A summer of live-trapping small mammals

As part of my project looking at the effects OLYMPUS DIGITAL CAMERAof industrial noise on OLYMPUS DIGITAL CAMERAowls, I’m also interested in determining what effect noise has on their prey. So this summer, I set out to look at small mammal population dynamics at noisy and quiet sites by conducting live-trapping of small mammals.

The type of traps we used are called Longworth traps, and they consist of a metal tunnel connected to a nest box. A small bar at the end of the tunnel trips the door of the trap. The traps were baited with sunflower seeds and pieces of apple, and bedding was placed in the traps so the animals could make a nest to keep warm overnight. We set the traps in the evening, and checked them first thing in the morning.

We caught a total of 8 species. The most numerous were red-backed voles, followed by deer mice and meadow voles. We also had a number of shrews, which are not rodents but insectivores. We also caught a few squirrels, both red squirrels and flying squirrels. And we caught a jumping mouse,    they’re about the same size as a deer mouse, but have much larger back feet and very long tails to help them jump!

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Each animal was weighed, sexed and tagged with a metal ear tag. The ear tags each have a unique number, so we can tell apart individuals when we recapture them.OLYMPUS DIGITAL CAMERA

In addition, we caught two ermine. They are about the same size as a red squirrel, but with a much longer body. We were not trying to catch weasels, and they likely went into the traps because they smelled like their small mammal prey.

Now that I’m back in the lab, I’m working on analyzing the data to estimate the small OLYMPUS DIGITAL CAMERAmammal populations trapped at each site.

Photos and text by Julia Shonfield

Southern Rockies Grizzly Bear Project End of Summer Update

Fall is upon us in the Southern Rockies. The leaves are changing, the elk are bugling, and we have seen a number   of snowfalls on the mountains.1

The berry crop has been great this year and the grizzly bears have likely benefited greatly. Pictured below are buffaloberry (Sheperdia canadiensis) and black huckleberry (Vaccinium membranaceum) with good fruit yields.32

 

 

 

 

Of course, no good study on huckleberry is complete without eating a few yourself and ending up with the indelible stains.

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Last week we took advantage of the good fruit crop and the bear’s insatiable appetite. We darted and collared a few female bears with GPS collars while they were out feeding in the alpine huckleberry fields.

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Of course, what good is a blog post without some shameless pictures of my field partners!

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By Clayton Lamb

Job Posting

We are looking to hire 2-3 field assistants to begin working for the University of Alberta as soon as possible through the end of September and into October. Main duties will include collecting vegetation information at sites used during the breeding season by telemetered hawks. Additional duties will include groundtruthing hawk home ranges to confirm the presence of various habitat types and human infrastructure (e.g., presence of oil gas/wells, roads, crop/native habitat, etc.). Work will be conducted throughout the prairies across southern Alberta and Saskatchewan. Pay will range between $2000-2500/mo depending on experience.
Work will be completed in teams of 3-6 people. Vegetation surveys will require ~10 km walking per day. The job will also require a fair amount of commuting between sites. Accommodations will be provided and will consist of either a field house or motels. Food and vehicles are also provided.
Please send a resume and references to Jesse Watson with your available start date: (jlwatson@ualberta.ca)

Tracking Canada Warblers: Research takes off with flying colours

These brightly-coloured songbirds CAWA1look like they would be easy to spot against the deep green of the boreal forest, but looks can be deceiving. Canada Warblers are a shrub-loving species, and spend much of their time either foraging for insects in dense hazelnut bushes, or singing ten metres up in a tall aspen, defending their territory from intruding strangers. In addition, when good habitat is available, birds can be clustered very close together. So they are not only difficult to find, but it is nearly impossible to tell individuals apart. This can pose challenges to studying habitat use and breeding success of these birds throughout the season, as individuals must be located and correctly identified on multiple visits.

Luckily for researchers such as CAWA2myself, there are several “name tag” tools that help us distinguish who’s who, and let us track the birds more effectively. Firstly, we attach tiny coloured bands to their lower leg, with a different colour combination for each individual. A glimpse of these distinct combinations through our binoculars helps us differentiate Tom, Dick, and Harry. Another method is to attach miniature radio transmitters to the birds’ backs. Each bird gets a transmitter that emits a distinct frequency, which we can detect using a handheld receiver and antenna. Along with distinguishing individuals, this technique allows us to hone in on the birds’ locations from greater distances. This makes it possible to detect and locate birds even when they have strayed from their usual hangouts, providing valuable information on habitat use and home range size.

CAWA3So why does this matter? Canada Warblers are defined as a threatened species in Canada, and are listed as special concern in Alberta. To protect and recover populations of at risk species, it is important that we know details about the habitat they require to make a home and raise their young. We know from previous studies that Canada Warblers are found in old-growth forest dominated by aspen trees. However, little is known about what they select under the forest canopy. Factors such as shrub density and terrain could have a large influence on where Canada Warblers live and breed successfully. My research involves investigating the microhabitats and breeding success of these threatened birds within areas extensively managed by forestry companies. This information could inform forest management strategies to ensure preservation of important Canada Warbler habitat. This research would not be possible without the valuable collaborative work and resources contributed by Alberta-Pacific Forest Industries (ALPAC) and the Lesser Slave Lake Bird Observatory (LSLBO).

Written by Anjolene Hunt