Metabolic adjustments to winter severity in two geographically separated great tit (Parus major) populations.

Understanding the potential limits placed on organisms by their ecophysiology is crucial for predicting their responses to varying environmental conditions. A main hypothesis for explaining avian thermoregulatory mechanisms is the aerobic capacity model, which posits a positive correlation between basal (basal metabolic rate [BMR]) and summit (M) metabolism. Most evidence for this hypothesis, however, comes from interspecific comparisons, and the ecophysiological underpinnings of avian thermoregulatory capacities hence remain controversial.

Great tits (Parus major) in a west European temperate forest show little seasonal variation in metabolic energy requirements.

Understanding how birds annually allocate energy to cope with changing environmental conditions and physiological states is a crucial question in avian ecology. There are several hypotheses to explain species' energy allocation. One prominent hypothesis suggests higher energy expenditure in winter due to increased thermoregulatory costs.

Biophysical models accurately characterize the thermal energetics of a small invasive passerine bird.

Effective management of invasive species requires accurate predictions of their invasion potential in different environments. By considering species' physiological tolerances and requirements, biophysical mechanistic models can potentially deliver accurate predictions of where introduced species are likely to establish. Here, we evaluate biophysical model predictions of energy use by comparing them to experimentally obtained energy expenditure (EE) and thermoneutral zones (TNZs) for the common waxbill , a small-bodied avian invader.

Seasonal variation in thermoregulatory capacity of three closely related Afrotropical Estrildid finches introduced to Europe.

A species' potential geographical range is largely determined by how the species responds physiologically to its changing environment. It is therefore crucial to study the physiological mechanisms that species use to maintain their homeothermy in order to address biodiversity conservation challenges, such as the success of invasions of introduced species. The common waxbill Estrilda astrild, the orange-cheeked waxbill E.

Rising from the ashes: resurrection of the Malagasy chameleons Furcifer monoceras and F. voeltzkowi (Squamata: Chamaeleonidae), based on micro-CT scans and external morphology.

The taxonomy of the Malagasy chameleon Furcifer rhinoceratus (Gray, 1845) is poorly resolved. The aim of this study is to clarify the taxonomic status of Chamaeleon voeltzkowi Boettger, 1893 and Chamaeleon monoceras Boettger, 1913 both only known from single or very few specimens mostly collected more than 100 years ago and currently considered as synonyms of Furcifer rhinoceratus. Using osteological data from micro-X-ray computed tomography (micro-CT) combined with traditional morphological characters and morphometrics we resurrect both taxa from the synonymy of F.