Red Squirrel Blog

The start of 2010

Mon, 8 Mar 2010 00:37:33 -0500

The winter 2010 season of the Kluane Red Squirrel Project is well underway. The crew arrived in February and has been hard at work opening up camp, setting up projects and preparing for the year ahead. There are some returning squirrelers, new technicians, and we’ve already had several visitors to camp. The weather has been fantastic and we’ve seen all sorts of wildlife and spectacular mountain views.

On February 12, Ben Dantzer, a Michigan State University grad student and his field technician, Frances Stewart, arrived at Squirrel Camp. By February 15 they had camp organized and were starting to deliver peanut butter to the squirrels on the food addition grids. Manu Landry-Cuerrier arrived from McGill in Montreal to really help them out with this huge task. Together, they delivered over 320 kilos of peanut butter in less than four days. Once the peanut butter was all in place, Ben and Frances started trapping squirrels to start Ben’s current project. They are trying to determine how perceived population densities affect red squirrel reproduction.

The rest of the late winter and spring crew arrived at Squirrel Camp on Wednesday, March 3. The five of us had driven for three days from Edmonton after watching Team Canada take the gold medal in Men’s Olympic Hockey and successfully completing our University of Alberta Driver’s Tests. Returning to Squirrel Camp for their third time were McGill grad student, Devan Archibald, and Kristen Rostad. New to camp this year, were Dylan White, Lindsey Valliant, and myself, Cass Stabler. Ben and Frances welcomed us all into camp with a delicious dinner and we all found warm places to sleep in the loft of the data hut and the PhD hut.

The next day we started training. The spring crew is responsible for collecting information about all of the squirrels living on the six long-term research grids. We need to know which squirrel lives on each midden and the reproductive status of each female. This allows us to determine when and where the new pups will be born on each grid. We can then find the nests and identify the pups. Training went very well as we learned how to set traps, monitor the trap line, and collect information about the squirrels we saw and trapped on the grids.

Since training, we’ve all been out trapping each day to gain an understanding of where each squirrel in the current population lives. During this time, Dr. Stan Boutin from the University of Alberta came to visit camp. Stan is one of the principle investigators on the Red Squirrel Project and the person who set up this camp back in the 1980’s. He passed on a lot of great advice about trapping squirrels, told us interesting information about the history of the camp, and got our snowmobile running.

On grid we’ve seen moose, lynx, goshawk, snow bunting, snowshoe hare, ermine, and several grey jays and chickadees. The birds like to rob the peanut butter bait from our traps and that can make it difficult to catch squirrels. We’ve found two nests and have successfully counted and identified the new male and female pups. This has been pretty exciting for everyone involved because squirrel pups sure are cute! This past week we also completed our second peanut butter addition. With the entire crew working hard we had all the peanut butter delivered in one day.

As spring begins in the Yukon, we’re already noticing the increase in daylight hours. The sun sets around 8:30 pm, but it’s still quite light out when we go to bed. We’ve had a few very mild days and it seems like the snow will be melting soon too. The returning crew has told us all about how muddy the area can be when this happens. We’ve still got a few squirrels to find and a lot of nests to come. Business as usual at Squirrel Camp!

Winter 2009 Crew in Camp

Fri, 20 Mar 2009 22:58:01 -0400

The winter crew arrived at squirrel camp on March 2: Claire, Josiane, Emily, Kyle, Jamie, Sara and myself. For most of the crew it was the end of two and half days of driving from Edmonton, while for Emily and I it marked the end of a full week of driving from Guelph. By far the best part of the drive was from Fort Nelson, BC to Whitehorse, YT, where we saw a lot of wildlife: moose, caribou, bison, a couple foxes, and an owl.
The snow is surprisingly deep around camp and on the grids. Most camp chores seem to involve shoveling snow, and it keeps snowing! On the positive side, the snow has made for some great sledding! During the peanut butter addition to the food experiment grids it seemed as if we were wading through snow. Even with snowshoes on we were sometimes up to our waists in the fluffy white stuff. There have been quite a few grouse sightings on the grids, and lots of lynx and moose tracks.
The new crew started their squirrel trapping and handling training after the peanut butter addition was completed. Training went well and now the new crew have been assigned to their own respective grids. Temperatures have been pretty cold lately, around -20C in the mornings, and warming up to around -15C during the day. There have been no nests yet, and only a handful of females caught so far are pregnant. This is quite the change from last year where we were finding squirrel pups in the buckets during the peanut butter addition in March.
Julia S.

Mt Decoeli

Sat, 5 Jul 2008 15:32:26 -0400

The summer crew at squirrel camp did an overnight hike up Mt. Decoeli on July 3-4. There were 7 of us: Cate, Katherine, Meghan, Bastien, Ben, Issac and Julia. We started after dinner on Thursday night and hiked until 11pm. Starting from the pullout on the Alaska highway we hiked along a wide trail to a stream, and then continued along the bank to the slopes of Mt. Decoeli. Hiking along the stony bank of the river wasn’t too hard, but several times we were forced to cut into the willows which were unbelievably thick and tangled.

On the slopes of Mt. Decoeli we saw some mountain sheep and marmots. We camped overnight in an alpine meadow with lots of wildflowers. The midnight sunset was spectacular!

The next morning we continued our trek to the peak. The climb was steep and rocky, but the view from the top was incredible. We could see a large rain cloud raining down on camp, but everywhere else was sunny. Oddly enough that pretty much describes the current weather at camp for this past week. The way down was faster, but only involved a short slide down a small patch of snow in one of the valleys.
Julia

Spring in Squirrel Camp

Fri, 16 May 2008 15:44:14 -0400

Spring has arrived here at squirrel camp and it's pretty exciting! Chipmunks are up and running around all over the place, the ground squirrels are also out and there’s one that’s living under the data hut. The snowshoe hares have started to change colour and are mottled looking right now, with brown fur coming in on their backs and the white winter fur still on their legs and feet. Bear tracks have been spotted on Agnes but no one has seen any bears yet. More birds have arrived in the area including yellow-rumped warblers, varied thrushes, white-crowned sparrows, and buffleheads have been seen on Sulphur pond. Lots of raptors have been spotted lately including bald eagles, red tailed hawks, harriers, and goshawks. A large porcupine has been roaming around the huts in camp. Almost all the snow has melted and even the mud has mostly dried up. A few mosquitoes have been seen flying around, but they’re not a problem yet. Juvenile red squirrels have started to emerge from their nests on all of the food addition grids, and they seem to be running around and rattling all over the place. The May midden census is in full swing, and the crew has been assessing the activity and conditions of the middens on each grid as well as trying to determine which squirrel owns each midden. The crew went on another short hike along the Alsek valley last week. It was a beautiful warm sunny day and the highlight was seeing a moose swim across the river.
JKS

Blog photo 1: A vigilant least chipmunk

Blog photo 2: The squirrel camp crew hiking along the Alsek valley

Blog photo 3: A snowshoe hare with its summer and winter coat

Blog photo 4: A juvenile red squirrel eating a spruce cone

Radio Telemetry

Thu, 10 Apr 2008 22:29:03 -0400

Definition
Telemetry (tele = distance, metry = measurement) refers to measuring from a distance. "Radio" telemetry refers specifically to telemetry in which information is transmitted over VHF radio waves. Although several aspects of an animal's biology can be measured remotely with telemetry, we use this tool specifically to measure a squirrel's position in space.

Components
There are three components to a radio telemetry system.:

1. A transmitter is worn by the animal subject. It transmits a pulsed signal (every 1.5 seconds) as a VHF radio wave. Squirrel transmitters weigh 4 grams and are worn around the neck.

2. A receiver receives the radio signal and translates it into something we can interpret such as an audible beep. The receiver can be tuned to receive specific radio frequencies within a broad range, thus one receiver can be used to identify and track multiple animals whose radio collars transmit at different frequencies.

3. An antenna amplifies the radio signal being received. A "directional" antenna receives the radio signal with different sensitivity (gain) depending on the orientation of the antenna - the beep is loud when the antenna pointed toward the animal, but becomes increasingly softer as the antenna turns away from the animal.

Techniques
In Squirrel Camp, we use radio telemetry primarily for radio tracking - following the radio signal until the animal is located visually. Starting at some distance from the squirrel, we travel in the direction in which the radio signal is strongest. As we get closer to the squirrel, the radio signal increases in strength, i.e. the beep gets louder, and we can reduce the sensitivity (gain) on the receiver for better sound resolution. We home in on the squirrel until we make visual contact. This gives us the squirrel's exact location in space, and allows us to observe its behavior at the time. Experienced researchers can locate squirrels in less than ten minutes with this technique.

Occasionally, we use triangulation to locate squirrels from a greater distance. Triangulation involves recording the direction from the observer to the squirrel as a compass bearing from two or more observer locations. These bearings are then plotted as lines on a map, which intersect at the animal's location. Unlike radio tracking which gives an exact location, triangulation involves some estimation error, but can be kept small by experienced researchers.

On foot in the boreal forest, we can detect the radio signals from squirrel radio collars from distances of about 300 meters. Antennas positioned higher can receive signals from greater distances. Common tactics to increase the range involve gaining elevation, and include climbing hills and trees, or when these are not available, standing on your vehicle.

Applications
Radio telemetry has many applications in wildlife biology. Telemetry-based analyses we conduct on the red squirrel project include:

Resource use - nest sites, feeding locations
Habitat selection - used sites chosen from among those available for use
Survival - Longevity, location and cause of death
Movement patterns - sequential locations of moving animals such as dispersing juveniles
Activity patterns - timing and duration of activity and sleep, nest use
Behavioral observation - focal sampling for determining diet, mating choices, caching behavior
Home range analysis - drawing polygons around a large set of mapped locations

-MCA

Mating Chases

Thu, 10 Apr 2008 21:58:16 -0400

Mating Chases

Among the many differences between red (and other tree) squirrels and the other members of the squirrel family (Sciuridae), is that the tree squirrels don’t hibernate. While it may be asked how this relates to reproduction, for researchers monitoring the mating behaviour of red squirrels, the relevance is all too apparent. The compressed active season imposed by the hibernation period of ground squirrels, for example, requires that mating occur in a brief 1-2 week window in the spring following emergence. By contrast, as red squirrels are active all winter, they are able to commence mating earlier. Furthermore, as juvenile red squirrels require a territory and midden to survive, the earlier a female can start mating, the better.

The mating season at Kluane typically commences in either in February or March and continues until May or June. During this time, individual females are only in estrus (i.e., sexually receptive) for a single day. The relatively short receptive period of individual females and extended mating season means that few females are in estrus on any given day of the mating season. The first challenge for researchers at Kluane is consequently to find any receptive females. As we are still in the depths of winter in the Yukon for much of the mating season, this means heading out on snowshoes first thing in the morning and using radio-telemetry to locate our focal females. The female’s receptive period continues for the entire day until she retires to her nest when the sun goes down. While keeping track of the focal female, new researchers will quickly learn the significance of the term ‘mating chase’!

Because few females in the population will be receptive, individual estrus bouts attract great numbers of males. As the attending males jockey for position next to the receptive female she attempts to evade the queue and will travel great distances (at great speeds!) to do so. Keeping track of the squirrels, which are able to travel on the snow crust, while we’re sinking through on snowshoes can represent a challenge, to say the least. Researchers are granted temporary reprieve due to key points during the day when the female must stop traveling…to copulate. Copulations of red squirrels can occur in the tree, in snow tunnels, under downed trees or underground, but because they are stationary during this time, it means that, despite the extensive intervening travels, we are usually able to get a good census of the females mates. This research showed that females mate with among the highest number of males of any squirrel species so far studied (up to 13!).

Currently we are investigating what influences whether a copulating male will sire any of the resulting offspring. Although many of the litters are multiply-sired, on average, there are fewer offspring produced by the female than males she has copulated with. This means that some copulating males are unsuccessful in siring offspring. The high levels of multiple mating by females, and the detailed information that is collected as part of the Kluane Red Squirrel Project makes this a potentially very powerful system to address questions on male siring success and patterns of female choice.

Hungry Lynx

Wed, 2 Apr 2008 22:18:58 -0400

Lynx are showing up everywhere this spring. We've been seeing fresh tracks every day Lynx every other day. There is some speculation that the lynx are extra hungry because the snowshoe hares are in decline, but I'm not so sure. In any case it's exciting sharing the grids with the big cats.

Lynx on Kloo

Still a few hares around, actually I haven't really noticed a decline.

The other day I stumbled upon a lynx eating a squirrel! I was radiotracking a Kloo female (to see if she was in estrus) and she led me right to the lynx. Turns out she was in estrus today and the unlucky male was likely distracted by that.

"What squirrel?"

Female squirrels come into estrus for one day and spend the whole day leading what we call a mating chase. The males involved in the chase seem to turn off their predator avoidance (Sara even had one run up her leg) so it's not too surprising that the lynx was successful. Also, the night before we had about 3 inches of snow which slowed the squirrels down a lot. They look a little like otters swimming through the powder.

After the lynx finished off the male it took off towards the negatives and found Abe and the mating chase that he was following. Abe had lost the female for a minute and by the time he found her she too had been caught by the lynx! The females are usually more cautious so I'm a little surprised that she was nabbed.

Radio collar untouched. Lynx ate the liver this time but left an arm?
-Ryan

What’s there to do in Squirrel Camp?

Mon, 17 Mar 2008 22:03:18 -0400

What's there to do in Squirrel Camp?

When I try and describe Squirrel Camp to people who haven't been there they always want to know what people do on those long snowy nights in the winter. Here are a few of the things that folks have been up to this spring.

Group crosswords by the Coleman lantern.

Cooking Tandoori in the wood stove

A musical jam with Elsabe from town.

Wearing crazy home-made glasses and drinking tea.

Watching TV in the kitchen - actually it is a mating chase going on outside the cookshack, which is even more interesting.

-AMc

Peanut Butter Experiment

Thu, 21 Jun 2007 22:40:00 -0400

Part of what we are studying with the red squirrels is how their survival and reproduction is affected by how much food they have access to (you can read more about this on our project page). We are experimentally testing some of our hypotheses by giving some squirrels access to supplemental food - peanut butter!

Peanut butter might seem like a strange thing to be giving them but it's actually very nutritionally similar to spruce seed, which is their primary food source in the Yukon.

We study a lot of squirrels and so there's a lot of peanut butter to put out! It can also be a bit messy. In the winter we need to heat up the peanut butter next to our woodstove so that it can be poured into 1kg containers. Each of our supplemented squirrels gets one of these 1kg containers of peanut butter every two months through the winter.

We have then been keeping track of their survival and reproduction to see how they differ between on food supplemented and control squirrels, which aren't receiving any food.

We will keep you updated on the results of the experiment as they come in.

Outhouses and Intelligence

Mon, 1 May 2006 22:14:40 -0400

While searching the internet for plans for the new outhouses in Squirrel Camp, I came across some plans by Ernest Thompson Seton (author and naturalist) and I was reminded of one of his quotes.

"The rodents are very low in the scale of intelligence, but the red squirrel ranks high in its class. It is gifted with a burning curiosity, which, tempered by prudence and aided by agility, is an excellent start on the road to knowledge"
Ernest T. Seton, 1909