How does industrial noise affect owls in Northeastern Alberta?

Recently published research by Julia Shonfield, a PhD student in Erin Bayne’s lab:

Shonfield, J & Bayne, EM. 2017. The effect of industrial noise on owl occupancy in the boreal forest at multiple spatial scales. Avian Conservation and Ecology, 12 (2): 13. doi: 10.5751/ACE-01042-120213.

Photo 1 – Barred Owl, one of three species of owls I’m studying in this project.

Energy development creates several types of disturbance that can impact wildlife, including the physical footprint of the infrastructure and the chronic noise from facilities. Chronic noise sources can pose problems for animals that communicate vocally because the noise can mask important signals.

Owls use vocal communication to attract mates and defend territories, and hunt by listening for acoustic cues made by prey (e.g. mice scurrying along the forest floor). Chronic noise has been shown to negatively affect owl hunting success and ability to detect prey. So this suggests that noise can have negative effects on owls, but we don’t know whether this affects where owls are distributed on the landscape.

For part of my PhD work in Erin Bayne’s lab, I wanted to know if owls avoid chronic industrial noise sources. To get at this question, I used autonomous recordings units (ARUs) to survey for owls.

Photo 2 – An autonomous recording unit (ARU) all set up and ready to record some owls calling.

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These units were programmed to record every hour for 10 minutes throughout the night for up to 2 weeks at each site. I surveyed at three types of sites in northern Alberta:

  1. Chronic noise sites – with a compressor station or oil processing facility at the center of the site
  2. Intermittent noise sites – with a road bisecting the site
  3. No noise sites – with no traffic noise or industrial noise sources

I processed the recordings using recognizers I developed in a program called Song Scope to detect the calls 3 owl species found in northern Alberta: Barred owls, Great Horned owls and Boreal owls.

Photo 3 – An example of the call of the Great Horned owl, shown as a spectrogram in the program Song Scope.

Once I obtained the owl detections from the recordings, I analyzed the data using occupancy models. I analyzed the data at two spatial scales, at a larger scale that is roughly equivalent to an owl’s home range size, and a smaller scale representing an area within a home range.

Photo 4 – The two spatial scales that I analyzed to determine owl occupancy. The small white circles are ARU stations.

I found that the occupancy of all three owl species was not different between sites in the three noise categories at the larger scale. I also found that at the smaller scale, owl occupancy was not affected by industrial noise levels.

Photo 5 – Results of the owl occupancy models at the larger scale, showing occupancy estimates for each of the three noise categories of sites.

Take-home message:

At the spatial extent I assessed there was no evidence of noise effects on owls, suggesting that noise is not likely to have negatively affected owl populations at current noise levels.

  • Photos and blog post written by Julia Shonfield

 

 

 

Effects of habitat quality and access management on the density of a recovering grizzly bear population

Clayton Lamb and colleagues from the Provincial Government of British Columbia and University of Alberta recently published an article in the Journal of Applied Ecology. This work investigates the factors driving the density of a threatened grizzly bear population in southern British Columbia.

Key results and conclusions:

  1. Heavily roaded areas had lower grizzly bear density.
  2. Closing roads to the public restored bear density in this area.
  3. Maintaining roadless areas in productive bear habitat is critical.
  4. Areas of low road density and high habitat quality occur as islands surrounded by either high road densities or poor habitat, limiting grizzly bear connectivity.

The Open Access article can be found here:

http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.13056/full

Infographic by Wild 49 Alumnus Kate Broadley, MSc.

An adventure in the far north – Deline, NWT

 Deline in the Sahtu region, NWT

One of the perks of graduate studies are opportunities to go to remote places that few other people get the chance to see. Earlier this summer I had the opportunity to travel to a remote fly-in only community in the Northwest Territory. The purpose of the trip was not directly related to my thesis, but to help start a local community bird monitoring program in two communities in the Sahtu region of the NWT, a project that the Bioacoustic Unit at the University of Alberta (http://bioacoustic.abmi.ca/) and my supervisor, Erin Bayne, is involved in. So in June, I travelled to Deline on the shores of the Great Bear Lake, and another graduate student, Michelle Knaggs travelled to Tulita on the MacKenzie River. Our roles were to bring autonomous recording units (ARUs) to the communities and start deploying them at various locations nearby with the help of locally hired guides.

The day I arrived in Deline was summer solstice and National Indigenous Day, and the following day was another holiday, Sahtu Day. The festivities involved a delicious BBQ cooked over a wood fire, a variety of games including egg tosses and obstacle courses, and a drum circle. These two days of local celebrations served as an excellent introduction to the community of Deline and gave me the opportunity to meet many of the locals.

In the week that I stayed there, I deployed the ARUs in several different locations around Deline. Though Deline is probably the furthest north I’ve ever been in Canada, the habitat was quite familiar. This area is still within the boreal forest, and the predominant habitat here is black spruce forest.

Black spruce forest in the area surrounding Deline

There were only a few roads and trails, so the access was relatively limited in the first couple of days because there was still so much ice on Great Bear Lake. Talking to people in the community, it was not that unusual to still have ice on the lake in mid-June, and it was largely dependent on the wind direction.

Ice on Great Bear Lake

Finally, the wind changed direction and pushed the ice out into the middle of the lake and away from the shores of Deline. In the last couple days I was there, I was able to get out by boat on Great Bear Lake and put some of the ARUs along the shore.

Boats along the shore of Great Bear Lake

The lake in the evenings was truly mesmerizing, flat as glass and incredibly clear, I could still see the rocky bottom several hundred meters out from shore. It was calm and peaceful being out in a boat on the lake in the evenings. The long days meant there was no rush to get things done before it got dark.

View of Deline from a very calm Great Bear Lake

There was a diversity of birds on the lake including Common Loons, and a variety of ducks such as Northern Pintails, Mergansers, and Scoters. In town, there were large numbers of Ravens and Herring Gulls.

A Raven and Herring Gull, abundant in town and especially at the town dump

It’ll be really interesting to see what birds we get on the recordings, the listening will be starting this fall. Since this area is so far north, it’s at the northern limit of the distribution of many birds. For me, it was a unique experience in the far north, one that I won’t soon forget.

  • Photos and blog post by Julia Shonfield

 

Kluane Lynx Research Feature

Lynx research out of Kluane, Yukon will be featured in the 4th episode “Winter” of the CBC documentary series “The Wild Canadian Year.” The Wild Canadian Year airs on Sundays at 8 PM / 8:30 NT on CBC Television. The Winter episode premieres this Sunday, October 15th. University of Alberta students in the Boutin lab worked with filmmakers to help catch unique footage of lynx for the documentary.

Watch a preview of the series and find more information about the Winter episode HERE.

Watch a sneak peek of a lynx chasing a snowshoe hare HERE.