Date of this Version
A tota1 of 873 Flehmen (lip curl) displays by bison (Bison bison) was recorded and statistically analyzed in relation to individual factors such as age and sex, and external factors such as wind speed, wind direction, temperature, humidity, and Flehmen stimulus to determine if differences between subgroups of individuals existed and if Flehmen was environmentally affected. The mean lip curl display duration for all individuals was 8.4 seconds. Statistical tests of Flehmen duration means grouped by Flehmen stimuli showed a significant difference (p < 0.05). Lip curl duration means for males (8.3 sec.) and females (9.3 sec.), "maturity classes", all age-classes, cow age-classes, and bull age-classes were significantly different (p < 0.05). Because of a marked decrease of duration means for "prime" bulls, some relationship between Flehmen duration and sexual behavior of bulls was suggested. Windspeed, humidity, and temperature were determined to have little influence on lip curl duration. No significant correlation was found between lip curl direction and wind direction. Local variations of windspeed, wind direction, humidity, and temperature around the lip curling individual do not permit legitimate conclusions regarding their effect on Flehmen duration and direction.