Comparisons of thermogenic features in four coexisting songbirds:Is the northward colonized White-browed Laughingthrush different?

Thermogenic features are often invoked to illustrate animal’s colonization,distribution,and response to climate change.To understand why the White-browed Laughingthrush(Pterorhinus sannio)has expanded its distribution to temperate zones in recent years,we compared its thermogenic features with three species of songbirds that cooccur in its newly colonized areas.Thermogenic parameters of these four species were measured under different ambient temperatures,ranging from 0 to 40℃.The results showed that basal metabolic rate(BMR)was 44.5±3.9 mL O2/h in P.sannio,which is lower than predicted value by its body weight.This is also lower than the BMR of both its temperate congener the Plain Laughingthrush(P.davidi)and the montane,similar species Elliot’s Laughingthrush(Trochalopteron elliotii).The thermal neutral zone(TNZ)in P.sannio was 15-35℃,as compared to 10-27.5℃in P.davidi,25-30℃in T.elliotii,and 7.5-32.5℃in the Green-capped Greenfinch(Chloris sinica).Thermal conductance was lowest in P.sannio,with the minimum value lower than the predicted value based on its body weight.Our results showed that the northward-colonizing P.sannio exhibited different thermogenic characteristics compared with its coexisting species in the new habitat,even its congener P.davidi,which shared similar microhabitats to P.sannio.We suggest that researchers further explore the physiological mechanisms of birds’northward expansion.

Survival in spatially variable thermal environments:Consequences of induced thermal defense

As Earth’s climate warms,plants and animals are likely to encounter increased frequency and severity of extreme thermal events,and the ensuing destruction is likely to play an important role in structuring ecological communities.However,accurate prediction of the population-scale consequences of extreme thermal events requires detailed knowledge of the small-scale interaction between individual organisms and their thermal environment.In this study I propose a simple model that allows one to explore how individual-to-individual variation in body temperature and thermal physiology determines what fraction of a population will be killed by an extreme thermal event.The model takes into account the possibility that each individual plant or animal can respond to an event by adjusting its thermal tolerance in proportion to the stress it encounters.When thermal stress is relatively mild,the model shows that a graded physiological response of this sort leads to increased survivorship.However,the model predicts that in more severe events a proportional induced defense can actually reduce survivorship,a counterintuitive possibility that is not predicted by standard theory.The model can easily be tailored to different species and thermal environments to provide an estimate of when,where and how physiology can buffer the effects of climate warming.

Qualitative Experimental Evidences for the Thermal Wave Mechanisms of Temperature Oscillations in Living Tissues

To make it possible for the thermal wave theory on temperature oscillation (TO) effects in living tissues to be founded on the substantial experimental basis, a series of typical decisive experiments in vivo as well as in artificially simulating constructions were carried out. Conclusions obtained including some other scholars' animal experimental results all greatly support the thermal wave viewpoint qualitatively.A few experimental facts used hot to be easily understood from the classical viewpoint are also well reinterpreted. The revealing on the thermal wave mechanisms of TO in living tissues is a brand new discovery and deep insight into this important thermophysiological phenomenon. It may possibly promote new investigations on the corresponding topics in the field of bioheat transfer science.

Landscape effects on the thermotolerance of carabid beetles and the role of behavioral thermoregulation

Physiological thermotolerance and behavioral thermoregulation are central to seasonal cold adaptation in ectothermic organisms.For species with enhanced mobility,behavioral responses may be of greater importance in the cold stress response.Employing the carabid beetles as a study organism,the current study compared physiological thermotolerance and behavioral thermoregulation in carabid species inhabiting cereal fields in different landscape contexts,from fine grain heterogeneous“complex”landscapes to homogenous“simple”landscapes.Physiological thermotolerance was determined via measurement of the CTmin and chill coma temperature.Behavioral responses to cold temperature exposure were determined employing a purpose built arena,and thoracic temperature measured to estimate the efficacy of the behavior as a form of behavioral thermoregulation.Results revealed an influence of landscape composition on the cold tolerance of carabid beetles,although species differed in their sensitivity to landscape intensification.A reduced effect of landscape on the thermotolerance of larger carabid beetles was observed,thought to be the consequence of greater mobility preventing local acclimation to microclimatic variation along the landscape intensification gradient.Investigation into behavioral thermoregulation of the 3 largest species revealed burrowing behavior to be the main behavioral response to cold stress,acting to significantly raise carabid body temperature.This finding highlights the importance of behavioral thermoregulation as a strategy to evade cold stress.The use of behavioral thermoregulation may negate the need to invest in physiological thermotolerance,further offering explanation for the lack of landscape effect on the physiological thermotolerance of larger carabids.