scholarly journals Heterothermy in a Small Passerine: Eastern Yellow Robins Use Nocturnal Torpor in Winter

2021 ◽  
Vol 9 ◽  
Author(s):  
Yaara Aharon-Rotman ◽  
John F. McEvoy ◽  
Christa Beckmann ◽  
Fritz Geiser

Torpor is a controlled reduction of metabolism and body temperature, and its appropriate use allows small birds to adapt to and survive challenging conditions. However, despite its great energy conservation potential, torpor use by passerine birds is understudied although they are small and comprise over half of extant bird species. Here, we first determined whether a free-living, small ∼20 g Australian passerine, the eastern yellow robin (Eopsaltria australis), expresses torpor by measuring skin temperature (Ts) as a proxy for body temperature. Second, we tested if skin temperature fluctuated in relation to ambient temperature (Ta). We found that the Ts of eastern yellow robins fluctuated during winter by 9.1 ± 3.9°C on average (average minimum Ts 30.1 ± 2.3°C), providing the first evidence of torpor expression in this species. Daily minimum Ts decreased with Ta, reducing the estimated metabolic rate by as much as 32%. We hope that our results will encourage further studies to expand our knowledge on the use of torpor in wild passerines. The implications of such studies are important because species with highly flexible energy requirements may have an advantage over strict homeotherms during the current increasing frequency of extreme and unpredictable weather events, driven by changing climate.

2021 ◽  
pp. 102973
Author(s):  
M.K. Oosthuizen ◽  
G. Robb ◽  
A. Harrison ◽  
A. Froneman ◽  
K. Joubert ◽  
...  

1991 ◽  
Vol 77 (1) ◽  
pp. 41-47
Author(s):  
A. J. Allsopp ◽  
Kerry A. Poole

AbstractThe effects of hand immersion on body temperature have been investigated in men wearing impermeable NBC clothing. Six men worked continuously at a rate of approximately 490 J.sec−1 in an environmental temperature of 30°C. Each subject was permitted to rest for a period of 20 minutes when their aural temperature reached 37.5°C, and again on reaching 38°C, and for a third time on reaching 38.5°C (three rest periods in total). Each subject completed three experimental conditions whereby, during the rest periods they either: a.Did not immerse their hands (control).b.Immersed both hands in a water bath set at 25°c.c.Immersed both hands in water at 10°C.Physiological measures of core temperature, skin temperature and heart rate were recorded at intervals throughout the experiment.Measures of mean aural temperature and mean skin temperature were significantly (P<0.05) reduced if hands were immersed during these rest periods, compared to non immersion. As a result, the total work time of subjects was extended when in the immersed conditions by some 10–20 minutes within the confines of the protocol.It is concluded that this technique of simple hand immersion may be effective in reducing heat stress where normal routes to heat loss are compromised.


1984 ◽  
Vol 57 (6) ◽  
pp. 1738-1741 ◽  
Author(s):  
T. G. Waldrop ◽  
D. E. Millhorn ◽  
F. L. Eldridge ◽  
L. E. Klingler

Respiratory responses to increased skin temperatures were recorded in anesthetized cerebrate and in unanesthetized decerebrate cats. All were vagotomized, glomectomized, and paralyzed. Core body temperature and end-tidal Pco2 were kept constant with servoncontrollers. Stimulation of cutaneous nociceptors by heating the skin to 46 degrees C caused respiration to increase in both cerebrate and decerebrate cats. An even larger facilitation of respiration occurred when the skin temperature was elevated to 51 degrees C. However, respiration did not increase in either group of cats when the skin was heated to 41 degrees C to activate cutaneous warm receptors. The phenomenon of sensitization of nociceptors was observed. Spinal transection prevented all the respiratory responses to cutaneous heating. We conclude that noxious, but not nonnoxious, increases in skin temperature cause increases in respiratory output.


2017 ◽  
Vol 12 (5) ◽  
pp. 662-667 ◽  
Author(s):  
Matthijs T.W. Veltmeijer ◽  
Dineke Veeneman ◽  
Coen C.C.W. Bongers ◽  
Mihai G. Netea ◽  
Jos W. van der Meer ◽  
...  

Purpose:Exercise increases core body temperature (TC) due to metabolic heat production. However, the exercise-induced release of inflammatory cytokines including interleukin-6 (IL-6) may also contribute to the rise in TC by increasing the hypothalamic temperature set point. This study investigated whether the exercise-induced increase in TC is partly caused by an altered hypothalamic temperature set point.Methods:Fifteen healthy, active men age 36 ± 14 y were recruited. Subjects performed submaximal treadmill exercise in 3 randomized test conditions: (1) 400 mg ibuprofen and 1000 mg acetaminophen (IBU/APAP), (2) 1000 mg acetaminophen (APAP), and (3) a control condition (CTRL). Acetaminophen and ibuprofen were used to block the effect of IL-6 at a central and peripheral level, respectively. TC, skin temperature, and heart rate were measured continuously during the submaximal exercise tests.Results:Baseline values of TC, skin temperature, and heart rate did not differ across conditions. Serum IL-6 concentrations increased in all 3 conditions. A significantly lower peak TC was observed in IBU/APAP (38.8°C ± 0.4°C) vs CTRL (39.2°C ± 0.5°C, P = .02) but not in APAP (38.9°C ± 0.4°C) vs CTRL. Similarly, a lower ΔTC was observed in IBU/APAP (1.7°C ± 0.3°C) vs CTRL (2.0°C ± 0.5°C, P < .02) but not in APAP (1.7°C ± 0.5°C) vs CTRL. No differences were observed in skin temperature and heart-rate responses across conditions.Conclusions:The combined administration of acetaminophen and ibuprofen resulted in an attenuated increase in TC during exercise compared with a CTRL. This observation suggests that a prostaglandin-E2-induced elevated hypothalamic temperature set point may contribute to the exercise-induced rise in TC.


2012 ◽  
Vol 21 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Fabiane Sebaio ◽  
Érika Martins Braga ◽  
Felipe Branquinho ◽  
Alan Fecchio ◽  
Miguel Ângelo Marini

Parasites may lead bird species to extinction, affect host temporal and spatial population dynamics, alter community structure and alter individuals’ social status. We evaluated blood parasite prevalence and intensity according to bird families and species, among 925 birds that were caught in 2000 and 2001, in the Atlantic Forest in the State of Minas Gerais, Brazil. We applied Giemsa staining to thin blood smears, to detect blood parasites. The birds (n = 15.8%) in 11 families, were infected by at least one parasite genus, especially Muscicapidae (28.3%) and Conopophagidae (25%). Among the 146 infected birds, Plasmodium was detected in all bird families and had the highest prevalence (54.8%). Trypanosoma, Haemoproteus and microfilaria had lower prevalence rates (23.3, 23.3 and 2.1%, respectively). Birds caught during the rainy season were more infected than birds caught during the dry season. The overall low prevalence of blood parasites in birds is similar to the patterns found elsewhere in the Neotropical region.


2016 ◽  
Author(s):  
Alexander Suh ◽  
Sandra Bachg ◽  
Stephen Donnellan ◽  
Leo Joseph ◽  
Jürgen Brosius ◽  
...  

AbstractPasseriformes (“perching birds” or passerines) make up more than half of all extant bird species. Here, we resolve their deep phylogenetic relationships using presence/absence patterns of short interspersed elements (SINEs), a group of retroposons which is abundant in mammalian genomes but considered largely inactive in avian genomes. The resultant retroposon-based phylogeny provides a powerful and independent corroboration of previous indications derived from sequence-based analyses. Notably, SINE activity began in the common ancestor of Eupasseres (passerines excl. the New Zealand wrens Acanthisittidae) and ceased before the rapid diversification of oscine passerines (songbirds). Furthermore, we find evidence for very recent SINE activity within suboscine passerines, following the emergence of a SINE via acquisition of a different tRNA head as we suggest through template switching. We propose that the early evolution of passerines was unusual among birds in that it was accompanied by activity of SINEs. Their genomic and transcriptomic impact warrants further study in the light of the massive diversification of passerines.


2019 ◽  
Author(s):  
Tanja Himmel ◽  
Josef Harl ◽  
Simone Pfanner ◽  
Nora Nedorost ◽  
Norbert Nowotny ◽  
...  

Abstract Background Passerine birds are frequently infected with diverse haemosporidian parasites. While infections are traditionally considered benign in wild birds, recent studies demonstrated mortalities of passerine species due to exo-erythrocytic development of the parasites, which can damage organs in affected hosts. However, exo-erythrocytic development remains insufficiently investigated for most haemosporidian species and thus little is known about the virulence of tissue stages in wild passerine birds. The aim of the present study was to investigate natural haemosporidian infections in deceased Eurasian blackbirds (Turdus merula) and song thrushes (T. philomelos) and to determine parasite burden and associated histological effects.Methods For molecular analysis, blood and tissue samples from 306 thrushes were screened for Plasmodium, Haemoproteus and Leucocytozoon parasites by nested PCR. For the detection of parasite stages in organ samples, tissue sections were subjected to chromogenic in situ hybridization using genus- and species-specific probes targeting the rRNAs of parasites. Exo-erythrocytic parasite load was semi-quantitatively assessed and histological lesions were evaluated in haematoxylin-eosin-stained sections.Results 179 of 277 Eurasian blackbirds and 15 of 29 song thrushes were positive for haemosporidians. Parasites of all three genera were detected, with Plasmodium matutinum LINN1 and P. vaughani SYAT05 showing the highest prevalences. CISH revealed significant differences in exo-erythrocytic parasite burden between lineages in Eurasian blackbirds, with P. matutinum LINN1 frequently causing high parasite loads in various organs that were associated with histological alterations. Song thrushes infected with P. matutinum LINN1 and birds infected with other haemosporidian lineages showed mostly low parasite burdens. Two Eurasian blackbirds infected with Leucocytozoon sp. TUMER01 showed megalomeronts in various organs that were associated with inflammatory reactions and necroses.Conclusion This study suggests that P. matutinum LINN1, a common lineage among native thrushes, regularly causes high exo-erythrocytic parasite burdens in Eurasian blackbirds, which may result in disease and mortalities, indicating its high pathogenic potential. The findings further illustrate that the same parasite lineage may show different levels of virulence in related bird species which should be considered when assessing the pathogenicity of haemosporidian parasite species. Finally, the study provides evidence of virulent Leucocytozoon sp. TUMER01 infections in two Eurasian blackbirds caused by megalomeront formation.


2019 ◽  
Vol 96 (9) ◽  
pp. 896-899
Author(s):  
S. M. Rasinkin ◽  
Viktoriya V. Petrova ◽  
M. M. Bogomolova ◽  
E. P. Gorbaneva ◽  
A. G. Kamchatnikov ◽  
...  

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.


2019 ◽  
Vol 44 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Keiji Hayashi ◽  
Nozomi Ito ◽  
Yoko Ichikawa ◽  
Yuichi Suzuki

Food intake increases metabolism and body temperature, which may in turn influence ventilatory responses. Our aim was to assess the effect of food intake on ventilatory sensitivity to rising core temperature during exercise. Nine healthy male subjects exercised on a cycle ergometer at 50% of peak oxygen uptake in sessions with and without prior food intake. Ventilatory sensitivity to rising core temperature was defined by the slopes of regression lines relating ventilatory parameters to core temperature. Mean skin temperature, mean body temperature (calculated from esophageal temperature and mean skin temperature), oxygen uptake, carbon dioxide elimination, minute ventilation, alveolar ventilation, and tidal volume (VT) were all significantly higher at baseline in sessions with food intake than without food intake. During exercise, esophageal temperature, mean skin temperature, mean body temperature, carbon dioxide elimination, and end-tidal CO2 pressure were all significantly higher in sessions with food intake than without it. By contrast, ventilatory parameters did not differ between sessions with and without food intake, with the exception of VT during the first 5 min of exercise. The ventilatory sensitivities to rising core temperature also did not differ, with the exception of an early transient effect on VT. Food intake increases body temperature before and during exercise. Other than during the first 5 min of exercise, food intake does not affect ventilatory parameters during exercise, despite elevation of both body temperature and metabolism. Thus, with the exception of an early transient effect on VT, ventilatory sensitivity to rising core temperature is not affected by food intake.


Sign in / Sign up

Export Citation Format

Share Document