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. : 177-178.


THE EFFECTS OF FOOD ADAPTATIONS OF MARMOTS DEPENDING ON THEIR HABITAT


I.A. Plotnikov

Prof. Zhitkov' YNIIOZ, Kirov, Bussia


The objects of research are black-capped and steppe marmots the habitats of which are substantially different. We carried out a series of balance experiments on the research of estability and the level ot digestion of food and ration nutrients by marmots, their accumulation of protein, fat, carbohydrates and other substances. In every experiment carried out at the biostation of the Institute the marmots living in cages were given the same ration for both species. As a result we found substantial differences in food adaptations in marmots of various species.

Blaok-capped marmot fingerlings are mixed fodder 47% lower than steppe ones, but they were not behind in eating roots and other succulent feeds. The coefficient of digestibility (CD) of organic subntance and nitrogen-free extractive substances in the ration consisting of carrot-roots and mixed fodder was higher in black-capped marmots. The only thing that steppe marots digest better is cellulose. CD of cellulose in that ration made up 39.4 ± 1.6% in steppe and 30.8 ± 3.1% (P < 0.1) in black-capped marmots. CD of protein was higher in black-capped (75.5 ± 1.0%) than in steppe marmots (71.0 ± 1.9%). CD of fat was 73.5 ± 3.6% and 63.2 ± 2.7% (P<0.1) correspondingly. The fingerlings of black-capped marmots accumulated 30.5% of nitrogen taken with food that is 2 times as high as that in steppe ones (15.3%).

Similar experiments were made on the marmots of 1 year old. The ration of both species of marmots consisted of a full ration granulated mixed fodder for rabbits and the root "Kuuziku". CD of a dry and organic substance of a ration in both marmot species didn't practically differ and was at the level of 79...81%. CD of nitrogen-free extractive substances in steppe marmots was 89.3 ± 0.4%, in blacg-capped marmots - 91.8 ± 0.6%.

We didn't find in yearlings any significant specilic differences in protein and fat digestibility of a given ration. Steppe marmot yearlings digested cellulose at the level of 44.0 2.5% that is reliably higher than in the yearlings of black-capped marmots (31.8 ± 1.0%, P<0.01).

Black-capped marmots more efficiently accumulate calcium and sodium from tbe ration taken. As to the level of phosphorus steppe marmots show superiority. Nitrogen is accumulated by the yearlings ot black-capped naimots at the level of 28.2% of the amount taken and at the level of 42.2% of the digested one and steppe marmot yearlings at the level of 27% of the amount taken and only at the level of 38.6% of the digested one.

When carrying out balance experiments the differences in the use of water by marmots was observed. Steppe marmot yearlings eat dry mixed fodder more readily and drink water even when there are succulent roots. On the average they drink 130...160 ml of water per 24 hours. Black-capped marmots don't drink water when there is a sufficient amount of succulent food, but use it to wet dry fodders. Black-capped marmots rather eat mixed fodder with the food of animal origin (meat, fisb, subproducts etc.) as additives than demonstrate their demand for the quality and full value of nutrient substances in food.

Our data explain the ability of black-capped marmots during a short summer period in the north to accumulate fat enough for winter hibernation. The peculiarities in nutrition and digestion are the result of adaptive evolution of marmots to the conditions of the habitat.


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