FOAM LAKE BIRDING
No. 92
Most transient birds are best seen in the spring, but there are a few that are more numerous in the fall. A few such birds are: Nashville Warblers, Orange Crowned Warblers, Yellow Rumped (Myrtle) Warblers, Oven Birds and Rose Breasted Grosbeaks. Though more colourful in the spring and easier to identify, part of the charm of fall bird watching is trying to identify juveniles and adults in fall plumage. While difficult, with practice it can be done and it certainly sharpens one's identification skills in the process.
This week I am introducing a new family of birds, the grosbeaks. Related to sparrows and finches they have, as the name implies, large beaks attached to powerful muscles with which to crack hard seeds especially from evergreens. Like their cousins, grosbeaks will visit feeders making short work of the food offered them. For example, a flock of Evening Grosbeaks will consume a litre of sunflower seeds in a few minutes. Rationing is essential.
It should be noted that the Pine Grosbeaks that I mentioned in Article No. 66 are not grosbeaks at all, but finches. Why the misnomer? Well, grosbeaks are generally larger than finches and have larger and more massive bills. Our largest finch, the Pine Grosbeak, looked more like a grosbeak than a finch and was so named. Properly, its name should be Pine Finch. Perhaps ornithologists will change it like they have changed so many other names in the last few decades. Some examples are: Rock Dove is now Rock Pigeon (the common pigeon seen around elevators); The Upland Plover is now the Upland Sandpiper; the Canada Jay is now the Grey Jay and so on. Time will tell.
The first grosbeak chosen for these articles is the beautiful Rose Breasted Grosbeak that normally nests in the boreal forests of North America and seen here only in the spring and fall. However, with many plantings of evergreen shelterbelts some have started to nest locally. In the spring the males, with their black and white tuxedo-like plumage set off by bright rose coloured bibs, are simply stunning. This is one of only a few birds that is much more beautiful in real life than in a painting or photo. The females are brown overall with white markings and a distinctive broad white stripe that runs lengthwise along the side of the head just above the eye. Except for size (between that of a sparrow and robin) and a more massive bill, the females can easily be mistaken for female Purple Finches. They look like big and small versions of the same bird.
In the fall the male Rose Breasted Grosbeak's colours are much more subdued but the bird is still easily identified. The rose bib is paler and the solid black head has the white stripe of the female. The females do not change colours in the fall and the young are much like the females with the young males showing some slight differences. The juvenile males will usually, but not always, show a little pink on the throat where the rose bib will eventually be. The best field mark to separate juvenile males from females is the pink under wing linings that all males have and that are very apparent in flight.
The Rose Breasted Grosbeak occurs from the Atlantic to the Rocky Mountains where it is replaced westward by its very close relative the Black Headed Grosbeak. Where their ranges overlap they hybridize freely producing viable offspring. For that reason some taxonomists believe the two to be one species with two distinctive races. At present they are still considered two different species.
Every few years a family group of the current year's hatch spends a day or two in our, and our neighbours', yards. This fall is one of those years. This week's photos are of a Rose Breasted Grosbeak taken in our backyard in the fall, and a Black Headed Grosbeak taken in the Cayumaca State Park in California. The fall male Rose Breasted clearly shows the striped head of the female. A few years back a male Black Headed Grosbeak spent a couple of days in our neighbourhood in spring. It was rewarding seeing a stray so far from its normal range. Too bad that I did not have a camera back then.
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