Inhibiting ventilatory evaporation produces an adaptive increase in cutaneous evaporation in mourning doves Zenaida macroura

1999 ◽  
Vol 202 (21) ◽  
pp. 3021-3028 ◽  
Author(s):  
T.C. Hoffman ◽  
G.E. Walsberg
Keyword(s):  
Skin Surface ◽  
The Body ◽  
Evaporative Heat Loss ◽  
Evaporative Water ◽  
Zenaida Macroura ◽  
Ambient Temperatures ◽  
Rapid Adjustment ◽  
Mourning Doves ◽  
A Minor ◽  
Cutaneous Evaporation

We tested the hypothesis that birds can rapidly change the conductance of water vapor at the skin surface in response to a changing need for evaporative heat loss. Mourning doves (Zenaida macroura) were placed in a two-compartment chamber separating the head from the rest of the body. The rate of cutaneous evaporation was measured in response to dry ventilatory inflow at three ambient temperatures and in response to vapor-saturated ventilatory inflow at two ambient temperatures. At 35 degrees C, cutaneous evaporation increased by 72 % when evaporative water loss from the mouth was prevented, but no increase was observed at 45 degrees C. For both dry and vapor-saturated treatments, cutaneous evaporation increased significantly with increased ambient temperature. Changes in skin temperature made only a minor contribution to any observed increase in cutaneous evaporation. This indicates that Z. macroura can effect rapid adjustment of evaporative conductance at the skin in response to acute change in thermoregulatory demand.

Cutaneous Water Loss at Rest and Exercise in Two Species of Marsupials

1983 ◽  
Vol 31 (1) ◽  
pp. 93 ◽  
Author(s):  
CJ Bell ◽  
RV Baudinette ◽  
SC Nicol
Keyword(s):  
Heat Loss ◽  
Brushtail Possum ◽  
Evaporative Heat Loss ◽  
Tasmanian Devil ◽  
Ambient Temperatures ◽  
Marsupial Species ◽  
Gland Function ◽  
A Minor ◽  
Cutaneous Evaporation ◽  
And Function

The relative roles of heat storage, evaporative, and non-evaporative heat loss were examined in the brushtail possum, Trichosurus vulpecula, and the Tasmanian devil, Sarcophilus harrisii, during exercise. Rates of water conductance across the skin were also measured at rest and while running at two ambient temperatures. Evaporative heat loss from the general body surface in S. harrisii is a minor contribution to the overall heat balance, and sweat gland function is not apparent. T. vulpecula relies more on heat loss mediated by cutaneous evaporation than from respiratory routes, but changes in cutaneous blood flow are more important than glandular activity in augmenting this response. These results and earlier reports in the literature suggest that the occurrence and function of cutaneous evaporation varies among marsupial species.

Modelling skin surface areas involved in water transfer in the Palmate Newt (Lissotriton helveticus)

2014 ◽  
Vol 92 (8) ◽  
pp. 707-714 ◽  
Author(s):  
Thomas Wardziak ◽  
Laurent Oxarango ◽  
Sébastien Valette ◽  
Laurent Mahieu-Williame ◽  
Pierre Joly
Keyword(s):  
Surface Area ◽  
Skin Surface ◽  
Water Transfer ◽  
The Body ◽  
Body Volume ◽  
3D Analysis ◽  
Evaporative Water ◽  
Surface Areas ◽  
Lissotriton Helveticus ◽  
Palmate Newt

Magnetic resonance imaging (MRI) based 3D reconstructions were used to derive accurate quantitative data on body volume and functional skin surface areas involved in water transfer in the Palmate Newt (Lissotriton helveticus (Razoumovsky, 1789)). Body surface area can be functionally divided into evaporative surface area that interacts with the atmosphere and controls the transepidermal evaporative water loss (TEWL); ventral surface area in contact with the substratum that controls transepidermal water absorption (TWA); and skin surface area in contact with other skin surfaces when amphibians adopt water-conserving postures. We generated 3D geometries of the newts via volume-rendering by a “segmentation” process carried out using a graph-cuts algorithm and a Web-based interface. The geometries reproduced the two postures adopted by the newts, i.e., an I-shaped posture characterized by a straight body without tail coiling and an S-shaped posture where the body is huddled up with the tail coiling along it. As a guide to the quality of the surface area estimations, we compared measurements of TEWL rates between living newts and their agar replicas (reproducing their two postures) at 20 °C and 60% relative humidity. Whereas the newts did not show any physiological adaptations to restrain evaporation, they expressed an efficient S-shaped posture with a resulting water economy of 22.9%, which is very close to the 23.6% reduction in evaporative surface area measured using 3D analysis.

Temperature regulation and water balance of day-active Zophosis congesta beetles in East Africa

1986 ◽  
Vol 2 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Eivin Røskaft ◽  
Karl Erik Zachariassen ◽  
Geoffrey M. O. Maloiy ◽  
John M. Z. Kamau
Keyword(s):  
Body Temperature ◽  
Water Loss ◽  
The Body ◽  
Evaporative Heat Loss ◽  
The Sun ◽  
East African ◽  
Ambient Temperatures ◽  
Cooling Period ◽  
Lethal Level ◽  
Heat Influx

ABSTRACTEast African tenebrionid beetles of the species Zophosis congesta are active on sun-exposed surfaces in dry habitats during the hottest part of the day, when most other animals have retreated to protected areas. They remain on the surface at ambient temperatures up to 65°C which is 15°C above their highest tolerated body temperature. The beetles appear to regulate their body temperature behaviourally. They frequently rest and cool in the shade, and after each cooling period they remain on the sun-exposed surface until the heat influx from the environment has caused the body temperature to rise close to the lethal level. They have relatively low rates of transpiratory water loss, and appear unable to depress their body temperature by means of evaporative heat loss. The rate of metabolic production of water amounts to only about 20% of the rate of transpiratory water loss. Thus, the beetles depend strongly on water intake from dietary sources. The advantage of this type of activity pattern is probably avoidance of predators.

Effect of ambient temperature on development of prostaglandin E1 hyperthermia in the rhesus monkey

1978 ◽  
Vol 44 (5) ◽  
pp. 751-758 ◽  
Author(s):  
C. C. Barney ◽  
R. S. Elizondo
Keyword(s):  
Rhesus Monkey ◽  
Metabolic Rate ◽  
Rhesus Monkeys ◽  
Prostaglandin E1 ◽  
Co2 Production ◽  
Evaporative Heat Loss ◽  
Water Losses ◽  
Evaporative Water ◽  
Ambient Temperatures ◽  
Skin Temperatures

Prostaglandin E1 (PGE1) hyperthermia (fever) was studied at ambient temperatures (Ta) of 18, 27, and 35 degrees C in four male unanesthetized rhesus monkeys (Macaca mulatta) implanted with four guide tubes and one reentrant tube within the preoptic anterior hypothalamus (PO/AH). Rectal, hypothalamic, and mean weighted skin temperatures, O2 consumption, CO2 production, and respiratory and total evaporative water losses were measured continuously before and during PGE1 fever at each Ta. The febrile reponse to PO/AH PGE1 injection was dose responsive and was less at a Ta of 35 degrees C than at the other Ta's. At a Ta of 18 degrees C, fever was brought about primarily by an increase in metabolic rate. At a Ta of 27 degrees C, fever was produced by an increase in metabolic rate and by skin vasoconstriction. At a Ta of 35 degrees C, fever was the result of an increase in metabolic rate and a decrease in sweating evaporative heat loss. At each Ta some generalized skin vasconstriction also occurred. During the plateau phase of the fever, the measured heat losses and gains returned to near control levels. The data indicate that the rhesus monkey shows specific thermoregulatory responses to PO/AH PGE1 injection and would be a good model for the study of thermoregulation during fever in higher primates.

Energetics of the Little Penguin, Eudyptula Minor: Temperature Regulation, the Calorigenic Effect of Food, and Moulting.

1986 ◽  
Vol 34 (1) ◽  
pp. 35 ◽  
Author(s):  
RV Baudinette ◽  
P Gill ◽  
M O'driscoll
Keyword(s):  
Heat Production ◽  
Water Loss ◽  
Thermal Conductance ◽  
Fold Increase ◽  
The Body ◽  
Evaporative Water Loss ◽  
Evaporative Water ◽  
Ambient Temperatures ◽  
Effect Of Food ◽  
Little Penguin

Rates of oxygen consumption and means of augmenting the resultant heat production were studied in the little penguin, Eudyptula minor. Metabolic rates were lower than those predicted for a 1-kg bird, but shivering and an energy response to feeding were both present. The latter effect was independent of ambient temperatures between 2 deg and 22 deg C. The birds have limited ability to dissipate heat by evaporative water loss. About 40% of the total heat production was the maximum amount lost by this route. Cooling of expired respiratory gas provided an effective saving of heat and water. Moulting resulted in a 1.5-fold increase in metabolic rate but rates of evaporative water loss were reduced. The increase in heat production is correlated with increased thermal conductance across the body surface, as new feathers are synthesized, but body temperature is the same as in non-moulting penguins. The results suggest that increased heat loss when the birds are in water might be replaced by calorigenesis associated with the response to feeding, and by shivering, as well as by activity.

scholarly journals Avian thermoregulation in the heat: phylogenetic variation among avian orders in evaporative cooling capacity and heat tolerance

2017 ◽  
Author(s):  
Ben Smit ◽  
Maxine C. Whitfield ◽  
William A. Talbot ◽  
Alexander R. Gerson ◽  
Andrew E. McKechnie ◽  
...  
Keyword(s):  
Heat Tolerance ◽  
Heat Dissipation ◽  
Resting Metabolic Rate ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Evaporative Heat Loss ◽  
Cooling Efficiency ◽  
Evaporative Water ◽  
Cutaneous Evaporation ◽  
Hot Environments

AbstractLittle is known about the phylogenetic variation of avian evaporative cooling efficiency and heat tolerance in hot environments. We quantified thermoregulatory responses to high air temperature (Ta) in ~100-g representatives of three orders: African cuckoo (Cuculus gularis, Cuculiformes), lilac-breasted roller (Coracias caudatus, Coraciiformes), and Burchell’s starling (Lamprotornis australis, Passeriformes). All three species initiated respiratory mechanisms to increase evaporative heat dissipation when body temperature (Tb) approached 41.5°C in response to increasing Ta, with gular flutter observed in cuckoos and panting in rollers and starlings. Resting metabolic rate (RMR) and evaporative water loss (EWL) increased by quantitatively similar magnitudes in all three species, although maximum rates of EWL were proportionately lower in starlings. Evaporative cooling efficiency [defined as the ratio of evaporative heat loss (EHL) to metabolic heat production (MHP)] generally remained below 2.0 in cuckoos and starlings, but reached a maximum of ~3.5 in rollers. The high value for rollers reveals a very efficient evaporative cooling mechanism, and is similar to EHL/MHP maxima for similarly sized columbids which very effectively dissipate heat via cutaneous evaporation. This unexpected phylogenetic variation among the orders tested in the physiological mechanisms of heat dissipation is an important step toward determining the evolution of heat tolerance traits in desert birds.Summary statementWe show that avian evaporative cooling efficiency and heat tolerance display substantial taxonomic variation that are, unexpectedly, not systematically related to the use of panting versus gular flutter processes.

The effects of temperature and relative humidity on the thermoregulatory responses of grouped and isolated neonate chicks

1976 ◽  
Vol 86 (1) ◽  
pp. 35-43 ◽  
Author(s):  
B. H. Misson
Keyword(s):  
Body Size ◽  
Relative Humidity ◽  
Rectal Temperature ◽  
Heat Production ◽  
Water Loss ◽  
Evaporative Heat Loss ◽  
Evaporative Water ◽  
Ambient Temperatures ◽  
Metabolic Heat ◽  
Effects Of Temperature

SUMMARYMeasurements of O2 consumption (Vo2), CO2 production (VCO2) evaporative water loss and rectal temperature (Tr) have been made and metabolic heat production (H), evaporative heat loss (—E) and respiratory quotient (RQ) calculated with individual and groups of 1-day-old chicks at constant ambient temperatures (To) in the range 20—43 °C and 80 or 20% relative humidity (R.H.).Minimal metabolism (10·7 kJ/kgJ/h) occurred at 35 °C.One-day-old chicks act as heterotherms outside the zone of minimal metabolism since neither H nor —E are sufficiently developed mechanisms to maintain homeothermy.Huddling allows chicks to maintain a higher TT at a lower H per unit metabolic body size.Reducing E.H. from 80 to 20% raised the upper temperature survival limit (UTSL) from 41·5 to 43 °C.Panting was initiated when Ta = 38 °C and Tr was between 39·5 and 39·9 °C.

Open-loop gain of evaporative heat loss during radiant heat exposure in the mouse

1982 ◽  
Vol 242 (3) ◽  
pp. R275-R279
Author(s):  
C. J. Gordon
Keyword(s):  
Ambient Temperature ◽  
Heat Exposure ◽  
Radiant Heat ◽  
Open Loop ◽  
Whole Body ◽  
Evaporative Heat Loss ◽  
Loop Gain ◽  
Evaporative Water ◽  
Future Studies ◽  
Ambient Temperatures

Whole-body evaporative water loss of the mouse during radiant heating was determined at ambient temperatures of 20-35 degrees C. The ratio of evaporated to absorbed heat per gram body weight, which is equal to open-loop gain (OLGEHL), increased over sixfold with each 1 degrees C increase in ambient temperature. At 35 degrees C, OLGEHL was equal to 0.8, which implies that the mouse evaporates 80% of the absorbed radiant heat. At 20 degrees C, less than 1% of the absorbed heat is evaporated and the remainder of the heat load is dissipated passively. A previous estimate of OLG for the mouse is similar to the data from this study at an ambient temperature of 35 degrees C. Determining OLG with natural ambient stimulation may make future studies in thermoregulation comparable.

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