Talking scents

The canine nose is an astonishingly complex piece of biotechnology that man has harnessed for sustenance and sport for thousands of years

- Janet Menzies

HUNTING with dogs is one thing, and hunting with hounds is quite another. Dogs do things differently from hounds. Whether they are gundogs (spaniels or pointers, for example) or hounds such as foxhounds and bloodhounds, every breed and type of dog working in the field has its own approach. Modern bloodhounds have been trained to hunt the clean boot. Spaniels are best following bodily odours on the ground. Pointers are air scenters. Some hounds greyhounds, for instance - are sighthounds and will ignore their noses in favour of their eyes.

In the bitterly divisive days when the Hunting Act 2004 was passed, one small detail was particularly hard for hunting folk to swallow. The phrase 'hunting with dogs' seemed deliberately calculated to cause offence: because foxes and other banned quarry were not hunted with dogs but with hounds. There is more to this than hurt feelings. Having a thorough understanding of the way different breeds and species use their senses is a huge element of successful fieldcraft, no matter what the sport. For anyone who works a hound or a gundog, the distinctions between how they find and follow scent are important, and humans must learn what a hound knows instinctively about scent.

The science of scent

Scent begins its life as an organic compound of chemicals contained within a molecule. Scent molecules have many different homes (the medium) from where they gradually diffuse into the environment. Depending on conditions, many get swept into the air or washed away completely but most odour molecules are attached to the ground or objects on the ground. This is where they encounter an extraordinarily complex piece of biotechnology called a nose, which has a hound, gundog or detection dog operating it.