Implications of being born late in the active season for growth, fattening, torpor use, winter survival and fecundity
- Research Institute of Wildlife Ecology, University of Veterinary Medicine, Austria
- Université de Strasbourg, IPHC, France
- CNRS, UMR7178, France
Figures
Figure 1
Changes in (a) structural growth (body length), (b) body mass, (c) total torpor duration, (d) energy intake and (e) activity time of early (‘EB’) and late-born (‘LB’) female juvenile garden dormice either fed ad libitum (‘AL’) or intermittently fasted (‘IF’) from the start of experiments until hibernation onset.
N = 6 individuals per group. Values are means ±SE. Torpor duration and activity time were estimated from measurements of nest temperature (for details see the ‘Material and methods’ part).
Figure 2
Levels of (a) total energy expenditure and (b) water turnover of early and late-born female juvenile garden dormice either fed ad libitum (‘AL’) or intermittently fasted (‘IF’) prior to hibernation onset (weeks 11–12 for EB and weeks 7–8 for LB).
Groups differing significantly (p<0.05, Tukey’s post-hoc comparisons) are denoted by different superscripts.
Figure 3
Changes in (a) torpor frequency and (b) mean torpor duration of early (‘EB’) and late-born (‘LB’) female juvenile garden dormice either fed ad libitum (‘AL’) or intermittently fasted (‘IF’) from the start of experiments until hibernation onset.
N = 6 individuals per group. Values are means ±SE. Torpor patterns were assessed by measurements of nest temperature (for details see the ‘Materials and methods’ part).
Figure 4
Box-plot graphs of overwintering loss of body mass (‘BM’), fat-free mass (‘FFM’) and fat mass (‘FM’) of female juvenile garden dormice born early (‘Early-born Juveniles’) or late (‘Late-born Juveniles’) in the reproductive season.
Groups differing significantly (p<0.05, Tukey’s post-hoc comparisons) are denoted by different superscripts.
Figure 5
Proportion of breeding occurrence (‘breeding proportion’) of early-born (‘EB’) and late-born (‘LB’) female garden dormice at early and late reproductive events.
Females were either fed ad libitum (AL) or intermittently fasted (‘IF’) during their juvenile period, that is, from the start of experiments until hibernation onset. Values are means ±SD.
Tables
Table 1
Parameters of analyses of variance for the effects of group (early-born, late-born) and diet (fed ad libitum or intermittently fasted) on the rate (‘slope’) of body mass gain and structural growth (assessed by body length), the maximal level (‘plateau’) at which BM and BL levelled off and the time (‘time of plateau’) at which the plateau of BM or BL occurred during the pre-hibernation period.
p-values shown in bold correspond to statistically significant and interpretable values.
| Parameter | Term | Response variables | |||||
|---|---|---|---|---|---|---|---|
| Slope | Plateau | Time of plateau | |||||
| F-value | p-value | F-value | p-value | F-value | p-value | ||
| Body mass | Group Diet Group х Diet | 70.93 1.00 3.58 | <0.001 0.33 0.07 | 5.73 0.05 0.13 | <0.05 0.83 0.72 | 368.71 0.07 0.44 | <0.001 0.80 0.52 |
| Body length | Group Diet Group х Diet | 103.55 0.01 1.65 | <0.001 0.92 0.21 | 1.46 0.01 0.12 | 0.24 0.97 0.73 | 190.11 0.43 0.29 | <0.001 0.52 0.60 |
Table 2
Parameters of linear models for the effects of time, group (early-born, late-born) and diet (fed ad libitum or intermittently fasted) on body mass, fat mass and fat-free mass of juvenile garden dormice.
p-values shown in bold correspond to statistically significant and interpretable values.
| Response variable | Term | Estimate ± SD | t-value | p-value |
|---|---|---|---|---|
| Body mass (g) | Time Group Diet Time x Group Time x Diet Group x Diet | 34.39 ± 2.17 −9.13 ± 4.36 −5.36 ± 4.89 −16.63 ± 2.71 −0.79 ± 2.73 9.14 ± 6.26 | 15.85 −2.09 −1.10 −6.14 0.29 1.46 | <0.001 0.06 0.29 <0.001 0.78 0.17 |
| Fat mass (g) | Time Group Diet Time x Group Time x Diet Group x Diet | 29.68 ± 1.70 −3.61 ± 2.80 −2.52 ± 3.10 −13.36 ± 2.11 −2.02 ± 2.13 5.41 ± 3.90 | 17.49 −1.29 −0.81 −6.32 −0.95 1.39 | <0.001 0.22 0.43 <0.001 0.36 0.19 |
| Fat-free mass (g) | Time Group Diet Time x Group Time x Diet Group x Diet | 4.72 ± 0.86 −5.36 ± 1.95 −2.82 ± 2.20 −3.45 ± 1.07 1.19 ± 1.08 3.76 ± 2.83 | 5.48 −2.75 −1.28 −3.21 1.10 1.33 | <0.001 <0.05 0.22 <0.01 0.29 0.21 |
Table 3
Means and standard deviations for pre- and post-hibernation body mass, fat mass and fat-free mass of the experimental animal groups, according to the time of birth (early-born ‘EB’, late-born ‘LB’) and feeding treatment (ad libitum ‘AL’ and intermittently fasted ‘IF’).
Groups differing significantly (p<0.05, Tukey’s post-hoc comparisons) are denoted by different superscripts.
| Variable | Time | Group | Mean ± SD |
|---|---|---|---|
| Body mass (g) | Pre-hibernation Post-hibernation | EB-AL EB-IF LB-AL LB-IF EB-AL EB-IF LB-AL LB-IF | 100.0 ± 0.7a 101.8 ± 2.1a 77.4 ± 1.3b 77.3 ± 2.1b 65.7 ± 0.4c 63.7 ± 1.0c 59.3 ± 0.6c 60.5 ± 1.7c |
| Fat mass (g) | Pre-hibernation Post-hibernation | EB-AL EB-IF LB-AL LB-IF EB-AL EB-IF LB-AL LB-IF | 47.5 ± 0.6a 49.2 ± 1.4a 32.6 ± 1.0b 32.3 ± 1.3b 18.5 ± 0.2c 18.0 ± 0.7c 15.5 ± 0.4c 17.6 ± 0.9c |
| Fat-free mass (g) | Pre-hibernation Post-hibernation | EB-AL EB-IF LB-AL LB-IF EB-AL EB-IF LB-AL LB-IF | 52.5 ± 0.4a 52.6 ± 0.7a 44.8 ± 0.5bc 44.9 ± 0.9bc 47.2 ± 0.5bc 45.7 ± 0.4c 43.9 ± 0.5c 43.0 ± 4.3c |
Table 4
Parameters of analyses of variance for the effects of group and diet on the time (‘starting time’) and the rate (‘slope’) of torpor increase or decrease of activity time.
Mean torpor duration was also added as a predictor variable in the model for activity time and mean ambient temperature was included as a random effect in all models. p-values shown in bold correspond to statistically significant and interpretable values.
| Response variable | Term | Parameters | |||
|---|---|---|---|---|---|
| Starting time | Slope | ||||
| χ2 | p-value | χ 2 | p-value | ||
| Torpor frequency | Group Diet Group х Diet | 46.47 8.64 1.82 | <0.001 <0.01 0.18 | 3.16 1.18 7.02 | 0.08 0.28 <0.01 |
| Mean torpor duration | Group Diet Group х Diet | 43.49 8.84 0.50 | <0.001 <0.01 0.48 | 38.26 0.35 16.64 | <0.001 0.55 <0.001 |
| Total torpor duration | Group Diet Group х Diet | 43.49 8.84 0.50 | <0.001 <0.01 0.48 | 77.86 0.55 9.66 | <0.001 0.46 <0.01 |
| Activity time | Group Diet Group х Diet Mean torpor duration | 0.09 14.06 6.96 7.61 | 0.76 <0.001 <0.01 <0.01 | 6.45 2.64 0.22 2.68 | <0.05 0.10 0.64 0.10 |
Additional files
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Supplementary file 1
Parameters of linear models for the effects of group and diet on total energy expenditure and water turnover of juvenile garden dormice.
Body mass was also assessed as an explanatory variable in the models. p-Values shown in bold correspond to statistically significant and interpretable values.
- https://doi.org/10.7554/eLife.31225.012
-
Supplementary file 2
Means ± standard errors and parameters of analyses of variance for the effects of group (early-born ‘EB’ vs. late-born ‘LB’), diet (ad-libitum ‘AL’ vs. intermittently fasted ‘IF’) and time (‘start of growth’ vs. ‘body mass plateau’) on average daily metabolic rate (‘ADMR’) of garden dormice, metabolic rate during night (‘MR-night’) and metabolic rate during day (‘MR-day’).
Metabolic rate is expressed in ml O2 h−1 g−1. Body mass and animal ID were included as random effects in all models. p-Values shown in bold correspond to statistically significant and interpretable values.
- https://doi.org/10.7554/eLife.31225.013
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Supplementary file 3
Means and standard errors for the time (‘starting time’) and rate (‘slope’) of increase in torpor frequency, mean and total torpor duration of early-born (‘EB’) and late-born (‘LB’) juvenile garden dormice, either fed ad libitum (‘AL’) or intermittently fasted (‘IF’).
- https://doi.org/10.7554/eLife.31225.014
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Supplementary file 4
Parameters of linear models for the effects of group and diet on the hibernation duration, arousal frequency, mean torpor and arousal durations and minimal body temperature (Tb) during winter.
Hibernation duration was also assed as an explanatory variable in the model for arousal frequency. p-Values shown in italic correspond to statistically significant and interpretable values.
- https://doi.org/10.7554/eLife.31225.015
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Supplementary file 5
Means and standard deviations for the hibernation duration, arousal frequency, mean torpor and arousal durations and minimal body temperature (Tb) of juveniles during winter, according to their time of birth (early-born ‘EB’, late-born ‘LB’) and feeding treatment (ad libitum ‘AL’ and intermittently fasted ‘IF’).
- https://doi.org/10.7554/eLife.31225.016
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Supplementary file 6
Parameters of analyses of variance for the effects of time, group and diet on body mass and body mass changes of juvenile garden dormice during the post-hibernation breeding period.
Body mass changes were computed between post-hibernation and the start of early breeding, and between the start of early breeding and the start of late breeding. p-Values shown in bold correspond to statistically significant and interpretable values.
- https://doi.org/10.7554/eLife.31225.017
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Supplementary file 7
Means and standard deviations of body mass at post-hibernation, start of early breeding and start of late breeding, as well as body mass changes between pre-hibernation and the start of early breeding, and between the start of early breeding and the start of late breeding of the experimental animal groups, according to the time of birth (early-born ‘EB’, late-born ‘LB’) and feeding treatment (ad libitum ‘AL’ and intermittently fasted ‘IF’).
Groups differing significantly (p<0.05, Tukey’s post-hoc comparisons) are denoted by different superscripts.
- https://doi.org/10.7554/eLife.31225.018
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Supplementary file 8
Parameters of generalized linear models (in the case of breeding proportion) or linear models (in the case of litter size and litter mass) for the effects of timing of reproduction, group and diet on the female breeding proportion, litter size and litter mass.
p-Values shown in bold correspond to statistically significant and interpretable values.
- https://doi.org/10.7554/eLife.31225.019
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Transparent reporting form
- https://doi.org/10.7554/eLife.31225.020
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Implications of being born late in the active season for growth, fattening, torpor use, winter survival and fecundity
eLife 7:e31225.
https://doi.org/10.7554/eLife.31225
