My introduction to working with dogs came fifteen years ago, on the tall grass prairie of Kansas. With the assistance of two very willing Australian Shepherds and one more restrained Samoyed, the dogs’ owner and I designed and carried out an experiment to test how far canines could smell, and how their prodigious noses might be affected by changes in environmental conditions such as air temperature, wind speed, and relative humidity.
As it turned out, the dogs were able to pick up and alert us smell-challenged humans to the scent of a standard odor attractant pill up to 1 kilometer away if the winds were gentle, temperatures mild, and the relative humidity was high. While this finding alone was amazing (I could only smell the stinky pill if it was within an arm’s length of my nose), what our study implied was even more interesting.
You see, we were using the dogs as models for their wild cousins – Canis latrans, the coyote, to better understand the population dynamics of coyotes on the prairie, and large predator ecology of the region more generally. To study coyote population sizes at the time, wildlife ecologists typically set out an odor attractant, surrounded it with spread-out sand, and then came back later to record coyote tracks in the sand. But this method didn’t provide a good estimate for how large of an area is sampled. The question remained: from how far away could coyotes smell the odor of the attractant pill? Because coyotes are wild animals, designing a method to allow us to judge their ability to smell would have been difficult. Domesticated and agility trained dogs (with otherwise normal smelling capabilities for dogs) provide a rough approximation of what coyotes might be observing, thereby opening a window between humans and the wild, and giving us some insight into the coyote’s sensory world.
The ability of dogs to smell better than humans is legendary, and their ability to be trained to alert humans when they pick up a particular scent has allowed people to harness their sensory capability for a variety of purposes. In The Sign of Four, Sherlock Holmes prefers the help of a dog named Toby to “that of the whole detective force in London”. Dogs have also been trained to sniff out leaky gas lines underground, explosives, narcotics in the luggage of drug traffickers, even the onset of a seizure or cancer cells in the human body. The use of dogs in conservation is more recent, but no less potent. Examples include the ability to detect the unique scent of rare plants or the traces of small animals (such as salamanders) that are difficult for people to find easily.
While the methods used by predator ecologists to track larger animals have changed significantly in the past two decades due to advances in radio and GPS technologies, for a visually-focused species such as humans, dogs are still a huge boon. Until we all have Star-Trek tricorders that can mimic a dog’s capabilities, Man’s Best Friend is also our best bet for tracking scents. Kept on leash and properly trained, dogs can be one of conservation’s best friends, too.