Bluethroats breeding in north Yukon
The blustery, barren coastal plain of Ivvavik National Park doesn't seem a likely place to find a nesting songbird from Southeast Asia. But this is exactly what researchers with the Canadian Wildlife Service (CWS) have confirmed.
In June, a team of five spent close to three weeks camped between the Beaufort Sea and the park's mountain ranges, near the Yukon/Alaska border. The main target of their efforts was the Bluethroat, a small, secretive Eurasian thrush with an eye-catching iridescent blue throat and an impressive repertoire of songs.
The Bluethroat winters in places like India, Pakistan and southeast China, commonly migrating to Europe and Siberia and even across to Alaska. But few venture as far east as the Yukon border, where the Bluethroat is at the very edge of its range.
We've found Bluethroats on the North Slope in the past -- most recently during CWS fieldwork in 1993 -- but this is the first time we've confirmed that they're breeding here, says biologist Cameron Eckert, leader of the field crew.
The list of species 'believed', but not yet confirmed, to breed in Canada is very short. The Bluethroat has been at the top of the list.
Bluethroats are notoriously furtive, skulking through vegetation and hard to see. However, for a short time males engage in elaborate display flights and sing complex songs, making their locations easier to fix. To improve their chances of locating the elusive birds, the researchers carefully planned their fieldwork to overlap male courtship displays in mid-June and feeding of young in early July.
Less showy and more secretive during breeding, Bluethroat females lack the brilliant blue throat markings. Indeed, Eckert and his team reported 8 to 10 Bluethroat males and just two females. But once breeding males were confirmed, researchers spent long hours trying to pinpoint pairs coming into nests.
Locating even just one nest was a challenge. The nest they discovered had six eggs, and when they checked it once more before leaving the parents were feeding six hatchlings. Eckert is confident that other pairs in the area are also nesting.
The CWS team also monitored breeding activities of the Yellow Wagtail, another unusual migrant from Southeast Asia. They were previously known to breed here, but we wanted more information on this species, says Eckert.
The team found three Yellow Wagtail nests, and made observations of other rare Yukon breeders such as the Red Phalarope, Ruddy Turnstone and King Eider.
We do this kind of work focused on rarer species because it's important to understand more than just the conspicuous elements of the landscape, Eckert explains. We need to understand the needs of the rarer, sparser animals up here because they also define the environment.
Some of these species are at the edge of their ranges. If there are changes in habitat or the environment, we may see changes in these species -- perhaps their appearance or disappearance -- more easily than well-established ones. By studying birds that thrive at the edge of their range in the Yukon, but are perhaps experiencing population declines in the centre of their ranges, CWS can provide important information about what may be happening to these species.
Everywhere I go in the north, people are very interested and concerned about climate change. They have questions we want to be able to help address, says Eckert.
One of his crew members was Judy Selamio, a field assistant from Aklavik who has participated in research projects in the region for close to fifteen years. Many people in that community, including Selamio, have questions about changes they are seeing in the local birdlife.
What can appear much of the year to be an austere, barren environment is in fact a rich, thriving ecosystem that supports a surprising range of species. With the arrival of long days of light and the warming sun, the North Slope tundra teems with budding plants, wildflowers, insects, nesting and birthing.
Over 18 days, the CWS team recorded 80 species of birds. Eckert says that most of the 80 species likely nest in the region, and was very pleased with the high number of confirmed breeders the team observed -- 32 nesting species -- in a relatively short period of time.
Collecting this kind of breeding data builds a baseline of information, and it also reflect the incredible richness of this area, says Eckert.
It's also exciting to be able to contribute to a better understanding of birdlife in Ivvavik National Park. All the information we collect is of value to national park interests. Where other Canadian national parks are struggling to maintain a wild state, this park is 'doing it', he adds.
- For more information about CWS bird research in North Yukon, contact Pam Sinclair at (867) 667-3931.
