By Jill Hedgecock
In 1991, wood duck populations were in severe decline due to the lack of nesting habitat. To compensate for the lack of natural tree cavities, California Waterfowl launched the California Wood Duck Program to increase both nest boxes and citizen involvement in the fate of wood ducks. Since then, nearly 992,000 ducklings have hatched statewide.
Locally, the Mount Diablo Bird Alliance (MDBA) maintains and monitors wood duck nest boxes along both San Pablo and Upper San Leandro Reservoirs. The MDBA program has been in place for about thirty years. This year, biologists Julie Woodruff and Andrew Ford along with several volunteers, monitored sixteen nest boxes at the Upper San Leandro Reservoir and thirty-two at the San Pablo (SP) Reservoir.
“Wood duck nest box usage seems to be variable,” says Woodruff. “It was low a few years ago when California was experiencing drought conditions, but this last year there seemed to be a lot of nests and/or nesting attempts at the SP Reservoir. One wood duck female in particular that we had banded in 2020 returned this year to the same nest box and laid ten eggs,.”
Jerry Britten, president of MDBA, volunteered to be part of the 2024 California Wood Duck Program. He has always wanted to witness “jump day,” when the ducklings launch themselves out of the nest box. His wish was granted this year when he observed a nest with both hatchlings and eggs.
“Knowing that the hatched chicks spend very little time in the nest boxes,” said Britten, “I hoped that the remaining eggs would hatch that day and that the next morning would be “jump day” when the chicks leave the nest.”
The next morning, Britten’s three-hour wait was rewarded when the hen, after checking the area and deciding it was safe, hopped to the ground and waddled to the water, calling her chicks. After about five minutes, one chick launched itself out. Four more chicks followed within minutes, and soon the family joined the hen and swam off.
In addition to wood ducks, squirrels, mice, owls and bees invaded some boxes this year. This year, only two of the sixteen boxes hatched wood ducks at the Upper San Leandro Reservoir, and one Western Screech Owl was found inside a box.
At San Pablo Reservoir, seventy-three eggs hatched, and one adult and four nestling Western screech owls were found in the nest boxes thus far. In 2025, the program will be expanded to include nine nest boxes at Briones Reservoir.
Bird enthusiasts are invited to learn more about MDBA’s programs (www.mtdiabloaudubon.org) and anyone wishing to learn more about the nest box program should email President@mtdiablobirds.org.
Jill Hedgecock has a master’s degree in environmental management and a bachelor’s degree in biology. Her love of nature inspired her to write the award-winning novel, “Rhino in the Room” and the sequel, “Queen of the Rhino.” Photos by Jerry Britten