SEASONAL CHANGES IN INSULATION OF THE FUR

1956 ◽  
Vol 34 (1) ◽  
pp. 53-57 ◽  
Author(s):  
J. S. Hart
Keyword(s):  
Small Mammals ◽  
Heat Production ◽  
Seasonal Changes ◽  
Temperate Zone ◽  
Seasonal Acclimatization

Seasonal changes in insulation of the fur have been compared in nine species of arctic and North temperate zone mammals. Relative seasonal changes ranged from 12 to 52% of the winter value. Absolute changes were greatest in the larger mammals with thickest fur. The limited seasonal insulative change in small mammals suggests that changes in heat production may be important in seasonal acclimatization.

SEASONAL ACCLIMATIZATION IN WILD RATS (RATUS NORVEGICUS)

1963 ◽  
Vol 41 (5) ◽  
pp. 711-716 ◽  
Author(s):  
J. S. Hart ◽  
O. Heroux
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Seasonal Changes ◽  
Size Range ◽  
Metabolic Rates ◽  
Seasonal Acclimatization ◽  
Temperature Range ◽  
Wild Rats

Wild rats were collected from dumps at Cornwall, Ontario, and Kingston, Ontario, during summer and winter, and oxygen consumption was measured at various temperatures from 30 °C to −61 °C. Oxygen consumption varied with body weight0.83 over a size range of 100 to 400 g and was slightly but significantly higher for males than for females. The relation of oxygen consumption to temperature was similar in rats collected during summer and winter over the temperature range from 20° to about −10 °C but at lower and higher temperatures winter rats had higher metabolic rates. When tested at −40° the oxygen consumption of winter-caught rats was maintained for at least 50 minutes while that of the summer-caught rats declined progressively. It is concluded that wild rats exhibit a metabolic acclimatization to seasonal changes in their environment.

The ecology of small mammals in Ogba Forest Reserve, Nigeria

1989 ◽  
Vol 5 (1) ◽  
pp. 51-64 ◽  
Author(s):  
John Giobaguan Iyawe
Keyword(s):  
Small Mammals ◽  
Seasonal Changes ◽  
Common Species ◽  
Dry Season ◽  
Small Rodents ◽  
Wet Season ◽  
Forest Reserve ◽  
Percentage Composition ◽  
Monthly Variations ◽  
Arvicanthis Niloticus

ABSTRACTA total of 392 small mammals belonging to five species of small rodents and four species of shrews were caught. The small mammals and their percentage composition were Crocidura nigeriae (20.9%), Crocidura grandiceps (11.7%), Crocidura crossei (9.7%), Crocidura flavescens manni (20.4%), Mus musculoides (39.0%), Praomys tullbergi (11.5%), Lophuromys sikapusi (3.6%), Lemniscomys striatus (1.3%), and Arvicanthis niloticus (0.3%).There were monthly variations in the number of Mus musculoides and Crocidura nigeriae.In Mus musculoides breeding was at a maximum at the beginning and towards the end of the wet season and early dry season. In Crocidura nigeriae breeding was maximal during the wet season and low in the dry season.The seasonal changes in the age structure of the two most common species: Mus musculoides and Crocidura nigeriae, are described.

Analysis of temporal variation in the diversity of a small mammal community

1985 ◽  
Vol 63 (5) ◽  
pp. 1106-1109 ◽  
Author(s):  
S. C. Asher ◽  
V. G. Thomas
Keyword(s):  
Species Diversity ◽  
Temporal Variation ◽  
Small Mammals ◽  
Small Mammal ◽  
Seasonal Changes ◽  
Single Sample ◽  
Meadow Vole ◽  
Sample Surveys ◽  
Mammal Species ◽  
Mammal Diversity

The validity of using single-sample surveys to measure small mammal diversity was assessed by measuring the effect of short-term, temporal variation in species diversity on the spatial diversity of small mammals occupying fencerow habitats. The diversity of small mammals varied seasonally. Interaction between changes in richness and evenness accounted for the temporal variation in diversity. Temporal variation was attributed to the response of the small mammals to seasonal changes in the vegetation, to the fluctuation in meadow vole (Microtus pennsylvanicus) captures among seasons, and to the appearance of small numbers of several mammal species during the summer. Significant spatial variation in species diversity existed, but was masked by the effect of seasonal changes in habitat on the small mammals. Erroneous conclusions could therefore be drawn from the pooling of many single-sample surveys of small mammal diversity.

ACUTE EXPOSURE OF HUMAN SUBJECTS TO AN AMBIENT TEMPERATURE OF 10 °C

1964 ◽  
Vol 42 (2) ◽  
pp. 233-243 ◽  
Author(s):  
D. A. Hurley ◽  
E. D. L. Topliff ◽  
F. Girling
Keyword(s):  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Heat Production ◽  
Human Subjects ◽  
Healthy Male ◽  
Cold Acclimatization ◽  
Seasonal Acclimatization ◽  
Time Of Year ◽  
Male Subjects ◽  
Shivering Thermogenesis

Acute exposures to cold (10 °C) for 1 hour were carried out in early April on five unclothed healthy male subjects to follow their shivering responses, oxygen consumption, ventilation, skin and oral temperatures. Exposure to the cold resulted in immediate (within 5 minutes) and sustained increases in oxygen consumption, ventilation, and heat production. These subjects did not show generalized shivering, however, until after 30 minutes of exposure, even though short bursts of shivering were noted before this time. The immediate increase in heat production without shivering is indicative of a non-shivering thermogenesis which may be the result of cold-acclimatization in these subjects. Seasonal acclimatization would be maximal at the time of year during which the experiments were carried out.

Seasonal changes in the spatial distribution of phytoplankton in small, temperate-zone lakes

1992 ◽  
Vol 14 (7) ◽  
pp. 1017-1024 ◽  
Author(s):  
James E. Cloern ◽  
Andrea E. Alpine ◽  
Brian E. Cole ◽  
Terry Heller
Keyword(s):  
Spatial Distribution ◽  
Seasonal Changes ◽  
Temperate Zone

Diet of the Eastern Native-Cat, Dasyurus Viverrinus (Shaw), in Southern Tasmania.

1980 ◽  
Vol 7 (2) ◽  
pp. 191 ◽  
Author(s):  
S Blackhall
Keyword(s):  
Small Mammals ◽  
Seasonal Changes ◽  
Plant Material ◽  
New Information

New information on the diet of Dasyurus viverrinus from one locality in southern Tasmania is presented. A total of 64 droppings from 41 animals were collected during 3 intervals over 8 months and examined microscopically. Insects constituted the bulk of the diet and occurred in 97% of the droppings. The remains of birds and small mammals were found in 17% of the droppings. All droppings contained similar amounts of plant material. Seasonal changes in the contribution of different species of prey to the diet of native cats are discussed.

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