Dr. Bradley's home state of Oklahoma is one of several working with the One Health Initiative, a global program to improve communication between physicians and veterinarians to prevent the spread of infectious disease from animals to people, such as recommending tick collars, sprays or topical treatments with pesticides for dogs.

WSJ: This Season's Ticking Bomb

The study, the first of its kind to use the satellite-based global positioning system to provide the animals' locations, involved tagging 14 African elephants with sophisticated radio collars and monitoring their movements for several months.

ECONOMIST: Elephant behaviour