Influence of age, sex, season and living conditions on body weight in Marsican brown bear (Ursus arctos marsicanus) captured in Abruzzo, Lazio and Molise National Park.

• Main Authors: Leonardo Gentile, Roberta Latini, Vincenza Di Pirro, Elisa Tubiana, CONTIERO, BARBARA, DE BENEDICTIS, GIULIA MARIA
• Other Authors: Leonardo, Gentile, Roberta, Latini, Vincenza Di, Pirro, Elisa, Tubiana, Contiero, Barbara
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: Brown bear; body weight; Ursus arctos
• Online Access: http://hdl.handle.net/11577/2842506

The aim of this work is to define the physiological range of body weight in the Mariscan brown bear population in wild and captive living conditions. Data were extrapolated from selected anesthetic records collected during bear captures in the Abruzzo Lazio and Molise National Park from 1990 to 2013. Forty-four Marsican bears were chemically immobilized on 171 occasions and body weight recorded, for individual marking or for ecologic, genetic, and health reasons. Values were obtained from animals captured in wild (n=83) and captive situations (n=88). Weight data were analyzed by a linear model including the effects of class of age, sex, wild or captive environment and their interactions. The effects of period of the year and sex on body weight and their interactions were also analyzed by ANOVA tests. Statistical significance was set at P<0.05. Mean body weight was influenced by age class and sex. From juvenile and subadult age, weight gain is similar in both males and females; older male bears resulted heavier than females and this difference is statistically significant for both adult and mature age groups. Moreover, a significant difference in weight (least squares means±standard error) was observed in captive adult males (188.41±6.04 kg, n=14) compared to wild adult males (157.89±3.99 kg, n= 32), but not in adult females. In adults, body weight was influenced by seasonality. Female animals constantly increased their weight from post-hibernation to pre-hibernation period (mean weight gain 7%); males showed a weight loss during the reproductive period (-8%, P<0.05) and a significant weight gain after this period of time (13%). During all the period of time, from the post-hibernation, females have a increase of their initial weight of 23%, males of 16%. In conclusion, in Marsican bears body weight depends on age, sex, seasonality and living conditions.