Measuring the Metabolic Response Curves of Rufus and Melanistic Fox Squirrels (Sciurus niger)
Advisor Information
James Wilson
Location
UNO Criss Library, Room 231
Presentation Type
Oral Presentation
Start Date
2-3-2018 9:45 AM
End Date
2-3-2018 10:00 AM
Abstract
Melanism, the presence of black fur, skin, or feathers, is a trait commonly found in vertebrates. Eastern fox squirrels (Sciurus niger) are usually a reddish orange (rufus) color, but some individuals express a melanistic trait making them completely black. The proportion of these individuals is increasing and moving westward in the Omaha area. Melanism has been associated with crypsis from predators on dark substrate, but the selective advantage in Omaha is currently unknown. Previous research investigated melanism and skin temperature, but metabolic activity (heat production) was unknown. I assessed the metabolic rates of the two color morphs at eight temperatures in order to examine any differences in metabolic production. I measured the metabolic rates of 23 (13 rufus and 10 melanistic) wild-caught fox squirrels in the Omaha area. No significant difference was detected between the metabolic response curves of the two color morphs. The lower critical temperature for the combined melanistic and rufus fox squirrels was 28.63 ºC. In order to fully understand thermal advantages of S. niger in Omaha, further studies need to be carried out involving the assessment of hair morphology, genetics, and insulation (fat).
Measuring the Metabolic Response Curves of Rufus and Melanistic Fox Squirrels (Sciurus niger)
UNO Criss Library, Room 231
Melanism, the presence of black fur, skin, or feathers, is a trait commonly found in vertebrates. Eastern fox squirrels (Sciurus niger) are usually a reddish orange (rufus) color, but some individuals express a melanistic trait making them completely black. The proportion of these individuals is increasing and moving westward in the Omaha area. Melanism has been associated with crypsis from predators on dark substrate, but the selective advantage in Omaha is currently unknown. Previous research investigated melanism and skin temperature, but metabolic activity (heat production) was unknown. I assessed the metabolic rates of the two color morphs at eight temperatures in order to examine any differences in metabolic production. I measured the metabolic rates of 23 (13 rufus and 10 melanistic) wild-caught fox squirrels in the Omaha area. No significant difference was detected between the metabolic response curves of the two color morphs. The lower critical temperature for the combined melanistic and rufus fox squirrels was 28.63 ºC. In order to fully understand thermal advantages of S. niger in Omaha, further studies need to be carried out involving the assessment of hair morphology, genetics, and insulation (fat).