Effects of weather and early social environment on growth, health status and metabolic rate of juvenile European rabbits
Final Report Abstract
We investigated the effects of the weather conditions and the social environment experienced by juvenile European rabbits (Oryctolagus cuniculus) shortly after weaning on their endoparasite load in the end of the vegetation period. The study was conducted on animals from a field enclosure population. We found strong indications for the impact of different components of the juveniles’ environment experienced during early life: Infestations with nematodes as well as with coccidia were higher in animals, which experienced more (cold) rain during the first 2 months after they had left their breeding burrow, most probably because the infective stages of nematodes and coccidia are more persistent outside the host under humid conditions. In addition, we found lower numbers of nematodes in the gastrointestinal tract of young rabbits, which were involved in more positive social interactions with conspecifics during the following weeks after weaning. We suggest, that social support provided by familiar group members – in particular by the mother and by litter siblings, which were the decisive components of the correlation between positive social behaviour and endoparasite load – has weakened negative stress effects on the juveniles’ immune function and thus might have reduced the infestation with endoparasites. This notion is supported by the negative correlation between the level of positive social interactions that juveniles displayed with conspecifics during their early youth and corticosterone challenge levels shortly after the period of observation. This indicates lower stress in juveniles, which managed to integrate more successfully into the social network of their group. In conclusion, this study highlights the importance of the abiotic conditions as well as the early social environment that the animals experience shortly after weaning; both contributed in shaping the animals’ endoparasite load prior to the winter season. These effects might constitute an important mechanism explaining how conditions experienced during early life translate into long-term fitness consequences. In addition, we studied resting metabolic rates in juvenile rabbits. An animal’s resting metabolic rate is a useful physiological measure for assessing its maintenance costs under different environmental challenges. During the early juvenile period, animals are especially prone to heat loss due to their high surface area to volume ratio. Consequently, adverse environmental conditions such as low ambient temperature and wetness affect the energy balance in juveniles more strongly than in adults. We found interacting effects of temperature and wetness on resting metabolic rate RMR and on thermal conductance, which increased more strongly with decreasing temperature when the animals were wet. In addition, RMR decreased significantly with increasing body mass, but only under wet conditions when the temperature was low. However, we did not find significantly lower RMR or thermal conductance in huddling pairs than in single juveniles. In conclusion, our study highlights the importance of a high juvenile body mass, which helps to reduce maintenance costs under adverse environmental conditions. Such effects might have important implications for the individual’s preweaning growth and development and thus may exert long-term effects on fitness-related traits.
Publications
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(Oct 2006) Social environment and individual fitness in mammals. Invited lecture at the student course “Bases de la Conducta”, Tlaxcala, Mexico.
Rödel, H.G.
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(Sep 2007) Taking physiology to the field: correlates and consequences of the social and non-social environment on health and body condition of European rabbits. Invited speaker in the symposium “Fisiologia de la Conducta”, Puebla, Mexico.
Rödel, H.G.
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(2008) Age-specific endoparasite load in juvenile European rabbits prior to the winter season. Poster at the Annual Meeting of the German Zoological Society, Jena, Germany.
Starkloff, A., von Holst, D., Steineck, T., Rödel, H.G.
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(2008) Age-specific parasite load in juvenile rabbits prior to the winter season. Poster at the Annual Meeting of the German Society of Mammalogy, Vienna, Austria.
Starkloff, A., von Holst, D., Steineck, T., Rödel, H.G.
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(2008) Correlates and consequences of the social and non-social environment on health and body condition of juvenile European rabbits. Short talk at the Annual Meeting of the German Society of Mammalogy, Vienna, Austria.
Rödel, H.G., Starkloff, A.
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(2008) Cuddling bunnies: Does body contact among postweaned European rabbits lower their resting metabolic rate? Poster at the Annual Meeting of the German Society of Mammalogy, Vienna, Austria.
Seltmann, M., Ruf, T., Rödel, H.G.
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(2008) The impact of huddling on oxygen consumption of juvenile European rabbits at different simulated weather conditions. Poster at the Annual Meeting of the German Zoological Society, Jena, Germany.
Seltmann, M., Ruf, T., Rödel, H.G.
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(Sep 2008) Effects of the abiotic and social environment on body condition and health: a study on European rabbits. Invited speaker in the symposium “Behavioural Biology” of the Annual Meeting of the German Zoological Society, Jena, Germany.
Rödel, H.G.
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(2009) Effects of body mass and huddling on resting metabolic rates of post-weaned European rabbits under different simulated weather conditions. Functional Ecology 23, 1070–1080
Seltmann, M.W., Ruf, T., Rödel, H.G.
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(2009) Effects of body mass, but no effects of huddling on resting metabolic rates of post-weaned European rabbits under different simulated weather conditions. Poster at the Conference of the German Ethological Society “Behaviour and Evolution”, Göttingen, Germany.
Seltmann, M.W., Ruf, T., Rödel, H.G.
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(2009) The impact of weather conditions and the social environment on endoparasite load in juvenile European rabbits. Short talk at the Conference of the German Ethological Society “Behaviour and Evolution”, Göttingen, Germany.
Starkloff, A., Rödel, H.G.
