Midwinter Emergence in Hibernating Timber Rattlesnakes (<i>Crotalus horridus</i>)

Nordberg, Eric J.; Cobb, Vincent A.

doi:10.1670/14-113

Cited by 19 publications

(28 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Snakes living in the temperate-zone are well-adapted to harsh wintering conditions as they hibernate. During this dormant period, their body temperature is generally lower than during active periods in contrast to plasma corticosterone, which is generally higher during hibernation (Dupoué et al, 2013;Nordberg and Cobb, 2016). Subsequently, it has been assumed that mild winter conditions trigger a state of chronic stress and a decrease of body condition when emerging.…”

Section: Stress In Wild Snakesmentioning

confidence: 99%

Stress bij in het wild en in gevangenschap levende slangen: kwantificatie, gevolgen en het belang van management

Waeyenberge¹,

Aerts²,

Hellebuyck³

et al. 2018

Vlaams Diergeneeskundig Tijdschrift

View full text Add to dashboard Cite

As in other animals, distress and impaired welfare have a deleterious effect on the mental, physical and behavioral health of snakes in the wild and in captivity. Besides anthropogenic disturbance, the availability of food and shelter, the presence of predators, and environmental factors, such as seasonality and climatological changes, are important factors that affect the stress level and subsequent welfare in wild snake populations. In captive snakes, inappropriate management is the most prominent cause of chronic stress and impaired welfare. Chronic stress can be assumed by looking at the snake’s behavior, but there is need for a standardized quantification method to pin-point more accurately (chronic) stress levels. The biomarker suitable in this framework is the level of corticosterone in plasma, feces and shed skin.

show abstract

Section: Stress In Wild Snakesmentioning

confidence: 99%

Stress bij in het wild en in gevangenschap levende slangen: kwantificatie, gevolgen en het belang van management

Waeyenberge¹,

Aerts²,

Hellebuyck³

et al. 2018

Vlaams Diergeneeskundig Tijdschrift

View full text Add to dashboard Cite

show abstract

“…‘Drop‐and‐hold assays’ probably underestimate natural cold tolerance, as natural and slow cooling trajectories (Fig. 2b, Nordberg and Cobb, 2016, 2017) offer considerable time for acclimatization (Kelly and Lee, 1999) or potentially for injury, dehydration or starvation. This issue may never be resolved for squamates, for which survival experiments raise ethical issues.…”

Section: Question I Which Depth Minimizes Risk Of Cold Injury or Death?mentioning

confidence: 99%

“…While attempting to parameterize (e.g., lethal temperature) these simulations, we discovered that the required behavioural, ecological and physiological data – as well as field data required to test their predictions – often do not exist or are of dubious relevance. These issues likely reflect the difficulty of determining depth, temporal T b profiles and behaviour of overwintering ectotherms (Sinclair, 2001a), the logistical challenge of quantifying time series of physiological responses to chronic rather than acute temperature exposures (Huang and Tu, 2008; Sinclair et al ., 2015), and the incomplete information on cues (e.g., environmental, innate clocks) used for mid‐winter emergence (Heath, 1962; Bishop and Echternacht, 2004; Lutterschmidt et al ., 2006; Nordberg and Cobb, 2016). Our simulations thus rely on unvalidated parameter values, but nonetheless provide “approximate answers” (Tukey, 1962) to ecologically relevant questions.…”

Section: Introductionmentioning

confidence: 99%

Three questions about the eco‐physiology of overwintering underground

Huey

Levy³

et al. 2020

Ecology Letters

View full text Add to dashboard Cite

In cold environments ectotherms can be dormant underground for long periods. In 1941 Cowles proposed an ecological trade‐off involving the depth at which ectotherms overwintered: on warm days, only shallow reptiles could detect warming soils and become active; but on cold days, they risked freezing. Cowles discovered that most reptiles at a desert site overwintered at shallow depths. To extend his study, we compiled hourly soil temperatures (5 depths, 90 sites, continental USA) and physiological data, and simulated consequences of overwintering at fixed depths. In warm localities shallow ectotherms have lowest energy costs and largest reserves in spring, but in cold localities, they risk freezing. Ectotherms shifting hourly to the coldest depth potentially reduce energy expenses, but paradoxically sometimes have higher expenses than those at fixed depths. Biophysical simulations for a desert site predict that shallow ectotherms have increased opportunities for mid‐winter activity but need to move deep to digest captured food. Our simulations generate testable predictions to eco‐physiological questions but rely on physiological responses to acute cold rather than to natural cooling profiles. Furthermore, natural‐history data to test most predictions do not exist. Thus, our simulation approach uncovers knowledge gaps and suggests research agendas for studying ectotherms overwintering underground.

show abstract

mentioning

confidence: 99%

“…Radiotelemetry has provided insights into hibernation thermal ecology, the locations of hibernacula, site fidelity (Macartney et al, 1989;Johnson, 1995;Sage, 2005;Harvey and Weatherhead, 2006b), and the timing of ingress and egress (Nordberg and Cobb, 2016). Surgically implanted temperature data loggers or hygrochron data loggers fused to rattles and doubly labeled water have also been used to study the ecophysiology of hibernation (Agugliaro, 2011;Nordberg and Cobb, 2016). Because small numbers of relatively old and large snakes are monitored during radiotelemetry studies (Johnson, 1995;Harvey and Weatherhead, 2006b;Refsnider et al, 2012;Zappalorti et al, 2014), survival rates are difficult to determine (Jones et al, 2012).…”

mentioning

confidence: 99%