With the advent of autumn comes the annual seasonal spectacle in the regional parks and elsewhere — the march of the mating tarantulas.

You may spot the large, hairy spiders making slow progress across parkland roads and trails. Those are likely the males. The females wait in their silk-lined boudoirs for the gentleman callers.

Tarantulas are interesting spiders. Despite their intimidating appearance, they are actually docile and reclusive. They live underground in daytime, usually emerging only at night to hunt for the small insects that comprise their diet.

Males mature at between 7-10 years of age. Then, during September and October, they venture forth in search of females that are ready to lay eggs. Tarantula mating can be especially unsafe, because the female sometimes dines on her partner afterward. Even if she doesn’t, males die within a year of mating. Females can live as long as 30 years.

Neither sex lives happily ever after if there’s an encounter with a tarantula hawk. This is a variety of wasp that hunts the spider, delivers a paralyzing sting, then lays eggs on the live but helpless victim to provide a meal for the wasp larvae when the eggs hatch.

One disincentive to handling tarantulas is their defense mechanism — irritant hairs on their abdomens that they can scatter with their legs to discourage predators. Tarantulas also have fangs, and while their bite is not poisonous, it is painful — like a bee sting.

If you’d like to learn more about tarantulas and meet one under safe circumstances, naturalist aide Morgan Evans is hosting a program from 2 to 3 p.m. Sunday, Oct. 14, at the Environmental Education Center in Tilden Nature Area, Berkeley. The center is at the north end of Central Park Drive. For more information, call 510-544-2233.

n n Experience the beauty of Briones Regional Park at dusk during a short hike from 4 to 6 p.m. Saturday, Oct. 13, led by naturalist James Wilson. If you come, bring water and wear comfortable hiking shoes. Meet James at the Bear Creek staging area off Bear Creek Road east of Orinda Village. The hike is free. For information, call 510-544-2233.

n n The oldest redwood tree in the East Bay is located in the Oakland Hills. It’s hard to hike to, but you can see it from a distance during a walk from 9:30 a.m. to 12:30 p.m. Sunday, Oct. 14, starting in Leona Canyon and continuing to Oakland’s Leona Heights Park, led by naturalist Michael Charnofsky. The free hike is a five-miler, designed for ages 8 and older. Meet at the Canyon Oaks Drive staging area off Keller Avenue in Oakland. For more information, call 510-544-3187.

n n Ardenwood Historic Farm in Fremont stages its annual Harvest Festival from 10 a.m. to 5 p.m. Saturday and Sunday, Oct. 13-14. Diversions will include magic shows, cider pressing, live music, horse-drawn train rides, and corn harvesting. Ardenwood is located at 34600 Ardenwood Blvd., just north of Highway 84 in Fremont. Entry to the festival its $8 for adults, $6 for seniors 62 and older, $5 for children 4-17, and free for 3 years and under. Parking is free. For information, call 888-327-2757, ext. 2797.

n n Traces of the once-bustling 19th century mining town of Somersville will be explored during a walk from 10 a.m. to noon Saturday, Oct. 13, at Black Diamond Mines Regional Preserve in Antioch, led by naturalist Bob Kanagaki. The program is free, geared for ages 7 and older. Meet Bob in the parking lot at the end of Somersville Road, four miles south of Highway 4 in Antioch. For information, call 888-327-2757, ext. 2750.

n n Here’s an activity for experienced boaters who can provide their own kayaks and safety gear. It’s an exploration of Brooks Island off the Richmond Marina, led by naturalist “Trail Gail” Broesder. Brooks Island has an unusual cultural and natural history, plus panoramic views from its highest point. The trip is from 10 a.m. to 3:30 p.m. Saturday, Oct. 20. It’s limited to ages 14 and older and parent participation is required. There’s a fee of $20 per person ($22 for nondistrict residents); registration is required. For registration and information, call 888-327-2757. Select option 2 and refer to program number 30297.