Holarctic Marmots as a factor of Biodiversity.
Rumiantsev V.Yu;, Nikol'skii A.A. & Brandler O.V. eds.,
Abstracts, 3d Conference on Marmots (Cheboksary, Russia, 25-30 August 1997),
Moscow ABF 1997, 216p., 28-29 (Russian), 148 (English).


L. Graziani, D. Allainé

Laboratoire de Biologie des Populations d'Altitude (UMR 5553), Université Claude-Bernard LYON1, Campus de la DOUA, B t. 403, Villeurbanne Cédex;, France

We present here the body and behavioral development of Alpine marmot (Marmota marmota), between birth and the first emergence of the burrow. Although many information about the early body development of ground squirrels are available, studies of the ontogeny of social behavior are scarce and the absence of standardized method to collect data prevent for interspecific comparison. Most studies about development of ground squirrels concern north-American species of the genus Spermophilus and genus Cynomys. Only one work deals with a species of the genus marmota (Marmota monax), and this is the first time such a work has been performed on a European species of the genus Marmota.

We used the standardized method of Ferron (1981) to collect data. The post-natal growth was estimated from weight and several skeleton measurements taken each day on 13 young marmots born in captivity. The successive emergence of key behaviors is also presented here. We took in account locomotion, vigilance, exploration, feeding, comfort and social behaviors for behavioral ontogeny analysis, with particular attention to the chronology of the behavioral ontogeny and behavioral repertory.

Contrary to expected results, our work show a sexual dimorphism at birth. Young males were heavier at birth and this difference between males and females grew with age. The postnatal growth pattern was not linear but sigmoïd and the form of the sigmoïd varies with sex. Males have logistic postnatal growth pattern while females have Gompertz one.

Concerning behavioral ontogeny, walking regularly on all four appears near 30 days. With opening of the eyes near 27 days, these two events mark a threshold. Thereafter, behavioral ontogeny present a strong acceleration. Most social behaviors appeared during this lapse of time. The weaning time started from the 40th day.

These results were compared with other studies concerning ground dwelling squirrels : several ground squirrels and prairie-dogs and only one of the fourteen species of marmots.

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