What's in Flight
January 2019
An elaborate game of hide and seek is playing out in the park right now. It is not just the squirrels who hide nuts to eat during the long winter months, many birds do too. The ornithological term for this behavior is ‘caching’.
Tiny chickadees and nuthatches start caching seeds in the fall when they are abundant. They take one or two at a time and hide them in crevices in tree bark and tree crotches. It is a painstaking process involving hundreds of trips. It is also a huge test of their mental acuity, when in the winter months they have to remember hundreds and hundreds of storage locations. And seeds are often relocated multiple times to guard against theft.
White-brested Nuthatch
Dr. Barry Pinchefsky
Blue Jays and crows, who also winter in the park, have special physical adaptations for caching to allow them to carry a dozen or more seeds or several acorns at a time. The jays have a distended esophagus and the crows a special pouch under their tongue for carrying food.
Blue Jay caching
Deborah E. Bifulco
Now that the trees in the park are stripped of all their leaves and the uppermost branches are revealed, some of the most visible birds are the woodpeckers. Red-bellied Woodpeckers are often seen high up in the trees around Gracie Mansion. Their name can feel like a misnomer as their most visible red patch is on the head rather than the belly. The males have a red cap and the females a red patch on the back of the neck. They have a soft grey front, and black and white bars on the back. And a small reddish blush on the lower belly, which is often hard to detect.
Red-bellied Woodpecker caching
Deborah E. Bifulco
Red-bellied Woodpecker
Dr. Barry Pinchefsky
Woodpeckers cache nuts and seeds too. With their long sturdy beak, they drill into the tree bark to create holes for food storage. ‘Yellow-bellied Sapsuckers make rows of little holes in a straight line often on cherry and birch trees,’ says Paul Sweet, Collection Manager of the Ornithology department at the American Natural History Museum.
Yellow-bellied Sapsucker
Joseph Baider
Woodpeckers also make loud drumming sounds with their beaks. These steady rhythms are usually loudest in the spring and are a form of communication, to indicate territory and to attract a mate.
Downy Woodpecker drilling
Deborah E. Bifulco
One of the cutest, most acrobatic and noisiest woodpeckers in the park is the Downy Woodpecker. These year round residents are just five to seven inches tall (compared to the Red-bellied Woodpecker which can be up to ten inches in length). They have a checkerboard of black and white markings, bold stripes on the face and the male has a red flash on the nape of its neck. Paul Sweet explains: ‘The Downy drums very fast. Each woodpecker has their own drumming rhythm. And in the spring, you will often hear it when it drums on a dead branch with a good ring to it. Dead wood is an important part of the eco system for woodpeckers. At night the Red-bellied Woodpecker roosts in holes in dead parts of trees. And during the day they like to feed on beetle larvae they find in decaying wood.’
Downy Woodpecker
Dr. Barry Pinchefsky
Drumming and drilling exert tremendous pressure on woodpeckers small heads. Scientists estimate that each peck exerts about 1000 times the force of gravity (a pressure that would easily kill a human). But fortunately woodpeckers have a couple of anatomical adaptations to safeguard them from harm. ‘They have built in shock absorbers on the back of their skull to protect them from brain damage,’ says Paul Sweet. And their feet are designed with two foreword facing toes and two backward facing ones so they can remain steady while drumming. Also their stiff tail feathers act as a prop.
Northern Flicker
Deborah E. Bifulco
Hairy Woodpecker
Deborah E. Bifulco
Other Woodpeckers such as the Yellow-bellied Sapsucker, the Hairy Woodpecker and the Northern Flicker hang out in the city parks until the late fall/early winter months. And a handful of Northern Flickers and Sapsuckers stay on year round.
Female Red-bellied Woodpecker
Joseph Baider
Words: Lucie Young
Images: Deborah E Bifulco, Dr Barry Pinchefsky, Joseph Baider for exploringbirds.com
Link: American Natural History Museum Ornithology Department http://research.amnh.org/vz/ornithology/index.php