Life history traits of gaur Bos gaurus
Data were collected from a 20-month field study in South India and from captive gaur populations. Mean age of females at first parturition was 3 years; females remained fertile beyond the age of 15 years. Adult females were three times more abundant than adult males in the wild; survival of females was greater than males beyond three years of age. Life span of both sexes has not exceeded 24 years in captivity. Gaur life-history traits are similar to those of other similar-sized Bovini species.
Data were collected from a 20-month field study in South India and from captive gaur populations. Mean age of females at first parturition was 3 years; females remained fertile beyond the age of 15 years. Adult females were three times more abundant than adult males in the wild; survival of females was greater than males beyond three years of age. Life span of both sexes has not exceeded 24 years in captivity. Gaur life-history traits are similar to those of other similar-sized Bovini species.
Relative abundance of calves (<1yr), males (>1yr), and females (>1yr) found in five studies of gaur in India: Kanha National Park, Madhya Pradesh - Schaller (1967); Parambikulam Wildlife Sanctuary, Kerala - Vairavel (1998); Nagarahole National Park, Karnataka - Karanth and Sunquist (1995); Mudumalai National Park, Tamil Nadu - Kumar et al. (2004); This study: Mudumalai & Bandipur National Parks, South India.
Age and sex determination of gaur Bos gaurus
One reason why the gaur Bos gaurus is a poorly understood species is because there are no reliable data to age and sex individuals. We studied captive gaur for two years in Mysore Zoo, India, and Omaha Zoo, USA. We ascertained age-specific differences in the morphological features and the physical growth, by measuring the shoulder height, of male and female gaur. We fitted von Bertalanffy growth functions to the shoulder height data and found maximum shoulder heights of 175 cm and 147 cm for males and females respectively. This study ascertained for the first time that the greater the amount of white on horns, the older the gaur individual, and that the sexes can be distinguished based on horn shape and size differences. We found that gaur aged 15 months and below can be classified into three age classes, but are difficult to sex. The sex of gaur aged 15-36 months is best determined by a study of their horns. Adult gaur, greater than three years, are easy to sex, but are difficult to classify into single-year age classes and are reliably classified only into two ages classes for females and three for males.
One reason why the gaur Bos gaurus is a poorly understood species is because there are no reliable data to age and sex individuals. We studied captive gaur for two years in Mysore Zoo, India, and Omaha Zoo, USA. We ascertained age-specific differences in the morphological features and the physical growth, by measuring the shoulder height, of male and female gaur. We fitted von Bertalanffy growth functions to the shoulder height data and found maximum shoulder heights of 175 cm and 147 cm for males and females respectively. This study ascertained for the first time that the greater the amount of white on horns, the older the gaur individual, and that the sexes can be distinguished based on horn shape and size differences. We found that gaur aged 15 months and below can be classified into three age classes, but are difficult to sex. The sex of gaur aged 15-36 months is best determined by a study of their horns. Adult gaur, greater than three years, are easy to sex, but are difficult to classify into single-year age classes and are reliably classified only into two ages classes for females and three for males.