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Long-billed and Short-billed Dowitchers

Long-billed Dowitcher (L), Short-billed Dowitcher (R), late summer

Long-billed Dowitcher (L), Short-billed Dowitcher (hendersoni ssp) (R), nonbreeding

Long-billed Dowitcher (small-billed, slender-bodied male) (L), Short-billed Dowitcher (hendersoni ssp) (R), nonbreeding

Short-billed Dowitcher (hendersoni ssp) and Long-billed Dowitcher, breeding

Transition plumage (early April) for Long-billed Dowitcher (L) and Short-billed Dowitcher (hendersoni ssp) (R)

These two very similar species have long been regarded by experts as unidentifiable in many field conditions unless their distinctive calls are heard. Recent careful assessment of subtle differences in structure and bill shape has allowed us to identify most birds in all plumages. 

 

Physical Features:

A husky, front-heavy weight distribution, thick neck and bulkier head contribute to a physical profile on Long-billed Dowitcher that differs from Short-billed Dowitcher’s more even weight distribution, thinner neck, and smaller head. While both dowitchers can show a rounded upper body shape, Long-billed has a deeper, more egg-shaped lower body carriage compared to Short-billed’s straighter under carriage. These differences in body shape may also be seen in some flying birds. 

 

Care should be taken with juvenile and undernourished birds that don’t exhibit the typical egg-shaped body shape of Long-billed Dowitcher, but instead show a slender undercarriage similar to Short-billed. 

 

The front heavy body structure causes a weight imbalance in Long-billed that requires them to adjust their body angle and tilt upwards when sleeping or resting. This back angle may be as extreme as 40 degrees in larger females and differs noticeably from the more evenly balanced Short-billed Dowitcher, which shows a horizontal or slightly angled back in a resting posture. Sleeping birds are more easily identified using this back angle difference, unless a strong head wind causes both species to lean forward. 

 

The combination of rounded back and slightly rounded, egg-shaped under-carriage on Long-billed creates a "swallowed a tennis ball" profile on relaxed feeding Long-billed Dowitcher. Short-billed lacks this “tennis ball in the belly” impression because of the straighter undercarriage. The more rounded body shape on Long-billed is also obvious in head-on or tail-on views, with Short-billed showing a more slender, less rounded body shape.

 

Female dowitchers are larger-bodied, longer-billed and longer-legged than males, and these differences are especially noticeable in Long-billed Dowitcher. Female Long-billed is easier to ID because of its especially long bill and legs, and extra chest-heavy body structure.  Male Short-bills are easier to ID because of especially short bills and small, slender, compact bodies. It is the female Short-billed and male Long-billed Dowitchers that appear similar in size and structure. 

 

Short-billed has a bill that is thicker overall with a fairly blunt tip and a deeper base. This deeper base is a helpful feature for some Short-bills, and is not present in Long-billed. Many Short-bills also show a distinct “kink” in the bill near the tip, as if it got caught in a closing door. Long-billed has a uniformly tapered bill that flattens near the tip and has a shallower base. Some Long-billeds show a uniform downward arch to the outer bill half that superficially suggests the “kink” near Short-billed’s bill tip, but the longer arch versus a restricted kink in Short-billed is different.

 

Plumage and Bare Parts Details:  

Non-breeding plumage: Plumage is darker gray overall in Long-billed, with its head and neck often appearing as if dipped in a bucket of soot. A bold white lower eye crescent is also more obvious on Long-billed Dowitcher and accentuated by a uniformly darker face. Short-billed has a paler head and neck and a whitish upper breast with variable spotting. 

 

Upperpart feather shafts are darker in Long-billed, with dusky shading adjacent to the central shaft in many birds adding to the darker impression, especially in adults. Short-billed has paler upperpart feathers and less prominent dark central feather shafts, especially in the subspecies hendersoni, which gives them a lighter appearance overall, especially from a distance. Two other subspecies of Short-billed Dowitcher (griseus and caurinus) have darker upperpart feathers and shafts in nonbreeding plumage, but are still paler than Long-billed. Dark tail bands on Long-billed are noticeably wider than thinner white bands. Short-billed usually shows white and dark bands of equal width, or slightly wider white bands.

 

Transition and Breeding Plumage:

Upperpart markings and feather fringes on Short-billed Dowitcher are typically more orange in color and wider than Long-billed’s narrower rust colored feather fringes, which creates a more contrasting and colorful appearance in breeding Short-billed, and gives the impression of a mostly orange colored back with black feather centers.

 

Long-billed’s black feather centers and very narrow rusty fringes give the impression of a blackish back with minimal rusty highlights. Both species may show similar upperpart fringes in fresh transition and breeding plumage (see comparison photos), but late spring and summer breeding plumaged birds appear very different overall in terms of upperpart feather edge color and internal shading.

 

Underpart coloration is more brick red in Long-billed Dowitcher versus orange in Short-billed, and only the prairie subspecies (hendersoni) has orange color that extends to the undertail, similar to Long-billed. The other two subspecies have distinct white vents, and do not resemble breeding Long-billed. 

 

Differences in breeding hendersoni includes lighter spotting on the central upper breast compared to Long-billed’s denser, heavier spotting, and dark bars on the upper and lower flanks compared to mostly spotting on Short-billed. These dark bars on the upper flanks in Long-billed also have distinct white fringes, while Short-billed’s spots or bars do not. Late summer transition Long-billed and hendersoni Short-billed can be almost identical in plumage when the flank and upper breast markings wear off, and structural differences are more important in these instances.