Effects of day length, temperature, and endogenous control on annual rhythms of reproduction and hibernation in chipmunks (Eutamias ssp.)

Kenagy, G. J.

doi:10.1007/bf00609939

Cited by 21 publications

(6 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Endogenous, circannual clocks permit animals to persist in their cycles of hibernation, body mass and reproduction even during phases of the annual cycle when external time cues are absent. Although much of the early work emphasized the importance of predictable seasonal conditions in promoting the evolution of a robust circannual rhythm, it was also evident that, similar to circadian rhythms, the circannual rhythm must be entrained by external cues for individuals to maintain synchrony with the environment (Heller & Poulson, ; Armitage & Shulenberger, ; Kenagy, 1980, 1981 b ; Ward & Armitage, ).…”

Section: Clocks Photoperiod and Seasonal Timingmentioning

confidence: 99%

“…The expression of torpor is highly variable among sciurid species, with some exhibiting only daily episodes, others exhibiting multiday torpor bouts as long as 24 days repeated over the course of a hibernation season (Geiser & Ruf, 1995) and others that do not express torpor at all (Kenagy, 1981a;Brigham & Geiser, 2012;Dausmann et al, 2013). This review focuses on sciurids that hibernate, including 'obligate' hibernators, which predictably exhibit hibernation each year, and 'facultative' hibernators, which manifest the trait only under certain environmental conditions (Kenagy, 1981b;Humphries, Kramer & Thomas, 2003;Lehmer et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Phenology of hibernation and reproduction in ground squirrels: integration of environmental cues with endogenous programming

et al. 2013

Self Cite

View full text Add to dashboard Cite

Mammalian hibernation is characterized by prolonged dormancy consisting of pronounced depression of metabolism and body temperature. Though hibernation occurs in at least seven mammalian orders and several families of the order Rodentia, the ecology and physiology of hibernation in rodents has been most extensively studied in the family Sciuridae, particularly in the so‐called ground squirrels, that is, the tribe Marmotini. Early studies of these rodents demonstrated the important role of an endogenous circannual clock in the persistence of annual timing and phasing of key seasonal events, including weight gain, hibernation and reproduction. Here, we review the causes and consequences of intraspecific variation in the timing of hibernation and reproduction in these sciurids and examine the physiological mechanisms that contribute to phenotypic plasticity in seasonal timing. Although the duration, annual phasing and predictability of seasonal change in environmental conditions likely promoted the evolution of endogeneity, precision and brevity of breeding seasons in the annual cycles of sciurids, substantial intraspecific variation in hibernation and reproductive phenology exists along latitudinal and altitudinal clines, as well as among locally varying environmental micro‐conditions. We suggest that much of this variation is a function of plasticity in the physiological mechanisms controlling annual cycles. While studies of captive animals have been instrumental in establishing the role of an endogenous rhythm, a greater emphasis on experimental field manipulations is needed to better understand the function, causes and consequences of phenological shifts in wild populations. Ultimately, the capacity of hibernators to adjust their timing in response to changing environmental conditions, either through phenotypic plasticity or microevolution, will be an important determinant of the resilience of sciurid species to changing climate.

show abstract

Section: Clocks Photoperiod and Seasonal Timingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Phenology of hibernation and reproduction in ground squirrels: integration of environmental cues with endogenous programming

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, day-length was strongly correlated with video estimates of abundance in this study and is also a possible cue for crab migration. Many animal species have been shown to respond in various ways to changing photoperiod (Kenagy 1981, Silverin et al 1993, Gwinner 1996, Watari & Arai 1997, Last & Olive 2004, and several studies have shown that crustaceans respond to changing light conditions. Aguzzi et al (2004) attributed greater catches of the Norway lobster Nephrops norvegicus during spring and summer to higher light intensity, while Aguzzi et al (2005) suggested that creels should be deployed around sunset to sample, during the peak feeding period, the brackish water shrimp Palaemonetes varians, which exhibits daily feeding rhythmicity.…”

Section: Discussionmentioning

confidence: 99%

Determining whether catch per unit effort is a suitable proxy for relative crab abundance

Murray

Seed²

2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Stock assessments of crabs commonly rely on catch per unit effort (CPUE) data derived from catches in baited traps. Baited traps have been used for many years to estimate the relative abundance of predators in the marine environment. However, traps may result in biased estimates due to inter-and intra-species variations in physiology and behaviour. The aim of this study was to determine the suitability of CPUE as a proxy for the relative abundance of Carcinus maenas. Crab abundance estimates were obtained using underwater camera surveys. The study was conducted on commercial mussel beds in the Menai Strait, United Kingdom. CPUE data were obtained from the local C. maenas fishery operating over the mussel beds. The influence of temperature-dependent feeding rates on CPUE was predicted from the number of mussels consumed at different experimental temperatures in laboratory aquaria. Both CPUE and estimated abundance showed marked seasonal variation. Abundance maxima preceded temperature maxima by 2 mo. CPUE increased with temperature up to 15°C, while relative crab abundance based on visual surveys exhibited a strong positive correlation with day-length. CPUE appears not to be a suitable proxy for the relative abundance of C. maenas because of the effects of temperature on crab activity levels and thus catches. KEY WORDS: Carcinus maenas · Day-length · Feeding · Fisheries · Migration · Photoperiod · Mytilus edulis Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 401: [173][174][175][176][177][178][179][180][181][182] 2010 Several methods have been used previously to assess the relative abundance of Carcinus maenas, including traps with bait (Rewitz et al. 2004) and without bait (Hunter & Naylor 1993, Gascoigne et al. 2005. The effectiveness of baited trap catches as a proxy for relative abundance is dependent on the influence of factors such as feeding rates and reproductive condition, which may vary both temporally and spatially and thus affect the catchability of the species. Baited traps can be both size and sex biased (Williams & Hill 1982, Addison & Lovewell 1991. Population size does undoubtedly influence catches (Maceina et al. 1993, Wright et al. 2006, Walter et al. 2007). However, it is important that the effects of physiological and behavioural factors on baited trap CPUE are understood if these values are to be used to estimate changes in crab stock size.Migration of crabs has a major impact on the intraannual trends in abundance. Annual offshore migrations are undertaken by many crustacean species, including Macropipus holsatus (Venema & Creutzberg 1973), Cancer pagurus (Ungfors et al. 2007) and Carcinus maenas. Welch (1968) suggested that increases and decreases in C. maenas abundance are associated with rising and falling temperature. The estimates used by Welch (1968) were based on baited trap catches and the observations of fishers. There is no doubt that unusually low winter temperatures can result in mass mortality of C. maenas and other ...

show abstract

“…The physiological and behavioural adaptations that allow animals to survive in variable environments and the effects of temperature on their activity have been the focus of many studies on a variety of vertebrate groups including mammals (MacMillen, 1965;Chappell, Calvo & Heller, 1978;Kenagy, 1981;Ortmann et al, 1997;Wassmer & Wollnik, 1997;Sharpe & Van Horne, 1999). In Mediterranean ecosystems, microclimates can vary from cool and wet areas to extremely hot and dry areas, within a relatively short distance.…”

Section: Introductionmentioning

confidence: 99%

Activity patterns of the common dormouse (Muscardinus avellanarius) in different Mediterranean ecosystems

et al. 2004

View full text Add to dashboard Cite

The seasonal activity of the common dormouse Muscardinus avellanarius was studied in three different habitat types of central Italy: a deciduous beech wood dominated by Fagus sylvatica (Cimini Mountains), and a deciduous oak woodland with Quercus cerris and Q. pubescens and an evergreen wood dominated by holm oak Q. ilex, both along the central Tyrrhenic coast. In each site, 50 nest-boxes were fixed to trees and were monitored monthly for 2 years (May 1998-April 2000. In the beech wood site, the species showed an annual biological cycle similar to that described for populations of central and northern Europe: dormancy in winter, from the first 10 days of November to the end of December; end of hibernation in the first half of April; reproduction between May and July. On the contrary, in the two coastal sites, nest-boxes were occupied from October to June, and the breeding period was in autumn, showing that a winter dormancy phase is absent, probably owing to the mild winter. On the other hand, no dormice or new nests were observed in nest-boxes in summer suggesting that a dormancy phase occurred in summer, probably owing to dry climatic conditions. Two patterns of biological cycle therefore emerged from the results: a temperate pattern in beech forest with winter dormancy and spring reproduction, and a Mediterranean pattern in coastal habitats with autumnal reproduction, winter activity and summer dormancy.

show abstract

Effects of day length, temperature, and endogenous control on annual rhythms of reproduction and hibernation in chipmunks (Eutamias ssp.)

Cited by 21 publications

References 24 publications

Phenology of hibernation and reproduction in ground squirrels: integration of environmental cues with endogenous programming

Phenology of hibernation and reproduction in ground squirrels: integration of environmental cues with endogenous programming

Determining whether catch per unit effort is a suitable proxy for relative crab abundance

Activity patterns of the common dormouse (Muscardinus avellanarius) in different Mediterranean ecosystems

Contact Info

Product

Resources

About