The Baltimore Oriole
ANGLING from the slender, drooping branches of the elm in winter, these pocket nests look like some strange persistent fruit; and, indeed, they are the fruit of much labor on the part of the oriole weavers, those skilled artisans of the bird world. Sometimes the oriole "For the summer voyage his hammock swings" in a sapling, placing it near the main stem and near the top, otherwise it is almost invariably hung at the end of branches and is rarely less than twenty feet from the ground. The nest is pocket-shaped, and usually about seven inches long, and four and a half inches wide at the largest part, which is the bottom. The top is attached to forked twigs at the Y so that the mouth or door will be kept open to allow the bird to pass in and out; when within, the weight of the bird causes the opening to contract somewhat and protects the inmate from prying eyes. Often the pocket hangs free so that the breezes may rock it, but in one case we found a nest with the bottom stayed to a twig by guy lines. The bottom is much more closely woven than the upper part for a very good reason, since the open meshes admit air to the sitting bird. The nest is lined with hair or other soft material, and although this is added last, the inside of the nest is woven first. The orioles like to build the framework of twine, and it is marvellous how they will loop this around a twig almost as evenly knotted as if crocheted; in and out of this net the mother bird with her long, sharp beak weaves bits of wood fibre, strong, fine grass and scraps of weeds. The favorite lining is horse hair, which simply cushions the bottom of the pocket. Dr. Detwiler had a pet oriole which built her nest of his hair which she pulled from his head; is it possible that orioles get their supply of horse hair in a similar way? If we put in convenient places, bright colored twine or narrow ribbons the orioles will weave them into the nest, but the strings should not be long, lest the birds become entangled. If the nest is strong the birds will use it a second year.
That Lord Baltimore found in new America a bird wearing his colors, must have cheered him greatly; and it is well for us that this brilliant bird brings to our minds kindly thoughts of that tolerant, high-minded English nobleman. The oriole's head, neck, throat and part of the back are black; the wings are black but the feathers are margined with white; the tail is black except that the ends of the outer feathers are yellow; all the rest of the bird is golden orange, a luminous color which makes him seem a splash of brilliant sunshine. The female, although marked much the same, has the back so dull and mottled that it looks olive-brown; the rump, breast, and under parts are yellow but by no means showy. The advantage of these quiet colors to the mother bird is obvious since it is she that makes the nest and sits in it without attracting attention to its location. In fact, when she is sitting, her brilliant mate places himself far enough away to distract the attention of meddlers, yet near enough for her to see the flash of his breast in the sunshine and to hear his rich and cheering song. He is a good spouse and brings her the materials for the nest which she weaves in, hanging head downward from a twig and using her long sharp beak for a shuttle. And his glorious song is for her alone; some hold that no two orioles have the same song; I know of two individuals at least whose songs were sung by no other birds; one gave a phrase from the Waldvogel's song in Sigfried; the other whistled over and over, "Sweet birdie, hello, hello." The orioles can chatter and scold as well as sing.
The oriole is a brave defender of his nest and a most devoted father, working hard to feed his ever hungry nestlings; we can hear these hollow mites peeping for more food, "Tee dee dee, Tee dee dee", shrill and constant, if we stop for a moment under the nest in June. The young birds dress in the safe colors of the mother, the males not donning their bright plumage until the second year. A brilliant colored fledgling would not live long in a world where sharp eyes are in constant quest for little birds to fill empty stomachs.
The food of the oriole places it among our most beneficial birds, since it is always ready to cope with the hairy caterpillars avoided by most birds; it has learned to abstract the caterpillar from his spines and is thus able to swallow him minus his "whiskers." The orioles are waging a great war against the terrible brown-tail and gipsy moths in New England; they also eat click beetles and many other noxious insects. Once when we were breeding big caterpillars in the Cornell insectary, an oriole came in through the open windows of the greenhouse, and, thinking he had found a bonanza, proceeded to work it, carrying off our precious crawlers before we discovered what he was at.
The orioles winter in Central America and give us scarcely four months of their company. They do not usually appear before May and leave in early September.
Leading thought—The oriole is the most skillful of all our bird architects. It is also one of our prized song birds and is very beneficial to the farmer and fruit grower because of the insect pests which it destroys.
Method—Begin during winter or early spring with a study of the nest, which may be obtained from the elms of the roadsides. During the first week in May, give the questions concerning the birds and their habits. Let the pupils keep the questions in their note-books and answer them when they have opportunity. The observations should be summed up once a week.
Observations by pupils—
1. Where did you find the nest? On what species of tree? Was it near the trunk of the tree or the tip of the branch?
2. What is the shape of the nest? How long is it? How wide? Is the opening as large as the bottom of the nest? How is it hung to the twigs so that the opening remains open and does not pull together with the weight of the bird at the bottom? Is the bottom of the nest stayed to a twig or does it hang loose?
3. With what material and how is the nest fastened to the branches? Of what material is the outside made? How is it woven together? Is it more loosely woven at the top than at the bottom? How many kinds of material can you find in the outside of the nest?
4. With what is the nest lined? How far up is it lined? With what tool was the nest woven? If you put out bright colored bits of ribbon and string do you think the orioles will use them? Why should you not put out long strings?
5. At what date did you first see the Baltimore oriole? Why is it called the Baltimore oriole? How many other names has it? Describe in the following way the colors of the male oriole: top of head, back, wings, tail, throat, breast, under parts. What are the colors of his mate? How would it endanger the nest and nestlings if the mother bird were as bright colored as the father bird?
6. Which weaves the nest, the father or the mother bird? Does the former assist in any way in nest building?
7. Where does the father bird stay and what does he do while the mother bird is sitting on the eggs?
8. What is the oriole's song? Has he more than one song? What other notes has he? After the young birds hatch does the father bird help take care of them?
9. By the middle of June the young birds are usually hatched and if you know where an oriole nest is hung, listen and describe the call of the nestlings for food.
10. Which parent do the young birds resemble in their colors? Why is this a benefit?
11. What is the oriole's food? How is the oriole of benefit to us in ways which other birds are not?
12. Do the orioles use the same nest two years in succession? How long does the oriole stay in the North? Where does it spend its winters?