Collecting Grizzly Hair for DNA Analysis - Volunteering Project
Summary: An important volunteering project with the Chilcotin Ark Institute is collecting grizzly bear hair for DNA analysis to learn more about their populations and health.
Riding along the trail, suddenly we stop at a tree that to the untrained eye looks like any other. But when you take a closer look, you can see what we are collecting – the hair caught on the bark. It’s grizzly bear hair and we use it for DNA analysis. This is an important part of conserving the bears and other animals of the Chilcotin Ark as we can gather a lot of information about the population from this simple act of collecting hair.
When we collect grizzly hair for DNA analysis for this conservation volunteering project, we need to be in the right place to find rub trees and make our collection successful. Just like with our horses that are free to graze on the range six months of the year, they are going to go where they want to go. If we put them where we want them to go, we’re going to be looking for them in the places they want to go anyway, so we might as well put them where they want to go.
The same concept applies to grizzly bears. They live in higher elevation alpine valleys and meadows. They don’t live above treeline or in the lower elevation valley bottoms, so there’s no point trying to collect grizzly hair here. Bear habitat is bear habitat. If a grizzly lived in a certain place last year, a grizzly will live here again this year, and every year going forward, barring major ecosystem disruption or human disturbance. So, we don’t try to collect grizzly hair in the places they aren’t. We use the trees the bears themselves use as rub trees. This is part of being a part of nature, not imposing ourselves on it.
Instead of traditional methods of collecting wildlife data, where you need a data collection station every 100 yards along a straight line, we have the freedom and the experience to collect data from places the bears actually use.
So, what is a grizzly rub tree? Bears rub against trees as they’re passing by to mark their territory as they spread their scent against it. This tells other passing bears that this territory is occupied, and they’d better stay away. A passing bear might also rub against this tree, trying to assert their claim to the territory. Scratch marks on the tree or in the ground also alert a grizzly to the presence of another bear using their tree. Rough bark or running sap on the tree will pull out some grizzly hair and leave it caught on the tree.
On every trip to the mountains, we stop at these trees we have previously identified and collect the grizzly hair. We put the hair in an envelope. We label it with the location of the tree and the date. If we dig up the ground around the tree a little with our feet, or make a few machete-cuts in the bark, we motivate the grizzlies to return to this tree and rub again as they think another bear has been in their territory. They are motivated to reassert their dominance of the territory by rubbing again and leaving more hair that can be collected next time we are riding or hiking past the tree.
On returning to the ranch, we carefully file all the hair samples in the Chilcotin Ark Institute office. They are then used by government biologists or other scientists. They analyze the DNA contained in the hair and can learn all kinds of things about the bears – their diet, their movements (by finding the same DNA on multiple trees) and who they’re related to (by finding samples with similar DNA). The results of this DNA analysis can tell us about the health of the grizzly population and even give us an idea of the number of bears based on the number of unique samples found. We have over 1,000 samples of bear hair, which means we have built up a huge database of grizzly bear hair in the South Chilcotin Mountains.
The results of these studies can be used to influence habitat and population management and assess the impact of humans on the bears. For example, if a previously well-used rub tree suddenly stops producing any more samples, we know the bear is no longer in this area. At first, the bear could have become old and died. But soon, a new bear should move into this territory and claim the rub tree. If no new hair appears for a long time, we can conclude something more impactful has happened. Our data collection is a holistic concept, and we don’t look at anything in isolation. If we know a trail was developed in this area, increasing human access, there was a change in helicopter use in the area or a decrease in prey numbers, we can conclude these things are linked to the grizzly’s disappearance. The grizzly moved to a new territory as this area was no longer suitable, no longer providing everything it needed to survive.
Conversely, if we notice an increase in prey numbers, or that it was a white bark pinecone year, after which each grizzly sow can have three or four cubs, we can expect a corresponding increase in bear numbers. As such, we can expect to find more hair samples on our trees.
This is one example of how, in nature, everything is connected. This is just one way we contribute to the environment we are benefiting from, by contributing to its conservation with one of our volunteering projects.
by Charlie B., UK / Canada
To find out more about our volunteering projects and how to join us as a conservation volunteer, check out the Chilcotin Ark Institute’s website
