Fallen logs, stones, and buildings give the nocturnal North American deer mouse cover across Pennsylvania’s lakeside woods and eastern mountains. Developed forest edges at Pymatuning and Presque Isle differ from Delaware Water Gap’s rocky connected woods, but each can conceal the species.
Records are highest in August and September, when fieldwork and nights outdoors may increase encounters before leaf fall. The peak marks submission timing, not a late-summer estimate of mouse numbers.
Full species profile
