When your children start to get this feisty, it’s time for them to leave the nest!
Between three and a half and four weeks of age, Pileated Woodpecker nestlings fledge. Their flight feathers are about 75% of adult size when they depart. Some fledglings are capable of sustained flight when they leave the nest, while others may need several days before they can fly any distance.
Initially parents and siblings stay in the vicinity of the nest, but once the young can fly well, they follow adults everywhere. All the young may stay with both parents, or the parents may split up and each take some of the young. The fledglings will remain with their parents into September. (Photo: male Pileated Woodpecker nestling about to fledge while his father watches.) Much gratitude to Amber Jones and Dave Bliven for sharing their deck, their sweet dog Briggs and their magnificent view of this Pileated Woodpecker family with me.
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Young birds defecate in little packages called fecal sacs. These structures serve several purposes, one being that having waste contained in a sac keeps the nest relatively clean. Often parents consume these sacs when their nestlings are small (when young the birds don’t completely digest the food they eat and fecal sacs may provide parents with a nutritional snack), but eventually the adults usually retrieve them and fly away from the nest before dropping them. (The young of some species of birds in open nests perch on the rim of the nest and defecate.) Two to five days before fledging, Pileated Woodpeckers stop removing their offsprings’ fecal sacs (perhaps as an incentive to depart the nest?).
Nestling meals consist primarily of invertebrates. Adult Pileated Woodpeckers feed their young by regurgitation, inserting their bill quite far into the throats of their young as they deliver food to them. A visit can consist of one to three regurgitations per nestling. (Photo: adult male Pileated Woodpecker feeding male nestling)
Recently I had the opportunity to observe nesting Pileated Woodpeckers, and I thought I would devote this week’s Naturally Curious posts to different aspects of my observations. I would like to thank Amber Jones and Dave Bliven for generously sharing their Picidae residents with me.
From start to finish, both Pileated Woodpecker parents are involved in raising their young and all that it entails. Together they excavate a nest cavity, usually in a dead or dying tree. Both have brood patches (areas on their undersides that lack feathers and are well supplied with blood vessels, allowing efficient transfer of body heat to eggs), and both incubate the eggs during the day (the male has night duty). The parents take turns brooding the nestlings and providing them with food. And finally, once fledging take place, both parents provide and help their young find food for several months. (Photo: male Pileated Woodpecker in nest cavity; female Pileated Woodpecker on nesting tree)
Cooper’s Hawks, Sharp-shinned Hawks and Goshawks are the three accipiters (a category of hawks possessing long tails and relatively short, rounded wings) found in New England. The one you’re most likely to see is the Cooper’s Hawk. Built for speed and maneuverability, these raptors are able to fly incredibly fast through the woods as they search for prey in amongst trees. Their diet consists largely of birds, but they also have been known to consume mammals, reptiles, amphibians, insects and fish.
You may have seen a Cooper’s Hawk perched near your feeder, or perhaps have been witness to an explosion of feathers after a songbird was captured by one, but for the most part, medium-size birds such as Mourning Doves, European Starlings, Northern Flickers, Ruffed Grouse and American Crows are preferred.
On a winter day several years ago, the pictured Cooper’s Hawk captured, killed and ate a Pileated Woodpecker, an unusually large prey that is about the same size as the hawk that caught it. Chances are great that this is a female Cooper’s Hawk, as female raptors are generally larger than males, and therefore capable of capturing larger prey.
Large rectangular excavations in trees, indicating Pileated Woodpecker feeding activity, are relatively common. These holes give the woodpecker access to carpenter ants living in galleries within the tree. What are not common are the horizontal lines radiating out from either side of the top rectangular Pileated Woodpecker feeding hole (and, more subtly, the bottom two holes) in the pictured tree.
Pileated Woodpeckers use methods other than drilling rectangular holes to locate insects – they glean branches, trunks and logs, peck bark and scale bark off of trees. But these lines are unusual, to say the least. If anyone is familiar with this pattern, and would care to explain the function of these horizontal lines, it would be greatly appreciated. After racking my brain and checking several resources, I cannot come up with a plausible explanation, though inevitably there has to be one, for no pileated woodpecker, or any other creature, is about to waste precious energy, especially in a winter as cold as this one. (Thanks to photographer, naturalist and keen-eyed John Snell (http://stilllearningtosee.com/about/) for finding and sharing this discovery with Naturally Curious.)
Pileated Woodpeckers typically make rectangular holes in trees in order to reach the carpenter ants that live in galleries they’ve created deep within a tree. While ants are high on a Pileated Woodpecker’s list of preferred food, wood-boring beetle larvae are not far behind. Sometimes the exertion of jackhammering isn’t necessary in order to reach insect larvae – removal of the outer bark is enough to expose tasty morsels.