Time budgets of adult Przewalski horses: Effects of sex, reproductive status and enclosure

Abstract

Fifteen male and 27 female Przewalski horses were observed in a variety of contexts to determine whether gender, reproductive status or type of enclosure influenced their time budget. The horses were maintained in small dirt-floored yards, large barren enclosures or large grassy pastures. The stallions were either solitary, in bachelor groups or in harems. All females were in harems and were classified as neither pregnant nor lactating, pregnant but not lactating, lactating but not pregnant, or both pregnant and lactating. Fifteen-minute focal-animal samples were used to determine time dudgets. The behavioral states recorded were feeding (with coprophagy as a subset), drinking, standing, stand-resting, self-grooming, mutual grooming, locomoting (with pacing as a sub-set), playing and recumbency. The average number of behavioral states occurring per hour, and the defecation, urination, flehmen, aggression and vocalization rates were also determined. Rates of marking and masturbation were also determined for males. Even in captivity, male Przewalski horses devoted more time to behaviors that would be necessary for harem acquisition and defense in the wild. Males were more active than females; they locomoted more and exhibited greater numbers of behaviours per hour. Females devoted more time to foraging and interacting with other herd members. Females mutual groomed more than males; perhaps because they had kin in the herd, whereas males did not. Solitary males and bachelors exhibited more transitions per hour than harem males. Solitary males paced more than bachelors or harem males. Pregnant and/or lactating females spent more time feeding than barren females. Horses in small enclosures spent less time stand-resting and changed behavior states frequently. The presence of forage ad libitum eliminated coprophagy and greatly reduced the amount of pacing observed.