We decided to head over to the Richmond Lagoons to see if all the geese were congregating there – it was getting late in the day, and they must have been flying somewhere close by to roost for the night. The ponds there too were mostly empty, with more geese flying overhead than settling on the water. It was not a wasted trip, however; a group of shorebirds was foraging in the muck at the edge of the middle cell, and Jon quickly got his scope on them (the quality of his Vortex Viper, by the way, was amazing). We were happy to identify three Greater Yellowlegs foraging with three Pectoral Sandpipers – I don’t get to see Pectoral Sandpipers as often as I do the yellowlegs, so they alone made the stop worthwhile.
Then I spotted something else – there were three large, chunky shorebirds in the middle of the cell on the far side of the lagoon, and lurking in the reeds close to the water’s edge was a photographer. Jon had the scope at that point, and when he said the three birds were all dowitchers, we both immediately headed over to where the photographer was standing to get a better view of them with the sun behind us.
When we reached the photographer, he confirmed that there were two Long-billed Dowitchers and a single Short-billed Dowitcher. They were foraging quite close to the shore, and didn’t flush when Jon and I scrambled down the steep bank to reach the edge of the water. We found a gap in the shoulder-high reeds where we spent a happy 20 minutes observing and photographing the birds.
Seeing both dowitcher species together – and so close to shore – was thrilling, and made my experience with the White-rumped Sandpipers and Dunlin earlier that morning almost dull in comparison. Dowitchers can be difficult to identify, so I was grateful for the opportunity to compare the two. Like Empidonax flycatchers, dowitchers are usually best distinguished by voice. However, most only call when flushed or in flight, and these three were placidly feeding with nary a call note to be heard. When seen together, the Short-billed Dowitcher is slightly smaller and slimmer than the Long-billed Dowitcher, with a flatter back when feeding. Both are fairly chunky, attenuated birds, but when feeding the Long-billed Dowitcher has a humped back and rounded belly, making it look as though it has swallowed a grapefruit. (Click to enlarge – can you tell the two dowitchers apart based on shape?)
Despite their names, bill length is not a key field mark in differentiating these two species, as there is much overlap in bill size and bill shape. Generally Short-billed Dowitchers have shorter, thicker bills with a blunt tip and a downward kink near the end, while Long-billed Dowitchers have longer, thinner bills with a fine tip with a very subtle downward arch in the outer half. However, female dowitchers have longer bills than males in both species, so most birders ignore bill length as a diagnostic field mark unless it is either extremely long or extremely short.
Even with some sort of food item in its bill, you can see that the bill of the Short-billed Dowitcher appears thicker and shorter than the Long-billed Dowitcher’s bill (above). Being able to compare the two together is helpful, but judging the bill length and shape on a single dowitcher foraging alone becomes much more difficult.
Plumage is much more useful in identification, particularly given that these birds are all juveniles, which are easier to differentiate than adults. Dowitchers are aged by the pale fringing on the feathers of their upper-parts. The feathers have crisp, bright, colorful edges – not at all like the worn and faded plumage of adults in non-breeding plumage.
Juvenile Short-billed Dowitchers are usually more colourful than juvenile Long-billed Dowitchers. In addition to the humpbacked appearance of the Long-billed Dowitcher above, note the plain, dark brown wing feathers above the tail. They are dark in the center with pale edging. In contrast, the same feathers of the Short-billed Dowitcher (called tertials) have pale spots in the center as well as the pale edging. This is the most reliable way of telling juveniles of the two species apart if they aren’t calling.
Note again the dark feathers above the tail and the less-patterned appearance of the two Long-billed Dowitchers.
I really benefited from the experience of seeing the two dowitcher species together, and think I have finally gotten a handle on their identification – at least for juveniles. Jon and I were lucky to have the time there that we did, for the sun soon sank below the tree-line, casting dull shadows over the lagoon. Just then the three Greater Yellowlegs began working their way in front of us, so I took a few photos before we left our cozy spot in the reeds and headed back to our cars.
It was a fantastic day for shorebirds – one of the best shorebird days I’ve had in Ottawa in a long time. Altogether I tallied eight species on Sunday, with two additional species (Spotted Sandpiper and Black-bellied Plover) at Shirley’s Bay the day before. It will probably be a long time before I see two dowitcher species together again, for they aren’t very common in Ottawa, and water levels aren’t always favourable for shorebird migration to begin with. What fantastic luck to see the three birds together!