Watcher of the herons: mom turned self-ornithologist suffers no empty nest

Mom turned self-taught ornithologist suffers no empty nest.

At the top of a steep mountain trail, 80-year-old Helen Pratt peers through a telescope at the treetop heronry across a forested canyon. A clear plastic raincoat and head cap keep the heavy mist from soaking her small frame. The drizzle enhances the coastal redwood forest's intense beauty, turning its color to a frosty evergreen. With the naked eye, the nesting herons and egrets across the canyon look almost comical--oversized creatures perched high in the redwoods, like Dr. Seuss's "ten tired turtles on a rattle-turtle tree."

For 30 years Pratt has voluntarily monitored the heron-egret rookery at Bolinas Lagoon Preserve on northern California's Point Reyes peninsula. She is a self-trained scientist--a housewife and bird enthusiast turned expert in heron and egret nesting biology, who has published in scientific journals despite no formal biology education.

Reserved and quiet, Pratt explains that her involvement began after her children were grown and gone and she began attending the local Audubon Society chapter meetings. Chapter volunteers initiated study groups to learn about the local ecology so they would become qualified to lead naturalist field trips. One of the study groups observed the heronry at Bolinas Lagoon Preserve, a private nature reserve owned and operated by Audubon Canyon Ranch (not officially connected with the National Audubon Society).

The constant activity in the rookery piqued Pratt's interest. She began watching the birds, taking notes, and recording their numbers once a week throughout the nesting season. Using a high-powered telescope, she counted individuals and eggs within nests from across Picher Canyon without disturbing the nesting birds.

The heronry consists mostly of great egrets, with a few snowy egrets and great blue herons. Because most herons and egrets nest far from human influence and their nest sites typically change from year to year, the Bolinas Lagoon Preserve's temporally stable heronry offered a rare opportunity to learn about these birds things that had never been documented.

Pratt quickly discovered that once a week wasn't enough to keep track of the changes in the heronry. "This was [the late 1960s,] when the DDT-induced eggshell thinning was occurring," Pratt explains. "You'd count three eggs one day, and a couple days later only one was left."

By the end of her first year, her forays up the steep Kent Trail to observe the heronry had evolved to three times weekly. She recorded the number of nesting pairs, eggs laid, eggs hatched, and successful fledglings. She diagramed nest locations, took observations of courtship rituals and bird behavior, and noted how long adults were gone from the nest for feedings.

Over the years, she turned her notes and diagrams into publishable research as she rapidly became an authority on these elusive nesters. Her findings have been published in the ornithological journals the Condor and the Auk and a self-published book, Herons and Egrets of Audubon Canyon Ranch. Asked how she learned the scientific method with no formal training, she replies, "It came naturally."

Such natural ability allowed her to become one of the first researchers to document DDT-related egg thinning in egrets and record ground-breaking observations on reproductive success, clutch size, and incubation periods. Her findings, Pratt modestly admits, "certainly aroused interest among visitors to Audubon Canyon Ranch."

The preserve, open to the public only from mid-March to mid-July, remains pristine. For several weeks it also offers environmental education to schoolchildren from around the San Francisco and Point Reyes area. Though Pratt wasn't directly involved in developing the preserve's education program, she feels that one of the best things they offer is a chance for inner-city kids from San Francisco to come and learn about the redwood forest and estuarine ecology. The kids just come alive.

What has kept Pratt's interest in the heronry over all the years is her love of being outdoors and her scientific curiosity. She is quick to change the conversation from herself to the birds. Sometimes the birds were quite entertaining. "The young fledglings would practice wing flapping before they were actually ready to fly," she explains. "They will hold onto a branch with one leg while tentatively waving the other in the air, as if they wanted to go but weren't quite sure of themselves." With companions like these, it would be hard to get bored.

Those who work with Pratt vouch for her independence and strength of spirit. Ray Peterson, a Bolinas Lagoon Preserve biologist, comments, "Helen is a really terrific person, and very independent at 80 years old." He tells of a recent experience. "I went to see her a few days after serious surgery. She is tiny to begin with, and we expected to find this white-headed, frail Helen, resting on the couch, in a condition that would be a step above clinging to life. Instead, as we drove up to her house, we found her rolling the garbage can out for the next day's pickup!"