The Spitzbergen reindeer‐a winter‐dormant ungulate?

Ringberg, Tata

doi:10.1111/j.1748-1716.1979.tb06341.x

Cited by 28 publications

(13 citation statements)

References 18 publications

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“…For example, Bubenik et al (1975) reported constant blood cortisol secretion for seven captive white-tailed deer (O. virginianus) in Ontario. Caribou (Rangifer tarandus) and moose (Alces alces) also had no clear seasonal pattern of cortisol secretion (Franzman et al, 1975;Ringbert, 1979). Although other studies found seasonal variation in ungulate cortisol and FGM levels, the timing of changes is inconsistent with our study.…”

Section: Discussioncontrasting

confidence: 99%

Relationships Among Fecal Lungworm Loads, Fecal Glucocorticoid Metabolites, and Lamb Recruitment in Free-Ranging Rocky Mountain Bighorn Sheep

Millspaugh

Washburn

Brundige

et al. 2005

Journal of Wildlife Diseases

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Most wild Rocky Mountain big-horn sheep (Ovis canadensis canadensis) in northern latitudes are infected with lungworms. Indirect effects of lungworms on bighorn sheep are unknown, but high pulmonary burdens might increase stress (i.e., elevated glucocorticoid levels), and chronic stress could in turn decrease fitness. We hypothesized that high lungworm burdens in Rocky Mountain bighorn ewes increase stress, thereby increasing lamb mortality. To test our hypothesis, one subherd of bighorn sheep in Custer State Park, South Dakota was provided a free-choice loose mineral mix containing the anthelmintic fenbendazole every six weeks from March 1999 to August 2000 to eliminate lungworms; another subherd served as the control. Daily, individually marked ewes were located telemetrically from the ground and uniquely marked animals were observed until they defecated. After the herd moved from the area, fecal samples were collected and stored at Ϫ23 C. A consistent number of samples per season per herd (xϭ16.56Ϯ3.99 samples) were collected. Fecal larval lungworm levels (LPG) in the treatment subherd were lower than levels in the control subherd; however, there was no difference in fecal glucocorticoid metabolite (FGM) levels between the two subherds. Fecal glucocorticoid metabolite levels varied by season in both subherds, with levels in winter lower than during the other three seasons. Lamb:ewe ratios were not different between the control and treatment subherds at the end of summer 1999. In contrast, the treatment group had a lower lamb:ewe ratio at the end of summer 2000 despite having lower LPG. However, this result was attributed to lower ewe production, not lower lamb survival. The LPG levels were not correlated with FGM concentrations; instead, FGM levels might reflect normal seasonal patterns. Other factors, including contagious ecthyma, were more important for determining lamb mortality than LPG and FGM levels during our study. We suggest further experimental work over a longer duration to address these relationships.

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Section: Discussioncontrasting

confidence: 99%

Relationships Among Fecal Lungworm Loads, Fecal Glucocorticoid Metabolites, and Lamb Recruitment in Free-Ranging Rocky Mountain Bighorn Sheep

Millspaugh

Washburn

Brundige

et al. 2005

Journal of Wildlife Diseases

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“…Seasonal changes in cortisol secretion have been reported in males of some other seasonally breeding deer species. Cortisol concentrations have been reported to decline during the rut in white-tailed deer (Bubenik et al 1983), reindeer (Nilssen et al 1985) and axis deer (Chapple et al 1991), while other studies have reported increased concentrations during the rut for red deer (Feher et al 1994), or no change in reindeer (Ringberg 1979) and Eld's deer (Monfort et al 1993). The metabolic and reproductive implications of a seasonal rhythm in basal cortisol concentrations in red deer stags are discussed below.…”

Section: Discussionmentioning

confidence: 99%

Ultradian, circadian and seasonal rhythms in cortisol secretion and adrenal responsiveness to ACTH and yarding in unrestrained red deer (Cervus elaphus) stags

Ingram

Crockford²,

Matthews³

1999

Journal of Endocrinology

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Seasonal changes in the activity and responsiveness of the adrenal gland in red deer (Cervus elaphus) stags were quantified by measuring 24 h endogenous cortisol secretory profiles and plasma cortisol responses to either administration of exogenous ACTH or a standardised stressor during November (period of velvet growth), February (pre-rut), April (mid-rut) and July (post-rut) (southern hemisphere) using a remote blood sampling device (DracPac).Ultradian rhythms in the concentration of plasma cortisol were observed resulting from the episodic secretion of cortisol from the adrenal cortex at a mean rate of 0·8 pulses/h. Circadian rhythms in plasma cortisol concentrations were also found in 11 out of the 20 complete 24 h profiles (mean amplitude, 3·8 1·4 ng/ml).Seasonal rhythms in mean 24 h plasma cortisol concentrations and cortisol pulse parameters were also observed. Mean 24 h plasma cortisol concentrations were higher in November (12·5 1·0 ng/ml) than in February (6·3 1·0 ng/ml), April (4·0 1·0 ng/ml) or July (4·2 1·0 ng/ml). Cortisol pulse height, nadir and amplitude were all significantly higher in November than at other times of the year (P<0·01).Peak cortisol concentrations following infusion of ACTH 1-24 (0·04 IU kg -1 ) were higher (P<0·05) in November (55·8 2·7 ng/ml) and lower (P<0·001) in April (33·7 1·8 ng/ml) than those in February and July (48·7 2·0 ng/ml and 45·4 2·0 ng/ml respectively). The area under the cortisol response curve was significantly smaller (P<0·05) in April (266·6 15·3 ng/ml/ 190 min) than at other times of the year (February, 366·1 15·3 ng/ml/190 min; July, 340·7 15·3 ng/ml/ 190 min and November, 387·8 21·2 ng/ml/190 min).These data demonstrate that the adrenal gland of the red deer stag exhibits ultradian, circadian and seasonal rhythms in activity, and that its responsiveness to ACTH varies with season. November, a period of reproductive quiescence in the southern hemisphere, with new antler growth and rapid weight gain, is associated with higher mean plasma cortisol concentrations and a greater responsiveness to exogenous ACTH. In contrast, the breeding season is associated with lower adrenal activity and responsiveness.

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“…Nevertheless, evidence is accumulating that certain ungulates significantly reduce endogenous heat production to cope with energetically challenging situations (food shortage, harsh climatic conditions) (32). Thus, seasonal fluctuations in metabolic rate and in body temperature (heterothermy) have been described for ungulates with a winter nadir in northern species (32)(33)(34) and with a summer nadir in desert species (35,36). Taking into account these recent advances in ungulate physiology, the zonal bone of Myotragus quite likely reflects seasonal fluctuations in metabolic rate and/or body temperature over an extended juvenile period in response to fluctuating resource conditions on the island.…”

Section: Discussionmentioning

confidence: 99%

Physiological and life history strategies of a fossil large mammal in a resource-limited environment

Köhler

Moyà‐Solà

2009

Proc. Natl. Acad. Sci. U.S.A.

130

116

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Because of their physiological and life history characteristics, mammals exploit adaptive zones unavailable to ectothermic reptiles. Yet, they perform best in energy-rich environments because their high and constant growth rates and their sustained levels of resting metabolism require continuous resource supply. In resourcelimited ecosystems such as islands, therefore, reptiles frequently displace mammals because their slow and flexible growth rates and low metabolic rates permit them to operate effectively with low energy flow. An apparent contradiction of this general principle is the long-term persistence of certain fossil large mammals on energy-poor Mediterranean islands. The purpose of the present study is to uncover the developmental and physiological strategies that allowed fossil large mammals to cope with the low levels of resource supply that characterize insular ecosystems. Long-bone histology of Myotragus, a Plio-Pleistocene bovid from the Balearic Islands, reveals lamellar-zonal tissue throughout the cortex, a trait exclusive to ectothermic reptiles. The bone microstructure indicates that Myotragus grew unlike any other mammal but similar to crocodiles at slow and flexible rates, ceased growth periodically, and attained somatic maturity extremely late by Ϸ12 years. This developmental pattern denotes that Myotragus, much like extant reptiles, synchronized its metabolic requirements with fluctuating resource levels. Our results suggest that developmental and physiological plasticity was crucial to the survival of this and, perhaps, other large mammals on resource-limited Mediterranean Islands, yet it eventually led to their extinction through a major predator, Homo sapiens.islands ͉ artiodactyl ͉ paleohistology ͉ growth rate ͉ metabolism

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The Spitzbergen reindeer‐a winter‐dormant ungulate?

Cited by 28 publications

References 18 publications

Relationships Among Fecal Lungworm Loads, Fecal Glucocorticoid Metabolites, and Lamb Recruitment in Free-Ranging Rocky Mountain Bighorn Sheep

Relationships Among Fecal Lungworm Loads, Fecal Glucocorticoid Metabolites, and Lamb Recruitment in Free-Ranging Rocky Mountain Bighorn Sheep

Ultradian, circadian and seasonal rhythms in cortisol secretion and adrenal responsiveness to ACTH and yarding in unrestrained red deer (Cervus elaphus) stags

Physiological and life history strategies of a fossil large mammal in a resource-limited environment

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