Background: Evaporation is of significant ecological interest.Evaporation from an animal always results in a decrease in the temperature of the surface from which the evaporation occurs.Therefore,evaporation is a one-...Background: Evaporation is of significant ecological interest.Evaporation from an animal always results in a decrease in the temperature of the surface from which the evaporation occurs.Therefore,evaporation is a one-way transfer which causes heat loss from the organism.Biological evaporation always involves the loss of water which is a vital resource for nearly all biochemical processes.Evaporation is loss of heat via loss of body mass.Methods: The simultaneous determination of energy expenditure and loss of body mass in resting birds allows us to estimate evaporative heat loss.This method includes direct measurements of the energetic equivalent of the loss of body mass as the ratio between heat production,determined by the rate of oxygen consumption and the loss of body mass at various ambient temperatures.Results: The data indicate that evaporation was minimal at lower critical temperature and that the rate of evaporation increased at lower or higher temperatures.Obtained results indicate that passerine and non-passerine species have the ability to change their non-evaporative heat conductance the same number of times(approximately fourfold),and that their abilities in this respect are similar.Conclusions: The novelty of the study resides in the stoichiometric approach to determination of total evaporative water loss.The analysis shows that determinations by stoichiometric approach of total evaporative water loss yielded the values,which fit into the confidence intervals of all equations from literatures.The basal metabolic rate and nonevaporative thermal conductance are fundamental parameters of energetics and determine the level of physiological organization of an endothermic animal.展开更多
Animal populations,with a known history of introduction events,provide opportunities to study the dynamics of how rapid shi s in ecological context a ect behavioral(e.g.,responses to brood parasitism) and life-history...Animal populations,with a known history of introduction events,provide opportunities to study the dynamics of how rapid shi s in ecological context a ect behavioral(e.g.,responses to brood parasitism) and life-history(e.g.,clutch and egg parameters) traits.We studied the European Green nch(Carduelis chloris) introduced to New Zealand,regarding foreign-egg rejection behaviors and also compared their clutch characteristics with data from the source populations in the United Kingdom.Although previously this species had been considered an unsuitable host for the Common Cuckoo(Cuculus canorus),and not impacted by selection pressure associated with brood parasitism,we found that Green nches in our study population were able to eject experimental eggs at low frequencies.In contrast,nest desertion rates were similar in experimentally parasitized and control unmanipulated nests,implying that nest desertion is not an antiparasite adaptation in this species.Contrary to previous studies,we did not nd signi cant di erences in clutch and egg sizes between introduced and source populations.is study emphasizes(1) the importance of using control treatments in studies of host responses to experimental parasitism,(2) including apparently unsuitable hosts of brood parasites,and(3) meta-replicating prior studies to further the process of gaining and validating scienti c knowledge.展开更多
基金the Russian Foundation for Basic Research for longterm support of my research (grants # 12-04-01288 and 16-04-00643)
文摘Background: Evaporation is of significant ecological interest.Evaporation from an animal always results in a decrease in the temperature of the surface from which the evaporation occurs.Therefore,evaporation is a one-way transfer which causes heat loss from the organism.Biological evaporation always involves the loss of water which is a vital resource for nearly all biochemical processes.Evaporation is loss of heat via loss of body mass.Methods: The simultaneous determination of energy expenditure and loss of body mass in resting birds allows us to estimate evaporative heat loss.This method includes direct measurements of the energetic equivalent of the loss of body mass as the ratio between heat production,determined by the rate of oxygen consumption and the loss of body mass at various ambient temperatures.Results: The data indicate that evaporation was minimal at lower critical temperature and that the rate of evaporation increased at lower or higher temperatures.Obtained results indicate that passerine and non-passerine species have the ability to change their non-evaporative heat conductance the same number of times(approximately fourfold),and that their abilities in this respect are similar.Conclusions: The novelty of the study resides in the stoichiometric approach to determination of total evaporative water loss.The analysis shows that determinations by stoichiometric approach of total evaporative water loss yielded the values,which fit into the confidence intervals of all equations from literatures.The basal metabolic rate and nonevaporative thermal conductance are fundamental parameters of energetics and determine the level of physiological organization of an endothermic animal.
基金supported by Human Frontier Science Program awards (RGY69/07 to TG,PC,and MEH and RGY86/12 to TG and MEH)
文摘Animal populations,with a known history of introduction events,provide opportunities to study the dynamics of how rapid shi s in ecological context a ect behavioral(e.g.,responses to brood parasitism) and life-history(e.g.,clutch and egg parameters) traits.We studied the European Green nch(Carduelis chloris) introduced to New Zealand,regarding foreign-egg rejection behaviors and also compared their clutch characteristics with data from the source populations in the United Kingdom.Although previously this species had been considered an unsuitable host for the Common Cuckoo(Cuculus canorus),and not impacted by selection pressure associated with brood parasitism,we found that Green nches in our study population were able to eject experimental eggs at low frequencies.In contrast,nest desertion rates were similar in experimentally parasitized and control unmanipulated nests,implying that nest desertion is not an antiparasite adaptation in this species.Contrary to previous studies,we did not nd signi cant di erences in clutch and egg sizes between introduced and source populations.is study emphasizes(1) the importance of using control treatments in studies of host responses to experimental parasitism,(2) including apparently unsuitable hosts of brood parasites,and(3) meta-replicating prior studies to further the process of gaining and validating scienti c knowledge.
