Updated: Feb 23
Even though we only have a silhouette view of this bird, its size, shape, and even its perch give us powerful identification clues. Any guesses? It’s a Wood Duck. Photo by Paul Nicholson
When we think about identifying a bird species, many of us go straight to a bird’s field marks. Does it have colourful plumage? What about wingbars? There is no doubt that this is useful information, but the truth is, there are other even more powerful keys to identification that we should never neglect.
1. Seasonal distribution and range
If we see a large white bird flying over a field outside London in July, the seasonal distribution of each species should generally point us to a swan or a Great Egret rather than a Snowy Owl. The bar chart feature on eBird Canada is an excellent resource in this regard. Similarly, if a smaller red bird with black wings and a black tail is seen in Warbler Woods, a birder might page through their bird guide and decide that it was a Vermillion Flycatcher. Experienced bird watchers know never to say never – after all a Vermillion Flycatcher was seen in Wallaceburg in December 2015 – but it is more likely that the sighting is a Scarlet Tanager. Check the range maps that are associated with each bird in any field guide.
2. Size and shape
Sometimes we have a poorly lit view of a bird instead of a perfectly illuminated, unobscured view. Or perhaps the bird we are looking at is a female or a male in basic plumage and not the more familiar breeding plumage. Are we stuck? Certainly not if we key in on the bird’s size and shape. Even novice birders have useful frames of reference. Is the bird we are looking at bigger than a Black-capped Chickadee? Is it about the same size as an American Crow. These are useful clues, and size and shape don’t change even when plumage does. Sometimes simply keying in on one small aspect of a bird such as the size or shape of its beak gives us the information we need to make an identification with confidence.
3. Plumage and field marks
This what many birders focus on when they first start. After all, many of us are drawn to the pursuit because of the beauty of the birds. So often we are captivated by a bird’s plumage, whether it is in nature or in a photograph or film. Field guides and birding apps also key in on plumage and field marks. Of course, these are important features for species identification. For some birds such as mature Bald Eagles and Blue Jays, it is obvious. The plumage takes us straight to the answer. But for others, we might need to know about whether or not a bird has an eyering or a curved beak.
Each bird species has evolved to exploit a particular habitat. This helps us in targeting and identifying species. In a scrubby grassland such as the south end of the Kirk-Cousins Conservation Area in south London, you might see an Eastern Meadowlark in the spring, but your are unlikely to see a Bank Swallow. Similarly, if you are birding at The Coves in the late summer, you might well see one or more heron species but not a Savannah Sparrow.
A bird’s behavior can be a very powerful identification clue. Is your warbler twitching its tail? You may well be looking at a Palm Warbler. When you are looking at a sandpiper foraging by a pond, is it useful to note that it is constantly pumping its rump? This should put Spotted Sandpiper on your list of candidate species.
6. Bird vocalizations and sounds
Some birders feel a little overwhelmed when facing the challenge of identifying a bird based on its song. But a really important aspect of birding by ear is simply hearing that there is a bird “over there” and then trying to spot it. Even a new birder has a frame of reference. Most of know the insistent, buzzy chick-a-dee-dee-dee call or the raucous caw-caw-caw of the American Crow.
Using several of these keys to identification together is powerful. Imagine that you are birding at Cavendish Woods along the Thames River in the summer and you hear some irritated chatter from a brambly tangle. A little brown bird with a relatively long beak and a perky tail pops out. Hopefully your thoughts go straight to the House Wren.
There are some excellent, short videos that highlight four of these six keys to bird identification on the Cornell Lab’s allaboutbirds.org website.