Now that warm weather has made them more active, this is a good time for the annual rattlesnake advisory.

Rattlesnakes are common in the East Bay Regional Park District and other Bay Area open spaces. Snakes regulate their body temperature by moving back and forth between sun and shade. In general, the best way to avoid rattlers is to stay on official trails and refrain from taking shortcuts through tall grass and brush. When you stop to rest, avoid the rock piles, logs and tall grass that are snake habitat.

Rattlesnakes are not aggressive. They will avoid us if at all possible; we’re much larger than the small rodents and lizards that are their usual diet. They may give a warning rattle if we pass too closely. If you see one, give it a wide berth and avenue of escape. And, of course, don’t try to pick up or otherwise disturb the snake.

Dogs can be problematic. They may investigate a snake by running right up to it and then get bitten. The resulting vet bill will be extremely expensive. So if you see a snake, or a sighting is reported, put your dog on leash.

If you see a rattlesnake in a parking lot, picnic area or other locale with lots of people around, alert the park staff. A ranger will relocate the snake to an area safer for both snake and people. The rangers have snake tongs designed for this purpose.

Gopher snakes look a lot like rattlesnakes. They can bite, too, although their bite is not venomous. Sometimes gopher snakes will vibrate their tails in dry brush and leaves to mimic a rattlesnake’s rattle. Information panels at most park district trailheads have posters illustrating the differences between the two snakes. If you or a companion is bitten by a rattlesnake, here are some first aid recommendations:

• Remain calm and move beyond the snake’s striking distance.

• Remove jewelry and tight clothing before the affected area starts to swell.

• Position the victim, if possible, so that the bite is at or below the level of the heart.

• Clean the wound, but don’t flush it with water. Cover it with a clean, dry dressing.

• Minimize the victim’s movement. If possible, carry a victim who must be transported or have him or her walk slowly.

The best first aid for a rattlesnake bite is to get the victim to a hospital as soon as possible for anti-venom treatment. First aid procedures such as cutting and suction have long been discredited. The emergency phone number within the regional parks is 510-881-1121. Using 911 works too, although it is routed through the California Highway Patrol, so there can be a delay.

The park district has lots of information about rattlesnakes online at ebparks.org/safety/wildlife-encounters. If you want to see a live rattlesnake under safe conditions, there are specimens in several park district visitor centers.

In sum, rattlesnakes are an important part of the Bay Area environment, keeping the rodent population in balance. With reasonable precautions and awareness of our surroundings, we can co-exist with them safely.

Fremont >> Coyote Hills Regional Park in Fremont will celebrate Earth Day with lots of family-friendly fun from 1 to 3 p.m. Saturday. Naturalist Dino Labiste will preside. Activities will include a litterbug craft, recycling games and an environmental puppet show starting at 2 p.m.

The program is free of charge, but registration and parental participation are required. For information, call 510-544-3220. Coyote Hills is at the end of Patterson Ranch Road off Paseo Padre Parkway. There’s a parking fee of $5 per vehicle.

Other regional parks plan Earth Day related volunteer activities too. Here’s a link for the schedule: ebrpd.samaritan.com/custom/501/opp_details/4534.

Martinez >> Butterflies may flutter by during a hike from 9 to 11:30 a.m. April 24 at Carquinez Strait Regional Shoreline in Martinez, led by naturalist Kevin Dixon. The group will learn about the relationship among flowers, butterflies and other winged insects.

The program is free, but registration is required. This is a 3-mile hike on sometimes uneven terrain, for ages 10 and older with parent participation. For information and registration, call 888-327-2757, and select option 2.

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