influence gut-retention time (GRT). Using frugivorous bats (Carollia perspicillata: Phyllostomidae) and Neotropical plants in the genus Piper, we compared GRT of seeds among five plant species (Piper colonense, Piper peltatum, Piper reticulatum, Piper sancti-felicis, and Piper silvivagum) and investigated the role of fruit amides (piperine, piplartine and whole fruit amide extracts from P.