San Mateo

A fully melanistic black squirrel perched on a bare branch high in a large tree against a blue sky

Black squirrel in a tree

📍 San Mateo Eastern Fox Squirrel (Sciurus niger) North America’s largest tree squirrel, it spends more time foraging on the ground than most tree squirrels and scatter-hoards nuts across dozens of small caches to get through winter. Melanistic individuals are usually rare, but in parts of San Mateo they are so common that an all-black coat is practically the local norm rather than the exception. Modeled range · iNaturalist · CC BY 4.0 Wikipedia | iNaturalist | Range map

A solidly black Eastern Fox Squirrel clinging to the reddish fibrous trunk of a tall coastal redwood, photographed from below against a blue sky.

Black squirrel hugging a redwood tree

📍 San Mateo Eastern Fox Squirrel (Sciurus niger) The all-black coat comes from a recessive melanistic variant that switches off the usual rusty-orange pigment, leaving individuals uniformly dark from nose to tail. Fox squirrels are not native to California — they spread across the Bay Area after introductions in the early 20th century and now outnumber the native Western Gray Squirrel across much of San Mateo’s parks and neighborhoods. Modeled range · iNaturalist · CC BY 4.0 Wikipedia | iNaturalist | Range map