Boy Scouts Handbook Part 27

Many a boy thinks that just because a bird is alive and moves it is a proper target for his air rifle or his sling shot. {93} Let us be thankful that there has now arisen a new cla.s.s of boys, the scouts, who, like the knights of old, are champions of the defenceless, even the birds. Scouts are the birds' police, and wo betide the lad who is caught with a nest and eggs, or the limp corpse of some feathered songster that he has slaughtered. Scouts know that there is no value in birds that are shot, except a few scientific specimens collected by trained museum experts. Scouts will not commend a farmer for shooting a hawk or an owl as a harmful bird, even though it were seen to capture a young chicken. They will post themselves on the subject and find that most hawks and owls feed chiefly on field mice and large insects injurious to the farmer's crops, and that thus, in spite of an occasional toll on the poultry, they are as a whole of tremendous value. The way the birds help mankind is little short of a marvel. A band of nuthatches worked all winter in a pear orchard near Rochester and rid the trees of a certain insect that had entirely destroyed the crop of the previous summer. A pair of rose-breasted grosbeaks were seen to feed their nest of youngsters four hundred and twenty-six times in a day, each time with a billful of potato-bugs or other insects. A professor in Washington counted two hundred and fifty tent caterpillars in the stomach of a dead yellow-billed cuckoo, and, what appeals to us even more, five hundred bloodthirsty mosquitoes inside of one night-hawk.

[Ill.u.s.tration: White-breasted nuthatch]

[Ill.u.s.tration: Bluebird at entrance of nesting-box]

It must not be forgotten that large city parks are among the best places for observing birds. As an example of what can be accomplished, even with limited opportunities, there was a boy who happened to know where some owls roosted. {94} Now all owls swallow their prey whole, and in digesting this food they disgorge the skulls, bones, fur, and feathers in the form of hard dry pellets. This boy used to go out on Sat.u.r.day or Sunday afternoon and bring home his pockets full of pellets, and then in the evening he would break them apart. In this way he learned exactly what the owls had been eating (without killing them) and he even discovered the skulls of certain field mice that naturalists had never known existed in that region. He let the owl be his collector.

Patrol Work

It is a good idea to keep at patrol headquarters a large sheet on the wall, where a list of the year's bird observations can be tabulated.

Each time a new bird is seen, its name is added, together with the initial of the observer, and after that its various occurrences are noted opposite its name. The keenest eyed scouts are those whose initials appear most frequently in the table. In addition, the tables will show the appearance and relative abundance of birds in a given locality. For patrols of young boys, a plan of tacking up a colored picture of each bird, as soon as it is thoroughly known, has been found very successful, and the result provides a way to decorate the headquarters.

Such pictures can be obtained very cheaply from the Perry Pictures Co., Boston, Ma.s.s., or the National a.s.sociation of Audubon Societies, 1974 Broadway, New York City.

MOLLUSCA--Sh.e.l.ls and Sh.e.l.lfish

_By Dr. William Healey Dall, of the United States Geological Survey_

[Ill.u.s.tration: Fig. 1; White lipped snail (Polygyra albolabris)]

Among the shy and retiring animals which inhabit our woods and waters, or the borders of the sea, without making themselves conspicuous to man except when he seeks the larger ones for food, are the mollusca, usually confounded with crabs and crayfish under the popular name of "sh.e.l.lfish," except the few which have no external sh.e.l.l, which are generally called slugs. Hardly any part of the world (except deserts) is without them, but, shy as they are, it takes pretty sharp eyes to find them. Some come out of their hiding places {95} only at night, and nearly all our American kinds live under cover of some sort.

The mollusks can be conveniently divided into three groups: those which inhabit fresh water, those which breathe air and live on dry land, and lastly those which are confined to the sea. The land sh.e.l.ls, or snails, have generally thin sh.e.l.ls of spiral form and live upon vegetable matter, many of them laying small eggs which look like minute pearls. Their hiding places are under leaves in shady or moist places, under the bark of dead trees or stumps, or under loose stone.

They creep slowly and are most active after rain. Some of our larger kinds are an inch or two in diameter, (see Fig. 1., the white-lipped) but from this size there are others diminishing in size to the smallest, which are hardly larger than the head of a pin, In collecting them the little ones may be allowed to dry up. The big ones must be killed in boiling water, when the animal can be pulled out with a hook made of a crooked pin, leaving the sh.e.l.l clean and perfect. The slugs are not attractive on account of the slime which they throw out and can only be kept in spirits. Some of the species found in California are as large as a small cigar, but those of the states east of the Rocky Mountains are smaller and have mostly been introduced from Europe, where they do a lot of mischief by eating such garden plants as lettuce.

Many of the fresh-water snails are abundant in brooks and ponds, and their relations, the fresh-water mussels, are often very numerous in shallow rivers. They have a sh.e.l.l frequently beautifully pearly, white or purple, and sometimes have the brown outer skin prettily streaked with bright green.

[Ill.u.s.tration: Fig. 2 Whelk (Buccinum umatum)]

[Ill.u.s.tration: Fig. 3 Pond snail (Lymnaea pal.u.s.tris)]

The princ.i.p.al fresh-water snails are the pond snail (_Lymnaea_; see Fig. 3); the _Physa_ (see Fig. 6), which is remarkable for having the coil turned to the left instead of the right; and the orb-snail, (_Planorbis_: see Fig. 4) which has its coil flat. All of {96} these lay minute eggs in a ma.s.s of transparent jelly, and are to be found on lily pads and other water plants, or crawling on the bottom, while the mussels bury themselves more or less in the mud or lie on the gravelly bottom of streams. There is also a very numerous tribe of small bivalve sh.e.l.ls, varying from half an inch to very minute in size, which are also mud lovers and are known as Sphaerium or Pisidium, having no "common" English names, since only those who hunt for them know of their existence.

On the seash.o.r.e everybody knows the mussel (Mytilus: see Fig. 5), the soft clam, the round clam, and the oyster, as these are sought for food; but there is a mult.i.tude of smaller bivalves which are not so well known. The sea-snails best known on the coast north of Chesapeake Bay are the whelk (Buccinum: see Fig. 2), the sand snail or Natica, which bores the round holes often found in clam sh.e.l.ls on the beach, in order to suck the juices of its neighbors, and the various kinds of periwinkles (rock snails or Littorina) found by the millions on the rocks between tides. These, as well as the limpets, small boat-shaped or slipper-shaped conical sh.e.l.ls found in similar places, are vegetable feeders. Altogether, there are several hundred kinds found on the seash.o.r.e and the water near the sh.o.r.e, and a collection of them will not only contain many curious, pretty, and interesting things, but will have the advantage of requiring no preservative to keep them in good condition after the animal has been taken out.

[Ill.u.s.tration: Fig. 4 Orb-Sh.e.l.l (Planorbis trivolvis)]

[Ill.u.s.tration: Fig. 5 Black Mussel (Mytilus)]

[Ill.u.s.tration: Fig. 6 Bubble snail (Physa heterostropha)]

The squids, cuttle-fishes, octopus, and their allies are also mollusks, but not so accessible to the ordinary collector, and can only be kept in spirits.

Books which may help the collector to identify the sh.e.l.ls he may find are:

For the land and fresh-water sh.e.l.ls: {97}

"Mollusks of the Chicago Area" and "The Lymnaeidae of North America."

By F. C. Baker. Published by the Chicago Academy of Sciences.

For the American Marine Sh.e.l.ls: Bulletin No. 37. Published by the United States National Museum, at Washington.

For sh.e.l.ls in general: "The Sh.e.l.l Book." Published by Doubleday, Page & Co., Garden City, N.Y.

On the Pacific Coast the "West Coast Sh.e.l.ls," by Prof. Josiah Keep of Mills College, will be found very useful.

REPTILES

_By Dr. Leonhard Stejneger, Curator National Museum_

By reptiles we understand properly a certain cla.s.s of vertebrate or backboned animals, which, on the whole, may be described as possessing scales or h.o.r.n.y shields since most of them may be distinguished by this outer covering, as the mammals by their hair and the birds by their feathers. Such animals as thousand-legs, scorpions, tarantulas, etc., though often erroneously referred to as reptiles, do not concern us in this connection. Among the living reptiles we distinguish four separate groups, the crocodiles, the turtles, the lizards, and the snakes.

The crocodiles resemble lizards in shape, but are very much larger and live only in the tropics and the adjacent regions of the temperate zone. To this order belongs our North American alligator, which inhabits the states bordering the Gulf of Mexico and the coast country along the Atlantic Ocean as far north as North Carolina. They are hunted for their skin, which furnishes an excellent leather for traveling bags, purses, etc., and because of the incessant pursuit are now becoming quite rare in many localities where formerly they were numerous. The American crocodile, very much like the one occurring in the river Nile, is also found at the extreme southern end of Florida.

The turtles are easily recognized by the bony covering which encases their body, and into which most species can withdraw their heads and legs for protection. This bony box is usually covered with h.o.r.n.y plates, but in a large group, the so-called soft-sh.e.l.l turtles, the outer covering is a soft skin, thus forming a {98} notable exception to the rule that reptiles are characterized by being covered with scales or plates. While most of the turtles live in fresh water or on land, a few species pa.s.s their lives in the open ocean, only coming ash.o.r.e during the breeding season to deposit their eggs. Some of these marine turtles grow to an enormous size, sometimes reaching a weight of over eight hundred pounds. One of them is much sought for on account of the delicacy of its flesh; another because of the thickness and beauty of its h.o.r.n.y plates which furnish the so-called tortoise-sh.e.l.l, an important article of commerce. Turtles appear to reach a very old age, specimens having been known to have lived several hundred years. The box tortoise of our woods, the musk turtles, the snapping turtles are familiar examples of this order, while the terrapin, which lives in brackish ponds and swamps along our sea-coasts, is famous as a table delicacy.

[Ill.u.s.tration: Harlequin snake]

The lizards are four-legged reptiles, usually of small size, living on the ground or in the trees, out very rarely voluntarily entering water. The so-called water lizards are not lizards at all, but belong to the salamanders and are distinguished by having a naked body not covered with scales. Most of the true lizards are of very graceful form, exceedingly quick at running; others display the most gorgeous coloration which, in many of them, such as the chameleons, changes according to the light, or the temperature, or the mood of the animal.

Not all of them have four legs, however, there being a strong tendency to develop legless species which then externally become so much like snakes that they are told apart with some difficulty. Thus our so-called gla.s.s-snake, common in the Southern states, is not a snake at all, but a lizard, as we may easily see by observing the ear openings on each side of the head, as no snake has ears. This beautiful animal is also known as the joint-snake, and both names have reference to the exceeding brittleness of its long tail, which often breaks in many pieces in the hands of the enemy trying to capture the lizard. That these pieces ever join and heal together is of course a silly fable. As a matter of fact, the body in a comparatively short time grows a new tail, which, however, is much shorter and stumpier than the old one. The new piece is often of a different color from the rest of the body and {99} greatly resembles a "horn," being conical and pointed, and has thus given rise to another equally silly fable, viz., that of the horn snake, or hoop snake, which is said to have a sting in its tail and to be deadly poisonous. The lizards are all perfectly harmless, except the sluggish Gila monster (p.r.o.nounced Heela, named from the Gila River in Arizona) which lives in the deserts of Arizona and Mexico, and whose bite may be fatal to man. The poison glands are situated at the point of the lower jaw, and the venom is taken up by the wound while the animal hangs on to its victim with the tenacity of a bulldog. All the other lizards are harmless in spite of the dreadful stories told about the deadly quality of some of the species in various parts of the country.

[Ill.u.s.tration: Rattlesnake palate]

The snakes form the last group of the reptiles. Universally legless, though some of the boas and pythons have distinct outer rudiments of hind limbs, they are not easily mistaken. And it is perhaps well so, for unless one is an expert at distinguishing between the poisonous and the harmless kind it is just as well to keep at a respectful distance from them. It is safest not to interfere with them, especially as those that are not poisonous are usually very useful in destroying rats and mice and other vermin, except perhaps those living in trees and feeding on eggs and young birds, which certainly do not deserve our protection. Of course the rattlesnake is not to be mistaken. The h.o.r.n.y appendix to its tail, with which it sounds the warning of its presence, is enough to distinguish it. It should here be explained that both lizards and snakes at various intervals shed the outer layer of their skin, the so-called epidermis. This transparent layer, after a certain length of time, loosens and is usually stripped off whole by the animal crawling out of it and turning it inside out, as a tight glove is turned. Now, at the end of a rattlesnake's tail there is a h.o.r.n.y cap which is {100} called the b.u.t.ton, and being narrowed at the base and more strongly built than the rest of the epidermis it is not shed with the rest of the skin, but remains attached.

Thus for each shedding a new joint or ring is added to the rattle. How often the shedding takes place depends on various circ.u.mstances and may occur an uncertain number of times each year. Such a rattle, loose-jointed as it is, is rather brittle and the tip of the sounding instrument is easily broken and lost. It will therefore be easily understood that the common notion that a rattlesnake's age can be told by the number of the rings in its rattle is absolutely erroneous.

Another equally common and equally erroneous notion relates to the tongue of the snake, which the ignorant often term its "sting" and which they believe to be the death-dealing instrument. Of course, the soft, forked tongue which constantly darts out and in of the snake's mouth is perfectly harmless. It serves rather as a "feeler" than as a taste organ. The wound is inflicted by a pair of large, curved, teeth or fangs, in the upper jaw. These fangs are hollow and connected by a duct with the gland on the side of the head, in which the poison is formed. Pressure on this gland at the time of the strike--for our poisonous snakes strike rather than bite--squirts the poison into the wound like a hypodermic syringe. The fangs when shed or damaged are replaced within a short time with new ones, so that a poisonous snake can only be made harmless for a short period by breaking them off.

Only in exceptional cases need snake bites prove fatal. It is estimated that in North America only about two persons in a hundred bitten are killed by the poison, though many more die from carelessness or bad treatment, the worst of which is the filling up with whiskey, which aids the poison rather than counteracts it. The essential things in case of snake bite are: (1) keeping one's wits; (2) tying a string, or the like, tightly around the wounded limb between the wound and the heart, and loosening it about once in fifteen minutes, so as to admit the poison slowly into the circulation; (3) making the wound bleed freely by enlarging it with a knife or otherwise; (4) if permanganate of potash be handy it should at once be applied to the {101} wound; (5) treat the wound as antiseptically as it is possible with the means at hand and hurry to a doctor.