Monday, February 4, 2008

Common Feeder Birds: Hairy Woodpecker

Note the long bill on this male Hairy Woodpecker.

We are always pleased when our resident Hairy Woodpeckers ( Picoides villosus) show up at our feeders at the park. Hairy Woodpeckers are similar in appearance to the Downy Woodpecker, which I covered in an earlier post. You can click here to read that post. Later in this post, I will cover identification tips to tell the two apart, but first I will cover some of their fascinating natural history info.

The first word in the scientific name, or genus, for Hairy Woodpeckers is Picoides. The word Picoides is comprised of two parts: Picus, which means "woodpecker" and is a character in Greek mythology that was changed into a woodpecker by the witch, Circe. It is also a genus of large woodpeckers that live in Europe, Asia and North Africa. The second part, -oides, means "resembling". The second word in the scientific name, villosus, means "hairy or shaggy" and describes the long, filamentous hairs that form a white patch on the bird's back.
The Hairy Woodpecker is a year-round resident as far north-west as Alaska and as far south-east as Florida. This large variation in climate and habitat has produced a large number of subspecies. There are seventeen recognized subspecies of the Hairy Woodpecker with a large range in size and plumage. The subspecies of Hairy Woodpecker that lives here in Indiana and neighboring states is Picoides villosus villosus.

Hairy Woodpeckers, like all woodpeckers, are fascinating to watch as they forage for food. Hairy Woodpeckers will usually concentrate their efforts on the trunk of the tree, while the smaller Downy Woodpecker will explore the branches. Hairy Woodpeckers, even in the winter, feed on approximately 75% insects and 25% plant material, like seeds and berries. Most people would assume they feed by pounding like crazy on a tree, then extracting the insects, but Hairy Woodpeckers have a specialized feeding method called gleaning. They will glean insects by carefully inspecting the nooks and crannies of the tree and extract any insects along these areas. They will, also, check areas that larger woodpeckers, like the Pileated Woodpecker, have opened up and search for insects the bigger birds might have missed. The Hairy Woodpecker will excavate or open up areas of the bark by pounding a hole with its bill, but according to some studies, less than 25% of the time. The hammering noise we hear so often is mainly for communication and, also, a way of locating prey. They will tap along the trunk to find areas of varying resonance to locate insect tunnels.

Female Hairy Woodpecker foraging.

Male Hairy Woodpeckers have a red patch on the back of their head, like the Downy Woodpecker, that the females lack. They use this to display during courtship. The male will spy a lovely lady he is interested in, erect his red patch and spread wide his tail feathers in hopes of impressing her. If she is interested, they will then start a bounding display flight, with the birds following each other in great loops above and through the treetops.

An interesting tidbit is the females will do most of the egg incubation during the day, while the males will incubate the eggs during the night. Parents will feed the young by regurgitation, at first, then gradually offer whole insects to the young.

Now to tackle those identification differences between the Hairy and Downy that can be tricky. Here are a few of the field marks I like to use to tell the Hairy Woodpecker and Downy Woodpecker apart.

1. Overall Size
The Hairy Woodpecker is a much bigger bird than the Downy, with an average size of 9.25 inches in length. The Downy has an average size of 6.75 inches in length. This can be difficult to tell in the field, but I have found it is sometimes easier to use familiar birds as a comparison to help with size. With this method, the Hairy Woodpecker is a little smaller than an American Robin and a bit larger than a Northern Cardinal. The Downy is closer in size to a House Sparrow or Tufted Titmouse.

2. Bill Size
The Hairy Woodpecker has a much larger, stouter bill than the Downy Woodpecker. The Hairy Woodpecker's bill is almost the same size as the width of its head from the side while the Downy Woodpecker's bill is one third the size of its head. The Downy's bill appears more delicate than the Hairy's bill. A good site that shows two drawings of the birds is Cornell's Great Backyard Bird Count. (I will cover this in an upcoming post, this event is next weekend!)

3. Call
This takes a trained ear, and I will admit I am not the best at this. The Hairy produces a "peek" call which is louder and sharper than the Downy's call. It also has a "rattle call" which is a series of rapid notes all at the same pitch. The Downy's call is a more gentle "pik" with a rattle call that is slower and descending in pitch. (Downy= descending).
4.Outer Tail Feathers
I don't use this field mark too much, but it can be helpful if the bird is at a weird angle and you can't see the head. Hairy Woodpeckers in Indiana have white outer tail feathers, while the Downy Woodpecker has small dark bars on its outer feathers. There has been Hairy Woodpeckers with the dark bars, also, but if you have a woodpecker with white outer tail feathers, it is usually a safe bet it is a Hairy.
5. Division of Red Head Patch
On male Hairy Woodpeckers in Indiana and in the east, the red patch is divided by a dark line right down the middle of the patch. This is a field mark that is not mentioned in any of the field guides I own. I have seen it mentioned on a few websites and on The Birds of North America Online. They briefly say that male Hairy Woodpeckers have a "red band extending across back of head (often broken into 2 lateral spots in e. North America)." My friend, Steve Moeckel from Ohio, sent me a couple shots showing the back of the head on the male Hairy Woodpecker and the Downy Woodpecker. You can see the Hairy has the aforementioned dark line and the Downy does not.

Male Downy with the solid red patch. Photo by Steve Moeckel.

Male Hairy Woodpecker with the divided red patch. Photo by Steve Moeckel.

Another shot of the Hairy Woodpecker with the divided red patch. Photo by Steve Moeckel.

Hairy Woodpeckers love suet, peanuts and black-oil sunflower seeds. Keep an eye out for them at a feeder near you!


No comments: