FROM A POND exploration to a volcano walk, there's a lot of variety in the natural history programs scheduled in coming days at the East Bay Regional Parks.

This Saturday, naturalist James Wilson will lead a pond excursion from 10:30 a.m. to noon at the Tilden Nature Area in the Berkeley hills. The group will use dip nets to find out what lies beneath the calm waters of Jewel Lake. Be prepared to get somewhat wet.

Then on Sunday, naturalist Michael Charnofsky will lead a moderate hike from 1:30 to 4 p.m. at Sibley Volcanic Regional Preserve on Skyline Boulevard in Oakland.

At Sibley, geological evidence of a long-extinct volcano has been exposed by years of quarrying. Local artists have used the volcanic rock to construct some labyrinths in the old quarry pits. And the area is favored by raptors, including golden eagles.

Michael will point out all (more...)