Sniffing out the Tail of a Whale
The crotch sniff – quite uncomfortable when deployed as a greeting in human culture; standard practice in the dog world.
The sensitivity of a human nose (with its paltry 6 million olfactory receptors) pales in comparison with that of a dogs. According to Professor Alexandra Horowitz dogs have enough olfactory receptors (300 million) to detect a teaspoon of sugar in two Olympic-sized swimming pools’ worth of water. Dogs don’t so much see the world as they smell the world.
This is an incredibly useful skill and we have certainly taken advantage of it in a number of different ways. Dogs are deployed in disaster zones to search for people in the rubble; others are trained to detect bombs. You are probably familiar with the detection dogs at the airport charged with sniffing out things like fresh food or illegal substances – but did you know that dogs are increasingly being used for wildlife conservation research?
If you take a look at this ‘Working Dogs for Conservation‘ website, you’ll find profiles of around 20 different dogs each skilled with a unique list of scents – their scientific CV. The list includes things like shark fin, invasive plants, mussels, turtle eggs, and an extensive menu of poo belonging to bears, gorillas, snow leopards and Hawaiian rosy wolf snails. These animals and plants are either endangered or elusive; the target of poachers or an invasive species wreaking havoc on the ecosystem.
What can poo tell you?
Studying animal scats (scientific term for animal poo) has many advantages – especially when it comes to researching wild animals that are difficult to observe in their natural habitat.
For example, whales – they spend only ten percent of their lives on the surface (to take a breath), and dive to incredible depths where it’s difficult to follow. They don’t leave trails so they can’t be tracked that way – but they do poo. Whale poo (and all animal scats) can contain a wealth of scientific data.
Dr Sam Wasser is a pioneer and champion of non-invasive wildlife monitoring methods. He studies killer whales in Puget Sound in Washington, where they have been listed as endangered since 2005.
Wasser and his team analyse whale poo to find out the answers to obvious questions such as diet and the origin of their prey. They can also ascertain a whale’s genetic identity, which means they can compare multiple samples from the same whale and roughly track an individual’s movements and monitor their health over time. They can also find out the sex of the whale and by looking at levels of certain hormones scientists work out whether a whale is pregnant and the stage of its pregnancy. Stress hormones can also be detected from collected samples as well as residues of chemical pollutants and microplastics which are increasingly plaguing our oceans unfortunately.
Although extraordinarily useful in wildlife research, finding whale poo presents a logistical challenge. Killer whale poo disperses and sinks quickly. The ocean is expansive and whale poo isn’t that easy to spot from a distance. Remember when I said that dogs have the ability to detect sugar in a swimming pool? Well, they can also detect globs of whale poo in an entire ocean. These seafaring dogs work closely with their handlers, sitting on the bow of the boat they sniff the air and are trained to make a signal when something is detected. Scientists and boat captains must then hone in on the target by taking instructions from the handler who is watching the dog’s response as they motor along. On a very windy day dogs can pick up whale scat scent from up to one nautical mile away.
Wasser and his team have worked successfully with a number of conservation canines to collect over 150 samples each year. These samples enable them to track individual whales over time and over large distances to try and piece together why killer whales continue to shrink in numbers.
Through scat analysis, researchers are beginning to understand that the killer whales of Washington are carrying a heavy load of chemicals in their bodies, resulting from pesticides and other industrial chemicals polluting the bay. The whales are also finding it increasingly difficult to find enough salmon to eat as those stocks are also dwindling in numbers.
Without the help of a dog’s nose, scientists would have to rely on less efficient, more expensive and invasive methods of research such as taking tissue samples or using trackers.
So, if you are a biologist or conservation researcher, don’t be too offended the next time you are greeted with a crotch sniff by a dog. You could be meeting a potentially very helpful new volunteer for your next research field trip.