Conspecific pheromone trailing and pheromone trail longevity in the African Colubrid Boaedon fuliginosus

In snakes, pheromone trailing is a strategy used for long-distance location of conspecifics. The two existing hypotheses for this behaviour are: a) to locate individuals for reproductive purposes; and b) to form aggregations during the winter/dry season. Pheromone trailing for reproductive purposes has been observed in over 20 snake species representing four different families. The ability of adult male African brown house snakes (Boaedon fuliginosus) to track a sexually attractive female (assumed to be producing pheromones), as well as a conspecific male, was tested using a standard Y-maze. The length of time a female's pheromone remained distinguishable to a male was also tested using the same methodology. Male B. fuliginosus showed a strong ability to trail females both immediately after the trail was left by a female (100%; n = 14) and seven days after a female left a trail (100%; n = 14). After 14 days, however, only 71.4% (n = 14) of males chose the same arm as the female, demonstrating that the pheromone trail degraded over time. Males also trailed other males in 77.8% (n = 18) of trials, which suggests that males may use other male trails to locate females, or navigate through unfamiliar territories.