Nesting egrets abandoned lagoon preserve


Though the egret nesting season is not officially over, it’s over at Picher Canyon, where not a single nest was built, according to the head of conservation science at Audubon Canyon Ranch, the nonprofit that manages the 1,000-acre site near Stinson Beach. 

Typically birds begin to arrive in April, court and begin building nests, said John Kelly; though a few birds visited the canyon this year, none courted, meaning the area was abandoned for the first time since A.C.R. began monitoring the site in 1967. 

Last year saw a total nesting failure: though courtship and nest building took place, no nests fledged chicks. (Though Dr. Kelly said the failure was likely due to a raptor and that there were no worrisome regional trends, the nonprofit closed the canyon to the public this year.) A number of egrets did nest on the other side of Bolinas Lagoon.

The total number of egrets on the lagoon is still low, but Dr. Kelly expects the birds will return at some point—though research shows that about half of abandoned sites remain empty.

Gwen Heistand, the resident biologist at the Martin Griffin Preserve, said the student education program was moved to nearby Volunteer Canyon, where students focused on watershed issues, the lagoon and local geology. They studied fauna that don’t reside in Picher, like swallowtail butterflies, and took advantage of Volunteer Canyon’s trails. “A giant redwood tree fell directly along the edge of the trail [in Volunteer Canyon], so the kids paced out the height of a redwood, and we talked about redwoods and life cycles…We also talked about coastal scrub—there’s a trail that goes right through the scrub—and oak woodlands and grasslands,” Ms. Heistand said. “It was actually kind of exciting.” 


An open house for prospective docents at Audubon Canyon will be held next Wednesday.