Innovation Alberta by Cheryl Croucher

Program Item Details

TITLE: Dave Latham, PhD Candidate, ILM Program, Biological Sciences, University of Alberta

SUBJECT: #235 ILM Workshop: Wolves, Deer and Woodland Caribou

TRANSCRIPT:

#235 May 19, 2007

Interview starts 1:03

Intro: This past winter on a trip north, I passed four wolves standing beside the highway just south of Athabasca. It was an unusual sighting. But one that might become more common In the near future. Dave Latham is a PhD Candidate involved with the Integrated Landscape Management program at the University of Alberta. For the past five years, Dave has been tracking wolves in northeastern Alberta. This is part of his research on wolf populations and what impact these might have on woodland caribou. Predator-prey relationships seem to be changing quite quickly as wolves and whitetail deer move into what was traditionally caribou habitat – the peatlands.Dave talked about his findings at a recent workshop on integrated landscape management.

Dave Latham

DL: our understanding of this caribou range i was doing was wolves were pretty much absent from this large, expansive fen-bog area that the caribou used. So we were just interested to see, based on some anecdotal information that we had that wolves were starting to increase the use of this area, to see if they were indeed out there.

And so, this predator inventory for wolves proved to be pretty useful in the fact that we worked out what bits of the landscape wolves were using and so it's sort of given us the drive to then go on and look at things in a little bit more depth.

CC: SO YOU FOUND THEN THAT THERE WERE SUBSTANTIAL NUMBERS OF WOLVES MOVING INTO THE AREA?

DL: Well, we don’t know about numbers of wolves, but we certainly had plenty of wolf activity out in areas where, based on past research, we believe they shouldn’t have been. And these areas were in very close proximity to caribou. So they were definitely out there.

CC: WHAT’S THE SIGNIFICANCE THEN OF THAT?

DL: Well, the belief is, based on some of this past research, that caribou occupy these large peatland areas where there are no moose or very few moose and other primary prey species, and so wolves tend not to frequent these areas. So in other words, they are spatially separated from these other players in the system and likely have a lower risk of predation because of it.

If you have increased use of an area by wolves, then just by chance,perhaps you’re going to have more encounters between caribou and wolves and caribou being killed.

CC: WHAT HAS BEEN THE NEXT STEP?

DL: Well there’s been a number of steps. Firstly we’ve been monitoring and surveying for moose and deer, distribution and relative abundance's. And we’ve been doing this via aerial surveys in the winter. We’ve completed 5 aerial surveys to date. And we’ve also looked at this in the snow free months using pellet transects to try to get some sort of an idea where abouts moose and deer are distributed during the caribou calving season.

With regard to the wolves, what we’ve done is we’ve gone on and employed VHF and GPS radio collars on the animals to try and work out what bits of the range they’re really using. To date we’ve had 32 wolves from 12 packs radio collared.

CC: WHAT THEN IS THE INTERPLAY BETWEEN ALL OF THESE DIFFERENT ANIMALS?

DL, Well, it’s pretty complex. There are a number of different hypotheses as to how things could be working. But with regard to the primary prey, our belief is that if you have increases in the number of moose and deer in a system, that this may be able to increase the number of wolves. In other words, you can have a numeric response to an increase in amount of food on the landscape, and with more wolves over the landscape, you’re going to have more hunting units out in the caribou range. So by chance, you’re likely to have more caribou-wolf encounters and thus more caribou being killed.

CC: WHAT DID THESE AERIAL SURVEYS SHOW YOU? WHAT DID YOU FIND?

DL: Well with regard to the moose, which have always been the traditional primary prey species for wolves in this area, we didn’t find a great deal. However, the big driver when new species that we’ve seen in the system is white tail deer. They just appear to have gone through the roof. This comes out in the aerial surveys and in the pellet transects we’ve been doing.

Now based on kill site investigations and wolf diet analysis, it appears that white tail deer are particularly important in the system during winter. We’re not sure why this is, but it might be that deer are less able to escape in deep snow conditions. So they may be an important factor for wolves particularly in the winter. So you may have decreased wolf mortality over the winter months.

CC: NOW THE PRESENTATION YOU GAVE THIS MORNING FOCUSED ON WHITE TAIL DEER AS BEING AN INVASIVE SPECIES IN NORTH EASTERN ALBERTA. SO WHAT’S HAPPENING THERE?

DL: Well, we’re not really sure. They’re have always been deer in NE Alberta. However they tend to have been confined in relatively low numbers to the well drained upland habitat. At the moment we’re seeing them move out into this area that we've traditional thought of as caribou range.

There are a number of different mechanisms for why they may be moving out there and these are currently starting to be investigated. At the moment all we’ve really managed to do is document that they are out there. The rest is speculation. Is it climate? Is it agriculture further to the south? Or is it perhaps some sort of footprint from industry such as cut blocks?

CC: SO ARE YOU SAYING THEN RATHER THAN FINDING THEM JUST BEHIND TREES IN THE FOREST THERE’S ACTUALLY OUT THERE IN THE PEAT BOGS?

DL, In winter we found good numbers of them out in the peat bog. Even in summer you’ll even find quite a few out there. But we’re not sure if it’s the distribution of deer that’s important or just the fact that we’ve got an increase in prey over this landscape and you have seasonal differences and the importance of various prey species and wolves perhaps using different parts of their range seasonally as well and concentrating on different prey species accordingly.

So as I say, it might be just that white tail deer are particularily important during a time when maybe pups have survived, struggled to get enough food to survive, and so white tail deer might be filling that sort of traditional gap.

CC: WHAT WOULD ENTICE THEM TO MOVE. WHAT WOULD THEY BE EATING? WHEN YOU DRIVE DOWN HIWY 2 FROM EDMONTON TO CALGARY, YOU SEE DEER EVERYWHERE OUT IN THE FARMS FIELDS EATING GRAIN. WHAT ARE THEY EATING UP NORTH IN PEAT BOGS?

DL: Well there’s a great question. We’re not really sure what’ they’re eating out in the bog. This last survey I did we have very deep snow conditions. And a number of the locals up there, outfitters, trappers etc. have suggested that maybe tree lichens are very important for white tail deer during these lean months. We’re not so sure about that, so we’re going to have to focus in on.

CC: DO YOU HAVE ANY INDICATION WHAT THE ACTUAL INCREASE IS IN TERMS OF THEIR NUMBERS OR THEIR PROPORTION ON THE LANDSCAPE?

DL: Well we do have historic information from this range. It was done in the mid 1990’s by a guy called Adam James . And he surveyed the range in the exact way that we have. So we've in other words replicated his design.

And he had very few deer sightings during the time he did it. In fact I believe it was about 12 deer seen over two surveys. And they were confined exclusively to upland habitat.

Since we’ve been doing it, we’ve been seeing anywhere from 50 to 150 deer a survey. So it’s increased substantially.

CC: SINCE THE WOLVES ARE GOING AFTER THE WHITE TAIL DEER AND THE DEER ARE GOING OUT IN THE BOGS, HAS THAT CHANGED WHAT THE WOLVES DO IN ANY WAY?

DL: Well the biggest thing we’ve seen with the wolves is that they’re utilizing this range that has been exclusive to caribou in the past. But we’re not sure if it’s white tail deer that are necessarily driving this use of bog habitat. The time we’re seeing the greatest proportion of wolf use of this caribou range is during the snow free months. So there are some very interesting things going on there that we haven’t really worked out yet.

But during the snow free months, beaver are very, very, very high in wolf diet. It appears as though beaver numbers are highest in the fen-bog area and so it might simply be the wolves are going out after the beaver and then encountering caribou on their way out.

So, as I say, the white tail deer may be playing a different role and it could be with causing a numeric response by the predators by providing a good food source during winter.

CC: GETTING BACK TO THE DEER THEN, IS THERE ANY INDICATION THEN AT THIS TIME AS TO WHY THE WHITE TAIL DEER ARE MOVING FURTHER NORTH OR MOVING INTO THESE AREAS WHERE TRADITIONALLY THEY HAVEN’T BEEN?

DL: You know, that’s a good question. There are a number of possibilities. One is climate. A lot of people suggest that it is simply the warmer winters that we’re having. Less snow on the ground. But then it’s quite likely that it could just be the increased amount of forage available on features such as cutblocks that are providing more food for them to allow them to expand further north.

An area that I’m working in, it’s a comparatively small area to answer a question like that. So you need to answer this question at a much larger scale to try and isolate these different factors. So, as I say, we’re trying to get at it with a different project currently.

CC: SO YOU HAVE AN INDICATION NOW THAT THESE THINGS ARE HAPPENING ON THE LANDSCAPE. WHAT ARE YOUR NEXT STEPS TO FIGURE OUT WHY THESE THINGS ARE HAPPENING?

DL: Well as I say, the deer is the white tail deer problem is currently being investigated by another researcher. So hopefully we’ll be able to pull her work in to try and work out what effect this might be having for the caribou in Alberta.

My next steps are to try and work out if we have indeed had an increase in the number of wolves in the area and how this may affect the caribou. And also to try and work out what role features such as seismic lines are having for wolf movements and where we’re finding wolf kills. Whether they’re close to or further from these features than we would expect.

So that’s sort where I’m headed next. But at the moment, we’ve completed Phase One which is really shoring up this idea of change that has been an increased risk of predation for caribou since the mid-1990’s.

CC: WHAT DOES THAT MEAN FOR THE CARIBOU?

DL: Well the caribou in my particular range have been declining quite dramatically for the past three or four years. They were relatively stable through out the late 1990’s to about 2001. And since then the population has been declining. And this is definitely in line with recent results where we have found that the proportion of caribou in wolfe diet has increased substantially.

CC: WHAT THEN ARE THE IMPLICATIONS FOR CARIBOU AND CARIBOU MANAGEMENT BASED ON WHAT YOU’VE FOUND SO FAR?

DL: Well I think one of the biggest things is we’ve found is that these whitetail deer have proliferated in the system. And a large number of those deer are confined to areas around the periphery of the range. And yet the wolf pack territories themselves overlap both the adjacent upland habitat where you’ve got high numbers of deer and the caribou.

So one of the large unknowns in our system is if you’ve got these prey species that are in very high numbers around the periphery of the range and appear to be very important in wolf diet and potentially increase in wolf numbers, what scale do we actually need to manage the landscape at for caribou?

How far out from the caribou range do we need to go? Do we need to manage the deer and the adjacent upland habitats? Or is it just within the caribou range itself?

So these are pretty big unknowns and we need to work that out currently.

CC: THANK YOU VERY MUCH, DAVE.

DL: You’re welcome.

Dave Latham is a PhD candidate In the Integrated Landscape management Program at the University of Alberta.

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