NATCHEZ NATURALIST
NEWSLETTER:
from the woods near Natchez, Mississippi, USA

February 15, 2004

PREENING
Last week I reported a Thursday rain of 5 inches. From that Thursday morning until now we've received 10.6 inches (27 cm). That's left the ground so saturated that, I'm told, all over the county trees are toppling and mud slides are slumping onto roads. A couple of large trees in the woods here have succumbed as well.

The Carolina Wrens beneath my trailer have sometimes emerged into the rain, staying as neat and unruffled looking as if they were protected by magic shields. When a modest murder of crows alighted in a Water Oak, however, some appeared fine but others were disheveled, and obviously cold and wet. Some birds have dealt with this deluge better than others.

Occasionally the rain has paused long enough for me to walk around, to see how things were holding out. During these walks I've seen a lot of birds preening. After going so long without being able to eat normally, you might think that a bird's first priority would be to gorge itself. Instead, the rain seems to have made them yearn for running their beaks through their feathers, nibbling their feathers' bases, and scratching their heads. This reminds me that for any bird preening is serious business, sometimes even more important than eating.

Preening accomplishes two main jobs. First, it returns feathers to their right places. If you've ever faced spending a cold night in a down sleeping bag that has "lost its loft," you know how dramatically you can increase the bag's insulation capacity by giving it a good shaking and a paddling. Well arranged feathers keep the cold out, crunched together ones don't.

Just as important, preening involves oiling the feathers. If you watch a bird preening, occasionally you'll see it arch its head over its back, poke its tail skyward, and appear to bite something where its back joins its tail. When a bird does that, it's gathering oil from its "preen gland," more technically known as its uropygial gland. When a bird nibbles and combs its feathers with its beak smeared with uropygial oil it's not only arranging them, but also oiling them. Like oil rubbed onto leather boots, preening oil keeps feathers flexible, resilient and somewhat waterproof. Also it inhibits the growth of fungi and bacteria. In short, my Carolina Wrens do have a "magic shield" when it rains, and that shield is the consequence of preening with oil.

You can see a pretty picture of an Eurasian Collared Dove nibbling at his uropygial gland at http://birds.cornell.edu/crows/images/ECollar-Dove-preening-339a.jpg

*****

A MURDER OF CROWS
Most of you know full well that my above phrase "murder of crows" employs one of those perfectly acceptable but nearly never heard "collectives" used to describe animal groupings. Unfortunately, my best Googling efforts haven't turned up the phrase's etymology, though while searching I did bump into a number of other colorful and seldom-used collectives, such as "an unkindness of ravens" and "a pulchritude of peacocks." The book "An Exaltation of Larks" deals with such terms. There's a nice list of more animal collectives at a site in England, at www.hintsandthings.co.uk/kennel/collectives.htm

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PURPLE FINCHES EATING HOPHORNBEAM SEEDS
Eastern Hophornbeam trees, OSTRYA VIRGINIANA, are very common in our forest's understory here. At this time of year they're easy to spot because the tips of their slender, leafless branches are graced with curious light-brown fruiting clusters about the size of Guinea eggs. The clusters are composed of several flattened, papery bladders similar to the fruiting clusters on the hops vine of beer-making fame -- thus the "hop" in "hophornbeam." (Another abundant understory tree here, the hornbeam, bears leaves similar to the hophornbeam's, thus the "hornbeam" in "hophornbeam.") Suspended inside each of the hophornbeam's papery bladders is a ΒΌ-inch long (6 mm) seed looking like a small grain of brown rice, and these seeds are eaten by wildlife such as White-footed Mice, squirrels and various seed-eating birds. You can see such a fruiting cluster on a green-leafed, late-summer twig at www.hort.uconn.edu/plants/o/ostvir/ostvir01.jpg

To see how similar these fruits are to the completely unrelated hops fruits from which beer is brewed, go to www.hopunion.com/saaz1.jpg

Despite this week's rains, a couple of times the open crowns of our larger hophornbeams have been busy with Purple Finches, CARPODACUS PURPUREUS. A flock of maybe ten of these sparrow-size birds with their short, thick, seed-cracking beaks would wheel out of the sky and form a loose flock inside the tree, each bird then setting about visiting one fruiting cluster after another. They'd rip into a bladder, perch for a moment as they'd grind the seed and swallow it, then instantly move to the next meal. Up close I could hear the birds' soft, sharply metallic notes. Their intense foraging would continue for half an hour or so before suddenly the flock would take to the sky and disappear. You can see what male and female Purple Finches look like, and hear an audio file beginning with their song (which they are NOT singing now) and ending with about three metallic-squeaky notes of the kind I heard at www.ronausting.com/purfinch.htm

Hophornbeam is not at all one of the Purple Finch's preferred foods. Above all things, Purple Finches adore the seeds and buds of elms, the winged fruit of Tuliptrees, the buds of fruit trees, redcedar fruits, buds and fruits of maple, fruits of ash, Sweetgum, ragweed, cocklebur, and a lot of other things that are NOT hophornbeam seeds. However, now in mid February it's too early for the elm's fruits and plump buds, but fall's Tuliptree, maple and ash fruits are long gone, and the ragweeds and cockleburs of that season now have been picked clean, their herbaceous stems dark, pithy, and collapsed onto the ground.

Fact is, nowadays Purple Finches are feeling the food crunch that comes for so many animals at this time of year. Now many animal species are having to take a second look at foods that just a few weeks ago they passed by.

Happily, the forest here is still diverse enough to supply wildlife these emergency foods. Of course, wherever intense clearcutting of the national forest results in monocultured Loblolly Pine, such ceases to be the case.

*****

THOSE RASPBERRY-COLORED FINCHES AT BIRD FEEDERS
Seeing Purple Finches in our hophornbeams was especially a pleasure because during recent years populations of these birds have diminished because of one of the most spectacular events in recent North American zoogeographical history. Here's the story:

When I was a kid in Kentucky learning my birds, my Peterson fieldguide taught me that in the US there were two look-alike, raspberry-colored species of finch likely to appear at bird feeders. One was our Purple Finch and the other was the House Finch, CARPODACUS MEXICANUS. Though these two species looked a lot alike, in Kentucky there was no problem distinguishing them because the House Finch was a native of western North America, so it simply didn't occur there.

Back in the 70s when I lived in Nashville, Tennessee, one day a birding friend called excitedly reporting that a House Finch from out West had turned up at a feeder on the south side of town. That day a hoard of Nashville birders descended on that feeder, hoping to add the House Finch to their Life Lists.

Sometime in the 80s while visiting my mother in Kentucky, one morning while jogging down a street I noticed a long line of finches perched along a power line. I assumed that they were Purple Finches, despite their seeming louder, shriller, and somehow more assertive than I'd remembered Purple Finches to be. When I got back to the house I found the feeder swarming with these birds, which turned out to be, of course, House Finches, not Purple Finches.

Today, throughout most of eastern North America, if a raspberry-colored finch turns up at a feeder, probably, but not always, it's a House Finch. In places, House Finches are absolutely abundant.

The speed with which House Finches have occupied eastern North America is mind-boggling. The distribution map in my old fieldguide still shows House Finches as completely absent from eastern North America, except for a small area around southern New York where a few birds had begun showing up by the fieldguide's copyright date of 1966.

At this point you might want to go to the USGS pages for these two birds and compare their CURRENT summer distribution maps (BBS map) and winter maps (CBC), at:

House: www.mbr-pwrc.usgs.gov/id/framlst/i5190id.html
Purple: www.mbr-pwrc.usgs.gov/id/framlst/i5170id.html

Just look at where House Finches are found today! They are common to abundant throughout eastern North America, with very high concentrations in the Northeast. Also, notice how our "native" Purple Finches are highly migratory, being mainly Canadian during the summer and found in most of the US only during the winter. Compare this with the House Finches' modest seasonal shifts in distribution. House Finches don't undergo dramatic seasonal migrations because seeds at birdfeeders are available year round.

For some reason, it hasn't been so easy for Purple Finches to exploit the new backyard-feeder niche as it has been for House Finches. If finches were people, we'd call Purple Finches conservative traditionalists, and label House Finches, who breeze through the cold months prettily fussing and gorging themselves at backyard feeders, wild-eyed liberals.

I have mixed feelings. My default response is to regard House Finches in our area as little more than bird weeds -- especially since populations of "native" Purple Finches began declining just as House Finches invaded their territory. On the other hand, backyard feeders are for many families their main connection with "nature." Often these same feeders have inspired family members to get involved in more in-depth nature study and even to become concerned about the environment in general. Back in the 50s I myself began birding through our family's kitchen window, outside which my father had erected a homemade feeder.

In that light, the invading House Finches, by being attractive emissaries of nature, may be benefiting nature in ways that Purple Finches never could. Thus, even at our backyard feeders, the wild-eyed liberals, with their focus on education, turn out to be pro-environment...

*****

FROG REPRODUCTION GONE HAYWIRE
After reading my comments last week about frog eggs, Greg in Wisconsin wrote to me about seeing a female frog who had been "attacked" by several males:

"Each had tried grasping her and in the process of each holding on to a different part of her body they had held her underwater long enough that she had drowned... but they were still holding on to various parts of her body."

Such a story might be hard to believe, but Greg is a wildlife photographer and he sent a picture showing several male frogs trying to mate with parts of the poor, dead female. You can see this picture yourself on my Frog Reproduction page at www.backyardnature.net/frogsex.htm

How could such a macabre thing happen in nature? As I explain on my page, maybe the answer lies with a study on toads, not frogs, conducted by Dr. Susumu Ishii in Japan. Among the toads he was studying, he found that when during mating season an adult male finds ANY elastic object approximately the size of another adult toad, he mounts it and tries to clasp it. If the object he's mounted shows no response, he keeps holding on for hours. If the object is a female ready to mate, then mating proceeds normally. However, if the object mounted is a female not ready to produce eggs, she will vibrate her body. When the clasping male feels the vibration, he suddenly stops clasping, jumps from her back, and leaves quickly.

Maybe something similar was going on with Greg's Wood Frogs, though only further studies will make that clear.

*****

WOODPECKERS WITH FUNGUSY BEAKS
My old birding buddy Jarvis in North Carolina sent me an article reporting the newly documented fact that woodpecker beaks carry spores and fragments of a variety of wood-inhabiting fungi. This is one of those discoveries you'd guess to be true beforehand, for you'd expect any beak used all day to peck at fungusy wood to get covered with fungal spores, and you'd expect that, as that beak travels from tree to tree, it would spread those spores, contributing to the decay of other dead trees.

Still, it's good that someone has proved that all this is actually the case. Woodpeckers help dead trees decay, and the fungi they spread serve to soften dead wood so that a variety of animals, including woodpeckers themselves, later have an easier job tearing wood away to get at grubs inside the tree, and to make nests and dens.

This study is well timed because of the current political obsession with clearing away underbrush and dead trees for fire protection. Underbrush and dead trees are vital components of any healthy forest ecosystem. Take away dead trees and you diminish not only the woodpeckers' homes and food supply, but also their ability to distribute decay-assisting organisms throughout the rest of the ecosystem.

And don't get me started about people building houses in the woods, then complaining about wildlife and forest fires...

*****

MY GREAT BACKYARD BIRD COUNT
I'll bet that most of you taking part in the Great Backyard Bird Count this weekend see/saw more birds than I. I have no birdfeeder here, plus, on Friday morning, the non-rainy time available for my count, it was so darkly overcast and penetratingly chilly that the birds didn't seem any more excited about a count than I was.

Defining my "backyard" as everyplace within a literal stone's throw of my trailer, and counting birds sailing overhead, here's my pitiful list:

American Crows, 3; Turkey Vulture, 1; Carolina Wrens, 2; Red-bellied Woodpecker, 1; Blue Jay, 1.

*****

ON THE GIFT OF COLD, RAINY DAYS
On a couple of mornings this week it rained too hard for campfires, so on those days I made do with raw oatmeal, pecans and cold water. A friend suggested that I should get an electric hotplate. If such days came along more often, I probably would, but, since such occasions are rare, I told my friend that I prefer to keep depending on campfires.

One reason is that I would regret having a hotplate deny me the pleasure of occasionally rediscovering how wonderful hot meals are. In my experience, continual comfort and ease blunt the senses and make us forget how lucky we are most of the time. Just imagine what a pleasure it'll be when this cold, rainy period finally ends and the sun shines through! Will I not experience that moment more exquisitely than anyone who every day this week has enjoyed his or her hot meals and cups of steamy tea or coffee?

In fact, maybe, by having my days of raw oatmeal, pecans and cold water, in the long run I am indulging my senses as intemperately as any kid with a lollipop. Maybe the accomplished sensualist keeps his or her body fit and practices disciplined and highly selective abnegation in order to "keep the palate clean" and the body's hungry senses honed for rare epicurean events.

Maybe it's true that the practitioners of many or most austere-looking lives know that less is more -- that the disciplined lives of hermits and monks can actually be more voluptuous than any season of general meat and potatoes.

At least, maybe I just like to fancy such notions when it's cold and rainy, I've put off hanging a roof over my campfire, and I'm sitting with my raw oatmeal, pecans and cold water... !