One. Step. At. A. Time.

And remember to smack the data logger before we go. I repeat this mantra under my breath as my fellow Parks Canada ecologist and I assemble one last caribou summer range monitoring site in Nanh Thok Natr’iniin’aii, also known as Vuntut National Park, in northern Yukon. We’re trying to work carefully, but dark clouds are rolling in from the east and mosquitoes are working themselves through the gaps in our bug jackets. The helicopter pilot stands nearby, warily watching the sky and us.

It’s early September and we’re well above the Arctic Circle. If the storm catches us we may be stuck in impenetrable fog and mosquitoes until morning. As we push to finish up, I try to focus on why we’re here—we’re among many working to build a bright future for a caribou herd.
The Porcupine Caribou Herd is one of the largest barren-ground caribou herds in North America. It numbered approximately 220,000 when it was last counted in 2017, a record-breaking high. Despite this, the herd faces challenges. Among them, climate change is expected to dramatically affect snow, vegetation and permafrost throughout the herd’s range, including Nanh Thok Natr’iniin’aii. How a warming climate will affect caribou is what we’re so eager to understand.

Nanh Thok Natr’iniin’aii was created in 1995 through the Vuntut Gwitchin First Nation Final Agreement. It is cooperatively managed by Vuntut Gwitchin Government, North Yukon Renewable Resources Council and Parks Canada. The park protects summer range vital to the herd. It’s an important stop along their yearly route through Alaska, Yukon and the Northwest Territories. This journey represents one of the longest migrations of any land mammal in the world.

By mid-July, many caribou are on their summer range in the park and surrounding area, feasting on abundant, nitrogen-rich foods, including leafy shrubs and flowering plants. These important foods help caribou recover energy reserves lost during the winter. They help females produce milk for their new calves and males to build strength for the fall rut. Caribou also seek out the park’s windy mountain ridges and snow and ice patches to find relief from the hordes of biting insects that have plagued them since early summer.

Understanding ecological changes to key habitats and their effects on caribou is a group effort. It involves many partners and relies on both Indigenous Knowledge and western science. On this day, our Parks Canada team is collecting ground-based scientific measurements, which can be tricky. The nearest road is more than 150 kilometres away and there are no cabins or aircraft landing strips in the park. A helicopter is the only practical means of getting around. In a typical year we get just one chance to visit the summer range. Thanks to the commitment of cooperative management partners and stubborn determination from our crew, we now have a network of 10 monitoring sites in the middle of prime caribou summer habitat.


Each site has equipment that measures key information and records it in a data logger—a digital processor with sensors, housed in a protective case. We are capturing things such as permafrost temperatures, snow season duration, snow depth, growing season duration and depth of ground thaw. There is no room here for fussy scientific equipment. Things have to work at -40 degrees C and colder, be simple to maintain and tough enough to handle inquisitive wildlife. We bolster the precise equipment with hardware store parts, creating a scientific Frankenstein that loses in looks, but wins in reliability. And we remember to smack the data logger before we go, a few knocks to make sure that it’s up for a year alone in northern Yukon. That’s not something you’ll find in the owner’s manual, but better to test it now.

We finish our work in Nanh Thok Natr’iniin’aii and leave in the helicopter before the storm arrives. The tundra passing below us is mesmerizing. It’s bright red and yellow now and, in many places, goes on as far as the eye can see. The caribou need it badly, especially these days. I sit back and can finally enjoy the view as another field season wraps up. I hope the data loggers work all winter. I hope they help the caribou find that bright future.

The Gwich’in’s journey to protect the Arctic Refuge