Thermoregulation by foxes

The main objective of this study was to develop a model of the thermoregulatory control system which could be used to predict the responses of unrestrained foxes of different species to naturally occurring thermal stress. The studied species included the red fox (Vulpes vulpes), arctic fox (Alopex l...

Full description

Bibliographic Details
Main Author: Klir, John Jan
Other Authors: Heath, J. E.
Format: Text
Language:English
Published: 1991
Subjects:
Online Access:http://hdl.handle.net/2142/22216
id ftunivillidea:oai:www.ideals.illinois.edu:2142/22216
record_format openpolar
spelling ftunivillidea:oai:www.ideals.illinois.edu:2142/22216 2023-05-15T13:19:56+02:00 Thermoregulation by foxes Klir, John Jan Heath, J. E. 1991 http://hdl.handle.net/2142/22216 eng eng http://hdl.handle.net/2142/22216 (UMI)AAI9210873 AAI9210873 Copyright 1991 Klir, John Jan Biology Animal Physiology text 1991 ftunivillidea 2014-01-12T19:38:39Z The main objective of this study was to develop a model of the thermoregulatory control system which could be used to predict the responses of unrestrained foxes of different species to naturally occurring thermal stress. The studied species included the red fox (Vulpes vulpes), arctic fox (Alopex lagopus), and kit fox (Vulpes macrotis). The model was used to test hypothesis whether species of foxes occupying different habitats do or do not use the same thermoregulatory control system. First, infrared (IR) thermography was used to study the control of surface temperature in undisturbed foxes exposed to naturally occurring thermal stress. The resting metabolic rate (RMR) and evaporative water loss (EWL) in the red and arctic fox was measured as oxygen consumption at various ambient temperatures (T$\sb{\rm a}$) using metabolic chamber. Total heat flow from the animal's surface (Q$\sb{\rm t}$) was calculated using the surface temperature measurements. Second, red foxes were surgically implanted in the POAH with two thermodes to control the temperatures of this region. The temperature of the POAH (T$\sb{\rm poah}$) was monitored with an implanted thermocouple. Deep body temperature (T$\sb{\rm b}$), surface temperature, and metabolic rate (MR) were measured. The animals were exposed to various T$\sb{\rm a}$ in a temperature chamber. The most important thermoregulatory surfaces include the area of the dorsal head, face, nose, pinna, lower legs, and paws in the red and kit fox, and the face, nose, front of the pinna, lower legs, and paws in the arctic fox. Although the thermoregulatory effective surface areas represent only about 30% of the total surface area, the animals can lose more than 70% of the total radiative and convective heat loss through these areas. These surfaces are relatively large in the kit fox, small in the arctic fox, and intermediate in the red fox. MR increased during both heating and cooling of the POAH. Resting T$\sb{\rm poah}$ was lower than T$\sb{\rm b}$ at all temperatures which indicates presence of some form of brain cooling mechanism. The surface temperature responses to POAH heating or cooling indicated that the thermoregulatory vasomotor responses can occur within one minute following POAH stimulation. The data support the hypothesis that species of foxes occupying different habitats use the same central thermoregulatory control system, and that they differ basically only in thermoregulatory effectors such as relative size of the thermoregulatory effective surface areas, insulation, vasomotor control, and evaporative heat loss. Text Alopex lagopus Arctic Fox Arctic University of Illinois at Urbana-Champaign: IDEALS (Illinois Digital Environment for Access to Learning and Scholarship) Arctic
institution Open Polar
collection University of Illinois at Urbana-Champaign: IDEALS (Illinois Digital Environment for Access to Learning and Scholarship)
op_collection_id ftunivillidea
language English
topic Biology
Animal Physiology
spellingShingle Biology
Animal Physiology
Klir, John Jan
Thermoregulation by foxes
topic_facet Biology
Animal Physiology
description The main objective of this study was to develop a model of the thermoregulatory control system which could be used to predict the responses of unrestrained foxes of different species to naturally occurring thermal stress. The studied species included the red fox (Vulpes vulpes), arctic fox (Alopex lagopus), and kit fox (Vulpes macrotis). The model was used to test hypothesis whether species of foxes occupying different habitats do or do not use the same thermoregulatory control system. First, infrared (IR) thermography was used to study the control of surface temperature in undisturbed foxes exposed to naturally occurring thermal stress. The resting metabolic rate (RMR) and evaporative water loss (EWL) in the red and arctic fox was measured as oxygen consumption at various ambient temperatures (T$\sb{\rm a}$) using metabolic chamber. Total heat flow from the animal's surface (Q$\sb{\rm t}$) was calculated using the surface temperature measurements. Second, red foxes were surgically implanted in the POAH with two thermodes to control the temperatures of this region. The temperature of the POAH (T$\sb{\rm poah}$) was monitored with an implanted thermocouple. Deep body temperature (T$\sb{\rm b}$), surface temperature, and metabolic rate (MR) were measured. The animals were exposed to various T$\sb{\rm a}$ in a temperature chamber. The most important thermoregulatory surfaces include the area of the dorsal head, face, nose, pinna, lower legs, and paws in the red and kit fox, and the face, nose, front of the pinna, lower legs, and paws in the arctic fox. Although the thermoregulatory effective surface areas represent only about 30% of the total surface area, the animals can lose more than 70% of the total radiative and convective heat loss through these areas. These surfaces are relatively large in the kit fox, small in the arctic fox, and intermediate in the red fox. MR increased during both heating and cooling of the POAH. Resting T$\sb{\rm poah}$ was lower than T$\sb{\rm b}$ at all temperatures which indicates presence of some form of brain cooling mechanism. The surface temperature responses to POAH heating or cooling indicated that the thermoregulatory vasomotor responses can occur within one minute following POAH stimulation. The data support the hypothesis that species of foxes occupying different habitats use the same central thermoregulatory control system, and that they differ basically only in thermoregulatory effectors such as relative size of the thermoregulatory effective surface areas, insulation, vasomotor control, and evaporative heat loss.
author2 Heath, J. E.
format Text
author Klir, John Jan
author_facet Klir, John Jan
author_sort Klir, John Jan
title Thermoregulation by foxes
title_short Thermoregulation by foxes
title_full Thermoregulation by foxes
title_fullStr Thermoregulation by foxes
title_full_unstemmed Thermoregulation by foxes
title_sort thermoregulation by foxes
publishDate 1991
url http://hdl.handle.net/2142/22216
geographic Arctic
geographic_facet Arctic
genre Alopex lagopus
Arctic Fox
Arctic
genre_facet Alopex lagopus
Arctic Fox
Arctic
op_relation http://hdl.handle.net/2142/22216
(UMI)AAI9210873
AAI9210873
op_rights Copyright 1991 Klir, John Jan
_version_ 1766350317056688128