An online resource based on the award-winning nature guide

Woodpeckers

Avian Toe Arrangment

3-17-14 mourning dove tracks 004As opposed to humans, who use the entire bottom of their feet for support, birds stand and walk only on the ball of their foot and with their toes. When you look at a bird’s leg, what appears to be its knee, bending backward instead of forward as it does in humans, is actually its heel.

Most birds have four toes, arranged differently according to the life style of the bird. Songbirds, as well as most other birds, have three toes pointing forward and one pointing back. Most woodpeckers, being active climbers, have two toes pointing in each direction, which provides added clinging support. The outer toe (of the three forward toes) of ospreys and owls is reversible, so that they can have two toes in back should they need to get a better grasp on slippery fish or other prey. Some birds that do a lot of running, such as sanderlings and most plovers, have only the three forward toes. (Photo: Mourning Dove tracks)

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White-tailed Deer Scavengers

deer carcass2  028According to NPR, each year Americans waste 33 million tons of food (and much of this ends up in landfills where it produces methane, a potent greenhouse gas). This situation is totally alien to that of other animals in the natural world, which seem to find a use for any and every organic particle. Great crested flycatchers incorporate shed snake skins into their nests, beavers build dams and lodges with branches they have eaten the bark off of, ermine line their nests with the fur and feathers of prey — the list goes on and on. When it comes to food, there is equally little waste. The carcasses of animals do not linger long, as almost every atom of their bodies is recycled. Fishers, coyotes, foxes, raccoons, opossums, bald eagles, hawks, woodpeckers, ravens, crows and many other animals make short work of a dead deer in winter. Come spring, if there’s anything left, the final clean-up crew consists of legions of turkey vultures, beetles, flies and bacteria, among others. How unfortunate we’ve strayed so far from a process that’s worked for so many for so long.

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Hairy and Downy Woodpecker Bills

12-31-13 woodpecker billsDistinguishing Hairy Woodpeckers (Picoides villosus) from their smaller relatives, Downy Woodpeckers (Picoides pubescens), can be challenging if you don’t have a chance to view both species at the same time. The easiest way to tell them apart is to note the relative size of their bills. The Hairy Woodpecker’s bill is proportionately much larger than the Downy Woodpecker’s – it’s almost as long as its head — whereas the Downy Woodpecker’s bill is not nearly as impressive. Although a Downy Woodpecker can’t drill or probe as deeply into trees as a Hairy Woodpecker, it does have at least one advantage due to its overall smaller size; it is light enough to balance on the stems of goldenrods, which usually aren’t strong enough to support Hairy Woodpeckers. It is here that Downy Woodpeckers drill for overwintering goldenrod fly larvae inside goldenrod ball galls – a popular winter snack for this species.

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Pileated Woodpecker Sign

12-26-13 pileated sign2 IMG_8246Pileated 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.

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Do Yellow-bellied Sapsuckers Really Suck Sap?

9-12-13  yellow-bellied sapsucker tongue IMG_9715My apologies for not posting yesterday — two days without electricity or telephone!

A tell-tale sign of Yellow-bellied Sapsucker activity is the presence of rows of 1/4–inch holes, often drilled in Sugar Maples and birch trees in order to gain access to their nutritious phloem sap. Once the sap begins to flow, sapsuckers insert their tongues into these holes. Here is where their name is misleading, as sapsuckers don’t actually suck the sap, they lap it up with the aid of tiny hair-like projections on the edge of their tongue, which hold the sap by capillary action (see insert). Each flick of the tongue brings more sap into the woodpecker’s mouth.
Because sap is so essential to a tree, wounds are quickly healed over to prevent loss of sap. Scientists still have not figured out how sapsuckers overcome a tree’s defenses and maintain a continuous flow of sap. One theory is that sapsucker saliva may contain a substance that acts as an anticoagulant, preventing sap from clogging up and sealing over the holes the bird creates.

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Hairy Woodpeckers Raising Young

6-3-13 hairy woodpecker looking right 330The chipping of hungry Hairy Woodpecker nestlings can easily be detected by human ears, even though it comes from deep within a tree cavity. One is reminded of how beneficial this species is when observing the steady delivery of food by these woodpeckers to their young. More than 75% of an adult Hairy Woodpecker’s diet consists of injurious insects, while the amount of useful insects and cultivated fruits that they destroy is insignificant. Beetle larvae (mostly wood-boring) make up 30% of the insects that are consumed, with ants ranking second, at 17%. Caterpillars, such as those pictured, comprise about 10% of an adult Hairy Woodpecker’s diet, but given this parent’s beakful, one wonders if the percentage is greater for nestlings.


Goldenrod Ball Gall Fly Larva

3-22-13 goldenrod ball gall fly larva IMG_6182The round “ball” that is often present on the stem of goldenrod plants contains the overwintering larva of a fly (Eurosta solidaginis). A year ago an adult female fly laid an egg in the stem of the goldenrod plant. The egg hatched and the larva proceeded to eat the interior of the stem. As it did so, the larva excreted chemicals which caused the plant to grow abnormally, creating a ball-shaped “gall.” If you were to open a goldenrod ball gall today, you would probably find an overwintering larva (if a downy woodpecker or parasitic wasp hadn’t gotten there before you). Within the next few weeks the larva will pupate, and as early as April the adult fly will emerge from the gall, having crawled out the passageway that it chewed last fall. An inflatable “balloon” on its forehead allows the fly to burst through the remaining outermost layer of tissue at the end of the passageway. The adult fly lives about two weeks, just long enough to mate and begin the process all over again.


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