ML352196201
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Observation details
Dowitcher with mellow two-two-two call notes (see audio). L. griseus griseus is the more expected subspecies. This bird has a fair amount of orange in the lower belly region, though, so it’s worth a closer look at field marks used to distinguish between L. g. griseus, L. g. hendersoni, and especially intermediates between the two. The bird has more orange on the belly than is typical of the standard depiction of L. g. griseus. The lower belly is mostly orange with some whitish splotching, whereas a typical L. g. griseus is mostly white in the lower belly. The amount of orange on the flanks appears slightly greater on the bird’s right side than left side. The bird also has more limited marking on the sides of the breast and flanks than the standard depiction of L. g. griseus. L. g. griseus has dense spotting and barring on the sides of the breast and extensive barring on the flanks. This bird has the sides of the breast “spotted,” though the spots are for the most part not perfectly round; most have a slightly oblong shape. L. g. hendersoni should have only round spots on the side of the breast (Jaramillo et al., 1991). The flanks have only a moderate amount of barring, less than a typical L. g. griseus. The reduced markings could be a result of feather wear (i.e., the dark tips wearing off), though Jaramillo et al. (1991) say that the dark patterning on the sides and flanks in L. g. griseus does not change much with wear, unlike in hendersoni and Long-billed Dowitchers (presumably because the dark bars on the feathers are placed further back from the tip?). Next time I’m on the coast with a group of dowitchers in mid summer, I’d like to take some notes on how much wear impacts the dark markings on the flanks of L. g. griseus. The bird was fairly whitish in the vent region, but with some orange patches in between the legs, on rear flanks, and on a few undertail coverts—more like L. g. griseus. Some of Mary Mckitrick’s photos of the bird show the vent region better than my photos (https://ebird.org/checklist/S91168531). The number of alternate upper wing coverts tends to be few in L. g. griseus (variable in hendersoni). The left side has few alternate wing coverts. The right side has slightly more, but still relatively few. The pale edges on the alternate scapulars and wing coverts are relatively thin as in griseus, but this could also be affected by feather wear. Jaramillo et al. (1991) say that on alternate plumage lower scapulars and tertials, the internal bars reach the feather shaft on L. g. hendersoni, but usually don’t on L. g. griseus. In photographs showing these feathers, the internal pale bars do not reach the feather shaft on some feathers, but on others appear to reach the shaft or at least come very close, so I’m not sure what to make of that field mark. Some say hendersoni’s foreneck is unspotted (e.g., O’Brien et al., 2006). Other guides show hendersoni with the foreneck clearly spotted (e.g., Crossley, 2011). This bird has the foreneck spotted. The sides of the nape and rear auriculars are more orange in L. g. hendersoni and a duller brownish with only slight orange cast in L. g. griseus. This bird better fits the latter in my opinion. O’Brien et al. 2006 consider hendersoni to move slightly earlier than griseus. This date is relatively early (though certainly within range for L. g. griseus). On a very quick look at eBird records in the western half of the state, this was second earliest “fall” migration date, with others generally starting around July 10th-15th. Three close dates were a Silver Lake (Berkshire Co.) record on 6/30/2015, a 7/6/1983 record in Longmeadow, and a 7/5/1967 record for Bolton Flats. Overall this bird has many characteristics of L. g. griseus, but seems to deviate somewhat from the standard L. g. griseus by having more orange in the lower belly and more limited barring on the flanks. It also lack many features of L. g. hendersoni. So this bird is probably best labeled as an intermediate. Intermediates between the two subspecies are discussed in a number of sources. O’Brien et al. (2006) note that the populations that breed on the south shore of the Hudson Bay are apparent intergrades and appear intermediate between griseus and hendersoni. Jaramillo et al. (1991) also discuss the possibility of a clinal gradation of some of these field marks/traits along an east-west gradient. It is certainly enjoyable to wonder from which breeding grounds this bird came and what its origin is. It was fun to come across it in the field and—because it was cooperative and came close for photographs—it provided a good exercise for studying the differences between L. g. griseus and L. g. hendersoni. Grateful to have crossed paths with it. Refs: Jaramillo, A., R Pittaway, and P Burke. 1991. The Identification and Migration of Breeding Plumage Dowitchers in Southern Ontario. Birders Journal. Volume 1, pg 8-25. O’Brien, M.O., R. Crossley, and K. Karlson. 2006. The Shorebird Guide. Houghton Mifflin: New York, NY. Crossley., R. 2011. The Crossley ID Guide. Princeton, Univ. Press: Princeton, NJ.
Technical information
- Recorder
- Microphone
- Accessories
- Original file size
- 4.39 MB