Naturalist Notes

Flora and fauna to watch for this fall.

Acorn Woodpecker

Acorn Woodpecker

Red-capped, clown-faced flocks are easy to spot in oak woodlands. They live in big noisy groups; listen for their raucous, laugh-like calls. In fall they get busy, drilling holes and stashing acorns in trees, fence posts, and other wooden structures. A single tree may hold thousands of hidden morsels, serving as a communal food pantry through winter. The birds carefully tend stored food, making sure acorns are wedged tightly so other animals can’t snatch. They also practice cooperative breeding with all the adults working together to raise the young from a single nest. Add sightings of Melanerpes formicivorus to iNaturalist.

Bigleaf Maple

Maple tree leaves in fall colors

One of our few native trees to offer autumnal color, the deciduous leaves of bigleaf maple carpet woodland floors in shades of yellow and orange during the fall. Having the largest leaves of any maple, leaf widths of nearly two feet are possible but 6-12 inches are more common. Capable of crown-sprouting, these trees can quickly regenerate after fire. Although the sugar content is comparable, the taste differs from common maple syrup and therefore this species isn’t typically tapped for its sugary sap. Add sightings of Acer macrophyllum to iNaturalist.

California Black Oak

Black oak leaves, colorful in fall

Native oaks are woven deep into the life of California ecosystems. Owls, woodpeckers, and squirrels nest in the safety of oaks. Many wild mammals and birds survive the winter thanks to nutritious acorns. Black oak acorns are a favorite wild forage, and native Americans preferred black oak acorns when making meal. Black oaks also offer a luxurious display of fall color uncommon to the Bay area’s native trees. With thick bark, and a rich supply of nutrients stored in their roots, oaks have adapted to survive wildfire. Sadly, they are not resistant to sudden oak death, a pathogen exacerbated by climate change, that is claiming the lives of thousands of oaks across the state. Add your sightings of Quercus kelloggii to iNaturalist.

Cedar Waxwing

Cedar waxwing eating berries

With a stylish crest, harlequin black mask, yellow-tipped tail, and red-splashed wings this bird is a stunner. They are one of the few avian species that specializes in eating fruit. In fall and winter, groups flock to savor berries–toyon, madrone, and cedar. Listen for high-pitched whistles among the branches as they feast. Late in the season, when berries are overripe and partially fermented, younger, smaller, less experienced birds can eat too much and become intoxicated by the alcohol. Add sightings of Bombycilla cedrorum to iNaturalist.

Coyote Brush

Coyote brush in flower

This bushy shrub up to 9 feet high is common from coastal California to the Cascade ranges. In autumn, male plants produce small clusters of white flowers with yellow pollen. This fertilizes nearby female plants, which produce seeds carried on the wind by fluffy white “pappi.” An integral component of native coastal scrub and chaparral habitat, Coyote Brush frequently has galls, harmless abnormal growths that shelter insects. Over time mature plants build up dead wood, nature’s way of encouraging the fires that have been part of California ecosystems for thousands of years. Add sightings of Baccharis pilularis to iNaturalist.

Pacific Common Seal

Harbor seals hauled out on rocks

Also known as Pacific harbor seals, these marine mammals have pretty spotted coats in a range of shades from silver to brown. They spend half their time in water, diving for seafood: sole, flounder, hake, cod, herring, or squid. Safe in the surf, they often stop to bob and fix curious eyes on shore dwellers. When they haul out on land, they prefer to be left alone, snoozing in groups as they recuperate from swimming and foraging. Although rare, mothers will sometimes leave a pup on the shore when they move off in search of a meal. If you spot a solitary youngster, leave the pup alone–mom will soon return. Any disturbance reduces the young one’s chance of survival. Add sightings Phoca vitulina to iNaturalist.

Pacific Poison Oak

Close up of shiny poison oak leaves

This common native plant, a member of the cashew family, defends itself against infection with an oily sap that causes a severe allergic reaction in humans. As problematic as the irritating chemical urushiol can be for people other animals, including deer and squirrels, love to eat the leaves. Squirrels, foxes, and woodrats nest in poison oak, and over fifty species of birds feed on the seasonal berries. Open space visitors should avoid contact with this plant, but they can feast their eyes on vibrant colors when the leaves turn in fall. Add sightings of Toxicodendron diversilobum to iNaturalist.

Pallid Bat

Pallid bats hanging in a cave

Primarily insectivores, pallid bats eat up to half their body weight in bugs each night, eating as they fly or even landing on the ground and chasing down prey on all fours. Antrozous pallidus uses echolocation much less than most other bats and often hunts by sight or by using their large ears to listen for the rustling of insect wings. In desert climes they have adapted to feed on cactus nectar, helping seasonal pollination. Add sightings of Antrozous pallidus to iNaturalist.

Peregrine Falcom

Peregrine falcon in flight

The name peregrine comes from the Latin peregrinus, “wanderer”, and true to its name, this long-distance migrant is also the world’s most widespread raptor. Northern breeders move south along the Pacific Flyway following the fall migrations of their prey species. When hunting, peregrines turn into feathered bullets, plummeting from great heights and reaching speeds of 250mph – making them the fastest animal on earth. Watch for their strong flight on pointed wings, cruising over wetlands and swooping down on flocks of ducks and shorebirds. Add sightings of Falco peregrinus to iNaturalist.

Western Gray Squirrel

Western gray squirrel foraging for nuts

Cool gray and white, without a hint of brown, these tree squirrels are California natives. Unfortunately, the woodland creatures are more sensitive to the intrusion of human settlement than their non-native cousins the fox squirrel and eastern gray squirrel, which are established in the Bay Area. Western grays thrive in oak forest, eating acorns, nuts, and fungi, and only have one litter of kits a year. Fox squirrels and eastern grays have adapted more easily to fragmented suburban habitat, even crossing along power lines between trees. And they breed more frequently. Consider yourself lucky if you see one of the truly indigenous Sciurus griseus. Read more in Bay Nature.