Government of Yukon biologists are conducting the latest, and largest, aerial survey of Dall sheep this month.

The survey will focus on an area in southern Yukon from Carcross to past Kluane Lake. Biologists say that's the area most accessible to hunters. Previous surveys have focused on the Richardson Mountains in northern Yukon.

"Often we will do our sheep surveys on smaller areas, say a handful of game management subzones," said biologist Troy Hegel. "But in this case, it gives us this regional perspective so we can look at what the status of sheep populations are across, essentially, southwest Yukon."

One question biologists hope to answer is whether recent changes to permitting have put extra pressure on areas where permits aren't required. Hegel said hunters are moving into other permit zones because they didn't get permits in other areas. "We wanted to look at the status of sheep populations that are more accessible."

Biologists are counting the number of sheep, lambs and rams from the air. Rams are classified based on the amount of curl in the horns. Full-curl rams are older and are the only ones that can be hunted in Yukon, Hegel said.

"You have to have a pretty keen eye and be able to classify these things really quickly," he said. "We don't hover over a group of animals long."

Hegel says the survey may prompt changes to sheep hunting regulations.

But he says it will likely take a few more weeks to complete the survey and then a few months to analyse the data.