Indices Using External Measurements for Assessing Fat Deposition of Adult Feral Raccoons (Procyon lotor) in Kanagawa Prefecture, Japan

Abstract

ABSTRACT. We examined the use of external measurements and relative fat deposition of adult feral raccoons (Procyon lotor) to develop relative indices of body fat deposition in post-growth feral raccoons. From March 2006 to March 2010, 288 adult raccoon carcasses (110 males, 178 females) collected in Kanagawa Prefecture, Japan, which were determined to be 24 months old, were subjected to external measurements of body weight (BW), girth measurement (GM), and body mass index (BMI). To assess relative body fat deposition, we visually classified abdominal subcutaneous fat into three grades (Visible Fat Index [VFI]: I-III). Significant differences in the means of BW (both sexes:P<0.01), GM (females: P<0.05, males: P<0.01), and BMI (both sexes: P<0.01) were detected between seasons. Notably, the means of BW, GM, and BMI (all, both sexes: P<0.01) differed significantly between VFI grades. However, by discriminant analysis with BW, GM, and BMI as independent variables, we obtained a significant discriminant function (both sexes: P<0.01) for distinguishing VFI I from higher VFI grades, but no significant equation was obtained for distinguishing between VFI II and VFI III. Based on the obtained structure matrix of discriminant analysis, BMI was the most valuable component for the discrimination of VFI grades. Thus, we conclude that BMI is a suitable complementary index for assessing relative body fat deposition of adult feral raccoons in Kanagawa Prefecture and may be generalizable to populations in other areas.KEY WORDS: body mass index, external measurement, fat deposition, Procyon lotor, raccoon.

Difference in Age at First Conception between Early and Late Litters of Feral Raccoon (<i>Procyon lotor</i>) in Kanagawa Prefecture

“…Due to the small sample size, we could not evaluate the pregnancy rate or litter size in each age class. Additionally, we evaluated body mass index (BMI; BMI=BW (kg)/ BL (m) 2 ) as a relative index of body fat deposition according to previous studies [16,24]. The BW of pregnant females was calculated by excluding fetal weight.…”

Body Length and Craniometrics of Non-Native Raccoons in Two Regions in Middle Japan during Early Invasion Stages

“…In addition, the BMI of female raccoons in Kamakura was reported to increase with their growth until maturity despite seasonal fluctuations [63]. Based on BMI evaluation of the body condition index of raccoons [40,64], individuals with high BMI can be considered to have good physiques. Raccoon cranial width dimensions in particular, indicated an advantageous factor for competition among individuals and was related to body length growth and BMI in the two introduced populations in middle Japan.…”

“…Body weight (in g) and length (in mm: nose to tail, subtracting the tail length) were then measured. To analyze the body condition and nutritional status of individuals, the body mass index (BMI) was estimated using the formula W/L 2 , where W is the body weight expressed in kg and L is the body length expressed in meters [40].…”

Methods of evaluating the spermatogenic ability of male raccoons (Procyon lotor)

“…We examined BW and BL, which was calculated according to the equation BL (mm) = TL (mm) – LTV (mm), to evaluate the spermatogenic ability of raccoons. BMI was calculated according to the equation BMI = BW (kg) / BL (m) 2 and was used as an index of nutritional status because it was a suitable complementary index for assessing the relative body fat of raccoons [ 21 ]. TW and EW were taken as the means of the right and left organs.…”