Posted by Robin Diaz on January 01, 1970 at 00:00:00
Justin - Some tips: Timing - Louisiana is an early migrant, both in spring and fall and is already on breeding grounds in NC by late April. Northern has a more protracted migration through South Florida and what we tend to see in late spring. Field marks - Louisiana has a large, robust bill; streaking is many times blurry and not under the chin; a peach flank patch is usually visible; the supercilium tends to flair toward the back of the head and looks like it wants to meet. Northern tends to have a daintier bill; more defined and intense streaking; the supercilium tends to be the same color as the underparts and it seems to follow the contour of the head. Subtle differences - There's the chocolate factor (dark Vs. milk chocolate) but Michelle needs to expand on this. Then, there's the tail bobbing differences of up-and-down (Northern) Vs. up-down-and-around (Louisiana) but Elsa needs to demonstrate.