Expired mouse. Not sure what killed it.
I encountered this juvenile mouse in the exterior environment of a residential area, but just one meter from a relatively intact oak woodland. His right rear leg appeared injured, but he was able to engage in locomotion fairly well. So i assisted him in re-entering the woodland, where he would be safer. I hope he is recovering. I deemed his prospects better to survive in the native environment, rather than to stress him with captivity and transport to the nearest wildlife rescue, which would be closed at the late hour.
O'Neill Ranch Master Plan Draft Environmental Impact Report, February 1995
What looked like deep wounds from some birds talons; killed, but then dropped?
This is the same observation as recorded by Ken-ichi here.
Definitely Peromyscus as opposed to house mouse or harvest mice because tail is more than 1/3 length of body, and no grooves on upper incisors. Pinyon mouse as opposed to deer mouse because ears are longer than 18 mm and hind feet longer than 21 mm. This would be out of range, and slightly too small for P. californicus (which would be about 20 mm longer)
Peromyscus truei (Shufedlt, 1885) or the pinyon mouse, is native to the southwestern United States and Baja California in Mexico. These medium sized mice are often distinguished by their relatively large ears. The range of this species extends from southern Oregon and Wyoming in the north, and extends south to roughly the U.S.-Mexico border, with a disjunct population designated as Peromyscus truei comanche which occupies an area in the vicinity of Palo Duro Canyon in the...