Climate Change Affecting Prairie Hawks
January 21, 2014

How Climate Change Impacts Endangered Prairie Hawks

[ Watch the Video: Helping Hawks Weather The Storm ]

Lee Rannals for - Your Universe Online

Researchers are studying how climate change is impacting endangered prairie hawks. Scientists from the University of Alberta and the Alberta Biodiversity Monitoring Institute (ABMI) are working together on a project to understand how climate change is affecting hawk populations. This study will not only shed more light on how the changing environment is impacting hawks, but could also find solutions to reduce its negative effects.

Ferruginous hawks are North America’s largest hawk species, and they are listed as endangered in Alberta and are threatened throughout Canada. In 23 years, the hawk population in the province dropped from 1,791 nest pairs to just 643 pairs.

“Ferruginous hawks—in fact, most birds that breed in the prairie—are at the mercy of the elements simply because there aren’t a lot of places they can take cover during harsh weather events,” said Ryan Fisher, former post-doctoral fellow with the U of A’s Raptor Ecology and Conservation team (REACt) and project co-leader.

[ Watch the Video: Alberta’s Ferruginous Hawks in a Changing Climate ]

As longer periods of heavy rain continue, adult birds lose opportunities to hunt food for their young. If an adult has to hunt in the rain, the chicks are left unattended and are vulnerable to the cold and wet conditions. Windstorms also are problematic because they threaten hawk nests and trees, sometimes even blowing a nest to the ground.

The researchers monitor up to 300 Ferruginous Hawk nests every year, measuring the impact of more frequent extreme weather on hawk reproduction and survival.

“To monitor nests we basically check on them once a week. We use a painter’s pole with a camera secured on top to count chicks and eggs,” explains Janet Ng, a PhD candidate at the University of Alberta. “We ultimately want to see how many young fledge come out of that nest at the end of the season.”

The team also monitors adult hawks using satellite transmitting, helping to track the movements of the raptors as they defend their territory.

“Knowing the hawk’s territory helps us understand where the hawks will hunt and how far away from the nest they will travel,” said Jesse Watson, a science master’s student at the University of Alberta.

Researchers collected information on local weather by using portable weather stations and compared this with data collected on hawk reproductive success, survival and territory size. The study showed that ferruginous hawks are very vulnerable to heavy rain and high winds, However, the team said that this link could be combatted by building artificial nest platforms to act as a buffer against high winds.

“We’re trying to identify which types of artificial platforms might be best to prevent wind damage to nests,” says Fisher. “If we know which designs are best from a weather perspective, those are the ones we can recommend.”