Black-necked Stilt
Himantopus mexicanus
Measurements: Length: 13.8–15.3 in (35–39 cm) Weight: 5.3–6.2 oz (150–180 g) Wingspan: 28.1–29.7 in (71–75 cm) They have long pink legs and a long thin black bill. They are white below and have black wings and backs. The tail is white with some grey banding. A continuous area of black extends from the back along the hind neck to the head. There, it forms a cap covering the entire head from the top to just below eye-level, with the exception of the areas surrounding the bill and a small white spot above the eye.
ID text from Wikipedia, CC BY-SA 4.0
Black-winged Stilt
Himantopus himantopus
Adults are 33–36 cm (13–14 in) long, with long, pink legs, and a long, rather thin black bill. The birds are generally black above and white below, with a white head and neck (with a varying amount of black, species-dependent). Males have a black back, often with a greenish gloss or sheen. Females' backs have a brownish hue, contrasting with the black remiges. In populations where the top of the head is normally white (at least in winter), females tend to have less black on the head and neck the entire year-round, while males often have much more black, particularly in summer.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
Learn this pair in BeakBrain
Photo and call practice, free in any browser.
Play BeakBrainPhotos and recordings are credited to their authors under the licence shown. Full profiles: Black-necked Stilt and Black-winged Stilt.