The winter rains have arrived, the hills have turned green again, and it's a beautiful time of year to explore your regional parks -- between storms, of course.

Though it's colder and sometimes wetter, winter brings fresh air, running streams, migrating birds and even some early-season wildflowers.

Here are a few tips to help keep your regional park winter safari safe and enjoyable:

  • Rule Number One: especially if you're going out alone, always tell a responsible person where you are headed and when you expect to return. That way, in the unlikely event there is an emergency, rescuers will know where to start their search. Cell phones and radios don't always work in wooded or hilly terrain.

  • Get a map. Maps of almost all the regional parks can be downloaded from the park district website, www.ebparks.org. Free park brochures that include a trail map can be obtained from the information panels at most regional park trailheads. Signposts mark the trail junctions. Keep track of where you are.

  • Prepare for variable weather. Winter weather can change suddenly from mild to severe. If it gets warm, it's easy to remove clothing that you brought. If it gets cold, it's hard to put on clothing that you don't have.

  • Take water and a snack. Food will give you an energy boost if you need it.

  • In wet weather, the East Bay's famous clay soil can turn your hiking boots into platform shoes. I've found that a sideways scrape often peels off the mud. When you return to your vehicle, change into dry footwear and put those muddy boots in the cardboard box you wisely brought for that purpose.

  • A small flashlight, pocketknife, suntan lotion, whistle, hand sanitizer and some toilet paper are all useful.

  • If it gets dark and you're lost, find a sheltered spot and stay put. Because you followed Rule Number One, park district emergency staff will begin looking for you. Use the whistle to indicate your location. You can blow a whistle for a lot longer than you can shout. Three blasts at a time are a generally recognized distress signal.

  • With all the above in mind, don't worry. Enjoy yourself! Even if problems arise, a positive attitude is an important step in solving them.

    Ardenwood: Programs showcasing the park's overwintering butterflies continue at Ardenwood Historic Farm in Fremont.

    For "Marvelous Monarchs," meet at the park's granary to hear a talk about the butterflies' life cycle, make a butterfly craft to take home, then walk to the eucalyptus grove to see the butterflies in "person." The program is from 11 a.m. to noon this Saturday and Sunday and Dec. 22, 23, 29 and 30. And there are walks from the granary to the grove from 1:30 to 2:15 on those same dates.

    Leaders are Chris Garcia, Jenna Scimeca and other Ardenwood naturalist staff. Heavy rain cancels. Ardenwood is located at 34600 Ardenwood Blvd., just north of Highway 84 in Fremont. For information on entry fees, call 510-544-2797. Parking is free.

    TILDEN: The Over-the-Hills Gang, that informal, intrepid group of hikers ages 55 and older, will explore the Tilden Nature Area in Berkeley on a walk from 10 a.m. to 12:30 p.m., led by Tilden supervising naturalist Dave Zuckermann. For information, call 510-544-2233.

    SOLSTICE HIKE: The winter solstice, the shortest day of the year, is generally considered to be the start of that season. This year it's Dec. 21. Naturalist "Trail Gail" Broesder will celebrate it with an early morning hike from 6:15 to 8:15 a.m. that day, from Tilden's Environmental Education Center to the top of Wildcat Peak to catch the sunrise. The hike is for ages 10 and older and free of charge; bring your own coffee. For more information, call the center at 510-544-2233.

    REDWOOD REGIONAL: For the younger set, naturalist Sara Fetterley will lead a free "Hike for Tykes" from 10:30 to 11:30 a.m. Tuesday, starting at the Skyline Gate entrance to Redwood Regional Park in Oakland. It's on Skyline Boulevard just south of Evergreen Avenue.

    Never strenuous, the tyke hikes are designed for young children accompanied by parents. Strollers are not recommended. For more information, call 510-544-3187.

    EASTSHORE: Bird-watching enthusiasts will enjoy a walk from 2 to 4 p.m. Saturday at the Eastshore State Park, led by naturalist Anthony Fisher. Meet at the Seabreeze Market lot at the foot of University Avenue in Berkeley. The program is free. For information, call 510-544-2233.

    INVASION ABATEMENT: French broom is an introduced plant that crowds out native species. Volunteers are needed for a work session at 9 a.m. Sunday to help sweep the broom from Sibley Volcanic Regional Preserve in the Oakland Hills.

    If you're willing, meet at the Sibley entrance on Skyline Boulevard just south of the intersection with Grizzly Peak Boulevard. Tools will be provided. For information, call 510-544-3111.

    Ned MacKay writes a regular column about East Bay Regional Park District sites and activities. Email him at nedmackay@comcast.net.