Short-billed and Long-billed Dowitchers can be identified by call. The flight call of the Short-billed is a “tu” note repeated up to three or four times. Long-billed Dowitchers gives a high “keek” note, given once or repeated several times (Jehl et al. 2001). When I began birding, the dowitchers were considered to be one species. Peterson, in his early field guide, wrote, “the Dowitcher feeds like a sewing-machine, rapidly jabbing its long bill perpendicularly into the mud.” You can see this feeding strategy in the second photo.
Silent dowitchers, like this one Erika and I photographed last Saturday at the Jirik Sod Farm in Dakota County, are another matter. Some dowitchers, depending on the season and the birds’ race, are probably not separable in the field. Long-bills can have shorter bills than some Short-billed Dowitchers. Most plumage characteristics are shared by at least some birds of both species.
I think, nevertheless, that our bird is clearly a Short-billed Dowitcher. Compare it to a Long-billed Dowitcher that I photographed some time ago in South Dakota (see last photo). The Minnesota bird clearly has a much shorter bill than the Long-billed. The Minnesota dowitcher also appears to be a much smaller bird, although females of both species are smaller than their males. As a result, the relative size of the bird can only be used in extreme individuals. Note the speckles along the Minnesota bird’s flanks. The Long-billed has barred flanks. The Short-billed Dowitcher is a much paler species. Finally, if you use a bit of imagination, you can see that with wing tips of the Minnesota bird extend a few millimeters beyond the tail tip. Long-billed Dowitcher wing tips usually do not extend beyond the tail.