Hot bats go cold: heterothermy in neotropical bats

2017 ◽  
Vol 95 (12) ◽  
pp. 909-912 ◽  
Author(s):  
Zenon J. Czenze ◽  
Miranda B. Dunbar
Keyword(s):  
Body Temperature ◽  
Central America ◽  
Tropical Forests ◽  
Rectal Temperature ◽  
Environmental Conditions ◽  
Tropical Africa ◽  
Acclimation Period ◽  
Neotropical Bats ◽  
Energy Saving Technique ◽  
Shed Light

Torpor is common in bats, but has historically been viewed as an energy-saving technique reserved for temperate and subarctic climates; however, torpor use is common across several tropical bat families. Central America hosts a great diversity of bats with approximately 150 species, yet data from this area are lacking compared with tropical Africa and Australia. We investigated thermoregulatory responses of bats from neotropical Belize and captured adult bats in the tropical forests of Lamanai Archeological Reserve, Belize. After a 12 h acclimation period, we recorded rectal temperature prior to and after exposing bats to an ambient temperature (Ta) of 7 °C for up to 2 h in an environmental chamber. All 11 species across four families expressed torpor to some degree upon exposure to cool temperatures. Individuals from Vespertilionidae defended the lowest resting body temperature (Tb) and showed the greatest decrease in Tb after acute exposure to low Ta. Our data help to establish a new spectrum of physiological ability for this group of mammals and shed light on the evolution of torpor and heterothermy. We show that energy conservation is important even in warm and energetically stable environmental conditions. Understanding how and why torpor is used in warm climates will help to better define paradigms in physiological ecology.

ADAPTATION OF WHITE MICE (MUS MUSCULUS) TO REPEATED COOLING

1967 ◽  
Vol 45 (3) ◽  
pp. 321-327 ◽  
Author(s):  
David M. Ogilvie
Keyword(s):  
Body Temperature ◽  
Rectal Temperature ◽  
Cold Exposure ◽  
Mus Musculus ◽  
Room Temperature ◽  
The Body ◽  
Progressive Decrease

The effects, on the body temperature of white mice, of repeated short exposures to cold were investigated using two methods of restraint. Animals held in a flattened posture became hypothermic at room temperature, cooled more than five times as fast at −10 °C as mice that could adopt a heat-conserving posture, and continued to cool for some time after they were removed from the cold. With repeated tests, cooling at room temperature decreased, and an improvement in re warming ability was observed. In addition, with lightly restrained mice, the fall in rectal temperature during cold exposure showed a progressive decrease, a phenomenon not observed with severely restrained animals.

scholarly journals Human thermoregulatory responses during serial cold-water immersions

1998 ◽  
Vol 85 (1) ◽  
pp. 204-209 ◽  
Author(s):  
John W. Castellani ◽  
Andrew J. Young ◽  
Michael N. Sawka ◽  
Kent B. Pandolf
Keyword(s):  
Body Temperature ◽  
Rectal Temperature ◽  
Heat Production ◽  
Alternative Explanation ◽  
Cold Water ◽  
Metabolic Heat Production ◽  
Normal Body Temperature ◽  
Repeat Trial ◽  
Metabolic Heat ◽  
Made In

This study examined whether serial cold-water immersions over a 10-h period would lead to fatigue of shivering and vasoconstriction. Eight men were immersed (2 h) in 20°C water three times (0700, 1100, and 1500) in 1 day (Repeat). This trial was compared with single immersions (Control) conducted at the same times of day. Before Repeat exposures at 1100 and 1500, rewarming was employed to standardize initial rectal temperature. The following observations were made in the Repeat relative to the Control trial: 1) rectal temperature was lower and heat debt was higher ( P < 0.05) at 1100; 2) metabolic heat production was lower ( P < 0.05) at 1100 and 1500; 3) subjects perceived the Repeat trial as warmer at 1100. These data suggest that repeated cold exposures may impair the ability to maintain normal body temperature because of a blunting of metabolic heat production, perhaps reflecting a fatigue mechanism. An alternative explanation is that shivering habituation develops rapidly during serially repeated cold exposures.

Wetting and the physiological responses of grain-fed cattle in a heated environment

2004 ◽  
Vol 55 (3) ◽  
pp. 253 ◽  
Author(s):  
John B. Gaughan ◽  
M. Shane Davis ◽  
Terry L. Mader
Keyword(s):  
Heat Stress ◽  
Experimental Design ◽  
Rectal Temperature ◽  
Environmental Conditions ◽  
Dry Matter ◽  
Physiological Responses ◽  
Dry Matter Intake ◽  
Metabolic Responses ◽  
Hot Days ◽  
Carry Over

A controlled crossover experimental design was used to determine the effect of altered water sprinkling duration on heifers subjected to heat stress conditions. Heifers were subjected to 3 days of thermoneutral conditions followed by 3 days of hot conditions accompanied by water sprinkling between 1300 and 1500 h (HOT1–3). Then on the following 2 days (HOT4–5), environmental conditions remained similar, but 3 heifers were sprinkled between 1200 and 1600 h (WET) and 3 were not sprinkled (NONWET). This was followed by a 1-day period (HOT6) in which environmental conditions and sprinkling regimen were similar to HOT1–3. Rectal temperature (RT) was collected hourly, and respiration rate (RR) was monitored every 2 h on HOT Days 2, 4, 5, and 6. Dry matter intake and rate of eating were also determined. Sprinkling reduced RR and RT (P < 0.01) of all heifers during HOT1–3. During HOT4–5, WET heifers had lower (P < 0.05) RT than NONWET from 1300 to 700 h and lower RR from 1400 to 2000 h. Dry matter intake of NONWET heifers was reduced by 30.6% (P < 0.05) during HOT4–5 and by 51.2% on HOT6. On HOT4–5 the dry matter intakes of WET heifers were similar to intakes under thermoneutral conditions. During HOT6, RT was again reduced following sprinkling in all heifers. Comparison of RT and RR of NONWET and WET heifers on HOT1–3 v. HOT6 revealed that under similar environmental conditions, NONWET heifers had increased RT, partially due to carry-over from HOT4–5. However, NONWET heifers had 40% lower feed intake but tended to have lower RR on HOT6 v. HOT1–3. Only RR of WET heifers was greater on HOT6, possibly a result of switching from a 4-h back to a 2-h sprinkling period, while maintaining a 62% greater intake (5.80 v. 3.58 kg/day) than NONWET heifers during this time. Results suggest that inconsistent cooling regimens may increase the susceptibility of cattle to heat stress and elicit different physiological and metabolic responses.

scholarly journals Isolated individuals and groups show opposite preferences toward humidity

2018 ◽  
Author(s):  
Mariano Calvo Martín ◽  
Stamatios C. Nicolis ◽  
Isaac Planas-Sitjà ◽  
Jean-Christophe de Biseau ◽  
Jean-Louis Deneubourg
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Group Level ◽  
Individual Level ◽  
Negative Effect ◽  
Multi Level ◽  
The Individual ◽  
Shed Light ◽  
Selection Of

AbstractCockroaches, like most social arthropods, are led to choose collectively among different alternative resting places. These decisions are modulated by different factors, such as environmental conditions (temperature, relative humidity) and sociality (groups size, nature of communications). The aim of this study is to establish the interplay between environmental conditions and the modulation of the interactions between individuals within a group leading to an inversion of preferences. We show that the preferences of isolated cockroaches and groups of 16 individuals, on the selection of the relative humidity of a shelter are inversed and shed light on the mechanisms involved. We suggest that the relative humidity has a multi-level influence on cockroaches, manifested as an attractant effect at the individual level and as a negative effect at the group level, modulating the interactions.

scholarly journals Infrared thermography to assess thermoregulatory reactions of buffaloes supplemented with antioxidant and dense energy source in summer season

2021 ◽  
Vol 23 (3) ◽  
pp. 243-248
Author(s):  
YALLAPPA M. SOMAGOND ◽  
S. V. SINGH ◽  
ADITYA DESHPANDE ◽  
PARVENDER SHEORAN ◽  
V. P. CHAHAL
Keyword(s):  
Heat Stress ◽  
Body Temperature ◽  
Infrared Thermography ◽  
Rectal Temperature ◽  
Control Group ◽  
Group I ◽  
Close Relationship ◽  
Region Temperature ◽  
Cortisol Levels ◽  
Lower Magnitude

Twenty-four lactating buffaloes were chosen and subsequently divided into 4 groups i.e. group-I (control), group-II (supplemented astaxanthin at 0.25 mg kg-1 BW/day), group-III (prill fat at 100 g day-1), and group-IV (combination). Surface body temperature at different anatomical regions of buffaloes was recorded using infrared thermography (IRT), rectal temperature using a digital thermometer, and cortisol hormone by ELISA kit at the fortnightly interval. Forehead region temperature showed a higher correlation (0.390) with THI compared to other anatomical regions. The change in surface body temperature was positively correlated with THI and cortisol levels. The increase in the IRT temperature at different anatomical sites of buffaloes was at a lower magnitude in treatment groups compared to the control group. Udder surface temperature was higher in peak lactation and high producing buffaloes. Forehead region temperature showed a close relationship with rectal temperature and cortisol levels of buffaloes. According to the research findings, astaxanthin and prill fat can be used in ameliorating heat stress. Infrared thermography (non-invasive method) of the forehead and udder can be used as indicators for measuring the heat stress and production levels of buffaloes, respectively.

scholarly journals The legacy of the extinct Neotropical megafauna on plants and biomes

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Vinicius L. Dantas ◽  
Juli G. Pausas
Keyword(s):  
Central America ◽  
Environmental Conditions ◽  
Plant Defence ◽  
Leaf Size ◽  
Plant Evolution ◽  
Vegetation Patterns ◽  
Plant Defences ◽  
Large Mammal ◽  
Plant Trait ◽  
Historical Distribution

AbstractLarge mammal herbivores are important drivers of plant evolution and vegetation patterns, but the extent to which plant trait and ecosystem geography currently reflect the historical distribution of extinct megafauna is unknown. We address this question for South and Central America (Neotropical biogeographic realm) by compiling data on plant defence traits, climate, soil, and fire, as well as on the historical distribution of extinct megafauna and extant mammal herbivores. We show that historical mammal herbivory, especially by extinct megafauna, and soil fertility explain substantial variability in wood density, leaf size, spines and latex. We also identified three distinct regions (‘‘antiherbiomes’’), differing in plant defences, environmental conditions, and megafauna history. These patterns largely matched those observed in African ecosystems, where abundant megafauna still roams, and suggest that some ecoregions experienced savanna-to-forest shifts following megafauna extinctions. Here, we show that extinct megafauna left a significant imprint on current ecosystem biogeography.

scholarly journals INVESTIGATION OF THE THERMAL STATE OF ATHLETES IN NATURAL HOT CLIMATE

2019 ◽  
Vol 96 (9) ◽  
pp. 896-899
Author(s):  
S. M. Rasinkin ◽  
Viktoriya V. Petrova ◽  
M. M. Bogomolova ◽  
E. P. Gorbaneva ◽  
A. G. Kamchatnikov ◽  
...  
Keyword(s):  
Body Temperature ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Thermal State ◽  
Subjective Evaluation ◽  
Climate Indices ◽  
Hot Climate ◽  
The Cross ◽  
Average Skin ◽  
Average Body

The article presents results of a study of the thermal stability in athletes during specific activities in hot climate. This happened on a training camp at the sports center, located in the district Sredneakhtubinsky of the Volgograd region with the registration of climate indices. The study was conducted in July at an effective temperature +44,6° - +45,4°C. The study involved 6 athletes, representatives of athletics, sports category on the following candidate for master of sports. During the endurance, training (cross) in athletes showed a significant increase in the rectal temperature (RT), average skin temperature (AST), average body temperature (ABT) against the background of the gain in the heart rate. During the training as "repeated cuts", the increase in indices of the thermal state in athletes also persisted, but their values were significantly lower than on the cross. The comparison of the dynamics of indices of the thermal state with the level of sports skills of each athlete showed the following features: the smallest gain in the rectal temperature, average skin temperature and average body temperature observed in cross-country race was observed in sportsman, whose level of training coach the evaluated as a minimal in the group. The highest gain in indices of the thermal state at the cross happened in the athlete with an average fitness level. Optimal gain in such indices as RT, AST and ABT was observed in the most prepared athlete. There was revealed a high level of adaptationness of athletes to the exposure to high temperatures. This is confirmed by the data of the evaluation of dynamics of subjective evaluation of warmth sense modality in athletes during the study period.

Effect of continuous cold exposure on nocturnal body temperatures of man

1959 ◽  
Vol 14 (1) ◽  
pp. 43-45 ◽  
Author(s):  
M. B. Kreider ◽  
P. F. Iampietro ◽  
E. R. Buskirk ◽  
David E. Bass
Keyword(s):  
Body Temperature ◽  
Cold Stress ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Cold Exposure ◽  
Control Period ◽  
Cold Period ◽  
Body Temperatures ◽  
Temperature Responses

Effects of continuous cold stress on 24-hour patterns of body temperature were studied in five men. Cold stress consisted in living at 15.6℃ (60℉) for 14 days wearing only shorts. The cold period was preceded and followed by 2 weeks at 26.7℃ (80℉). Activity (minimal) and diet were the same for all periods. One blanket was used at night. Rectal temperature (Tr) and skin temperature (Ts) were measured. Tr during sleep fell more rapidly and to lower values during cold exposure (35.6℃) than during the control period (36.1℃). Ts during sleep was slightly lower in the cold than in the control period; also, Ts did not exhibit the gradual drop characteristic of sleep in the control period. Comparison of Tr and Ts between early and later cold days revealed the following differences: a) nocturnal Tr fell to lower levels on the later cold days; b) nocturnal toe temperatures were 15℃ (27℉) higher on the later cold days. The arch temperatures followed the same pattern as the toes. No significant differences were found in daytime temperatures between early and later cold days. The data suggest that evidence for acclimatization to cold in terms of altered body temperature responses may be fruitfully sought in responses during rewarming and/or sleep. Submitted on September 19, 1958

V.—Observations on the Body Temperature of some Diving and Swimming Birds

1913 ◽  
Vol 32 ◽  
pp. 19-35 ◽  
Author(s):  
Sutherland Simpson
Keyword(s):  
Body Temperature ◽  
Rectal Temperature ◽  
The Body ◽  
Orkney Islands ◽  
Cayuga Lake ◽  
Firth Of Forth

SUMMARYObservations were made on the body temperature of a large number of diving and swimming birds of eighteen different species in the Orkney Islands and Firth of Forth, Scotland, and on and around Cayuga Lake, N.Y., U.S.A., immediately after they were killed by shooting.1. In all the species examined, where the sex was determined, it was found that the rectal temperature of the male was slightly below that of the female.2. Of the orders examined the highest temperatures were found in the Longipennes and the lowest in the Tubinares. When arranged according to body temperature the series does not run parallel with the zoological series.In conclusion, I wish to express my indebtedness to Dr H. D. Reed and Dr A. H. Wright for help in identifying the specimens obtained from Cayuga Lake and the surrounding district.

Cholecystokinin reduces body temperature in vehicle- but not capsaicin-pretreated rats

1992 ◽  
Vol 263 (6) ◽  
pp. R1215-R1221 ◽  
Author(s):  
E. H. South
Keyword(s):  
Food Intake ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Rectal Temperature ◽  
Neural Substrates ◽  
Systemic Administration ◽  
Capsaicin Application ◽  
Presence And Absence ◽  
Sensory Fibers ◽  
Maximal Suppression

Systemic administration of cholecystokinin C-terminal octapeptide (CCK-8) decreases body temperature. However, it remains unclear whether reduction of body temperature is concomitant with suppression of food intake at CCK-8 doses that approach physiological levels. We examined rectal temperature after intraperitoneal CCK-8, 4 micrograms/kg, both in the presence and absence of a preferred food. We found that rectal temperature was significantly reduced by CCK-8 in both conditions and that the reduction of temperature coincided with the time of maximal suppression of food intake by CCK-8. In rats pretreated systemically with 25 or 175 mg/kg of the sensory neurotoxin capsaicin, both suppression of food intake and reduction of body temperature were significantly attenuated or abolished. The 25 mg/kg capsaicin treatment did not alter corneal chemosensitivity or the ability of rats to maintain normothermia at elevated ambient temperature, suggesting that capsaicin damage to neural substrates mediating CCK-8-induced reduction of body temperature 1) did not generalize to cephalic or peripheral warm-sensitive structures, and 2) was limited to fine sensory fibers accessible to intraperitoneal capsaicin application.

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