|An acorn woodpecker works on its granary at Tucker Wildlife Sanctuary. Photo by J.J. Meyer|
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Avid birders Ken and Diann Tomb have spotted various species of woodpeckers moving up and down tree trunks and hanging upside down while hunting insects.
“I've seen them drilling holes and placing acorns for storage,” Diann Tomb said. “They're very social and can be loud and noisy. So not everyone in the neighborhood is enamored by them.” But the Tombs enjoy watching the woodpeckers in wooded areas around their home in Coto de Caza.
To understand their behavior, you can visit Tucker Wildlife Sanctuary in Modjeska Canyon adjacent to the Cleveland National Forest, where a noisy colony of acorn woodpeckers have taken up residence.
“They're very industrious,” said naturalist Kurt Miethke who leads bird walks at the sanctuary. “They work and live communally with a division of labor. Some breed, while others are designated helper birds.”
While they are primarily insect eaters, they store acorns for the lean part of the year, he said. The acorns are stored in a granary, which they've drilled into the utility poles on site. Granaries require constant maintenance. As the acorns dry out, they shrink. So the birds move them to smaller holes. The colony also bands together to defend their cache from daily raids by scrub jays and squirrels.
Species commonly found in Orange County include Nuttall's, Lewis', downy and hairy woodpeckers, northern flickers and red-breasted sapsuckers, Miethke said.
Their adaptations include a long tongue with barbs for locating insects; strong claws with opposing toes for grasping tree trunks, and a shock-absorbing skull.
While a study of woodpeckers in wilderness areas can be quite interesting, the birds can be annoying and destructive for homeowners. Woodpeckers are known to drill into wood siding and even stucco. Homes built near wooded areas tend to be more vulnerable to woodpecker damage.
When these birds are looking for insects, the holes will be small and irregular. They are particularly fond of the larvae of carpenter bees, leafcutter bees and grass bagworms. Often, treating the underlying insect infestation will eliminate the woodpecker problem.
Woodpeckers also drum on loose boards and metal surfaces, which can be a headache for homeowners. It may help to know that they drum to establish a territory or attract a mate, and it generally stops once breeding has begun in the spring.
Dangling Mylar strips or shiny objects, such as CDs, can scare off the birds. But screening or capping the affected areas and securing boards to minimize resonance are often the best answer.
Cornell University tested six woodpecker deterrents and the results were published in the August 2007 issue of the Journal of Wildlife Management. The methods tested included life-size plastic owls, reflective streamers, plastic eyes strung on fishing line, roost boxes, suet feeders and a sound system that broadcast woodpecker distress calls.
Only the streamers worked with any consistency.
No matter how frustrating a woodpecker problem can be, remember that the Migratory Bird Treaty Act of 1918 protects all native birds. This means the California Department of Fish and Game and U.S. Fish and Wildlife Service can fine those who blatantly harass or harm a protected bird or nest.