from the woods near Natchez, Mississippi, USA
February 29, 2004
BUILDING A BLUEBIRD NESTING BOX
As during most of February, it's been an unusually rainy, chilly week here. It was a good time to build a bird box. The box I built was one designed with bluebirds in mind. Naturally I've set up a "How to Build a Nest Box for Bluebirds" on the Internet, providing the design I used, a picture of the final product being held by neighbor Karen Wise, and a nice picture of an Eastern Bluebird itself, at www.backyardnature.net/101/birdbox.htm
One good thing about that design is that all you need is a board six inches wide and five feet long, and basic carpenter tools. It took me about an hour to build the whole thing. Constructing a box like this would be fun to do with a kid. The North American Bluebird Society provides several other nest box plans at www.nabluebirdsociety.org/plans.htm
By the way, yesterday I heard my first Purple Martin of the season, a bit later than usual, probably because of the rains and because I'm farther from the river than in previous years.
I see Eastern Bluebirds, SIALIA SIALIS, throughout the year here but usually they just fly over and never spend the day. I hear their sweet, high-pitched, quavering calls from high in the sky, spot five or six flying together too high to see their pretty colors, and then they're gone. I remember when their calls were as much a part of a hot summer day in Kentucky as the sounds of cicadas and katydids, and I miss them. You can hear the calls made by a small flock, just as they sound as they fly over here, at www.mbr-pwrc.usgs.gov/id/htmwav/h7660so.wav
Probably I'm not the only "old country person" missing bluebirds because during the last century Eastern Bluebird populations declined by up to 90%. In a way that's surprising because during pioneer days bluebird numbers actually increased as forests were converted to the open fields with scattered trees and bushes favored by bluebirds. However, with the 20th Century came pesticides, to which bluebirds seem particularly vulnerable. Also, European Starlings and House Sparrows out-competed our bluebirds for nesting sites as they spread from coast to coast after being introduced from Europe. House Sparrows even destroy bluebird eggs and kill the nestlings. One way to discourage those invasive species from taking over a bluebird box is to place the box as far as possible from buildings. Starlings and House Sparrows need human society, but bluebirds get along fine without us.
Because pesticides are better controlled now and many programs are afoot to help bluebirds, in some places their numbers are modestly rebounding. However, the new emphasis on removing deadwood and undergrowth to reduce fire hazard near people's homes may well set these efforts back. Bluebirds as well as many other creatures NEED dead snags for nesting.
All kinds of information about bluebirds, including their distribution map, a variety of nest box diagrams, and several pages of FAQs, can be found at the North American Bluebird Society Web site at www.nabluebirdsociety.org/
SIGNS OF BEAVER -- OR MAYBE NUTRIA?
For the last two or three weeks, at both the Field Pond and the Forest Pond, something has been gnawing on the stems of Black Willows along the banks. On some willows, debarked patches a foot or more long extend up the trunks, sometimes nearly encircling them. A few stems an inch thick or more have been completely severed as cleanly as with a sharp knife. Several slender, two-ft-long stem segments of 10-ft-high plumegrass (genus Erianthus) float at the water's edge as well. The willows' debarked patches and the floating plumegrass stems are almost white, so in the rain-saturated pond area beneath overcast skies, these signs show up like beacons. In a marshy area where grass emerges from shallow water there's a network of runways, and the water in the runways' vicinity is cloudy.
These are all classic signs of Beaver, CASTOR CANADENSIS. Even before I moved to the Sandy Creek area often I'd admired beaver dams at several locations in Homochitto National Forest, which adjoins this property. Beaver are known to wander five or more miles from their birthplaces, and 150-mile moves have been documented, so there's no reason to be surprised to see beaver signs here.
Still, I can't say with 100% certainty that what I'm seeing is made by beaver, and not nutria, MYOCASTOR COYPUS. I just have no experience with nutria, though in southern Louisiana this rodent has in some places become a major problem. Nutria, nearly as large as beaver, was introduced from Argentina into the US by people hoping to farm them for their fur. Nutria fur never did catch on, animals escaped and were released, and now certain wetlands are being devastated by the rapidly multiplying critters. You can read an article entitled "Louisiana Puts Bounty on Rodents," where you meet to a fellow who plops down more than 1,200 nutria tails and is paid $4,824 in bounty, at www.wildlifedamagecontrol.com/animaluse/trapresearch/animaldamage/nutria.htm
The Louisiana Department of Wildlife and Fisheries provides a fine page on the history of nutria in our area, entitled "Nutria Population Dynamics - A Timeline," along with illustrations of them, at www.nutria.com/site2.php
I'm 99% sure that we have beaver visiting our ponds, not nutria. For one thing, the highest nutria concentrations are a bit south of here. More importantly, the other day I was standing next to a stream in the woods not far from the ponds when suddenly a splash detonated next to me so loud that it only could have been made by a beaver who had surfaced, seen me, then slapped his flat tail on the water before diving to his underwater den entrance. Nutrias don't have flat tails to slap with. Also, nearby was a mammal track in which the footprints were obliterated by something being dragged over them -- like a beaver tail.
Maybe someone out there can tell me how to distinguish gnawings and floating food debris of a beaver from that of a nutria. Do nutria leave broad, flat toothmarks on debarked, standing willow trunks, as beaver do?
My comments last week on how to meet your local violets stirred up less interest in identifying the various species than in eating them. Genevieve of Natchez wrote about her sister's violet-blossom jelly, which has a very delicate flavor and is great on homemade bread. Gloria in New York candies the blossoms, but warns that "they are very delicate and the sugar is very heavy so they kind of turn out like little sugarized violet blobs."
When I go salad-picking I often pick violet leaves and flowers to be added with other items such as wild cress, oxalis, sorrel, dandelion, wild lettuce, wild onion, unfolding basswood leaves, etc. With my hypoglycemia I've avoided candying and jellying the flowers. In case you have plenty of blue violet flowers at hand and want to try candying them, there's a recipe for "Crystallized Violets" at www.naturenode.com/recipes/r_violets.html
A recipe for "Violet Jelly" can be accessed at http://prairielandherbs.com/violetjelly.htm
DAWN GOBBLING & STRUTTING
For the last couple of weeks on several mornings at dawn I've been hearing a turkey gobble not far away. This makes sense because at this time of year tom turkeys go strutting and gobbling, advertising for hens. Studies show that this breeding behavior is triggered by increasing day length. Apparently our recent colder-and-rainier-than-usual weather hasn't fazed this particular tom, though that can be the case.
The gobbles seem to originate from two grassy clearings in the woods established for deer browsing. Hunters refer to such strutting locations as strut zones, and a tom might strut on as many as six of them. During the cold months the turkeys have kept together in flocks, but until lately I've not seen or heard a single one of them. That's something, because during the hot months just about every time I walk down to the pond I can count on seeing one or more hanging out on the grassy road between the woods and the Loblolly Field. Now that gobbling has begun, the flocks will fracture into individuals and small groups.
In Mississippi, turkey hunting season is from March 20 to May 1. It's estimated that in our state we have about 294,000 Wild Turkeys, and last year 35-40,000 were killed. That means that, if you're a wild turkey in Mississippi, each year you stand about one in eight chances of getting shot. It also means that, taking the entire state as a whole, about 0.8 turkeys occur per square mile.
There's an interesting page on "Wild Turkey Reproductive Habits" at www.tracker-outdoors.com/reproduction.htm
ROUND SAND BEETLE DISCOVERY
Just inside Homochitto National Forest not far from here there's a little stream about 15 feet across and six inches deep with clear water rippling over a sandy bottom. One of my favorite sitting places is on a bank of nearly white sand built up near a sharp curve. The sound of trickling, clear water, sunlight filtering down through the pines, the fine, white sand to sit on...
So one day this week I was sitting there when a small beetle landed on the sand next to me and furiously begin digging into a crack in the dry sand. Immediately I was on my belly with my handlens about half an inch above him. He was dome-topped like a ladybug and just a little larger, and mottled brown and black. You can see exactly what he looked like at http://animals.timduru.org/dirlist/insect/InsectBeetle-Omophron_americanum.jpg
He was a Round Sand Beetle of the Ground Beetle Family, most likely OMOPHRON AMERICANUM. My fieldguide says little about him other than that he's infrequently collected, and that he occurs in burrows in sand or mud along shores of streams and lakes. His pincer-like mouthparts make clear that he's a predator. I was interested to see that he used his palps (antenna-like "feelers" near the mouth) to dislodge sandgrains as he dug.
It's always fun to see a new kind of living thing for the first time. Also, it's good to be reminded of the simple fact that if you want to observe new kinds of plants and animals, it's worthwhile going to an unusual habitat. If I always stayed in the fields and the general forest, probably I'd never have seen this species.
How does one identify such a rare insect? To figure out this one, first I went to my old Peterson Field Guide to the Insects, which provides illustrations of representative species of most insect FAMILIES found in North America. Having paid special attention to the structure of the beetle's mouthparts, antennae and legs, by thumbing through the fieldguide's drawings in the beetle section I figured out which family it probably belonged to. The beetle species itself was too rare to be illustrated in the fieldguide, so then I used the Google image feature to make a search using the family name as the keyword. Google came up with a number of thumbnail pictures, and one looked exactly like my beetle, and was linked to a Web page providing the beetle's name. This "integrated identification process" using both commonly available fieldguides and the Internet is a powerful tool for today's backyard naturalists.
Anyone interested in specializing in ground beetles, one of the largest and most interesting beetle families, should download the well illustrated "The Ground Beetles of Florida," in PDF format, at http://entnemdept.ifas.ufl.edu/choate/florida_carabidae.pdf
NATCHEZ'S "ACCUMULATED PRECIPITATION ANOMALY"
Hillary on the Mississippi Gulf Coast sent a link to an interesting NOAA page showing "accumulated weather anomalies" over the last month or so, for the entire US. It's gratifying to see that NOAA has noticed that in our area February has been much rainier and colder than usual. You can see that page highlighting several anomalous weather conditions nationwide at www.cpc.ncep.noaa.gov/soilmst/anomalies_composite.html#SMAMAP
The map at the bottom of that page shows three rather localized spots of unusually high rain accumulation for this month -- one in north-central California, another in southwestern Louisiana, and another exactly here in southwestern Mississippi. Interestingly, as nearby as my home area in western Kentucky, during the same time period they've seen LESS rain than usual. It's striking how these "accumulation anomalies" can be so local.
NATCHEZ AND THE GLOBAL THERMOHALINE CONVEYOR BELT
Speaking of localized weather conditions, during my freelance-writer years of Eurailing and backpacking throughout Europe, I often reflected on this: It was a lot cooler there than back home, but not nearly as cool as it seemed it should have been. That's because London is farther north than Winnipeg, Canada, and Denmark has the same latitude as Alaska's Aleutians. One summer I spent several weeks in Norway and Finland above the Arctic Circle, and it wasn't bad at all, though each night I camped in a summer tent. Europe is warmer than it seems it should be because the Atlantic's Gulf Stream carries warm water far to the north, and winds then convey warm air from above the Stream onto the European mainland. Palm trees grow on Ireland's southwestern coast.
The Gulf Stream is just one small component of something called the Global Thermohaline Conveyor Belt. Gradients in water temperature and water salinity power the Belt. Basically, the Belt sinks the world's warm surface water in the North Atlantic, this cooled water then flows at great depths to oceans all over the world, where it rises, and begins working its way back to the North Atlantic, rewarming as it goes. This is all illustrated by an "animated GIF" near the page top at www.cru.uea.ac.uk/cru/info/thc/
If the Belt should stop running, computer models show that northern Europe's average winter temperatures would drop 10°-20° F. Europe would become, literally, like locations of similar latitude in Siberia. Agriculture would become impossible. You can imagine the social, political and economic impacts. Some say the change could take place during just three or four years while others say a hundred years would be needed.
There's evidence that the Belt has "broken" before, and many scientists claim that conditions seem right for it to happen within this century, or even now... Increased carbon dioxide in the atmosphere would cause it (the Chinese are just entering their Industrial Revolution). Freshwater from the melting poles might also break the belt.
At the bottom of www.cru.uea.ac.uk/cru/info/thc/ you can see a world map showing how temperatures are projected to change worldwide, if the Belt breaks. Worst hit would be the North Atlantic and northern Europe. Antarctica would actually warm up (Water from its melting glaciers would raise sea level enough to flood many of the planet's major cities.
According to that particular map, the Natchez area might get by with less change than most of the world, at least with regard to AVERAGE temperatures. No one can say what will happen with storms, hurricanes and the like. With the millions and millions who will flee Europe, a goodly number of refugees can be expected to end up here.
There's a Washington Post article on this matter at www.washingtonpost.com/wp-srv/inatl/longterm/climate/stories/sci120197.htm
This is not hysterical science fiction or something thought up by conspiracy-minded people. Most of the world's leading climatologists agree that it is at least a "low probability, high impact" possibility, and some claim that it is practically inevitable. I invite you to make a Web search yourself using the keywords "THERMOHALINE CONVEYOR BELT," to learn about the issue from a variety of sources.
What can be said of a government who, in the face of such a real threat to all the people on Earth, and to the planetary ecosystem, not only ignores the predictions, but actively promotes policies that reduce air pollution standards, and encourage greater production and use of polluting energy sources?
Actually, the situation is even more serious than this. I will address that next week.