An unusual spring migration

Whistler Naturalists

May 31 st was the last day of spring for our feathered friends; actually the real end for many species was during the hot spell in mid-April.

The ever-increasing build-up of arriving migrants suddenly disappeared, leaving low numbers of all species to hang around for summer breeding.

Did the temperature burst generate the urge to move on to northern points, or were there other forces at play? The onset of migration was earlier than normal, thanks to the balmy and wet, late January period; water fowl were moving in then. But then winter finally arrived in late March while some song birds were arriving in droves — there were robust counts of Robins, Varied thrushes, Ruby-crowned kinglets and juncos. Suddenly, presto, the valley was quiet by the end of the heat wave in April.

Meanwhile, the weather in Southern California was vile, blocking movement of other species which inhabit the western Caribbean and Pacific coastal Central America during winter. As I write, some species which should be here in late spring, have yet to arrive. So, species-wise, what are the high- and low-lights of this topsy-turvy season?

The count of species seen was 139 (including the curlew) of the 197 species on the spring checklist, though some of the 139 are known only in other seasons. The "recovery" is 71 per cent, or about on par for the same period in years gone by. This figure overstates reality because there were deemed "very rare" sightings of Ruddy duck, Golden eagle, Hutton’s vireo, Say’s phoebe, Vesper sparrow and Yellow-headed blackbird. Several others rated "rare" were also seen.

Water fowl migration, while very strong early in the season, has been reduced to only a few of each species for breeding. Productive broods of new Mallards, Canada geese, goldeneyes and mergansers will likely be below normal, as shown so far by only a few families on our waterways.

The highlights of the water fowl movements were the Trumpeter swans and Surf scoters. In the second week of March, large flocks of 20-40 swans were nesting each day on our lakes; on March 12 th our proprietresses of the Bottle Depot lost count after 183 birds flew overhead —— a local record to be sure.

During this blitz, we received several erroneous reports of Snow geese on Green Lake which, when checked out, were the swans. In early May, the usual few Surf scoters had arrived when waterways had otherwise been empty for two weeks.

On May 11 th , there was an eye-popping 75 scoters, along with 200 Bufflehead ducks on the lakes. The next day, all had left, and empty lake surfaces have prevailed ever since. Water fowl species not seen to date, but should have been here, are four species of grebes, and Long-tailed, Canvasback and White-winged scoter ducks; they may be no-shows until autumn. And, though Harlequin ducks are present in the Cheakamus system, their usual hang-out at Calcheak campground is still without them.


Subscribe to this thread:

Add a comment

Readers also liked…

Latest in Environment

More by Karl Ricker

© 1994-2019 Pique Publishing Inc., Glacier Community Media

- Website powered by Foundation