scholarly journals Endothermy in African Dung Beetles During Flight, Ball Making, and Ball Rolling

1978 ◽  
Vol 73 (1) ◽  
pp. 65-83 ◽  
Author(s):  
GEORGE A. BARTHOLOMEW ◽  
BERND HEINRICH
Keyword(s):  
Cooling Rate ◽  
Body Mass ◽  
Partial Correlation ◽  
Dung Beetles ◽  
Necessary Condition ◽  
Body Temperatures ◽  
Wing Loading ◽  
Ambient Temperatures ◽  
Ball Rolling ◽  
Competition For Food

1. Body temperatures of diurnal and nocturnal ball-rolling and non ballrolling dung beetles (in particular the genera Scarabaeus, Kheper, Gymnopleurus and Heliocopris) were studied in the field in Kenya. 2. The beetles were conspicuously endothermic during flight, ball making, and ball rolling. When at rest, their body temperatures did not differ significantly from that of their surroundings. They did not always generate high body temperatures while walking. However, they sometimes warmed up prior to walking and subsequently maintained a large difference between body and ambient temperatures. 3. The nocturnal species, S. laevistriatus, was conspicuously endothermic during ball making and ball rolling, often maintaining thoracic temperatures of 40 °C or more in an ambient temperature of 25–26 °C. In this species, the velocity of ball rolling increased linearly with body temperature from 5 cm/sec at 28 °C to 18 cm/sec at 40 °C. 4. The take-off temperatures of dung beetles increased with body mass up to 2.5g. In beetles larger than 2.5g metathoracic temperatures at take-off ranged from 40 to 44 °CC and were independent of mass. 5. Flight temperatures showed essentially the same pattern as take-off temperatures, increasing with mass up to about 42 °C at 2.5 g and being independent of mass thereafter. 6. Both flight and take-off temperatures increased with wing-loading up to about 35 N/m2, but were independent of wing loading from 35 to 65 N/m2. 7. In each of the species for which we had an adequate sample, wing loading increased linearly with body mass. Partial correlation analysis suggests that metathoracic temperature is more dependent on body mass than on wing-loading. 8. During periods of endothermy, metathoracic temperature exceeded prothoracic temperature, and abdominal temperature was lower than that of either the prothorax or metathorax. 9. Cooling rate was inversely related to body mass. The removal of elytra and wings caused the cooling rate to increase by about one-quarter. 10. Elevated body temperatures in dung beetles during terrestrial activity is probably selectively advantageous in competition for food. A high metathoracic temperature is a necessary condition for take-off and flight in the larger species. 11. Mechanisms of heat production and the evidence for thermoregulation are discussed.

Free-ranging Van Gelder’s bat Bauerus dubiaquercus (Chiroptera: Vespertilionidae) preying on dung beetles in southern Mexico

Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pedro A. Aguilar-Rodríguez ◽  
Aline Méndez-Rodríguez ◽  
Sandra M. Ospina-Garcés ◽  
M. Cristina MacSwiney G. ◽  
Yossi Yovel
Keyword(s):  
Aspect Ratio ◽  
Body Mass ◽  
Prey Species ◽  
Dung Beetles ◽  
Forest Edges ◽  
Wing Morphology ◽  
Wing Loading ◽  
Southern Mexico ◽  
Free Ranging ◽  
Wing Aspect Ratio

Abstract We report the first prey species consumed by the free-ranging Van Gelder’s bat Bauerus dubiaquercus. We trapped four pregnant individuals of this species carrying freshly captured dung beetles. We describe the wing morphology and flight descriptors (wing loading and wing aspect ratio) of the species, which presents wings more suitable for capturing insects by aerial hawking, although the evidence suggests that is able to capture dung beetles of nearly 10% of its body mass in flight close to the ground. The species could obtain their prey while foraging on uncluttered pasture near forest edges.

Warm-Up Rates and Body Temperatures in Bees: The Importance of Body Size, Thermal Regime and Phylogeny

1989 ◽  
Vol 147 (1) ◽  
pp. 303-328 ◽  
Author(s):  
G. N. Stone ◽  
P. G. Willmer
Keyword(s):  
Body Mass ◽  
Thermal Environment ◽  
Regression Method ◽  
Lower Body ◽  
Body Temperatures ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thermal Environments ◽  
Phylogenetic Regression ◽  
The Relationship

1. We assess the importance of body mass and the minimum ambient temperature at which foraging occurs in determining the warm-up rates and thoracic temperatures in flight at an air temperature of 22°C of 55 species of bee (Hymenoptera: Apoidea) from six families adapted to a variety of thermal environments. 2. To control for the effects of taxonomic differences in the relationships between these variables, we use multiple regression incorporated in the phylogenetic regression method developed by Grafen (1989). 3. The prediction made by May (1976) that for very small heterotherms warmup rate will correlate positively with body mass is confirmed when the effects of phylogeny and the thermal environment to which the bee is adapted have been controlled for. The relationship between warm-up rate and body mass within the Apoidea is thus not an extension to lower body masses of the relationship found for heterothermic vertebrates. 4. Having controlled for the effects of body mass in our analyses, we demonstrate that bees able to fly at lower ambient temperatures have higher thoracic temperatures and warm-up rates than bees adapted to wanner environments. 5. There is some suggestion that kleptoparasitic bees, being freed from the need to forage in order to provision cells, have lower warm-up rates than provisioning species. 6. The significance of these relationships in the ecology of bees is discussed in relation to studies of body temperatures and warm-up rates in bees and other insects.

scholarly journals Contrasting capabilities of two ungulate species to cope with extremes of aridity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Melinda Boyers ◽  
Francesca Parrini ◽  
Norman Owen-Smith ◽  
Barend F. N. Erasmus ◽  
Robyn S. Hetem
Keyword(s):  
Climate Change ◽  
High Water ◽  
Future Climate Change ◽  
Body Temperatures ◽  
Wet Season ◽  
Trade Off ◽  
Ambient Temperatures ◽  
Mammalian Herbivores ◽  
Dry Seasons ◽  
Connochaetes Taurinus

AbstractSouthern Africa is expected to experience increased frequency and intensity of droughts through climate change, which will adversely affect mammalian herbivores. Using bio-loggers, we tested the expectation that wildebeest (Connochaetes taurinus), a grazer with high water-dependence, would be more sensitive to drought conditions than the arid-adapted gemsbok (Oryx gazella gazella). The study, conducted in the Kalahari, encompassed two hot-dry seasons with similar ambient temperatures but differing rainfall patterns during the preceding wet season. In the drier year both ungulates selected similar cooler microclimates, but wildebeest travelled larger distances than gemsbok, presumably in search of water. Body temperatures in both species reached lower daily minimums and higher daily maximums in the drier season but daily fluctuations were wider in wildebeest than in gemsbok. Lower daily minimum body temperatures displayed by wildebeest suggest that wildebeest were under greater nutritional stress than gemsbok. Moving large distances when water is scarce may have compromised the energy balance of the water dependent wildebeest, a trade-off likely to be exacerbated with future climate change.

Phenological development and seasonal distribution of the rutherglen bug, Nnysius vinitor Bergroth (Hemiptera: Lygaeidae), on various hosts in Victoria, south-eastern Australia

1988 ◽  
Vol 78 (4) ◽  
pp. 673-682 ◽  
Author(s):  
Garrick McDonald ◽  
A. Mark Smith
Keyword(s):  
Rapid Development ◽  
Early Spring ◽  
Common Source ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Polygonum Aviculare ◽  
Developmental Thresholds ◽  
Eastern Australia ◽  
Weed Hosts ◽  
Maximum Temperatures

AbstractPopulations of Nysius vinitor Bergroth were studied from 1979 to 1982 in two weed hosts, Arctotheca calendula and Polygonum aviculare, and eight irrigated sunflower crops in a summer cropping area of northern Victoria, Australia. The spring generation began with the adults colonizing flowering A.calendula plants in September and concluded with the rapid development of late stage nymphs and an exodus of adults from these plants from mid-November to December. Gradual invasion of sunflowers occurred mostly in late December and reached a peak at flowering, after which nymphs appeared. P. aviculare attracted adults from February and hosted a number of overlapping generations until winter. The weed sustained diminishing numbers of adults through the winter, except in 1982, when a further generation produced an early spring peak. Immigrant populations were regarded as a common source of adults for initiating the spring and summer generations. The rate of development of N. vinitor in spring was more rapid than that predicted by phenological simulation based on ambient temperatures and laboratory-derived day-degree estimates. This was attributed to increased body temperatures through absorption of solar radiation, and the simulation model was adjusted by increasing daily minimum and maximum temperatures by 1·3 and 5·5°C for young and older instars, respectively. This suggested that older nymphs have lower developmental thresholds or are better able to optimize body temperatures.

scholarly journals Mathematical modeling shows that ball-rolling dung beetles can use dances to avoid competition

2021 ◽  
Author(s):  
Zhanyuan Yin ◽  
Leif Zinn-Brooks
Keyword(s):  
Mathematical Modeling ◽  
Optimal Strategy ◽  
Rolling Direction ◽  
Dung Beetles ◽  
Time Interval ◽  
Angular Deviation ◽  
Ball Rolling ◽  
Wide Range

Abstract Ball-rolling dung beetles shape a portion of dung into a ball and roll it away from the dung pile for later burial and consumption. These beetles perform dances (rotations and pauses) atop their dung balls in order to choose an initial rolling direction and to correct their rolling direction (reorient). Previous mathematical modeling showed that dung beetles can use reorientation to move away from the dung pile more efficiently. In this work, we study if reorientation can help beetles avoid competition (i.e., avoid having their dung balls captured), and if so, under what circumstances? This is investigated by implementing a model with two different type of beetles, a roller with a dung ball and a searcher which seeks to capture that dung ball. We show that reorientation can help rollers avoid searchers in a wide range of conditions, but that there are some circumstances in which rolling without reorienting can be a beetle's optimal strategy. We also show that rollers can minimize the probability that their dung ball is captured without making precise measurements of the time interval between dances or the angular deviation for dances.

scholarly journals CHROMOSOME STUDIES IN WILD POPULATIONS OF DROSOPHILA MELANOGASTER. II. RELATIONSHIP OF INVERSION FREQUENCIES TO LATITUDE, SEASON, WING-LOADING AND FLIGHT ACTIVITY

Genetics ◽  
1980 ◽  
Vol 95 (1) ◽  
pp. 211-223
Author(s):  
Harrison D Stalker
Keyword(s):  
Drosophila Melanogaster ◽  
Warm Season ◽  
Cold Season ◽  
South Texas ◽  
Temperature Adaptation ◽  
Wing Loading ◽  
Ambient Temperatures ◽  
The North ◽  
Wing Load ◽  
Relationship Of

ABSTRACT In the midwestern and eastern U.S. populations of Drosophila melanogaster, the Standard gene arrangements show higher frequencies in the north than in the south. In a Missouri population, and to a lesser extent in a south Texas population, the frequencies of Standard chromosomes regularly rise during the cold season and drop during the warm season, thus paralleling the north-south frequency differences. In the Missouri population in 1976 and 1978, wild males were tested far their ability to fly to bait at different ambient temperatures. In both years, males flying in nature in the temperature range of 13° to 15° showed significantly higher frequencies of Standard chromosomes than did those flying in the 16° to 28° range. Wild males flying at 13° to 15° also have different tharax/wing proportions and significantly lower wingloading indices than do those flying at 16° to 28°. Moreover, wild flies homozygous Standard in 2R and/or 3R have significantly lower wing-loading indices than flies carrying inversions in these arms. Thus, wild flies with high frequencies of Standard chromosommes are karyotypically northern, are selectively favored during the cold season, have a relatively low wing-load and are most capable of flying at critically low ambient temperatures.—In summary, in Missouri, presence or absence of the common cosmopolitan inversions is an important factor in low temperature adaptation, and at least part of the adaptive mechanism involves control of thorax/wing proportions and thus control of wing-loading.

scholarly journals Body Temperatures in Some Australian Mammals II.Peramelidae

1962 ◽  
Vol 15 (2) ◽  
pp. 386 ◽  
Author(s):  
PR Morrison
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Active Phase ◽  
Temperature Measurements ◽  
Temperature Cycle ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Diurnal Temperature

Body temperature measurements on the short-nosed bandicoot (Thylacis obeaulus) have shown a nocturnal cycle with a range of 1� 2�C and a short active phase at 2200-0400 hr. The bilby or rabbit bandicoot (Macrotis lagoti8) had a sharply defined temperature cycle, with a range of almost 3�C after several months of captivity, during which the day-time resting temperature was progressively lowered from 36� 4 to 34� 2�C. Forced activity raised the diurnal temperature substantially but not to the nocturnal level. Forced activity did not raise the nocturnal level which was similar in the two species (37' O�C). Both species could regulate effectively at an ambient temperature of 5�C, but only Thylaci8 showed regulation at ambient temperatures of between 30 and 40�C.

Parasympathetic influence on heart rate in euthermic and hibernating ground squirrels.

1995 ◽  
Vol 198 (4) ◽  
pp. 931-937 ◽  
Author(s):  
M B Harris ◽  
W K Milsom
Keyword(s):  
Heart Rate ◽  
Ambient Temperature ◽  
Parasympathetic Nervous System ◽  
Ground Squirrels ◽  
Relative Role ◽  
Body Temperatures ◽  
Inotropic Effects ◽  
Ambient Temperatures ◽  
Isolated Hearts ◽  
C 32

The relative role of the parasympathetic nervous system during deep hibernation is enigmatic. Conflicting hypotheses exist, and both sides draw support from investigations of vagal influence on the heart. Recent studies have shown cardiac chronotropic and inotropic effects of parasympathetic stimulation and inhibition in isolated hearts and anesthetized animals at hibernating body temperatures. No studies, however, have demonstrated such occurrences in undisturbed deeply hibernating animals. The present study documents respiratory-related alterations in heart rate during euthermia and hibernation at ambient temperatures of 15, 10 and 5 degrees C mediated by parasympathetic influence. During quiet wakefulness, euthermic squirrels breathed continuously and exhibited a 29% acceleration in heart rate during inspiration. During deep undisturbed hibernation, at 15, 10 and 5 degrees C ambient temperature, animals exhibited an episodic breathing pattern and body temperatures were slightly above ambient temperature. At each temperature, heart rate during the respiratory episode was greater than that during the apnea. The magnitude of this ventilatory tachycardia decreased with ambient temperature, being 108% at 15 degrees C, 32% at 10 degrees C and 11.5% at 5 degrees C. Animals exposed to 3% CO2 at 5 degrees C, which significantly increased ventilation, still exhibited an 11.7% increase in heart rate during breathing. Thus, the magnitude of the ventilation tachycardia was independent of the level of ventilation, at least over the range studied. Inhibition of vagus nerve conduction at 5 degrees C was achieved using localized nerve block. This led to an increase in apneic heart rate and abolished the ventilatory tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Nocturnal Hypothermia in Seasonally Acclimatized Mountain Chickadees and Juniper Titmice

The Condor ◽  
2005 ◽  
Vol 107 (1) ◽  
pp. 151-155 ◽  
Author(s):  
Sheldon J. Cooper ◽  
James A. Gessaman
Keyword(s):  
Body Temperature ◽  
Body Mass ◽  
Energy Savings ◽  
Ambient Temperatures ◽  
Energy Expenditures ◽  
Poecile Gambeli ◽  
Daily Energy ◽  
Para Determinar ◽  
Mountain Chickadees

AbstractWe measured body temperature of Mountain Chickadees (Poecile gambeli) and Juniper Titmice (Baeolophus ridgwayi) at different times of day and under a range of ambient temperatures in order to determine the use of nocturnal hypothermia in seasonally acclimatized small passerines. Our findings show both species used nocturnal hypothermia year-round. Depth of hypothermia was inversely correlated to body mass in Juniper Titmice but not in Mountain Chickadees. In both species, depth of hypothermia did not vary seasonally but nocturnal body temperature was regulated 3–11°C lower than daytime values. Nocturnal energy savings range from 7%–50% in chickadees and from 10%–28% in titmice. These nocturnal energy savings translate into ecologically important reductions in daily energy expenditures for these two species.Hipotermia Nocturna en Individuos de Poecile gambeli y Baeolophus ridgwayi Aclimatados EstacionalmenteResumen. Medimos la temperatura corporal de Poecile gambeli y Baeolophus ridgwayi a diferentes horas del día y en un rango de temperaturas ambientales para determinar el uso de hipotermia nocturna en pequeñas aves paserinas aclimatadas estacionalmente. Nuestros resultados muestran que ambas especies presentaron hipotermia nocturna durante todo el año. La profundidad de la hipotermia estuvo inversamente correlacionada con la masa corporal en B. ridgwayi, pero no en P. gambeli. En ambas especies, la profundidad de la hipotermia no varió estacionalmente, pero la temperatura corporal nocturna estuvo regulada 3–11°C por debajo de los valores diurnos. El ahorro nocturno de energía varió entre 7%–50% en P. gambeli y entre 10%–28% en B. ridgwayi. Estos ahorros nocturnos de energía se tradujeron en reducciones ecológicamente importantes en los gastos diarios de energía para ambas especies.

scholarly journals Testing the heat dissipation limit theory in a breeding passerine

2018 ◽  
Vol 285 (1878) ◽  
pp. 20180652 ◽  
Author(s):  
Jan-Åke Nilsson ◽  
Andreas Nord
Keyword(s):  
Heat Dissipation ◽  
Work Rate ◽  
Body Temperatures ◽  
Limit Theory ◽  
Ambient Temperatures ◽  
Metabolic Heat ◽  
Thermal Window ◽  
Future Reproduction ◽  
Maximum Work ◽  
Males And Females

The maximum work rate of animals has recently been suggested to be determined by the rate at which excess metabolic heat generated during work can be dissipated (heat dissipation limitation (HDL) theory). As a first step towards testing this theory in wild animals, we experimentally manipulated brood size in breeding marsh tits ( Poecile palustris ) to change their work rate. Parents feeding nestlings generally operated at above-normal body temperatures. Body temperature in both males and females increased with maximum ambient temperature and with manipulated work rate, sometimes even exceeding 45°C, which is close to suggested lethal levels for birds. Such high body temperatures have previously only been described for birds living in hot and arid regions. Thus, reproductive effort in marsh tits may potentially be limited by the rate of heat dissipation. Females had lower body temperatures, a possible consequence of their brood patch serving as a thermal window facilitating heat dissipation. Because increasing body temperatures are connected to somatic costs, we suggest that the HDL theory may constitute a possible mediator of the trade-off between current and future reproduction. It follows that globally increasing, more stochastic, ambient temperatures may restrict the capacity for sustained work of animals in the future.

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