January 18, 2004
| FORAGING GRAY SQUIRRELS Most mornings in dawn's twilight, before the sun's rays begin shooting in from the east, several Eastern Gray Squirrels, SCIURUS CAROLINENSIS, work among the slender branches at the top of oak trees in the woods. Sometimes there's five or more. Acorns cluster at the outer branches, so when a squirrel goes there, the branches yield. A squirrel's acorn-nabbing foray usually begins with a brief pause on the stable part of a branch, then there's a hurried rush to a branch- tip acorn, and then a rush back. Sometimes a squirrel misjudges a branch's strength and momentarily finds himself dangling, or worse. If you ever see such a group of foraging squirrels, notice how each individual runs along a branch for a second or two, then freezes, then runs some more, then freezes. When several squirrels in a tree all move in this stop-motion manner, it's a funny thing to see. My guess is that they pause because it's easier for them to spot approaching hawks and owls. Seeing how all squirrels stick to such a disciplined program of stops and goes, we have a hint as to how serious the predator threat is for them. By the time sunlight hits the treetops, the squirrels are gone. I suppose that's because the bright light makes them more vulnerable to their predators. They don't always return to their dens for the rest of the day, for often in the middle of the day I hear the "Aaarghhhh!" call that's often made by aggravated female squirrels when they're being chased by several males. These chases can go on for hours. I have a true-to-life online story, "Mistletoe: One Year in the Life of a Gray Squirrel," describing one such chase, at www.backyardnature.net/mist02.htm. A Web site in Michigan says that up there breeding occurs in December-February and May-June. That site also says that most females begin their reproductive life at 1.25 years but can bear young as early as 5.5 months. Females may produce two litters a year for more than 8 years. Usually 2-4 young make up a litter, though litters of up to 8 are possible. When you do the math, that's an impressive reproductive rate. The Web site with this and other info is at http://animaldiversity.ummz.umich.edu/accounts/sciurus/s._carolinensis$narrative.html ***** GRAY FOX ON THE POND TRAIL The fox's coat was so thick and shiny that in the morning sunlight it looked absolutely luxuriant. It was so thick and glossy that if it were on a pet dog you'd want to sink your hands into it just for the pleasure of it. With such a splendid coat, this fox must have been doing well, getting his share of mice, rats, rabbits, opossums, armadillos, insects, squirrels, birds and roadkill. I'll bet I've been hearing this fox an hour or two before dawn on recent mornings. I'm awakened by a sound not quite a bark or a yelp, but rather like the voice of a hoarse teenage boy calling "airrr, airrr, airrr, airrr... " Is this my fox calling for a mate, or expressing his pleasure at having found one? I've seen both Red and Gray Foxes around here. Red Foxes generally prefer sparsely settled, rolling farm areas with wooded tracts, marshes and streams, while Gray Foxes prefer more rugged landscapes, especially those with brushy areas and swamps. Grays are usually more aggressive than Reds, so where their ranges overlap the Grays typically dominant. Studies show that on the average a fox travels about five miles in search of food on a winter night. I've known for a long time that female foxes are called vixens, but only this week did I read that male foxes can be called "dog foxes." The Pennsylvania Game Commission has a fox page at http://sites.state.pa.us/PA_Exec/PGC/w_notes/foxes.htm ***** LOWER JAW BONE OF A CHIPMUNK The identification was made possible by a 40-page, plastic-comb-bound pamphlet entitled "A Key-Guide to Mammal Skulls and Lower Jaws." You can review this publication and others along the same line by clicking their titles on my mammal-books page at www.backyardnature.net/amazon/mammal--.htm. Fortunately the pamphlet is illustrated, because to identify the jawbones I needed to check the features of such bone parts as the ramus, coronoid process, condyle and angle, and I'd never heard of those things. It turns out that a chipmunk's "tip of coronoid process lies about 4-5 mm in front of angle," and that the "lower edge of ramus, just in front of angle, curves or turns inward." I scanned the jawbone and you can confirm these details yourself by viewing the labeled image at the bottom of my mammal page, at www.backyardnature.net/mammals.htm ***** SPRING PEEPERS PEEPING ***** THE GREAT BACKYARD BIRD COUNT, 2004 At the above address special links help identify certain birds, particularly various woodpeckers, chickadees, sparrows and "red finches." Other links provide identification help for absolute beginners. Don't forget my own "How to Watch Birds" at www.backyardnature.net/birds.htm Last year some 50,000 checklists were sent in from all across North America, accounting for more than four million birds among 512 species. One benefit of the study was to highlight a drastic decline of crows in Illinois and Ohio, where West Nile Disease has a strong presence. You can read more results from last year's count at www.birdsource.org/gbbc/letterfromdirectors.html Teachers in Mississippi should note that as part of the event the Audubon Society and others have put together a "Great Backyard Bird Count - Mississippi Classroom Activity Kit." Materials in the kit are meant to help K-12 teachers introduce students of all ages to wildlife in their backyards. To obtain a copy of the kit, contact Audubon Mississippi's Central State Office in Vicksburg at 601-661-6189, or Dr. Mark W. LaSalle at Mississippi State University Coastal Research & Extension Center in Biloxi at 228-388-4710. ***** VELVET MITES Velvet mites, with their eight legs, are not insects, but rather more closely related to spiders and ticks. They are very closely related to chiggers, or redbugs. The adults of chiggers and velvet mites are about the same size, and neither adult chiggers nor adult velvet mites bother humans, since they are predators on insects and inset eggs. Among the chiggers, it's only the microscopic larvae that bite us, making us itch. The very tiny larvae of velvet mites are parasites on insects. If you look at a velvet mite with a 10X handlens, getting a good side view well lit from behind, you can barely see that below the mite's ticklike head some very slender, sharp fangs arise. They are carried pointed backwards and held almost horizontally. Velvet mites don't necessarily live easy existences simply rambling about looking for insect eggs. The adults cannibalize each other and are occasionally parasitized by larvae of other velvet mites. One species, the Red Velvet Mite, has long been used for the treatment of male infertility in traditional Eastern medicine. In the West, "chemical prospectors" grind them up, looking for interesting chemicals. ***** CURRENT WEATHER CONDITIONS IN NATCHEZ If occasionally you'd like to see what the current temperature, humidity and wind direction and velocity are at Natchez you might want to bookmark the above link. Keep in mind that during the coldest hours it may be 5-8° colder here 12 miles east of Natchez, and during the summer it may be several degrees warmer here than there. I'm amazed at these differences and guess that they are caused by the Mississippi River's moderating influences. ***** COLDFRAMES ARE BEAUTIFUL One reason coldframes are so appealing to me is that they are counterintuitive, yet they work. "Counterintuitive," in the sense that it just doesn't seem reasonable that any one object in the cold would accumulate heat any more than any other, such as a tree or a rock. Of course, intellectually we know that coldframes function because of the greenhouse effect. The hotter something is, the shorter the wavelength of the energy it radiates. Sunlight energy disposed in relatively short wavelengths penetrates the coldframe's plastic cover, then sunlight-warmed things inside the coldframe re-radiate heat energy, but now that energy is configured in longer wavelengths which, for their own reasons, can't pass through the plastic cover. So heat accumulates inside the structure. Coldframes don't have to be fancy. Once I simply dug up a spot of ground, sowed some lettuce, covered the spot with a dead Sweetgum sapling bearing plenty of leafless branches, covered the sapling with a clear plastic sheet, and finally sealed the sheet's edges by dumping dirt on them. That effort provided me with salads several weeks in advance of when it otherwise would have been possible. Something in my personality causes me to glow with satisfaction when I am in the presence of a worthy accomplishment brought about by thought and insight. A monkey can eat when hungry, sleep when tired, chortle when happy, and do what all the other monkeys around are doing. However, surviving and excelling because you've thought something out and carried it through, even though what you're doing seems counterintuitive, lies at the heart of what I think a human has that other animals don't. The University of Missouri provides a fine page called "Building and Using Hotbeds and Coldframes" at http://muextension.missouri.edu/explore/agguides/hort/g06965.htm |