Keeping up on events around Manitoba has been a challenge. We still need to update on our goose count at Netley-Libau Marsh and catch up on a few other volunteer based activities. For today, it is to Oak Lake and Plum Lakes IBA and a recent visit with volunteer Glennis Lewis.
Glennis is certainly very knowledgable about some of the unique biodiversity of the sandhills and other habitats around Oak Lake and Plum Lakes IBA. Having worked in the IBA (before it was an IBA) as a student (close to the former large Franklin’s Gull colony) or completing a contract looking for western spiderwort, Glennis has spent many days in the Oak Lake area and knows it very well.
On Wednesday October 11th, Glennis and Manitoba IBA Coordinator met up early morning in Brandon and travelled the 45 minutes down the road to Oak Lake. The primary objective was to take a look at a few areas of the IBA which Tim had not visited previously and maybe also get a count of any large concentrations of fall migrants.
The northern area of the IBA is covered by pasture, hay meadows and the dominant feature, the Assiniboine River Valley. Within this area is part of the Upper Assiniboine Wildlife Management Area. An old wetland project is also to be found in this area – but alas there were few waterfowl to be found here on a warm Wednesday morning in October. The groups of Eastern Bluebird were worth the trip at least.
The highlight of the day were the large concentrations of waterfowl, especially Tundra Swan. These northern breeders can be abundant in large concentrations during passage in some of Manitoba’s IBAs (see Saskatchewan River Delta, Whitewater and Churchill and Vicinity). From the southwest corner of Plum Lakes to the wetlands just to the north of Oak Lake we were able to count a minimum of 1765 Tundra Swans, just 135 short of the 1% North American breeding population. See below for a map of where the larger concentrations were encountered.
These large concentrations suggest that some concerted, targeted counts during fall by a group of volunteers should be able to identify significant concentrations of migratory waterfowl in the Oak Lake and Plum Lakes IBA boundary.
There were also thousands of Snow Geese in the area, their presence made public thanks to a passing Bald Eagle. Snow Geese tend to be more abundant in southwestern Manitoba at this time – a count of 22,000 was made by Colin Blyth and Gillian Richards on October 22nd at Whitewater Lake. In addition thousands of ducks were feeding along the weir, too many to stop and count at times. Anyway below are a couple of (not the best) videos just to demonstrate the sheer scale of Snow Geese encountered.
In terms of shorebirds, there were still a few around – and Plum Lakes remains in a state of drawdown. Long-billed Dowitcher and both species of yellowlegs were most abundant, with a single Black-bellied Plover flying overhead adding a bit of diversity. Raptors were also present in low numbers including a glimpse of a Northern Goshawk in forest on the Grande Clariere Road and a lovely view of a Great Horned Owl.
10 days later and this time Glennis was joined by Linda Boys another one of our IBA volunteers based out of Minnedosa. A focused Tundra Swan count was the aim of the day this time, avoiding the north which lacks good waterfowl habitat. In the intervening period it was apparent that although the numbers of waterfowl were still very high, there had been a certain amount of drop-off from the 11th. A very good total of 1133 Tundra Swans were present in the same areas, a drop of 600 from the high count. No trigger, but at least we now know that with some planning it would be possible to do target counts of swans and other waterfowl during fall.
Another major highlight of this trip was a surprisingly large concentration of Sandhill Cranes (for this late in the fall that is). These cranes were all concentrated in a single field in the west of the IBA. Sandhill Cranes are certainly a species to look out for in large concentrations in IBAs with open hay meadows and pastures. In 2016 around 2000 were counted in early October in fields in the Southwestern Manitoba Mixed-grass Prairie IBA and the adjacent Maple Lakes area and the Langruth-RM of Lakeview IBA has historically been a critical staging area for this species. Another species to look out and get more people reporting!
Other late season birds included Turkey Vulture:
The combined bird lists of these trips is outlined below. Thanks Glennis and Linda for your time!
|October 11th||October 21st|
|American White Pelican||0||1|
|Great Blue Heron||2||1|
|Rock Pigeon (Feral Pigeon)||2||8|
|Great Horned Owl||1||0|
|American Tree Sparrow||4||28|