Calgary, AB – Suspicions that migratory golden eagles might be in trouble have led the G8 Legacy fund to support a long-term project that has been monitoring the annual movement of golden eagles through the Kananaskis valley for the past 14 years.
Providing eagle counters with a home base at the University of Calgary’s Kananaskis Field Station and subjecting their data to rigorous scientific analysis is the latest example of how the environmental research fund established to commemorate the 2002 G8 Summit in Kananaskis Country is enhancing understanding and protection of the wilderness area west of Calgary.
“Getting this help has been fantastic and enormously useful,” said Peter Sherrington, founder and research director of the Rocky Mountain Eagle Research Foundation. “What started as just an interesting project is leading to some important findings for ecosystem management,” Sherrington said. “It’s good, old-fashioned, natural history-style of science, which is often the most important kind of biological study. Unfortunately, it’s often the most difficult study for which to find funding.”
University of Calgary biological science professor Dr Ed Johnson, holder of the G8 Legacy Chair in Wildlife Ecology and director of the Kananaskis Field Stations, said helping the foundation’s work is a perfect example of how citizens and scientists can work together to produce valuable knowledge.
“This eagle project has two important aspects that the G-8 chair wants to encourage: The first is to bring together citizen and university scientists to contribute to long-term monitoring of important ecological and environmental processes. The second is to encourage ecological research on what appears to be emerging topics of interest,” Dr Johnson said.
An avid naturalist, Sherrington is credited with discovering that thousands of golden eagles undertake annual long-distance migrations between wintering grounds in the southern United States and northern Mexico and breeding grounds in Yukon and Alaska. The initial discovery occurred in the spring of 1992 when Sherrington and a friend were conducting a bird survey in the Mount Lorette area and recorded over 100 eagles flying north through the area in a single day. Believing they may have found a migration route, Sherrington returned to the area in the autumn and counted over 2,000 eagles flying south. Sherrington and volunteers from the foundation have returned every spring and fall to count eagles and systematically document the migration, spending dawn until dusk counting eagles for as many as 200 days per year. They have completed over 2,000 days and 20,000 hours of observation and recorded over 90,000 golden eagles.
For reasons that are still unclear, an estimated 6,000 to 7,000 of North America’s 100,000 golden eagles travel upwards of 11,000 kilometres each year while the rest of population doesn’t migrate at all.
“Before we started the count, it was believed that golden eagle migration took place exclusively in the foothills, involved relatively few birds, and that long-distance migration wasn’t occurring,” Sherrington said.
Dr Johnson said discovery of the migration path will improve the long-term monitoring of the population.
” If, in fact, the front ranges of the Alberta Rocky Mountains form the single corridor on which they migrate, we may have an excellent way to monitor the population’s increases and decreases with the help of citizens,” Dr Johnson said. “However, we still need to know more about the breeding numbers in Alaska and what is happening to the wintering population in the United States.”
Thirteen years of population data have led Sherrington to believe the migratory golden eagle population is declining. The last three spring counts have recorded an average of 2,600 birds passing through the area, compared to more than 4,000 that were seen during spring counts in the 1990s.
That prompted University of Calgary research associate Dr Shane Richards to investigate Sherrington’s concerns.
“There are definitely some patterns in the data. The population could be declining or it could be due to natural population cycles related to food availability and other factors,” said Dr Richards, a mathematical ecologist who began working with the data last year. “Eagles can live for up to 20 years, so we’re going to need more data and expand the number of monitoring stations in order to make strong conclusions,” he said.
Dr Richards recently to a faculty position at the University of Durham in the United Kingdom but plans to continue working on the golden eagle project with the researchers in Calgary.
The G8 Legacy Chair in Wildlife Ecology represents half of the $5 million the federal government committed to environmental legacy initiatives related to the G8 summit. The other half was used to build wildlife crossing structures.