REACTing for Ferruginous Hawks

I’m an environmental advisor at AltaLink, and I’ve always been passionate about conservation and environmental issues. In 2011, when I first learned that the University of Alberta was engaging in the largest scale to date research project on Ferruginous Hawks, I knew I wanted to be a part of that team. AltaLink agreed to let me work part-time while I pursued my M.Sc. and I joined the Raptor Ecology and Conservation Team (REACT).

Marked nestling Ferruginous Hawks (Photo credit: Melynda Johnson, courtesy of AltaLink)

The research group was formed in 2010 and the study was a collaborative effort, which included people from the University of Alberta, provincial and federal governments, non-government conservation agencies and industry funding partners, such as AltaLink. AltaLink is committed to protecting natural areas and wildlife and has been actively conducting stewardship activities to aid in the recovery of Ferruginous Hawks in southern Alberta.

REACT began the three year research study to better understand the biology and ecology of the Hawk and to determine what is causing the population to decline. Ferruginous Hawks have been known to nest on transmission line structures. While the presence of the lines themselves may not pose a significant negative impact on Ferruginous Hawks, construction activities for new facilities may have an impact, especially during breeding, nesting and fledging. My role in the study specifically involved looking at the post-fledging period (the period after the young leave the nest). This stage is a hot topic within avian research and may be critical in understanding why avian populations are declining.

I was ecstatic when I got out into the field and saw these glorious birds up close – they are truly magnificent. They are North America’s largest soaring Hawk; their wingspan is nearly five feet. I did learn a quick lesson about always having an assistant when working with the fledglings, as they have sharp talons and their feet have evolved a locking mechanism. When they touch us with their talons, we call it a ‘footing.’

I had a lot to learn in my field research, including how to attach the 30-gram backpack transmitter to the Hawks, but first I had to figure out how to catch them! Once they fledge, Ferruginous Hawks are creatures of the wind and can be challenging to catch. A few sprained ankles and misleading chases later, we mastered the technique of watching where they landed, dashing madly to the spot and repeating the process until we caught them. I also worked with our research assistants (this project involved two principal investigators, four graduate students, more than 35 research assistants and countless volunteers over the three year study) to develop innovate ways to track the Hawks.  Attaching a yagi telemetry antenna to a research assistant’s head with duct tape is surprisingly not the best way – or at least not the most comfortable way – to track Hawks with transmitters.

Photo 1
Research assistant trying new methods to track Hawks using telemetry equipment. This prototype, although attractive, was not universally accepted. (photo: Melynda Johnson)

I quickly became aware of how vulnerable these young Hawks are in the fledging period. After discovering my first decapitated young Hawk, I had a clue as to what would be the leading cause of mortality for newly fledged Hawks – Great Horned Owl predation. Over the study area, which included the mixed grasslands of Alberta and Saskatchewan, the mortality rate for the post-fledging period is approximately 36 per cent. With such a high mortality rate, the post-fledging period may indeed be the period where the population experiences its greatest challenges in its recovery.

Photo 2
Processing chicks (weighing, taking measurements of wings, bill, legs and attaching bands) under a nesting platform on a 240 kV transmission line. (photo: Melynda Johnson)

My research is only a small component of the larger project. Now in its final year of research, REACT will be analyzing all the data collected which includes about 1,000 nests monitored, more than 42,000 hours of nest video footage and 140 tagged Hawks tracked. This data will be able to provide, for example:

  • Habitat suitability maps that define and predict areas of suitable habitat within the Canadian range of the species
  • Thresholds for disturbances at nests
  • Nesting behaviours and activities
  • Feeding behaviours
  • Causes of nest failure and mortality

In conjunction with AltaLink, REACT has also undertaken research to determine the effects of decommissioning a 240 kV (240,000 volt) transmission line within the breeding territories of several Ferruginous Hawk pairs. This research began in 2013 and should shed light on how Ferruginous Hawks adapt to a changing environment, as well as determine how removing existing nests, often found on the structures along the transmission line, alters the local distribution of the birds. This information will be useful when trying to develop future mitigation and conservation plans.

I’ve been delighted to be a part of this research project. I expect a lot of information to come out of the study that will be able to answer the big question – where are all the Ferruginous Hawks going and how can we bring them back?  Science is pretty cool that way. I believe the results of the REACT study will help regulators, industry and interest groups better understand how their operations impact this important and recovering species.

Photo 3
Processing a hooded nestling. Bands are placed on the legs as a visual marker (photo: Darcey Shyry)

If I can sum up everything I’ve learned in the past three years, it would be this: we can save this species, we just have to work to find the best way for us to responsibly coexist with the majestic Ferruginous Hawk.

Melynda Johnson is an environmental advisor at AltaLink.