Northern Waterthrush - Parkesia noveboracensis

Northern Waterthrush has a partial preformative molt, and limited prealternate molts that are restricted to the body and difficult to detect. Age-related differences in wing and tail patterns are often subtle; especially by spring, a fair number of intermediates should be considered M-FCU (AHY) unless multiple characteristics indicate a particular age. Sex can generally be determined only by brood patch / cloacal protuberance during the breeding season.

Note that Northern Waterthrush can be reliably distinguished from the similar Louisiana Waterthrush by a narrower and slightly yellowish supercilium and undertail coverts with distinct dark patches.

Quick tips

• Look at the tertials - in fall, FCF (HY) birds have narrow rusty or pale tips (sometimes still present on FCU/SY birds in spring); absence of such tips is not a reliable indicator of DCB/DCU (AHY/ASY) birds.
• Examine the rectrices - on FCF/FCU (HY/SY) birds they are relatively narrow and tapered to a point, while on DCB/DCU (AHY/ASY) birds they are more broad and rounded toward the tip, and may include white spots.

Species account prepared by McGill Bird Observatory (2016). Last updated by Marcel Gahbauer (Mar 2022)