Relationship of Mass to Girth in Raccoons, Procyon lotor (Mam- 

 malia: Procyonidae), from West Tennessee 



Troy A. Ladine 1 



The University of Memphis, Edward J. Meeman Biological Station 



and Ecology and Organismal Biology, Campus Box 526080, 



Memphis, Tennessee 38152-6080 



ABSTRACT--Mass to girth ratio of 103 captured, adult (>14 months) 

 raccoons (Procyon lotor) was analyzed to assess allometric relation- 

 ships. Use of this ratio as a measure of physical condition was investi- 

 gated with linear regression and a comparison of the ratio by year, sea- 

 son, sex, and age. There was no statistically significant difference 

 among years (F = 0.17; P = 0.8473) or between seasons (F = 1.13; P = 

 0.2916). The ratio differed significantly among ages and was smallest 

 for raccoons 14 to 38 months in age (F = 12.31; P = 0.0001). Males 

 exhibited a significantly larger ratio than females (F = 25.03; P = 

 0.0001). There was no difference found within all groupings in paral- 

 lelism or coincidence based on the regression equations. The regression 

 equation for mass to girth for all individuals was Mass = 0.02916 * 

 (Girth) - 5.5904 (r 2 = 0.8044; P = 0.0001). Although the allometric rela- 

 tionship between the mass and girth of raccoons was significant, this 

 relationship does not appear to be indicative of the physical condition 

 of the animal. 



Estimating fitness of individuals in a population requires direct count of 

 the reproductive success of the females or some other measure of physical con- 

 dition such as antler beam diameter of white-tailed deer (Odocoileus virgini- 

 anus)(Ua\\s 1984), or kidney fat index of white-tailed deer and raccoons (Procy- 

 on lotor)( Johnson 1970, Glenn and Clark 1990). When studying medium-sized 

 nocturnal mammals, it is difficult to accurately determine the number of off- 

 spring produced per female in live animals because typical measures of physical 

 condition (such as placental scar counts, body fat indices, kidney fat indices) 

 involve sacrificing the individual (Johnson 1970, Sanderson and Nalbandov 

 1973, Glenn and Clark 1990). In long-term population and community ecology 

 studies, sacrificing individuals is not a suitable method. Thus, a nondestructive 

 method of quantitatively reporting physical condition is needed. 



1 Present Address: Division of Mathematics and Science, Bethel College, McKenzie, Tennessee 38201. 



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