Black Storm Petrel:(shown below) 2.1oz.

Dark brown/sooty color overall. Tube nose. On wings the tip is more pointed. Larger than Least.

Least Storm Petrel:(shown below) 0.74oz.

Dark brown/sooty color overall. Tube nose. On wings the tip is more rounded. Larger than Least.

Similiar Species: Ashy Storm Petrel