The reason Mikal Saltveit has not seen a black squirrel on campus in years (letter to Dateline, June 22) is that there never were any. There are no black squirrels in California, native or otherwise. The black squirrel is a color morph of the eastern gray squirrel (Sciurus carolinensis).
Though this species is naturalized in Davis and occurs at quite low density, the black morph, which occurs at high frequency in southeastern Canada, the upper Midwest, and cold parts of the Northeast, is unrecorded here.
The native western gray squirrel (Sciurus griseus), which does not have a black morph, is very infrequently seen on campus but occurs along Putah Creek in native riparian vegetation.
The very common squirrels Saltveit is worried about are fox squirrels (Sciurus niger). They have been in the East Bay and in Capitol Park, Sacramento, for decades but only recently became established here.
Many people find them entertaining. Before advocating "control," Saltveit should consider what happened in Britain when our eastern gray squirrel was introduced. The government wanted to eradicate it, but the public was outraged at the idea. In an attempt to turn public opinion against the animal through linguistic manipulation, it began calling it the "tree rat."
It did not work. By the way, we have a booming population of Audubon's cottontail (Sylvilagus audubonii) on campus — little white-tailed bunnies you may observe scampering furtively around shrub borders early in the morning and in the evening.
I imagine they offend Saltveit's sensibilities too. After all, don't they potentially carry tularemia? If it's wild, let's kill it!