There was a nice selection of ducks and waterbirds in the lagoons. We saw a few Canada Geese, including a family with nine babies, a male Blue-winged Teal, a pair of Northern Shovelers, a pair of Redheads, a female Bufflehead, about 10 Ruddy Ducks, a Pied-Billed Grebe, and two American Coots. Several scaup were also present, including at least one Lesser Scaup resting on the bank – normally the scaup are too far out for me to feel confident in my identification, but this time it was actually close for me enough to identify it. We also saw a swan in the furthest lagoon. There have been reports of a Tundra Swan here, and although it seemed small enough to be a Tundra Swan, it was too far away for me to see the yellow lores through my scope.
We saw several Ring-billed Gulls resting on the berm next to the cell where the swan was. While we were watching, a large flock of larids flew in and swirled above them. I thought they were terns at first based on their grating calls, but when I got a good look at them I realized they were all non-breeding (or perhaps juvenile) Bonaparte’s Gulls. Unfortunately they didn’t land, merely circled the area a few times and then flew off.
The usual songbirds were present, including Yellow Warblers, Song Sparrows, Savannah Sparrows, a couple of Bobolinks singing in flight in the grassy area near the shorebird cells, and at least two swallow species. A few Barn Swallows and Purple Martins were hawking for insects, but there didn’t seem to be as many swallows as I recalled from previous years. If there were any Tree Swallows present I didn’t notice them. The lack of Tree Swallows and migrant songbirds made me realize that there no trees bordering any of the cells. In my very first visit there in 2010 it had been quite windy and rainy, and the Tree Swallows had lined the lower branches hanging out over the water, waiting for the weather to improve. In a subsequent visit in 2013, I remember trying to photograph a Trumpeter Swan through the trees and watching a Yellow-rumped Warbler flitting through the leaves. Now the small trees fringing the lagoon cells were gone, making it difficult to avoid detection by the birds on the water.
The highlight of our trip, as usual, was the shorebirds in the sprinkler cells. I could spend hours picking through them, searching for something different. I immediately noticed two things once I arrived: hundreds of Dunlin, and a beautiful dowitcher in breeding plumage fairly close.
I am always amazed by how many Dunlin stop over at Blenheim in the spring compared to how few I see in Ottawa (in fact, I’ve only seen Dunlin twice in Ottawa during the spring, both times at a wet field along March Valley Road). The black patch on the belly makes identification simple, even in flight.
Dowitcher identification is much more difficult. Despite the names, the length of the bill cannot be used to separate Long-billed and Short-billed Dowitchers as bill length varies between males and females of each species, and there is some overlap. Generally, Short-billed Dowitchers are more common in southern Ontario at this time of year, which is what this bird is.
Their call is the best way to distinguish between the two dowitchers, but these calls are most often given when flushed, and this bird seemed perfectly content to probe the muck with its typical sewing-machine-like motion. The Short-billed Dowitcher gives a quick “tu-tu-tu” that sounds a bit like a yellowlegs, while the Long-billed Dowitcher’s call is a higher and thinner “keek” reminiscent of a Hairy Woodpecker.
When the bird isn’t calling, some useful (but not diagnostic in themselves) features include the slight downward kink in its bill toward the end, the spotted pattern along the sides of its body, and the straight back when feeding (Long-billed Dowitchers have a straighter bill, barring on the flanks, and a more hunched appearance). With dowitchers, just like accipiters and other wildlife species, it is best to look at several features instead of relying on just one for identification. Although the identification of dowitchers is not covered in depth in a lot of field guides, articles on eBird.org and surfbirds.com provide some useful information on sorting these two species out.
After the Dunlin, the Least Sandpiper was the most numerous shorebird in the cell. You can see a hint of its back leg in the photo below, which is characteristically yellow, as well as the slightly drooping bill. I thought I saw a Semipalmated Sandpiper (which looks similar to the Least Sandpiper, but is grayer and has black legs and a straight bill) but lost it among all the other birds when something else caught my attention – possibly the two yellowlegs or the two Semipalmated Plovers further back. Spotted Sandpipers and Killdeer, both breeding residents rather than temporary migrants, were the only other species seen.
Least Sandpipers are very cute, and true to their name, very small. They have a slight “bib” which might confuse them with Pectoral Sandpipers, although Pectoral Sandpipers are larger, with a dense bib and a bill with a yellowish base.
I couldn’t resist taking a few more Dunlin photos. They were all in various stages of molt; some were still quite grayish while others had attained the bright reddish colouring of breeding plumage.
The shorebirds are one of my favourites groups of birds (along with warblers), and the Blenheim Sewage Lagoons are a terrific spot to get my shorebird fix. I only wish Ottawa had someplace like this or Hillman Marsh, designed for migrating shorebirds, that’s closer to home than the eastern lagoons (which are at least 40 minutes away and just as unproductive for shorebirds in the spring as the Ottawa River is due to high water levels). As usual, the lagoons did not disappoint, and made the stop completely worthwhile.