Arao Común vs Mérgulo Californiano Aliclaro

The Common Guillemot and Scripps's Murrelet can be distinguished by their structure and plumage. The Common Guillemot is larger and more robust with a longer bill, while Scripps's Murrelet is smaller and more delicate with a shorter bill. Plumage differences include the Guillemot's darker upperparts compared to the Murrelet's contrasting black-and-white pattern.

Check size and structure first: Common Guillemot is larger with a longer bill. Observe plumage: Guillemot has darker upperparts; Murrelet shows a stark black-and-white contrast.

Common Guillemot is larger and more robust than Scripps's Murrelet.

Common Guillemot has darker upperparts, while Scripps's Murrelet displays a more contrasting black-and-white pattern.