Hypothermia in foraging king penguins

Handrich, Yves; Bevan, R. M.; Charrassin, Jean‐Benoît; Butler, Patrick J.; Ptz, K.; Woakes, A. J.; Lage, Jochim; Maho, Yvon Le

doi:10.1038/40392

Cited by 138 publications

(117 citation statements)

References 25 publications

(25 reference statements)

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“…The reason why parents do not warm systematically the food before regurgitating it to their chick is not clear, but it is likely related to the length of the preceding foraging trip and the time delay between arrival from sea and chick-feeding. Temperature in abdomen and stomach decreases progressively with the length of a foraging trip 6 . Parents may first feed and digest for themselves but then continue to store (cold) food for the chick until the end of a foraging trip while suppressing digestion 21 .…”

Section: Discussionmentioning

confidence: 99%

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Heterothermy in growing king penguins

et al. 2011

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A drop in body temperature allows significant energy savings in endotherms, but facultative heterothermy is usually restricted to small animals. Here we report that king penguin chicks (Aptenodytes patagonicus), which are able to fast for up to 5 months in winter, undergo marked seasonal heterothermy during this period of general food scarcity and slow-down of growth. They also experience short-term heterothermy below 20 °C in the lower abdomen during the intense (re)feeding period in spring, induced by cold meals and adverse weather. The heterothermic response involves reductions in peripheral temperature, reductions in thermal core volume and temporal abandonment of high core temperature. Among climate variables, air temperature and wind speed show the strongest effect on body temperature, but their effect size depends on physiological state. The observed heterothermy is remarkable for such a large bird (10 kg before fasting), which may account for its unrivalled fasting capacity among birds.

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Section: Discussionmentioning

confidence: 99%

“…4). Similarly, although adult king penguins are known to tolerate heterothermy during deep foraging dives at sea, they apparently do not exhibit notable heterothermy during long-term fasts ashore 5,6 .…”

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confidence: 99%

Heterothermy in growing king penguins

et al. 2011

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“…For this reason they have to return to the water surface after an apneic period to replenish their oxygen stores and unload the accumulated carbon dioxide. The time that these animals can spend underwater between two successive surfacing events is affected by such factors as body mass, metabolic rate and temperature (Kooyman, 1989;Handrich et al, 1997). The latter has been shown to be an important factor in directing the vital activities of sea turtles, which are the major reptilian representatives in marine ecosystems (Mrosovsky, 1980).…”

Section: Introductionmentioning

confidence: 99%

Seasonal variability in voluntary dive duration of the Mediterranean loggerhead turtle, <i>Caretta caretta </i>

Bentivegna¹,

Hochscheid²,

Minucci³

2003

Sci. Mar.

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SUMMARY:We characterised the effect of seasonal fluctuations in water temperature (T w ) on the nonventilatory period (NVP) of Mediterranean loggerhead turtles, Caretta caretta. Ten captive turtles, that were subject to the natural variations in T w found in the Gulf of Naples, dived significantly longer when T w decreased. More than 50% of summer and winter dives lasted between 2 and 10 min; the maximum dive duration (120 min) occurred in winter at a T w of 13°C. The longest NVP coincided with a low level of activity and a lower food consumption. This, and a reduced metabolic rate consequent to acclimatisation to a low T w were likely to have influenced NVP. -En el presente estudio se caracterizó el efecto de la fluctuación estacional en la temperatura del agua (T w ) sobre el periodo no ventilatorio (NVP) de la Tortuga Boba del Mediterráneo, Caretta caretta. Diez tortugas mantenidas en cautividad fueron sometidas a las variaciones naturales de la T w del Golfo de Nápoles, la inmersión fue significativamente más larga cuando la T w decrecía. Más del 50% de las inmersiones, tanto en verano como en invierno, duraron entre 2 y 10 minutos; la inmersión de máxima duración (120 minutos) ocurrió en invierno a una T w de 13°C. El más largo NVP coincidió con el bajo nivel de actividad y el menor consumo de alimento. Ésto, y el reducido grado metabólico como consecuencia de la aclimatación a la baja T w probablemente influyeron en el NVP.Palabras clave: tiempo de inmersión, efecto de temperatura, tortuga marina, apnea.

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“…For instance, barnacle geese decrease their abdominal temperature to reduce total fat consumption during migration and to ease restoration of fat reserves after the migratory flight (11). Penguins tolerate during diving a decrease of T c (measured in the abdomen) to save energy and to extend their aerobic dive limit (5,11,25). A decrease of BMR is also a common response to water deprivation (61), food restriction and starvation (12,15,64,65), or low ambient temperatures (41).…”

Section: Annual Changes Of Mrs and Underlying Causesmentioning

confidence: 99%

Nocturnal hypometabolism as an overwintering strategy of red deer (Cervus elaphus)

Arnold

Ruf

Reimoser

et al. 2004

American Journal of Physiology-Regulatory, Integrative and Comp

126

143

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. Nocturnal hypometabolism as an overwintering strategy of red deer (Cervus elaphus). Am J Physiol Regul Integr Comp Physiol 286: R174-R181, 2004. First published September 11, 2003 10.1152/ajpregu.00593.2002Herbivores of temperate and arctic zones are confronted during winter with harsh climatic conditions and nutritional shortness. It is still not fully understood how large ungulates cope with this twofold challenge. We found that red deer, similar to many other northern ungulates, show large seasonal fluctuations of metabolic rate, as indicated by heart rate, with a 60% reduction at the winter nadir compared with the summer peak. A previously unknown mechanism of energy conservation, i.e., nocturnal hypometabolism associated with peripheral cooling, contributed significantly to lower energy expenditure during winter. Predominantly during late winter night and early morning hours, subcutaneous temperature could decrease substantially. Importantly, during these episodes of peripheral cooling, heart rate was not maintained at a constant level, as to be expected from classical models of thermoregulation in the thermoneutral zone, but continuously decreased with subcutaneous temperature, both during locomotor activity and at rest. This indicates that the circadian minimum of basal metabolic rate and of the set-point of body temperature regulation varied and dropped to particularly low levels during late winter. Our results suggest, together with accumulating evidence from other species, that reducing endogenous heat production is not restricted to hibernators and daily heterotherms but is a common and well-regulated physiological response of endothermic organisms to energetically challenging situations. Whether the temperature of all tissues is affected, or the body shell only, may simply be a result of the duration and degree of hypometabolism and its interaction with body size-dependent heat loss. hypometabolism; hypothermia; winter adaptation; body temperature regulation MANY UNGULATES ARE CAPABLE of withstanding long and cold winters with low food availability. Large body size, excellent fur insulation, and countercurrent heat exchange mechanisms contribute to minimize energy requirements under cold load. However, reduced heat loss alone can hardly explain the substantially lowered metabolic rate (MR) of northern ungulates and the apparently ubiquitous decrease of voluntary food intake during winter (4,13,18,28,35,37,42,44,59,63,72). The search for mechanism to explain reduced energy expenditure during winter has so far produced equivocal results. Studies on white-tailed deer [Odocoileus virginianus (66)], moose [Alces alces (56, 57)], roe deer [Capreolus capreolus (69)], and wapiti [Cervus elaphus nelsoni (49)] reported that animals had reduced MRs during winter. However, other studies failed to find any differences between summer and winter basal metabolic rate (BMR) and concluded that seasonal variations in MR were merely consequences of different activity levels and failures to measure animals within thei...

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Hypothermia in foraging king penguins

Cited by 138 publications

References 25 publications

Heterothermy in growing king penguins

Heterothermy in growing king penguins

Seasonal variability in voluntary dive duration of the Mediterranean loggerhead turtle, <i>Caretta caretta </i>

Nocturnal hypometabolism as an overwintering strategy of red deer (Cervus elaphus)

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