Abstract
Heated taxidermic mounts of the gray squirrel were used to analyze the thermal environment of a small arboreal endotherm. Changes in the standard operative temperature (T es) calculated from the temperatures of heated and unheated mounts agreed well with the power consumption (M−E) of mounts on the ground and on the wind-ward side of a 48-cm diameter tree trunk. As wind speed (u) rose and sky solar radiation (Q r) decreased, the windward side of the tree trunk became an increasingly more stressful thermal environment than the leeward side of the trunk or the ground, producingM−E differences of more than 30%. Although theM−E of a ground mount and a limb mount 4 m in the air are dependent onQ ras well asu, the ratio of the two value ofM−E is independent ofQ r, poorly predicted byu and well predicted byu 1/2.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Allen LH Jr (1968) Turbulence and wind speed spectra within a Japanese larch plantation. J Appl Meterol 7:73–78
Bakken GS (1976) A heat transfer analysis of animals: Unifying concepts and the application of metabolism chamber data to field ecology. J Theor Biol 60:337–384
Bakken GS (1980) The use of standard operative temperature in the study of the thermal energetics of birds. Physiol Zool 53:108–119
Bakken GS (1983) A battery-powered three-mode temperature-controller circuit. J Therm Biol 8:297–299
Bakken GS, Buttermer WA, Dawson WR, Gates DM (1981) Heated taxidermic mounts: a means of measuring the standard operative temperature affecting small animals. Ecology 62:311–318
Bakken GS, Erskine DJ, Santee WR (1983) Construction and operation of heated taxidermic mounts used to measure standard operative temperature. Ecology 64:1658–1662
Birkebak RC (1966) Heat transfer in biological systems. Int Rev General Exp Zool 2:369–344
Byman D (1979) Operative temperature: Evaluation and predictive value for diurnal small mammals. Thesis, Colorado State University
Chappell MA (1981) Standard operative temperatures and cost of thermoregulation in the Artic ground squirrel,Spermophilus undulatus. Oecologia 49:397–403
Chappell MA, Bartholomew GA (1981) Standard operative temperatures and thermal energetics of the anterlope ground squirrelAmmospermophilus leucurus. Physiol Zool 54:81–93
Ferron J (1976) Cycle annuel d'activite de l'ecureuil roux (Tamiasciurus hudsonicus), adultes et jeunes en semi-liberte, au Quebec. Nat Can (Que) 103:1–10
Ferron J (1983) Comparative activity patterns of two sympathetic sciurid species. Nat Can (Que) 110:207–212
Ferron J, Quellet JP, Lemay Y (1986) Spring and summer time budgets and feeding behaviour of the red squirrel (Tamiasciurus hudsonicus). Can J Zool 64:385–391
Geiger R (1975) The climate near the ground. Harvard University Press, Cambridge, pp 309–315
Golightly RT, Ohmart RD (1978) Heterothermy in free-ranging Abert's squirrels (Sciurus aberti). Ecology 59:897–909
Hicks EA (1949) Ecological factors affecting the activity of the western fox squirrel,Sciurus niger rufiwenter (Geoffrey). Ecol Monogr 19:287–302
Innes S, Lavigne DM (1979) Comparative energetics of coat colour polymorphs in the eastern grey squirrel,Sciurus carolinensis. Can J Zool 57:585–592
Irving L, Krog H, Monson M (1955) The metabolism of some Alaskan animals in winter and summer. Physiol Zool 28:173–185
Layne JN (1954) The biology of the red squirrel,Tamiasciurus hudsonicus loquax (Bangs), in central New York. Ecol Monogr 24:227–267
Lemnel PA (1970) Telemetry as a method of studying the home range: examples from a study of the red squirrel. Zoologisk Revy 32:51–56
List RJ (1976) Smithsonian Meterological Tables. Smithsonian Institution Press, Washington, DC, pp 411–413
Montgomery SD, Whelan JB, Mosby HS (1975) Bioenergetics of a woodlot gray squirrel population. J Wildl Manage 39:709–717
Morhardt SS, Gates DM (1974) Energy-exchange analysis of the Belding ground squirrel and its habitat. Ecol Monogr 44:17–44
Pauls RW (1978) Behavioral strategies relevant to the energy economy of the red squirrel (Tamiasciurus hudsonicus) Can J Zool 56:1519–1525
Pauls RW (1979) Body temperature dynamics of the red squirrel (Tamiasciurus hudsonicus): adaptations for energy conservation. Can J Zool 57:1349–1354
Pauls RW (1981) Energetics of the red squirrel: A laboratory study of the effects of temperature, seasonal acclimatization, use of the nest and exercise. J Therm Biol 6:79–86
Porter WP, Mitchell JW, Beckman WA, Dewitt CB (1973) Behavioral implications of mechanistic ecology. Thermal and behavior modeling of desert ectotherms and their microenvironment. Oecologia 13:1–54
Pruitt WO, Lucifer CV (1957) Winter activity of red squirrels in interior Alaska. J Mammal 39:443–444
Reynolds JC (1985) Autumn-winter energetics of Holarctic tree squirrels: a review. Mammal Rev 15:137–150
Rosenberg NJ (1974) Microclimate: The biological environment. Wiley, New York, pp 100–112
Thompson DC (1977) Diurnal and seasonal activity of the grey squirrel (Sciurus carolinensis). Can J Zool 55:1185–1189
Tracy CR (1972) Newton's Law: Its applicability for expressing heat losses from homeotherms. Bioscience 22:656–659
Vogel S (1981) Life in moving fluids. Princeton University Press, Princeton, pp 73–76
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Byman, D., Hay, D.B. & Bakken, G.S. Energetic costs of the winter arboreal microclimate: The gray squirrel in a tree. Int J Biometeorol 32, 112–122 (1988). https://doi.org/10.1007/BF01044904
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01044904