Sunday, April 05, 2015

Excavators at work!

Black-capped Chickadees are busy excavating nest cavities; they're not putting anything inside yet, but using their beaks to remove rotted wood. Both the male and female participate in removing substrate from the prospective cavity, and they may work on more than one site. Only the female works on building the nest and she usually selects the final site.

Chickadee cavity excavation is a great photographic opportunity to get nice portraits. The process is easy to follow. Each chickadee (male and female) takes a turn inside the cavity and fills its bill with tiny wood chips. When one leaves, its mate is quick to enter the cavity and take over the excavation. The bird with the full beak often keeps returning to the same branch to deposit the chips.

Upon landing...

Lean over...

And drop!

Just after the deposit, the chickadee will face the cavity before returning, but it will wait on its perch if its mate is still digging inside. Usually you'll only have a few seconds to take a few exposures of the perched chickadee as they are extremely efficient and hard workers!

About 100 yards away another chickadee pair were busily excavating a cavity. You can see from the two sites the type of cavity the creek corridor chickadees seem prefer. There are rotted stumps and logs all along the bank which make perfect sites to incubate eggs and raise their young. It's been my observation that the chickadees only select logs that are well above the highest potential waterline when the creek floods after a big storm.

While photographing the chickadees, a Winter Wren stopped by to see what the chickadees were up to. Though I missed photographing it, the wren tried to enter the cavity pictured in the above photograph, but one of the chickadees quickly chased the wren away. The wren popped up again on a nearby branch and I was able to take a quick shot before it sped off into the dense tangle of sticks and logs on the other side of the trail.

Another interesting bit of chickadee behavior I observed today was watching a pair of chickadees inspect a nest-in-progress of a Northern Cardinal. The female was bringing in nesting material and this caught the attention of the chickadees. With the female cardinal present, one of the chickadees sat in the nest and remained there for a few seconds. Eventually, the female cardinal chased it out and the two chickadees returned to their excavation efforts. Perhaps eye-balling the cardinal's nest for future material to stuff into their cavity?

Pheasant Branch, Dane, US-WI
Apr 5, 2015 7:15 AM - 10:45 AM
57 species

Canada Goose
Wood Duck
Blue-winged Teal
Northern Shoveler
Green-winged Teal
Lesser Scaup
Hooded Merganser
Pied-billed Grebe
Great Blue Heron
Turkey Vulture
Cooper's Hawk
Red-tailed Hawk
American Coot
Sandhill Crane
Ring-billed Gull
Rock Pigeon
Mourning Dove
Great Horned Owl
Red-bellied Woodpecker
Yellow-bellied Sapsucker
Downy Woodpecker
Hairy Woodpecker
Northern Flicker
American Kestrel
Eastern Phoebe
Blue Jay
American Crow
Tree Swallow
Barn Swallow
Black-capped Chickadee
Tufted Titmouse
White-breasted Nuthatch
Brown Creeper
Winter Wren
Golden-crowned Kinglet
Ruby-crowned Kinglet
Eastern Bluebird
Hermit Thrush
American Robin
European Starling
Yellow-rumped Warbler
Field Sparrow
Fox Sparrow
Song Sparrow
Dark-eyed Junco
Northern Cardinal
Red-winged Blackbird
Eastern Meadowlark
Common Grackle
Brown-headed Cowbird
House Finch
Pine Siskin
American Goldfinch
House Sparrow

All images © 2015 Mike McDowell

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