Several people whom I have encountered recently while hiking have asked if there are rattlesnakes in the regional parks. The answer is yes -- in fact, I saw a baby rattlesnake the other day at Castle Rock.

Warmer weather is likely to make the snakes more active, besides which, this is the time when female rattlesnakes give birth.

However, the presence of rattlesnakes really is not cause for concern. It's extremely rare for park visitors to be bitten by rattlesnakes. And in most cases the bite occurred because the victim tried to handle the snake.

Moreover, rattlesnake bites are seldom fatal. They are very painful, and recovery takes time, but the outlook is good. Here are some more rattlesnake facts:

The variety found in this area is the Northern Pacific rattlesnake. They usually live under logs, in rock piles or among scattered leaves, twigs and tall grass.

Rattlesnakes regulate their body temperature by moving back and forth between sun and shade. So you may see them basking in sunny spots, or they may be out of sight cooling off under the brush.

The snakes are ambush hunters, lying in wait for lizards and small rodents. They are prey, in turn, for hawks and kingsnakes. Unlike some other snakes, rattlers don't lay eggs. They bear their young live.

In case of a bite, forget the tourniquet, cut-and-suck treatment. Just keep the victim calm, call 9-1-1, and transport to a hospital as soon as possible.

The best way to avoid rattlesnakes is simply to be aware of your surroundings. Stay on the official trails; don't take shortcuts through tall grass and brush. If you stop to rest, avoid the rock piles and logs that are snake habitat. If you do see a snake on the trail, take a wide detour.

Northern Pacific rattlesnakes are not aggressive. They would much rather hide or run away than confront large animals such as ourselves. So give them an escape route and they are likely to take it.

Dogs can be at risk. Curious by nature, they may run right up to a snake, barking and sniffing. If they've found a rattler, the result can be a very sick pet and a very expensive vet bill. So keep your dog under control at all times.

If you see a rattlesnake at a parking lot, picnic area, or other place where people congregate, contact a park ranger and the ranger will relocate it.

Gopher snakes, which are nonvenomous, look a lot like rattlesnakes, and will even mimic the rattler by vibrating their tails rapidly in leaves and pebbles to produce a rattle-like sound. Their bite is painful, too, but they don't inject venom.

You can view a live rattlesnake in a vivarium at the Black Diamond Mines Regional Preserve visitor center on Somersville Road in Antioch.

Speaking of Black Diamond Mines, the park will stage a formal dedication of its reopened Greathouse Visitor Center on May 12, with lots of public programs from 11 a.m. to 3 p.m. More on that in the next column.

Contact Ned MacKay at nedmackay@comcast.net.

BRIONES: Wildflowers are still in bloom, and Briones Regional Park in central Contra Costa County is a great place to see them. Naturalist Aide Morgan Evans will lead a strenuous seven-mile floral safari there, from 11 a.m. to 3 p.m. Sunday.

The hike is listed on the 2012 Trails Challenge, so if you've enrolled in the challenge, this one counts. Wear sturdy, comfortable shoes; bring lunch and plenty of water.

The hike is free of charge and reservations are not necessary. Meet at the Bear Creek staging area. It's on Bear Creek Road about five miles east of San Pablo Dam Road in Orinda. For information, call 510-544-2233.

TILDEN: For a more leisurely experience, you can celebrate the advent of May with the Berkeley Morris Dancers, who will perform from 10:30 a.m. to noon on Sunday at the Environmental Education Center in the Tilden Nature Area in Berkeley.

The center is located at the north end of Tilden's Central Park Drive. The performance is free of charge. For information, call 510-544-2233.

CRAB COVE: At Crab Cove Visitor Center in Alameda, "Catch of the Day" programs continue from 2 to 3 p.m. every Saturday and Sunday in May and June. The programs are free, family friendly, led by the naturalist staff, and there's a different theme each weekend relating to the ecology of San Francisco Bay.

After the catch, it's fish feeding time from 3 to 3:30 p.m. at the center's large aquarium, where all kinds of bay fish are on exhibit.

Crab Cove is located at 1252 McKay Avenue off Central Avenue. For information, call 510-544-3187.

CHILDREN'S SERIES: Outdoor Discoveries is a series of nature programs for children ages 3 through 5, accompanied by a parent. It's organized by naturalists Katie Colbert and Cat Taylor.

On Thursday, the venue will be Brushy Peak Regional Preserve north of Livermore for a stargazing session from 8 to 9:30 p.m.

Reservations are required and there is a fee of $6 per person ($8 for nondistrict residents). To register or obtain more information, call 888-327-2757. Select option 2 and refer to program number 29336.

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