BANFF – A team of dedicated researchers is keeping an eagle eye on Banff’s bird populations.
With climate change affecting the range and survival of many wildlife species, scientists wanted to know what role it is was playing with birds in Banff, Yoho, Kootenay, Jasper and Waterton Lakes national parks.
“We wanted to take a look and see how our bird populations were changing over time and how climate change affected the bird populations,” said Jesse Whittington, a wildlife ecologist with Banff National Park who headed up the study.
Armed with 30 pounds of recording gear, including high-tech microphones, researchers trundle along trails to record birds at specific spots for about 10 minutes; then send the recordings to songbird specialists who can identify species based on their distinctive calls and songs.
“Staff will get up at 3:30 in the morning so they can be on the trail recording data at the crack of dawn,” Whittington said.
“We do our surveys in June and a little bit in July because that’s breeding season. In June, the males are singing their hearts out to try and attract mates.”
The study, which was recently published in the journal, Ecosphere, included 10 years worth of data collected in the five mountain national parks, including Banff. Throughout, there were 34,665 detections of 77 bird species collected.
While research indicates bird populations are declining throughout eastern North America and mountainous areas of Europe, this new study shows most birds in the mountain parks here are faring far better.
Overall, Whittington said the species that saw increases were primarily short- and long-distance migratory birds, whereas rates decreased slightly for winter residents.
Birds like dark-eyed juncos, yellow-rumped warblers, and white-crowned sparrows are stable or on the rise, he noted, while others birds such as pine siskins, red-breasted nuthatch and black-capped chickadee appear to be in a slight decline.
“We found that 91 per cent of the species were stable to increasing,” said Whittington, who noted the results are based on data from 2007-16.
“To break it down, 53 per cent of species were increasing and 38 per cent were stable and nine per cent were decreasing.”
Because it’s impossible to actually count the number of birds in Banff National Park, the researchers looked at the presence and absence of bird species, as well as range expansion and contraction.
“That’s usually correlated with abundance,” Whittington said.
The biggest jump in bird populations occurred in 2015 and 2016, which were both years with warmer and drier spring times than usual.
“We found that at least half of the birds in our study cued into spring temperature and precipitation, so their ranges expanded during warmer springs and drier springs,” Whittington said, noting that makes sense in places like Banff where there is snow most of the year.
“It’s a relatively cold, inhospitable place so a lot of bird species are at the edge of their range, and so I think that’s probably why their range has expanded during these warmer, drier springs because they’ve had more habitat available to them.”
In response to climate change, some mountainous bird populations may maintain their ‘climatic niche’ by shifting their range upslope as long as they are not constrained by rock, ice, and loss of habitat near the top of the mountains.
While most birds have a climatic niche related to temperature and precipitation, some birds may shift where they live in response to changes in temperature, or advance the timing of breeding and nesting.
Research has indicated the response of some birds to climate change may vary depend on their life history strategies, for example, whether they are specialists or generalists species, or whether they are migratory versus resident birds.
“As their environment changes they still have to maintain that niche,” said Whittington.
“In some cases with climate change, that may involve shifting their range northward or upward in elevation, or maybe they don’t have to move at all if they’re still within that niche. We saw some evidence of that in this study.”
Mountain ecosystems are highly susceptible to climate change, with some research indicating that Canada’s climate is warming twice as fast as the global average.
Whittington said this study contributes to a growing body of evidence aimed at better understanding how birds living in the mountains respond to changing climate conditions.
“I think in terms of birds in Banff National Park, we know increasing temperatures will probably increase the habitat quality for many species, but not all species, some will decline,” Whittington said.
“What’s also important to think about is that climate effects also the wintering grounds for migrant species and the southern range for some of these species; while it might be good for some birds in Banff National Park, it might not be good for birds broader throughout North America.”
The Bow Valley Naturalists, which organizes the annual Christmas bird count, say songbird populations worldwide are mainly the result of habitat loss and insecticides.
“As migratory species, song birds are directly impacted by the land management practices outside of national parks, particularly in wintering habitat in Central and South America,” said Reg Bunyan, the group’s vice-president.
While it may seem like positive news that 91 per cent of the bird populations in the mountain parks are relatively stable, he said it’s important to remember the mountain parks are harsh ecosystems.
“As a result, we have relatively little species diversity and the monitoring program results are not necessarily reflective of what is happening to bird populations North America wide,” he said.
“Nor does it fully capture the impact on the nine per cent of mountain park species that are declining; some of which have experienced catastrophic population losses.”
While this study gives a broad overview of what’s happening with bird species here, it did not delve into how temperature affects survival rates, habitat selection, recruitment of mates and how many young they have.
“Or how much what we’re seeing is natural fluctuations in their populations?” said Whittington.
A highly publicized recent paper estimated that 2.9 billion birds have disappeared from Canada and the United States since 1970, amounting to about a 29 per cent decline. The greatest losses were found in common species such as blackbirds, sparrows, finches and warblers.
Similarly, research has shown mountain bird populations in Europe have been in decline, with species shifting their ranges in elevation or latitude as temperatures change.
But Whittington said birds in protected areas, where some of the research in North America has occurred, may be more resilient to climate change, adding that species in protected areas have had lower extinction rates and higher colonization rates compared to unprotected areas.
He said results in the Banff study are similar ones indicating stable populations of birds found in national parks in the Cascade Mountains of the Pacific North-west in the United States.
While the reasons for the differing trends are unclear, Whittington said this points to the importance of protected areas.
“Other other studies have found birds and other wildlife species are generally more resilient to stressors like climate change in protected areas,” he said.
“That’s something we’d be interested in looking at over time, is the interacting effects of protected areas and say climate change on bird populations.”
