A Modified Letter to the Editor of Kamloops This Week published April 25, 2018
By Rick Howie, Registered Professional Biologist
I read with interest the comments by Hugh Jordan in Kamloops This Week regarding the Sandhill Cranes passing over Aberdeen recently. Indeed, it is exciting to see and hear these magnificent birds passing overhead at this time of year as they have done annually for thousands of years. April is the peak month for spring migration. Most of the birds normally pass just a bit west of Aberdeen enroute north but occasionally, winds will cause some flocks to drift over the city as I have observed on numerous occasions.
There are 3 races of Sandhill Cranes that can be observed in BC. They differ somewhat in their physical characteristics such as size, and occupy different geographical breeding locations.
The large numbers we see in the spring are a race of birds known as Lesser Sandhill Cranes. Their taxonomic name is Antigone canadensis canadensis. They breed in the extreme northern parts of the continent from northern Alaska east across the arctic. They often settle overnight on the ground in our area before continuing their migration. The exact spots where they touch down vary somewhat and depend upon flight conditions and possibly the time when they departed from their last big ground-staging area in northern Washington state. Flocks of Lesser Sandhills will return in the fall with large numbers passing through our area along a similar route to their spring migration. The timing then is a bit more protracted with September and October being the major migration period.
Another race of cranes that may fly mixed in with the Lessers or in their own flocks is known as the Canadian Sandhill Crane, A.c. rowani. They breed in the subarctic areas from northern BC east across boreal Canada to Ontario. They would be impossible to distinguish in flight from the Lessers.
We do have some cranes that breed locally and comprise the third race known as Greater Sandhill Crane, A.c. tabida. They are a more southerly breeder in west/central North America, nesting from southern BC down through Colorado and south to Tennessee. They may consort with the northbound migrants on occasion but although larger, would be difficult to distinguish from the others. They breed in small numbers in wetlands at higher elevations around Kamloops such as Pinantan, north of Red Lake, in the Campbell Range area, Opax Mountain and the McQueen Lake area to name a few spots. They also breed in the Caribou/Chilcotin area and at the coast in places like Pitt Meadows and on the islands of Haida Gwaii. Birds heard or seen around the BC interior during the summer will undoubtedly be this sub-species.
The exact routes and timing of the various sub-species passing through Kamloops add to the complexities of this spectacular migration that is so much enjoyed by many Kamloops residents. Be sure to make crane watching part of your annual activities.