Acorn Dropping reaches a crescendo early this month in the Cuyamaca, Laguna,and Palomar mountains. Wiry scrub oaks, massive canyon live oaks, and the golden-leaved black oaks all contribute to the growing collection of acorns littering the ground. Acorn woodpeckers are busy stuffing acorns into the small holes they drill into the bark of pine trees. Beneath the trees, the browns of bracken fern and the reds of poison oak and squaw bush are among the last expressions of autumn color we'll see in our local mountains this year.

Monarch Butterflies Arrive along the California coast this month, migrating from their summer homes in the Sierra Nevada and the Rocky Mountains. Some 25 of the 260 wintering sites on the West Coast lie within San Diego County. The local sites include Presidio Park in San Diego, the UCSD campus, San Diego Botanic Garden in Encinitas, and Hosp Grove in Carlsbad.

Tarantula Spiders are occasionally seen around this time of year, crawling across rural roads or sneaking through San Diego County's backcountry-bordering neighborhoods. Doggedly searching for a mate, a male will try to hold its course despite your best effort to deflect or hinder him. Docile in temperament, most tarantulas will tolerate gentle handling; they may bite, however, if provoked. Despite their fearsome reputation, tarantula venom is no more powerful than a bee's venom.