On Saturday, Calgary naturalist Brian Keating and his partner went out in search of spring, exploring the prairies and foothills to the south of the city, just looking to see who the latest migrants might be.
Their first stop was Frank Lake, the important bird area (IBA) that Keating has talked about so many times before, located just east of High River.
It’s the lake that most recently was made famous by the overwintering pelican, which, by the way, the couple saw.
But it was the swans that stole the show. They counted 400 in one flock, and there were many more in smaller flocks, of both species, the trumpeter and the tundra.
These are the only two types of swan that can be seen in Alberta but there are seven swan species around the world.
The tundra has a yellow mark at the bill base and has a dish-shaped beak. It is the smaller of the two.
The trumpeter has a straight beak off the forehead, which is jet black and does not have any yellow.
Immature birds can be difficult to identify, featuring shades of grey. You need to see the bill colour, but according to an expert, any grey ones are likely trumpeters, as the first-year tundra swans would have lost their grey feathers in December.
But from a distance, both species look very similar. Keating used a scope, which helped. However, the call of the trumpeter is very distinctive, giving their identity away from a distance.
It’s very easy to see why they are called trumpeter swans. Here’s what they sound like.
Both sexes give that characteristic deep bugle oh-oh call, with the second syllable emphasized. They call to keep the pair or family together, which was happening Saturday, but they will also call to defend their territory or to sound an alarm.
Young birds make a higher-pitched call and develop their adult tone at eight or nine months of age.
And just for a comparison, have a listen to the sound of Alberta’s other swan species, the tundra, which used to be called the whistling swan.
Tundras make a variety of nasal-honking calls that are smoother and higher-pitched compared with the trumpeter.
Keating called his buddy Greg Wagner to get his take on the numbers of swans at Frank Lake and their population health.
Wagner is a prominent High River naturalist and the volunteer caretaker of Frank Lake. He had seen some 600 on Saturday of both species, and told Keating that in any given year, the lake has about five per cent of the world’s population of trumpeters.
They use the lake as a staging area, and to rest and feed during their migration northward.
But he also reminded Keating that the trumpeters are an incredible conservation success story, having been as low as 120 breeding pairs back in 1933.
The present population is about 35,000 — that’s a huge increase from near-extinction.
The tundra have increased from about 34,000 since the early 1970s to about 180,000, Keating said.
The trumpeters’ main overwintering location is in one small area in the Yellowstone thermal areas, so there is a potential of a big population crash if a bad winter occurs.
Wagner told Keating that a significant cause of death around Frank Lake is power-line collision. He found one dead swan that died this way on Saturday.
He has suggested to AltaLink, the electricity transmission company, that it pay a farmer to plant and leave a row or two of peas to the east of the lake, to encourage the swans to avoid the lines.
The swans fly back and forth from the lake to neighbouring fields to feed on spilled peas from last year’s green pea crop, which is likely what Keating saw the flock of 400 feeding on.
Wagner is also concerned about the proposed 607-hectare (1,500-acre) solar farm to be built just northeast of the lake. The “lake effect” happens when water birds are tricked into landing on the [solar] panels and possibly getting injured.
Birds like loons and grebes cannot take off from a solid surface as they require a water runway to get airborne.
Trumpeters nest primarily in the boreal forest region of Alberta’s north, but there are more and more reports of them settling in lakes in the foothills, too, in mixed aspen and grassland landscapes.
Tundra swans nest in the Arctic. They have adapted well to the short season up there. Tundra swan cygnets grow faster than those swans that breed in a warmer climate, and will fledge in as few as 60 days. That’s twice as fast as the European mute swan.
Keating saw huge numbers of shoveler ducks on the lake, good numbers of mergansers, lots of scaups, some excellent numbers of common goldeneye with lots of courtship behaviour. Of course, lots of gulls, mallards, a few coots, grebes and some widgeon.
Wagner told Keating that Alberta is still a week away from the first of the shorebirds like avocets and yellowlegs arriving, but he did say that a black-necked stilt was seen on Saturday.
There is still some ice on Frank Lake, so there are lots more birds to come in the weeks ahead. Wagner updated Keating on his swan sightings: 1,500 on Sunday.
Further to the west, Keatring spotted a few bluebirds. Nothing says spring like a mountain bluebird sighting, he said.