Glacier National Park and Montana Fish, Wildlife and Parks joined forces last year to learn more about Montana’s breeding Harlequin Duck population. In 2016, six male Harlequins were outfitted with transmitters; data from the these birds indicated some wintering activity around Vancouver Island. The females of the pairs were outfitted with geolocation devices to similarly track their movements. However, unlike the male ducks, females have to be recaptured to retrieve their data. Four of the tracked pairs breed in Glacier Park, and they have already returned to their breeding grounds.
This work has continued through 2019, and as part of the Montana Audubon River Initiative, we’ll join the survey effort again this summer.
Lead by non-game biologist Lisa Bate along with a great group of volunteers, we have already re-captured two of the females and retrieved the data from their geolocation devices. The other positive news is that all of the marked birds are in excellent physical condition.
This data will help us answer questions about the species’ biology that are key to understanding management needs such as those surrounding home-range characteristics, site fidelity, the timing of movements, and more. Harlequins have experienced declines throughout their range, with the exception of Glacier National Park (an Important Bird Area where more than 25% of chicks are produced in the state), and we need to understand why.
Climate change has been indicated as a significant threat to these birds, given their dependence on the timing of spring runoff, but they are also threatened by having a limited amount of suitable habitat from the outset, along with their sensitivity to human disturbance and habitat loss (due to altered runoff).
Conservation Program Manager Amy Seaman will survey additional streams in Glacier to look for signs of breeding pairs, and to locate sites for an expanded marking effort of up to six pairs within the park next summer. Check in next month for a re-cap of the field season.
If you’re out birding and on the search for Harlequins yourselves, take note if you see leg bands! Some Harlequin Ducks in Montana, Idaho, Wyoming and British Columbia have been marked with colored leg bands or nasal discs. Anyone observing Harlequins with colored markers should report the color combination and shape or sequence. For instance, a female may have red over blue bands on the left leg, pink over silver (aluminum) on the right leg. Birds marked elsewhere have one colored and one aluminum leg band. Please report any sightings to Amy Seaman ([email protected] ).