By Geoff Holroyd, Chair, Beaverhill Bird Observatory
In central Alberta, 80 kilometers east of Edmonton is Beaverhill Lake, one of seven WHSRN sites in Canada. Designated in May 1996, this site celebrated its 25th WHSRN anniversary in 2021, a bittersweet celebration as the site has hosted only low numbers of shorebirds in recent years. When Beaverhill Lake was designated it was host to over 20,000 shorebirds annually, including the highest one day count of 52,334 in 1995. In the 1990s as the lake level receded, vast mudflats attracted numerous breeding and migrant shorebirds. However, drought conditions continued and even mudflats disappeared, providing habitat for only a few shorebirds in the 2000s.
After becoming almost completely dry, Beaverhill Lake began refilling in the past decade. In 2016, summer thunderstorms to the south of the lake filled the feeder creek for Lister Lake. Lister Lake, the southeast corner of Beaverhill Lake, was flooded though July and August that year. In the subsequent springs, 2017 to 2020, snow run-off filled the feeder creeks that continued to refill Beaverhill Lake. Heavy rains from May to July 2020 also contributed much needed water. Even though 2021 conditions were dry, the lake now covers three-fourths of the area it covered in the 1980s.
Aerial view Beaverhill lake. Photo: Beaverhill Bird Observatory
Has this brought the shorebirds back? Not quite. The signature habitat at this site, like many other lakes in the Midcontinent Flyway, was the mudflats created by a ‘wind tide’. Different shorelines of the lake can be periodically affected by the wind, at times flooded or exposed for short periods, depending on the intensity and direction of the wind. This variability kept the lake open and free of extensive vegetation, allowing for the shorebird preferred mudflats. When the lake was almost dry in the early 2000s, grasses, forbs and cattails filled the lake bed, poor shorebird habitat. Now as the lake refills, this vegetation is being flooded out, but the former mudflats have not returned yet. It’s not all bad news, as a major beneficiary of the flooded vegetation are White-faced Ibis which have been expanding their range north in Alberta. Flocks of over 100 have been seen at Beaverhill Lake, and recently fledged young have been seen in August.
For shorebirds, recent sightings of shorebirds have include Long-billed Dowitchers (L. scolopaceus), Short-billed Dowitcher (Limnodromus griseus), American Golden Plover (Pluvialis dominica), Greater Yellowlegs (Tringa melanoleuca), Lesser Yellowlegs (T. flavipes), Semipalmated Plover (Charadrius semipalmatus), Wilson’s Phalarope (Phalaropus tricolor), and others.
A Short-billed Dowitcher. Photo: Kim Stark.
While habitat recovers, conservation actions continue at the site. Beaverhill Bird Observatory operates an environmental education program and a songbird research station. Environment and Climate Change Canada is also preparing for the return of the shorebird with funding for the installation of a Motus station onto of an 80’ tower operated by Beaverhill Bird Observatory.
With the ever present variables of climate change, it is hard to predict when or even if Beaverhill Lake will regain its full size. And equally important, it is unknown if the former cycle of spring fill and autumn drying will return. It’s this cycle that benefits shorebirds and led to the WHSRN designation. Ever vigilant of the changes, habitat availability, and shorebird use, the Beaverhill Bird Observatory continues to monitor conditions and will be ready to welcome shorebirds if the habitat can recover from these past challenges and upcoming challenges.
Cover Photo: Beaverhill lake, Canada.
