- The proliferation of sheep on the island therefore impacted this species as its favoured vegetation was destroyed.
- Additionally, feral cats are present on the island, which may be predating upon this species.
The spotted towhee (Pipilo maculatus) is a large New World sparrow. The taxonomy of the towhees has been debated in recent decades, and until 1995 this bird and the eastern towhee were considered a single species, the rufous-sided towhee. Literature before 1995 referred to the spotted towhee as a rufous-sided towhee that resides in the western United States. An archaic name for the spotted towhee is the Oregon towhee (Pipilo maculatus oregonus). The call may be harsher and more varied than for the eastern towhee. The form that breeds on Socorro Island is much smaller than other rufous-sided towhees, and has gray upperparts. It is sometimes split as the Socorro towhee (Pipilo socorroensis).
The spotted towhee is a large New World sparrow, roughly the same size as a Robin. It has a long, dark fan shaped tail with white corners on the end. They have a round body (similar to New World sparrows) with bright red eyes and dull pink legs. The spotted towhee is between 17 cm (6.7 in) and 21 cm (8.3 in) long, and weighs in at between 33 g (1.2 oz) and 49 g (1.7 oz). Adult males have a generally darker head, upper body and tail with a white belly, rufous sides, white spots on their back and white wing bars. Females look similar but are dark brown and grey instead of black. The spotted towhee has white spots on its primary and secondary feathers, the Eastern towhee is the same bird in terms of its size and structure but does not have white spots.
The spotted towhee lives in dry upland forests and breeds across north-western North America. It is present in California, Nevada, Arizona, Utah, Oregon, Washington, and southern British Columbia year round. It is not found in arid climates and as a result does not reside in the Sonoran Desert, but resides in northern Arizona and the entirety of California except the southeast corner that borders Arizona. It has also been known to expand as far eastward as western Iowa and southwestern Minnesota. They also occur in fringe wetland forests and riparian forests near the border of upland forests. Because spotted towhees' habitat overlaps with areas of the United States that experience regular forest fires (Arizona, New Mexico, California), they tend to be found in unburned chaparral and avoid chaparral and forests which have been burned due to lack of ground cover and minimal foraging ability. Spotted towhees will be present in an area that is recovering after a burn (less than 15 years old), due to excellent ground cover and ease of ground foraging from the recovering understory vegetation, although populations will decrease after a forest fire until the vegetation has grown back.
Its breeding habitat in the southwest is largely dependent on Coastal sage scrub, as it provides cover from predators. They migrate to northern and northwestern United States and southwestern Canada to breed in scrubland, parks and suburban gardens. On the coast, it is much more common in the Coastal Douglas-fir present in Wyoming, Montana Idaho and British Columbia. Northwestern birds migrate eastwards to the central plains of the United States, mostly the northwestern-central Great Plains. In other areas, some birds may move to lower elevations in the winter. Their breeding habitat is chaparral, thickets or shrubby areas across western North America. This bird interbreeds with the collared towhee where their ranges overlap in southwestern Mexico.