Comparing Western and Semipalmated Sandpipers - 01 Sep 2026
On 31 Aug 2026 I had the opportunity to photograph a pair of Western Sandpipers ( Calidris mauri ) in Cell 3 at Point Mouillee SGA in Monroe Co., MI. Differentiating these birds from the more common Semipalmated Sandpipers ( Calidris pusilla ) is always a challenge as both species sport black legs and black bills, similar wing projections, and similar appearances in both breeding and non-breeding plumages with subtle differences that require a trained eye and good optics. When comparing Semipalmated Sandpiper with Western Sandpiper Cornell's Birds of the World states, "Field identification often difficult (Veit and Jonsson 1984; Hayman et al. 1986); distinguished from other similar Calidris ("peeps") with care. Of several similar species, the most problematic is Western Sandpiper (C. mauri), which also has black legs and small webs between toes. Structurally, Western is larger, bigger-headed and more 'front-heavy', with more rotund body shape. Bill of West...