Comparisons

[AlexHenry 973]

Aleutian Cackler (leucopareia) vs Ridgway's Cackler (minima) - Aleutians have white collar, Ridgway's has larger white cheek patch, very dark breast with some blackish gloss, as well as being smaller in size and having a rounder head and shorter bill.

 

[AlexHenry 973]

Eastern and Western Willets - T s semipalmata vs T s inornata

Eastern on left, Western on right. Western is larger, longer legged, paler overall. Eastern has a shorter thicker bill. There have been rumblings about splitting these into two separate species for years, but so far it has been shut down.

[Kevin 2,689]

Western Meadowlark.Eastern Meadowlark.

[HamRHead 1,278]

House Finch, Rose-breasted Grosbeak, Female Blue Grosbeak

[Bird Brain 856]

1 minute ago, HamRHead said:

House Finch, Rose-breasted Grosbeak, Female Blue Grosbeak

 

Nice shot!!

[HamRHead 1,278]

Today a county first Piping Plover and a Killdeer

[HamRHead 1,278]

A Barn Swallow and...umm...the other resident of the barn, a Brown Swiss.

[AlexHenry 973]

Baird's Sandpiper vs Least Sandpiper

Baird's (along with White-rumped) are significantly larger than the three other peeps (Least, Semipalmated, Western). However the size difference can be somewhat subtle, especially when multiple species aren't present for direct comparison. Perhaps more obvious are the differences in shape and structure, as Baird's have long wings, so they have long primaries that project well beyond the tertials and slightly beyond the tail, and cross. When viewed head on, Baird's are broad-shouldered, with a relatively flat back. The flat back and long, crossed primaries give Baird's Sandpiper a long, stretched out, slender look to their rear end, even though their upper body is noticeably much broader than other peeps. Baird's has relatively long black legs, and a medium length black bill, proportionately slightly longer and straighter than Least Sandpiper's bill, though still with perhaps a slight droop at the tip. Color wise, Baird's are brownish, most similar to Least or Pectoral Sandpiper and pretty distinct from Western, Semipalmated, or White-rumped Sandpiper. So I think Baird's is probably most likely to be confused with Least due to the coloration, but note the warm buffy face and neck and the silvery fringing on some of the scapulars. This photo lined up well to show the differences in size, shape, and coloration between these two relatively similar species.

[Seanbirds 60]

Semipalmated (back) and Western (front) Sandpipers

[AlexHenry 973]

Continuing the theme of shorebirds migration:

Lesser Yellowlegs vs Greater Yellowlegs:

Lesser on left with small point mostly dark bill, smaller head with steeper forehead, smaller overall vs Greater with a longer bill, which has a obvious pale base and looks slightly upturned. It also has a less steep forehead, more of an s-curve to the neck, and is larger overall.

[AlexHenry 973]

Pacific Golden-Plover vs Black-bellied Plover:

[AlexHenry 973]

Wilson’s Phalarope (left) vs Red-necked:

[Connor Cochrane 1,160]

Parasitic? Jaeger (Left) vs Heermann's Gull (Right). While it might seem odd, Heermann's gulls can look very similar to Jaegers when at a distance, as the can looks similar in flight in pattern.

Edited September 15 by Connor Cochrane

[Birding Boy 783]

Pectoral (Foreground and Left) and Least Sandpipers  

[RobinHood 922]

Green-winged Teal and Green-winged Teal.

I learned some time ago not to trust the apparent speculum colour.

[Kevin 2,689]

Turkey Vulture and Black Vultures.