Fig. 1. (a) Rock nesting habitat used by Fork-tailed Storm-Petrels (Oceanodroma furcata) on Kasatochi Island, Alaska. Nest sites vary from (b) nests made entirely of rock (here, nest material covers solid rock substrate), to (c) nests made up of a mix of rock and soil (here, soil composes substrate, right side, and part of roof; quantified as 40% rock). Arrows indicate location of chicks.

Fig. 1