The Fannin sheep around Faro are no longer an anonymous group of animals. If you know what you are looking for, you can pick out Zorro, Raggedy Anne, Bungy and about 50 other individuals just from their markings.

And soon, one might even be able to predict which individual sheep are startled by strangers and which pay them little attention. Researchers from the University of Jyvaskyla in Finland are studying how the sheep react to human disturbance when foraging or nursing their young. They have been observing and photographing the sheep since March, trying to pick out the characteristics that make each one unique.

With all-white Dall sheep, telling one ewe from another can be a tough task so researchers have to put ear tags on the animals to tell them apart. But Fannin sheep are known for their unique markings, and the researchers are using the dark patches on the tails, legs and backs of the animals to identify individuals.

Dr. Charles Jurasz with the Windfall International School of Environs in Faro is collaborating on the project. He had encouraged the researchers to identify the individual sheep by their markings as this approach had worked well for him while studying whales.

Fannin sheep, believed to be a distinct colour phase of thinhorn Stone's sheep, live only in the Yukon. Faro is the easiest place to watch these animals as in winter a herd of about 100 of them graze on south-facing slopes near the community.

People can now watch the sheep from a viewing centre built for that purpose, but wildlife officials want to ensure that the sheep will not be disturbed if more visitors start coming to see them.

"What we would like to do is come up with some guidelines so that we do not love them to death," says Jean Carey, the sheep biologist with the Yukon Department of Renewable Resources.

Carey hopes that this study, with its detailed monitoring of individual sheep, will help biologists determine when disturbance is becoming a problem. She says that visitors might not realize that they are disturbing the sheep if the animals just watch them without moving away, but this is not necessarily the case.

"It's the startle response that is the problem. Disturbance starts way before they get up and leave. If the sheep are being vigilant and watching someone, that is time spent not eating."

Very little research has been done on thinhorn sheep, and the only studies on disturbance have focussed on the affects of aircraft flying overhead. Research on other species of sheep has shown that they can get used to certain types of disturbance, such as cars on a highway, without being bothered too much.

In this project, the researchers are simulating disturbance by moving in to photograph the sheep. John Loehr, a Canadian working on his master's degree in Finland, is studying how disturbance affects the sheep's feeding time.

"When they have experience with a certain reliable form of disturbance, the sheep seem not to react. Right now around Faro the sheep do not encounter a lot of disturbances, but there will be more and more tourists so it could be a question of what they can take," he says.

Raimo Saunanen, the photographer on the project, says that before lambing season began, the sheep would sometimes approach him, coming as close as four metres away.

But sheep are known to be more wary during lambing season, which is taking place right now. For her master's thesis, Miina Kovanen is focussing on how disturbance affects nursing behaviour in the sheep.

"We do not know how they will react to disturbance with the lambs. It might be that they do not feel safe enough to nurse the lambs if there is a disturbance," she says, adding that the researchers will change their methods if they do seem to be disrupting the sheep.

The Faro sheep might not have a lot of experience with tourists, but this herd is well acquainted with mining activity. They migrate through the former mine area twice a year when moving between their winter and summer ranges, and did so even when the mine was running.

But every type of disturbance is unique, and Carey hopes that more studies will take place on this group of animals in the future. She says that research on how the sheep react to winter disturbances such as snowmobiling is also needed.

If the animals' markings do not vary too much from year to year, this herd of identifiable sheep could be a major bonus for any future research efforts.

"Someone else who wants to do behavioural research on the sheep would have more than 50 marked individuals without even having to touch them," says Carey. "Research is much more powerful when you can identify individuals."

The research is being supported by an endowment from the Northern Research Institute at Yukon College. For more information on this project, go to their web page at http://www.cc.jyu.fi/~johloeh/researchproject1.html.