Showing posts with label woodpeckers. Show all posts
Showing posts with label woodpeckers. Show all posts

Thursday, March 31, 2011

Quarrelling Hairy Woodpeckers

I had a lot of fun photographing this woodpecker spat in January. Two male hairy woodpeckers were debating who was going to go to a suet feeder. There are five suet feeders on the bird tree, so they kept themselves quite busy. They would fly at each other but neither was actually touched by the other. They kept this up for so long that I stopped watching them after thirty minutes. There were so many good shots, that I decided to give you a slide show.

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Monday, March 28, 2011

Downy or Hairy?

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Downy Woodpecker (Picoides pubescens)

A few years ago, I vowed to never try to identify downy and hairy woodpeckers again. Each identification I made was wrong and I couldn't seem to remember which was the smaller woodpecker. For some reason, that changed this winter. I created a mnemonic that helped me remember which bird was which. The constant repetition of the mnemonic finally created automatic knowledge. I look at a woodpecker and now I know which it is!

The downy woodpecker is above. It is the smaller bird, which you can see by its relative size as it perches on the suet feeder. The smaller bird also has the shorter beak. Also, look at the tail feathers. There are bands of black there with the rufous feathers filling some bands.

"Smaller" and "shorter" are meaningless without comparison, so we see in the photo below the hairy woodpecker which is larger and has a longer bill. It has no bands on its tail, only the rufous feathers. (However, I have read that some hairy woodpeckers in the northwest of the US have bands of black.)

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Hairy Woodpecker (Picoides villosus)

I have observed that hairy woodpeckers seem to be more aggressive than the downy. Downy woodpeckers have their spats, but the hairy woodpeckers attack each other more often and more violently (but I have not seen any injuries). I also think, but am not certain, that the hairy woodpecker gaze has an intensity, not seen by me in the downy, that you see in this photo. These are my observations and I have not verified then with any research.

What was my mnemonic? D is for downy and H is for hairy. D comes before H in the alphabet, as smaller/shorter comes before larger/longer (on an imaginary continuum). Therefore, the downy is smaller and has the shorter bill. If you have the same problem identifying these birds that I had, I hope this helps! Have fun watching the woodpeckers! I have to go to Flickr now and sort out my downy and hairy woodpeckers!

Flickr: My Downy Woodpecker Set

Flickr: My Hairy Woodpecker Set

Flickr:: My messed up Woodpecker Set

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Monday, October 26, 2009

Scenes from the John Hay Ecology Hike

Above: a white pine. These huge, straight trees were cut down by British forces while they colonized North America. They made masts for their ships. This ravaging of our forests was one of many irritations that led us to revolution.

Above: a geometer moth warming on a rock
There are over 1,400 geometer species in North America.

Above: the top of a tall tree. The tree has been cut in two by the woodpecker activity that you see here. Below: the rest of the tree from which this fell.


Above: an animal (probably squirrel or chipmunk) has excavated this dead tree for its lair.

Above: a hemlock tree. The difference between it and white pine is that the hemlock has small dead branches on the trunk as it rises into the forest.

Above: a midden — probably chipmunk, maybe squirrel.

Above: John and Amy have left the woods and are entering the fields of the main house.

The Main House at the Fells

Above: Mother and Child by sculptor Jack Dowd was on exhibit.

Above: Originally a stone barn at the Fells, this is now a private residence.

The John Hay Forest Ecology Trail Hike

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Saturday, August 22, 2009

Morey's Pond: A Natural History Adventure

In the middle of July we hiked around Morey Pond in Andover (elevation 1329 ft (405 m)) and saw many things that taught Wingnut about natural history. I thought this post would be an opportunity for you to see how we three explore nature together. All links are either to wikipedia.org articles that you can use for more information, to other posts on my blogs, or to photos on Flickr. If you click on a photo, you will open a new page to the Morey's Pond Set I created on Flickr for this hike. From that new page you may choose to view a larger image. Our greatest source of information is John, the most learned naturalist I have ever met. When none of us know a thing, or when we want to learn more, we search the Internet. Often, we find details in my photographs that we need to investigate more, also. Each hike, bike ride or kayaking trip is full of wonder, beauty and learning.

Geography

The first three photographs are scenic views of Mount Kearsarge as seen from the pond trail. Kearsarge has a fascinating history and geology. Kearsarge is classified as a monadnock mountain and can therefore be seen from numerous places in this area.



Morey Pond (or Morey's Pond) is listed in extremely brief mentions on the web as a reservoir for Andover, NH. There is a dam at the opposite end of the remote parking area. When we were at the dam, I turned around and photographed this outlet of the pond that runs to the dam (below). Beavers are re-engineering the human dam to better serve their own needs.


PLANTS: The plant life is typical for this area.

Above: Blue fruit of Lily of the Valley (Convallaria majalis).

These blueberries are the reason we went to Morey Pond: to see how the crop was this summer. In Vermont the blueberry farm was smaller than the acreage of wild blueberry bushes here! There are both low and high bush berries on the pond. They had just begun to ripen and we planned to return for picking. But because of construction in the house, two heat waves, grief from the cats, and other things, we never did.


Above: Blue Flag (Iris versicolor) is one of my favorite wildflowers.

Above: I haven't yet identified this mushroom (I could simply holler across the room and ask John but I haven't!).

Above: Cinnamon Fern (Osmunda cinnamomea)

Animal Life

Above: John and I saw this bird scat on a shoulder high branch with dead branches above it. Some carnivorous bird (but not an owl), such as a hawk or eagle, left this here while perched above waiting for prey.

Above and below: evidence of beaver (Castor canadensis). Above you see John standing while waiting for Wingnut to tie his shoe. We are near a tree that was not quite felled by beaver last winter. How do we know that they chewed it in the winter? The cut is high above the ground at just the height that the snow pack would be. A beaver can not climb a tree to cut it down and are not big enough to chew it at this height. The weathering of the cuts on the wood also tell us it was a few months ago that it was chewed. Below you see a closer shot of the tooth marks on the tree.


Above: the human dam as the beavers re-design it. I choose this shot because of the water effects that I got (after two years of trying) in the camera.

Above: halfway between the parking area and the dam is this underground beaver lodge on an outlet (or beaver canal) of the pond. I don't see too many lodges built under the bank of a stream, so this was a treat. I wanted to poke around inside it but was too nervous to try. Who knows who lived there still?

Above: a woodpecker tree. Used for food and nesting but I don't know by what species. Nobody was in residence this season. This was probably made by a pileated woodpecker (Dryocopus pileatus).

Above: a Red-spotted Newt (Notophthalmus viridescens viridescens) that I almost stepped on.


Morey's Pond Set

Finally, below you will find links to the blogs, photos and links of other people on Delicious, Technorati, Furl (now Diigo) and Flickr. These are excellent resources for any person interested in natural history. Often an amateur naturalist will have a clearer description or a better photo than a professionally created guide book.. Compulsive bloggers, like myself, will take the time to research what we post and to correctly tag every single post and photograph with the scientific and common names of plants and animals. I have organized my Flickr sets into collections of wildflowers, birds, insects, and more to make it easier for people to browse and perhaps identify a creature or plant from outdoors. Click here to see my collections.

Take advantage of our efforts for you and use us as a resource. We've learned a phenomenal amount about genus, species, origins of names and common misidentifications. On your next outing, take a close look around to see what you can find!

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Monday, April 14, 2008

Heads or Tails: Woodpecker Tips

David at Useless Facts posted Useless facts: More on Brains — The Woodpecker Factor which pointed me to this article at New Scientist, which I have lifted in full because of the humor. I hope you enjoy my photos (I took these shots outdoors, not through the bird window) and information.

Question: How is it possible for woodpeckers to peck so hard without getting brain damage?

Answer: This has been the subject of neurological research more than 20 years ago (The Lancet, 28 February 1976, p 454, Archives of Neurology, 1979, vol 36, p 370).

Shock waves are transmitted less readily in the woodpecker's head than in a human's because the former has a narrow space between the skull and the brain, with very little fluid, and the woodpecker's brain is packed tightly by dense yet spongy bone which buffers the force to the brain. Additionally, some of the muscles in the woodpecker's head contract, which helps to absorb and distribute the shock. Structures from the base of the tongue extend round the brain and may also absorb shocks.

Christopher Gardner-Thorpe, Consultant Neurologist, Exeter, Devon

We haven't discovered more recent studies of the risks of brain damage in woodpeckers than those mentioned by Christopher Gardner-Thorpe, but further references from readers would be welcome. A brief description of the 1979 study, carried out by Philip May, Joaquin Fuster, Jochen Haber and Ada Hirschman, may be of interest. The researchers filmed a tame acorn woodpecker using a high-speed camera capable of recording up to 2000 black and white frames per second. Analysis of the film showed that the impact deceleration when the bird's bill struck the trunk was staggering, sometimes reaching as high as 1200g.

Perhaps not surprisingly, the woodpecker was also seen to close its eyes just before impact, in order to stop its eyeballs flying out!

With repeated decelerations of this magnitude, it's hard to see why the woodpecker does not immediately fall down unconscious, even given the factors mentioned above that help cushion the brain. The secret may be in how the woodpecker hits the tree. The researchers discovered that the woodpecker always keeps its strike absolutely straight. First, it would tap the wood lightly a couple of times to line itself up, and then strike repeatedly with great accuracy, never allowing its head to twist at the moment of impact. This means it avoids rotational forces on its brain, which tend to shear neuronal connections and cause concussion. These are the same forces that can cause serious brain damage to passengers in a car hit from the side in an accident or when a boxer is punched in the head.

The researchers go on to suggest that the woodpecker's approach could be used to help design crash helmets which reduce whiplash rotational injury. Indeed, we may have discovered this once already. The shoulder and neck casings on armour used by medieval knights look as though they were designed to prevent rotational concussive injuries when the wearer was being bludgeoned by a mace.

The researchers also point out that the woodpecker has a natural advantage in resisting brain damage. Its brain is quite small which means that the ratio of brain weight to brain surface area is also small. Therefore, a given impact deceleration force would be spread out over a relatively large area, making its brain better able to resist concussion than that of a human. — Ed


Answer
: We have a picture of evolution in which life strives for, and tends to get closer and closer to, perfection. Perhaps a better picture might sometimes be one in which life manages to get by on whatever can be botched together just well enough to work.

For a bird to bang its face repeatedly against a tree looks like pretty dodgy behaviour, perhaps as dodgy as a mammal walking on its back legs while carrying things with its front legs. A woodpecker might get away with banging his head, just as I might get away with bipedalism. But I wouldn't be at all surprised if he was just as likely to get a headache as I am to get a bad back.

Richard Riscon. Canterbury, Kent

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Sunday, April 06, 2008

The (Hairy Little) Woodpecker

This tiny male hairy woodpecker (above) and female (below) are the smallest I have seen. They "look young," as if they are youngsters. But it was still snowing this weekend, so I don't know how they could be juvenile birds. The female was resting with her belly on the branch and her chin on another branch. When the male came, she chased him up and down the tree until he flew off.
The Woodpecker
by Emily Dickinson

His bill an auger is,
His head, a cap and frill.
He laboreth at every tree, —
A worm his utmost goal.

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Friday, April 04, 2008

Photo Hunters: Through My Glass Lens

Birds at the feeders in today's snowstorm
(yes, another snowstorm and we got out of school early because of it):
above: Mourning Dove

Northern Junco

Hairy Woodpecker (male)

Black-capped Chickadee

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Tuesday, March 25, 2008

Wordless Wednesday: Downy Woodpecker

The bill on this little girl is half the length of her skull, so I am pretty sure she is a downy, not a hairy, woodpecker. If you think I'm wrong (which I have been, 100% of the time, so far), please holler! I like her pose here.

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