The effects of GPS collars on African elephant (Loxodonta africana) behavior at the San Diego Zoo Safari Park

The use of tracking devices (e.g., VHF radio collars, GPS collars, ear transmitters) enables researchers to assess activity budgets, species-specific movement patterns, effects of environmental enrichment, and exercise levels in zoo animals. The fundamental assumption in these studies of tagged animals is that attachable tracking devices have negligible effects on the animals’ behavior. The present study examined solitary and social behavior rates, as well as overall activity budgets, in eight African elephants living at the San Diego Zoo Safari Park, Escondido, CA, USA. Each elephant was trained over several months to wear leather collars affixed with GPS units encased in watertight plastic containers. Behavioral data collected while the GPS collars were worn (16 daylight hours, 16 night hours) were compared to behavioral data when the GPS collars were not worn (16 daylight hours, 16 night hours) throughout June and July 2010. No significant differences (P < 0.05) in behavior rates or average percent of observation time the subjects were recorded in particular states were found. During the morning hours, while the collars were both worn and not worn, feeding was the most common behavior state (M = 44.7 ± 3.8%, M = 49.3 ± 15.3%), followed by resting (M = 35.5 ± 10%, M = 37.3 ± 12%) and walking (M = 10 ± 3.1%, M = 8.7 ± 1.9%). During the evening hours, feeding remained the most common behavior state for both worn and not worn conditions (M = 66.1 ± 12.3%, M = 63.3 ± 13.7%), followed by resting (M = 17.6 ± 7.7%, M = 19.4 ± 9.5%), and sleeping (M = 8.1 ± 8.9%, M = 7.8 ± 8.1%). This distribution of daily behavior state is similar to previous activity budgets examined in other zoo elephant herds. These results suggest that, with adequate training, GPS collars may have minimal impact on the behavior of zoo elephants.