scholarly journals Patterns of activity and inactivity in echidnas (Tachyglossus aculeatus) free-ranging in a hot dry climate: correlates with ambient temperature, time of day and season

2002 ◽  
Vol 50 (5) ◽  
pp. 461 ◽  
Author(s):  
P. H. Brice ◽  
G. C. Grigg ◽  
L. A. Beard ◽  
J. A. Donovan
Keyword(s):  
Ambient Temperature ◽  
Activity Patterns ◽  
Time Of Day ◽  
Temperature Sensitive ◽  
Ambient Temperatures ◽  
Radio Transmitters ◽  
Stevenson Screen ◽  
Hot Weather ◽  
Free Ranging ◽  
Temperature Time

Echidnas occur throughout Australia. They exhibit daily fluctuations in body temperature (Tb) and use torpor to various degrees throughout much of their range. Echidnas elsewhere are commonly diurnal except during hot weather. This study used temperature-sensitive radio-transmitters to investigate the activity patterns and temperature relations of echidnas in the relatively hot, dry climate of south-west Queensland with respect to temperature and photoperiod. During activity, echidnas were characterised by rising, but not necessarily high, Tbs. Activity was seen only within an ambient temperature range (as measured in a nearby Stevenson Screen: Tss) of 9–33�C so that activity was seen during the day and at night during the cool weather but only at night in summer. Echidnas used caves, burrows and logs when inactive. Tbs of inactive echidnas declined except when affected by rising ambient temperatures, as determined within these shelters (Ta). In summer, Tbs of echidnas in these shelters changed little or rose with increasing Ta to levels even higher than in active echidnas.Torpor was used by echidnas for periods up to nine days during winter and occasionally for up to one day during summer. Due to the difficulty of identifying the occurrence of torpor from Tb alone in warm conditions, the possibility that echidnas utilise torpor for less than one day remains inconclusive. Nevertheless, at least five bouts of torpor were identified in four (of eight) echidnas during winter/spring and two bouts of torpor from two echidnas in summer.

What's hot and what's not: defining torpor in free-ranging birds and mammals

2001 ◽  
Vol 79 (10) ◽  
pp. 1885-1890 ◽  
Author(s):  
Robert MR Barclay ◽  
Cori L Lausen ◽  
Lydia Hollis
Keyword(s):  
Body Temperature ◽  
The Body ◽  
Temperature Sensitive ◽  
The Past ◽  
Data Loggers ◽  
Temperature Thresholds ◽  
Radio Transmitters ◽  
Species Specific ◽  
Free Ranging ◽  
Lowered Body

With the development of small implantable data loggers and externally attached temperature-sensitive radio transmitters, increasing attention is being paid to determining the thermoregulatory strategies of free-ranging birds and mammals. One of the constraints of such studies is that without a direct measure of metabolic rate, it is difficult to determine the significance of lowered body temperatures. We surveyed the literature and found that many different definitions have been used to discriminate torpor from normothermy. Many studies use arbitrary temperature thresholds without regard for the normothermic body temperature of the individuals or species involved. This variation makes comparison among studies difficult and means that ecologically and energetically significant small reductions in body temperature may be overlooked. We suggest that normothermic body temperature for each individual animal should be determined and that torpor be defined as occurring when the body temperature drops below that level. When individuals' active temperatures are not available, a species-specific value should be used. Of greater value, however, are the depth and duration of torpor bouts. We suggest several advantages of this definition over those used in the past.

Influence of Time of Day On Live Weight Measurements for Feedlot Steers

1990 ◽  
Vol 68 (4) ◽  
pp. 915-918 ◽  
Author(s):  
R. A. Zinn
Keyword(s):  
Ambient Temperature ◽  
Water Intake ◽  
Water Consumption ◽  
Latin Square ◽  
Live Weight ◽  
Time Of Day ◽  
Dramatic Effect ◽  
Feedlot Steers ◽  
Time Period ◽  
Temperature Time

Abstract Three trials were conducted to evaluate the influence of time of day on live weight (LW) measurements of feedlot steers. Trial 1 was initiated November 30, 1988 and involved 15 crossbred steers that were housed and fed individually. Trial 2 was initiated February 28, 1989 and involved 75 crossbred steers that were housed and fed in groups of 5. Trial 3 was initiated June 13, 1989 and was otherwise similar to Trial 2. Weighing times were 0400, 0800 and 1200 with periods between weighing of 7 d. Treatments were assigned to individual steers or pen groups in a replicated 3 × 3 latin square arrangement. In Trial 1, there was a linear decrease (P < .01) in LW averaging 1 kg/h for measurements taken between 0400 and 1200. In Trial 2, both linear (P < .01) and quadratic (P < .05) responses in LW to weighing time were detected. Live weight decreased .75 kg/h between 0400 and 0800, similar to what was observed in Trial 1, but between 0800 and 1200 LW remained unchanged. In Trial 3, only a linear (P < .01) response of LW to time was detected. However, as with Trial 2, the greater rate of decrease in LW appeared to occur between 0400 and 0800 (averaging 1 kg/h). Differences between trials in pattern of water consumption were related to differences in ambient temperature. Time of day had a dramatic effect on LW of feedlot steers. Measurements of LW taken within the later morning hours are more likely to be affected by water intake than measurements taken during the earlier morning time period (0400 to 0800).

Body Mass, Ambient Temperature, Time of Day, and Vigilance in Tufted Titmice

The Auk ◽  
1998 ◽  
Vol 115 (1) ◽  
pp. 221-223 ◽  
Author(s):  
Vladimir V. Pravosudov ◽  
Thomas C. Grubb,
Keyword(s):  
Ambient Temperature ◽  
Body Mass ◽  
Time Of Day ◽  
Temperature Time

A songbird adjusts its heart rate and body temperature in response to season and fluctuating daily conditions

2021 ◽  
Vol 376 (1830) ◽  
pp. 20200213 ◽  
Author(s):  
Nils Linek ◽  
Tamara Volkmer ◽  
J. Ryan Shipley ◽  
Cornelia W. Twining ◽  
Daniel Zúñiga ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Environmental Conditions ◽  
Field Studies ◽  
Weather Extremes ◽  
Ambient Temperatures ◽  
In The Wild ◽  
Radio Transmitters ◽  
Save Energy ◽  
Free Ranging

In a seasonal world, organisms are continuously adjusting physiological processes relative to local environmental conditions. Owing to their limited heat and fat storage capacities, small animals, such as songbirds, must rapidly modulate their metabolism in response to weather extremes and changing seasons to ensure survival. As a consequence of previous technical limitations, most of our existing knowledge about how animals respond to changing environmental conditions comes from laboratory studies or field studies over short temporal scales. Here, we expanded beyond previous studies by outfitting 71 free-ranging Eurasian blackbirds ( Turdus merula ) with novel heart rate and body temperature loggers coupled with radio transmitters, and followed individuals in the wild from autumn to spring. Across seasons, blackbirds thermoconformed at night, i.e. their body temperature decreased with decreasing ambient temperature, but not so during daytime. By contrast, during all seasons blackbirds increased their heart rate when ambient temperatures became colder. However, the temperature setpoint at which heart rate was increased differed between seasons and between day and night. In our study, blackbirds showed an overall seasonal reduction in mean heart rate of 108 beats min −1 (21%) as well as a 1.2°C decrease in nighttime body temperature. Episodes of hypometabolism during cold periods likely allow the birds to save energy and, thus, help offset the increased energetic costs during the winter when also confronted with lower resource availability. Our data highlight that, similar to larger non-hibernating mammals and birds, small passerine birds such as Eurasian blackbirds not only adjust their heart rate and body temperature on daily timescales, but also exhibit pronounced seasonal changes in both that are modulated by local environmental conditions such as temperature. This article is part of the theme issue ‘Measuring physiology in free-living animals (Part I)’.

Responses of free-ranging brownsnakes (Pseudonaja textilis : Elapidae) to encounters with humans

1999 ◽  
Vol 26 (5) ◽  
pp. 689 ◽  
Author(s):  
P. B. Whitaker ◽  
R. Shine
Keyword(s):  
Public Opinion ◽  
Air Temperature ◽  
Cloud Cover ◽  
Weather Conditions ◽  
Time Of Day ◽  
Agricultural Landscapes ◽  
Human Observer ◽  
Eastern Australia ◽  
Radio Transmitters ◽  
Free Ranging

Eastern brownsnakes (Pseudonaja textilis) are large (to 2 m), slender, dangerously venomous elapid snakes that cause significant human mortality. We recorded the responses of free-ranging brownsnakes to 455 close encounters with a human observer, using 40 snakes implanted with miniature radio-transmitters, plus encounters with non-telemetered animals. Our study area (near Leeton in south-eastern Australia) is typical of many of the agricultural landscapes occupied by P. textilis. Contrary to public opinion, the snakes were rarely aggressive. About half of the encounters resulted in the snake retreating, and on most other occasions they relied on crypsis. Snakes advanced towards the observer on only 12 occasions (<3% of encounters) during initial approach, and only three of these advances were offensive. The snakes’ responses to an approach depended on the observer’s appearance (e.g. snakes were more likely to ignore an observer wearing light rather than dark shades of clothing) and behaviour (e.g. snakes were more likely to advance if approached rapidly, and touched immediately). Snakes were more likely to retreat if they were sub-adult rather than adult, if they were warm, or if they had been moving prior to an encounter. Weather conditions (air temperature, wind velocity and cloud cover) also influenced the snakes’ responses, as did season and time of day. The snakes’ response was relatively predictable from information on these factors, enabling us to suggest ways in which people can reduce the incidence of potentially fatal encounters with brownsnakes. ‘Snakes are first cowards, next bluffers, and last of all warriors’ (Pope 1958)

Evaluation of the accuracy of body temperature measurement using external radio transmitters

1996 ◽  
Vol 74 (9) ◽  
pp. 1778-1781 ◽  
Author(s):  
Doris Audet ◽  
Donald W. Thomas
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Field Conditions ◽  
Temperature Sensitive ◽  
External Temperature ◽  
Ambient Temperatures ◽  
Body Temperature Measurement ◽  
Radio Transmitters ◽  
The Difference ◽  
Skin Temperatures

The facultative depression of body temperature represents an important energy strategy for small homeotherms. However, measuring body temperature under field conditions by means other than externally attached temperature-sensitive radio transmitters is problematical. We show that skin temperatures measured by external radio transmitters can accurately reflect core temperature for the bat Carollia perspicillata. We compared body and skin temperatures at three ambient temperatures (Ta; 21, 26, and 31 °C). The difference between skin and body temperature (ΔT) was linearly correlated with Ta and can be predicted by ΔT = 4.396 − 0.118Ta. We argue that external temperature-sensitive radio transmitters can provide a reliable index of core temperature and so permit the study of torpor or facultative hypothermia under field conditions.

scholarly journals Facultative Rest-Phase Hypothermia in Free-Ranging White-Throated Sparrows

The Condor ◽  
2004 ◽  
Vol 106 (2) ◽  
pp. 386-390 ◽  
Author(s):  
Andrew S. Dolby ◽  
John G. Temple ◽  
Laura E. Williams ◽  
Emily K. Dilger ◽  
Katrina M. Stechler ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Significant Negative Correlation ◽  
Published Data ◽  
Temperature Sensitive ◽  
Body Density ◽  
Zonotrichia Albicollis ◽  
Radio Transmitters ◽  
Para Determinar ◽  
Free Ranging ◽  
Skin Temperatures

Abstract Shallow facultative rest-phase hypothermia has been reported in a number of passerine families, but few published data exist about its use by free- ranging birds. We used temperature-sensitive radio- transmitters to determine whether White-throated Sparrows (Zonotrichia albicollis) employ nocturnal hypothermia during winter. We measured skin temperatures of 24 free-ranging sparrows between 13:00 and 14:00 and between 02:00 and 03:00 for each of three days and nights per subject. The average nightly skin- temperature reduction per individual was 3.4 ± 1.0°C (SD). Skin temperature reductions ranged from 0.2°C to 7.0°C among all individuals. There was a significant negative correlation between the magnitude of skin temperature decline and nighttime ambient temperature. Additionally, we found a negative trend between depth of hypothermia and a body density index. Fase de Reposo Hipotérmica Facultativa en Individuos de Zonotrichia albicollis que se Desplazan Libremente Resumen. La fase de reposo facultativa somera ha sido mencionada para un número de familias de paseriformes, pero existen pocos datos publicados sobre su uso por parte de aves que se desplazan libremente. Usamos radio transmisores sensibles a la temperatura para determinar si Zonotrichia albicollis emplea hipotermia nocturna durante el invierno. Medimos la temperatura de la piel de 24 individuos que se desplazan libremente entre las 13:00 y 14:00 y entre las 02:00 y 03:00 durante tres días y tres noches por individuo. La reducción nocturna promedio de la temperatura de la piel por individuo fue 3.4 ± 1.0°C (DE). Las reducciones de la temperatura de la piel variaron entre 0.2°C y 7.0°C considerando todos los individuos. Hubo una correlación negativa significativa entre la disminución de la magnitud de la temperatura de la piel y la temperatura ambiental nocturna. Adicionalmente, encontramos una tendencia negativa entre la profundidad de la hipotermia y el índice de densidad corporal.

The Diurnal and Seasonal Patterns of Grazing of the Red Kangaroo, Macropus-Rufus, and the Western Gray-Kangaroo, Macropus-Fuliginosus

1986 ◽  
Vol 13 (2) ◽  
pp. 113 ◽  
Author(s):  
D Priddel
Keyword(s):  
Pulse Rate ◽  
Time Of Day ◽  
Seasonal Patterns ◽  
Red Kangaroo ◽  
Macropus Rufus ◽  
Before And After ◽  
Radio Transmitters ◽  
Free Ranging

Free-ranging red and western grey kangaroos were fitted with radio transmitters which, when the kangaroo grazed, emitted a pulse rate different to that emitted during other activities. Red kangaroos grazed for between 7.1 and 10.5 h day-1; western grey kangaroos grazed for between 5.9 and 9.8 h day-1 . Red kangaroos grazed for the same amount of time each season despite fourfold changes in pasture biomass. The grazing time of western grey kangaroos was similar in autumn, winter and spring, but decreased by 22% in summer when pasture was most abundant. Males of both species grazed for about an hour longer than females each day. Most grazing (78% for red kangaroos; 86% for western grey kangaroos) took place between sunset and sunrise. The distribution of grazing activity with respect to time of day was bimodal; kangaroos grazed for extensive periods during the 6 h immediately after sunset and again during the few hours before and after sunrise. The time of grazing changed seasonally and these changes were associated with differences in daylength.

Phenology and ecology of hibernation in spotted turtles (Clemmys guttata) near the northern limit of their range

1999 ◽  
Vol 77 (9) ◽  
pp. 1348-1357 ◽  
Author(s):  
Jacqueline D Litzgus ◽  
Jon P Costanzo ◽  
Ronald J Brooks ◽  
Richard E Lee, Jr.
Keyword(s):  
Body Temperature ◽  
Temperature Data ◽  
Temperature Sensitive ◽  
Data Logger ◽  
Ambient Temperatures ◽  
Air Temperatures ◽  
Data Loggers ◽  
Rock Cavern ◽  
Clemmys Guttata ◽  
Radio Transmitters

Using mark-recapture techniques, temperature-sensitive radio transmitters, and miniature temperature data loggers we investigated the hibernation ecology of northern temperate zone spotted turtles (Clemmys guttata) in Georgian Bay, Ontario, over 4 winters (1993-1997). We observed 18 hibernacula that were occupied by 34 turtles; 11 hibernacula were apparently occupied by single turtles, and 7 were used communally by up to 9 individuals. Hibernacula were located in swamps and were of 2 types: sphagnum moss hummock (n = 15) and rock cavern (n = 3). Almost half of the individuals (16 of 34) used the same hibernaculum in at least 2 winters. Turtles entered hibernacula between mid-September and October, when their body temperature was between 12 and 16°C, and exited them in mid to late April, when ambient temperatures ranged between 1 and 5°C. A waterproof temperature data logger attached to a turtle indicated that this turtle was protected from freezing in a thermally stable hibernaculum (body temperature range 0.3-3.9°C) despite highly variable (a 37°C change over 5 days) and low air temperatures (minimum -35°C). Loss of body mass (2%) during hibernation was not significant. We observed no mortality within hibernacula over the 4 winters; however, 3 turtles were destroyed by predators near the hibernacula. These data provide insight into the role of climate in limiting the northern distribution of this species.

Ecology of Frillneck Lizards, Chlamydosaurus-Kingii (Agamidae), in Tropical Australia

1989 ◽  
Vol 16 (5) ◽  
pp. 491 ◽  
Author(s):  
R Shine ◽  
R Lambeck
Keyword(s):  
Activity Patterns ◽  
Common Species ◽  
Body Temperatures ◽  
Wet Season ◽  
Ambient Temperatures ◽  
Air Temperatures ◽  
Highly Correlated ◽  
Vantage Points ◽  
Reproductive Cycles ◽  
Free Ranging

Radiotelemetric monitoring of 18 free-ranging frillneck lizards in Kakadu National Park, combined with dissection of museum specimens, provided extensive data on the natural history and general ecology of this large and spectacular lizard. Activity patterns and reproductive cycles are highly seasonal, with lizards inactive during the drier (and cooler) months of the year. Frillnecks are primarily arboreal and are relatively unselective with regard to the species of tree used except that one common species, Eucalyptus confertyora, is avoided. Telemetered lizards usually clung to branches high in the canopy. During the mating season (November-December), males had larger activity ranges than did females (means of 2.5 vs 0.7 ha) and made longer daily movements (means of 69 vs 23 m). Frillneck lizards bask briefly in the morning, but body temperatures follow ambient temperatures for most of the day. Thermal heterogeneity in the lizards' habitat is low, so opportunities for behavioural regulation (especially reduction) of body temperature are limited. Body temperatures are highly correlated with air temperatures and are often close to 40�C. Female frillnecks are considerably smaller than males, and they produce 4-13 eggs during the wet season. Chlamydosaurus are apparently unique among reptiles in using bipedal locomotion during routine foraging. These lizards are 'sit and wait' predators, descending from arboreal vantage points to seize lepidopteran larvae or massed swarms of hymenopteran or isopteran alates. Many different types of insects are eaten, but vertebrate prey items are rarely taken.

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