Age-Related Body Mass and Reproductive Measurements of Gray Wolves in Minnesota

• Published in: Journal of Mammalogy
• Main Author: Mech, L. David
• Format: Text
• Language: English
• Published: Oxford University Press 2006
• Subjects: Feature Articles; Canis lupus
• Online Access: http://jmammal.oxfordjournals.org/cgi/content/short/87/1/80; https://doi.org/10.1644/05-MAMM-F-212R1.1

Based on 65 free-ranging gray wolves ( Canis lupus ) of known age and 25 of estimated age examined during summers of 1970–2004 in northeastern Minnesota, body mass of both males and females peaked at 5 or 6 years of age, with mean masses of 40.8 kg and 31.2 kg, respectively. Testis size varied as a function of age and month through at least 8 years of age, with length plus width ranging from 1.9 to 7.8 cm. Most females aged 4–9 years bred based on assessment of nipple sizes; those that had not bred had average lower body mass than those that had. This is the 1st report of such data from known-aged wolves.