Sentence:  Pocket gophers appear to be abundant in the APWRA on both sides of Altamont Pass Road, whereas <WSD>ground squirrels</WSD> appear to be abundant only on the north side. 
Meaning of the word marked with <WSD> tags:  Any of a number of medium-sized squirrel-like borrowing rodents of the tribe Marmotini (i.e., excluding the smaller chipmunks and the larger marmots and prairie dogs).