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Temperature-induced shifts in hibernation behavior in experimental amphibian populations.

Gao X, Jin C, Llusia D, Li Y - Sci Rep (2015)

Bottom Line: Using outdoor mesocosm experiments, we examined the effects of temperature (ambient vs. + ~2.2/2.4 °C of pre-/post-hibernation warming) and food availability (normal vs. 1/3 food) on the date of entrance into/emergence from hibernation in Pelophylax nigromaculatus.We found temperature was the major factor determining the hibernation period, which showed a significant shortening under experimental warming (6-8 days), with delays in autumn and advances in spring.We believe that this study provides some of the first experimental evidence for the effect of climate warming on the timing of amphibian hibernation.

View Article: PubMed Central - PubMed

Affiliation: 1] Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China [2] University of Chinese Academy of Sciences, 19 Yuquan Road, Shijingshan District, Beijing 100049, China.

ABSTRACT
Phenological shifts are primary responses of species to recent climate change. Such changes might lead to temporal mismatches in food webs and exacerbate species vulnerability. Yet insights into this phenomenon through experimental approaches are still scarce, especially in amphibians, which are particularly sensitive to changing thermal environments. Here, under controlled warming conditions, we report a critical, but poorly studied, life-cycle stage (i.e., hibernation) in frogs inhabiting subtropical latitudes. Using outdoor mesocosm experiments, we examined the effects of temperature (ambient vs. + ~2.2/2.4 °C of pre-/post-hibernation warming) and food availability (normal vs. 1/3 food) on the date of entrance into/emergence from hibernation in Pelophylax nigromaculatus. We found temperature was the major factor determining the hibernation period, which showed a significant shortening under experimental warming (6-8 days), with delays in autumn and advances in spring. Moreover, the timing of hibernation was not affected by food availability, whereas sex and, particularly, age were key factors in the species' phenological responses. Specifically, male individuals emerged from hibernation earlier, while older individuals also entered and emerged from hibernation earlier. We believe that this study provides some of the first experimental evidence for the effect of climate warming on the timing of amphibian hibernation.

No MeSH data available.


Related in: MedlinePlus

The average air temperature of entrance into hibernation (°C) of P. nigromaculatus in outdoor mesocosms (mean ± SE) among experimental treatments: ambient temperature and normal (CG) or low food level (LF); and pre-hibernation warming (i.e., in autumn) and normal (AW) or low food level (AW-LF). The open bars indicate males, and the dark bars indicate females.
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f3: The average air temperature of entrance into hibernation (°C) of P. nigromaculatus in outdoor mesocosms (mean ± SE) among experimental treatments: ambient temperature and normal (CG) or low food level (LF); and pre-hibernation warming (i.e., in autumn) and normal (AW) or low food level (AW-LF). The open bars indicate males, and the dark bars indicate females.

Mentions: The date of entrance into hibernation of P. nigromaculatus differed among experimental treatments, as shown by a mixed-model ANCOVA (Table 2). Pre-hibernation warming and the age of the subjects had a highly significant effect. Pairwise comparisons indicated that the experimental warming in autumn (pre-hibernation warming with normal food ‘AW’ or low food level ‘AW-LF’) delayed the date of entrance into hibernation relative to the exposure to ambient temperature (control group ‘CG’ and ambient temperature with low food level ‘LF’; P < 0.001; Fig. 2). The air temperature of entrance into hibernation was not significantly different among treatments (one-way ANOVA, F = 0.134, df = 3, P = 0.940; Fig. 3), and the air temperature was negatively correlated with the date of entrance into hibernation (Pearson correlation test, CG: r = −0.672, P < 0.001; LF: r = −0.675, P < 0.001; AW: r = −0.817, P < 0.001; AW-LF: r = −0.846, P < 0.001). The age of experimental subjects also showed a negative correlation with this phenological event (β = −0.011, P < 0.001). Older individuals entered hibernation earlier than young ones (Fig. S1). No significant difference in the entered into hibernation behavior was detected between individuals supplied with normal and low food levels or between sexes (food supply: P = 0.557; sex: P = 0.411; Fig. 2).


Temperature-induced shifts in hibernation behavior in experimental amphibian populations.

Gao X, Jin C, Llusia D, Li Y - Sci Rep (2015)

The average air temperature of entrance into hibernation (°C) of P. nigromaculatus in outdoor mesocosms (mean ± SE) among experimental treatments: ambient temperature and normal (CG) or low food level (LF); and pre-hibernation warming (i.e., in autumn) and normal (AW) or low food level (AW-LF). The open bars indicate males, and the dark bars indicate females.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4477341&req=5

f3: The average air temperature of entrance into hibernation (°C) of P. nigromaculatus in outdoor mesocosms (mean ± SE) among experimental treatments: ambient temperature and normal (CG) or low food level (LF); and pre-hibernation warming (i.e., in autumn) and normal (AW) or low food level (AW-LF). The open bars indicate males, and the dark bars indicate females.
Mentions: The date of entrance into hibernation of P. nigromaculatus differed among experimental treatments, as shown by a mixed-model ANCOVA (Table 2). Pre-hibernation warming and the age of the subjects had a highly significant effect. Pairwise comparisons indicated that the experimental warming in autumn (pre-hibernation warming with normal food ‘AW’ or low food level ‘AW-LF’) delayed the date of entrance into hibernation relative to the exposure to ambient temperature (control group ‘CG’ and ambient temperature with low food level ‘LF’; P < 0.001; Fig. 2). The air temperature of entrance into hibernation was not significantly different among treatments (one-way ANOVA, F = 0.134, df = 3, P = 0.940; Fig. 3), and the air temperature was negatively correlated with the date of entrance into hibernation (Pearson correlation test, CG: r = −0.672, P < 0.001; LF: r = −0.675, P < 0.001; AW: r = −0.817, P < 0.001; AW-LF: r = −0.846, P < 0.001). The age of experimental subjects also showed a negative correlation with this phenological event (β = −0.011, P < 0.001). Older individuals entered hibernation earlier than young ones (Fig. S1). No significant difference in the entered into hibernation behavior was detected between individuals supplied with normal and low food levels or between sexes (food supply: P = 0.557; sex: P = 0.411; Fig. 2).

Bottom Line: Using outdoor mesocosm experiments, we examined the effects of temperature (ambient vs. + ~2.2/2.4 °C of pre-/post-hibernation warming) and food availability (normal vs. 1/3 food) on the date of entrance into/emergence from hibernation in Pelophylax nigromaculatus.We found temperature was the major factor determining the hibernation period, which showed a significant shortening under experimental warming (6-8 days), with delays in autumn and advances in spring.We believe that this study provides some of the first experimental evidence for the effect of climate warming on the timing of amphibian hibernation.

View Article: PubMed Central - PubMed

Affiliation: 1] Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China [2] University of Chinese Academy of Sciences, 19 Yuquan Road, Shijingshan District, Beijing 100049, China.

ABSTRACT
Phenological shifts are primary responses of species to recent climate change. Such changes might lead to temporal mismatches in food webs and exacerbate species vulnerability. Yet insights into this phenomenon through experimental approaches are still scarce, especially in amphibians, which are particularly sensitive to changing thermal environments. Here, under controlled warming conditions, we report a critical, but poorly studied, life-cycle stage (i.e., hibernation) in frogs inhabiting subtropical latitudes. Using outdoor mesocosm experiments, we examined the effects of temperature (ambient vs. + ~2.2/2.4 °C of pre-/post-hibernation warming) and food availability (normal vs. 1/3 food) on the date of entrance into/emergence from hibernation in Pelophylax nigromaculatus. We found temperature was the major factor determining the hibernation period, which showed a significant shortening under experimental warming (6-8 days), with delays in autumn and advances in spring. Moreover, the timing of hibernation was not affected by food availability, whereas sex and, particularly, age were key factors in the species' phenological responses. Specifically, male individuals emerged from hibernation earlier, while older individuals also entered and emerged from hibernation earlier. We believe that this study provides some of the first experimental evidence for the effect of climate warming on the timing of amphibian hibernation.

No MeSH data available.


Related in: MedlinePlus