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., 62-63 (Russian), 167 (English).
REACTIONS OF ADAPTATION TO HOMEOSTASIS OF ANIMALS
DURING WINTER HIBERNATION
V.I. Mashkin
Prof. Zhitkov' VNIIOZ,
Kirov, Russia
Carrying out experiments on Menzbir's marmots (Marmota menzbieri) in an artificial hole we showed that during winter hibernation the animals periodically (1-3 times a month) cleared their bodies from metabolic products. Before awakening the body temperature (taken in a rectal orifice) rises as high as 22-24oC. During hibernation and short periods of awakening the eyes and ears of the animals are tightly closed by a viscous black mass. The marmots don't respond to the light of an electric torch. As if being in "an autopilot regime" they slowly move with a resolute step along the hole passages to the defecation place, urinate and return to their nest. Three or five hours later the animals' body temperature falls and reaches the value that is 1-4o higher than the air temperature in the hole.
Studying of breaks in hibernation of the gopher (Citellus columbianus) showed that ketone compounds (acetylacetate and hydroxylbutyrate) accumulated in blood, heart and brown fat. They apparently cause the breaks in hibernation when accumulated over a certain level (Baumber et al., 1971). In nature grophers awake 12-21 times. The breaks in hibernation are observed also in hedgehogs and bats.
Studying of red-cheeked gophers (C. erythrogenus) revealed that thermokinetics of tissue breathing increases in animals during transition from hibernation to awakening. At the body temperature of about 22oC the intensity of oxygen consumption in different tissues of an individual changes distinctly. And probably that is not occasional. When the body temperature rises, the metabolic rate changes (Popov, 1973), and at 22oC it reaches its maximum size. This refers to a greater degree to a brown fat tissue and to muscles (Khaskin et al., 1977).
Tissue characteristics described are apparently of adaptive significance to clear a body from metabolic products during hibernation with a minimum loss of energy when the normal body temperature (35-38oC) is not reached.
The other important physiological function of hibernating animals is synchronization of changes in blood according to changing environment conditions. In bats the blood coagulability rate during hibernation delays from 7.4 to 140-190 min. (Smith et al., 1954). When the animals awoke after indoor transferring (the temperature indoors being 23oC), this index decreased to 19-20 min. on the second-third day of their activity.
We cut off a finger phalanx in Menzbir's marmots during their hibernation in an artificial hole (the body temperature being 6-8oC) to determine the age of an individual (Mashkin, 1979). The wound didn`t stop even 2-3 days later. When the animals were transferred indoors with the air temperature of 26-28oC and when they came out of hibernation (the body temperature being 34-36oC), the bleeding stopped 5-8 min. later.
Studying of the changes in blood coagulation in relict gophers (C. relictus) and red marmots (M. caudata) showed that hibernation is characterized by sharp disturbance in blood coagulation: in gophers blood coagulation was 230% longer than in the state of activity when preparing to hibernation. In marmots the same hypocoagulation changes were expressed more clearly. When plasma tolerance to heparin was studied in marmots, plasma in a tube didn't practically coagulate (Isabayeva et al., 1977).
The changes in blood coagulation in animals help probably to maintain optimum living conditions during hibernation and are a normal component of seasonal changes in functioning of hibernating animals.