"Yes, Rap, the inventions of man are very wonderful, but some of them have been sad things for Bird People, and this is another reason why we should protect them whenever we can. These journeys that the birds make when they leave their nesting haunts for the winter season, and return again in spring, are called _migrations_. The word 'migrate' means to move from one country to another with the intention of remaining there for some time. The birds who only make little trips about the country, never staying long in one place, we call visitors.

"Birds may be divided according to their journeys into three groups, which will help you to place them:

"1. Citizens.

"Those Bird People whose families stay in or near the same place the year round, roving about somewhat according to the food-supply and weather.

"2. Summer Citizens.

"The families that, though they are with us but six or eight months of the year, make their homes here, and pay their rent and taxes by working for the common good. As they are almost all insect-eaters, they are even more useful than the stay-at-home Citizens, who are chiefly seed-eaters or cannibals.

"3. Winter Visitors.

"The birds who come down from the North in severe weather, but do not stay in one place for any particular time, arriving one day and disappearing the next. They glean for their scanty board and return to the cold countries, of which they are Citizens, before nesting-time."

"Please tell me the names of some of the birds that live here all the time," said Nat. "Have I seen any yet?"

"I think the Bluebird, the Robin, and the Song Sparrow are Citizens,"

said Rap, "because last winter I used to see one of two almost every day, unless the snow and ice were very thick."

"Yes," said the Doctor, "the Bluebird is a Citizen in the Middle and Southern States, and the Robin also. But in the more northerly parts they are Summer Citizens, returning early and staying late. But the Song Sparrow is a Citizen almost everywhere, and is known about every bushy garden from the east coast to the west, and from the cotton plantation to the land of snow."

"Please tell me the names of some winter visitors," said Rap. "Isn't the Great White Owl one of these?"

"Yes, the Snowy Owl is one of them; so is the Snowflake, who comes to us on the wings of the storm; the tiny Winter Wren, the Great Northern Shrike, and many others, who arrive when snow-tide is upon us in the temperate part of the country, after our song birds have flown to the warmer south. You shall hear of all these, and learn where each one lives, in the bird stories I am going to write for you. But now let us go down by the river and see what some of these newly arrived birds are doing after their long journey.

"Hark! I hear the notes of a Thrasher in those bushes, and the Red-winged Blackbirds are calling all through the marsh meadow. When I was a boy the alder bushes were always full of nests."

"They have nests there now," said Rap eagerly; "a great many nests, and they are very pretty. Ah! There is the big brown bird that you call a Thrasher, with his striped breast and long tail that spreads like a fan.

I see him--he is building in that barberry bush!"

"Then the nest comes pretty soon after the up-journey," said Nat.

"Yes," answered the Doctor, as he watched the antics of the Thrasher; "right after the journey the mate, and next the nest. Do not forget the mate, Nat, for it is Mrs. Bird who usually makes the nest and _always_ lays the eggs, besides working in the guilds with her husband, whose greatest distinction is in being the family musician."

"When do the Summer Citizens begin to come back to their nesting places?" asked Nat. "And when do they go away again?"

"The great bird procession begins the first of March with Bluebirds, Robins, Redwings, and Meadowlarks, but it is the first of June before the latest comers, the little Marsh Wrens, are settled. Then in autumn, from September until the first snows of December fall, the procession flutters back south again, one by one or in great flocks, dropping away like falling leaves in the forest, and the birds that we see later are likely to be Citizens.

"The early Robin may have a second brood and the Hummingbird eggs in her nest, before the Marsh Wrens have even been seen.

"In the Southern States the birds arrive and build sooner than in the Northern. A cold spring may delay the on-coming migration, or a warm autumn r.e.t.a.r.d the return movement. But as you study birds you will soon see that each one has his own place in the procession, and usually keeps it. Year by year this vast procession goes on in the air, back and forth, night and day, like the ceaseless ebb and flow of the tides at sea. Bird-waves flow on forever, in their appointed times, and none of Nature's aspects are more regular or more unfailing. It almost seems, boys, as if birds made the seasons--as if winter in the Middle and Northern States might be called the 'songless season.'"

CHAPTER VII

THE BIRD'S NEST

"I wonder why some birds build their nests so very early, when it is cold, and there are no leaves on the trees, while others wait until it is almost summer," said Rap, as they walked down a narrow lane toward the river. There were bushes lining the path on each side, and from the singing you would think that every bush had a bird on each twig. In fact, there were so many birds in sight that Nat did not know which to ask about first, and so kept looking instead of talking.

"The birds who are Citizens are usually the first to build," answered the Doctor. "They merely roved about during the winter months, and had no long journey to make before they reached the home trees again, and then the hardy seed-eating birds can return from the South much earlier than their frailer kin."

"Last year," said Rap, "when the men were chopping trees in the great wood beyond the lake, the miller went up one day to hunt c.o.o.ns and took me with him. It was the beginning of March and terribly cold; there were long icicles hanging on the trees, and we were glad enough to go in by the fire in the lumbermen's camp. But what do you think?--if there wasn't an Owl's nest, up in a pine tree, with two eggs in it! It was in a very lonely place, and the miller said the Owl had borrowed an old Crow's nest and fixed it up a little."

"I should think the eggs would have frozen hard and been spoiled," said Nat.

"No, the old Owl sat on them ever so tight and would hardly budge to let the miller see them. We didn't stay long, for the Owl was a savage big thing, nearly two feet high, with yellow eyes and long feathers sticking up on its head like horns."

"A Great Horned Owl," said the Doctor. "I only wonder that it let the miller go near it at all; they are generally very wild and fierce."

"This one was sort of friends with the lumbermen," continued Rap, "for they used to hang lumps of raw meat on the bushes for it, and they said it kept the rats and mice away from the camp and was good company for them. It frightened me when I heard it first; it gave an awful scream, like a hurt person. After a while another one began to bark like a dog with a cold, just like this--'who-o-o-o--hoo--hoo--hoo.' And, Doctor, one of the lumbermen told me that with Owls and Hawks the female is mostly bigger than the male. Do you think that is so? Because with singing birds the male is the largest."

"Among cannibal birds the female is usually the largest," answered the Doctor, who was pleased to see that Rap so often had a "because" for his questions. "These birds do a great deal of fighting, both in catching their living prey and holding their own against enemies; and as the female stays most at home, being the chief protector of the nest, she needs more strength."

"Some singing birds are real plucky too," said Rap. "That same year I found a Robin's nest in April, when the water-pail by the well froze every night, and a Woodc.o.c.k's nest in the brushwood. It's hard to see a Woodc.o.c.k on the nest, they look so like dead leaves. It snowed a little that afternoon, and the poor bird's back was all white, but there she sat. It made me feel so sorry, and I was so afraid she might freeze, that I made a little roof over her of hemlock branches. And she liked that and didn't move at all; so then I wiped the snow off her back, and she seemed real comfortable. I used to go back every day after that to see her; we grew to be quite friends before the four eggs hatched, and I've seen them do queer little tricks; but I never told anybody where she lived, though, because lots of people don't seem to understand anything about birds but shooting or teasing them."

"Some day you shall tell us about what the Woodc.o.c.k did, my lad. You must tell us a great many stories, for you know what you have seen yourself. That is the best knowledge of all, and it will encourage Nat to hear you," and Dr. Hunter put his arm affectionately around the shoulders of each boy.

"Hush! Wait a moment and listen to that Thrasher," said the Doctor, stopping behind some thick bushes; "he is wooing his mate!"

"What is wooing?" whispered Nat.

"Asking her to marry him and come and build a cosy home in one of these nice bushes. Listen! See! There he is, up on the very top of that young birch, with his head thrown back, singing as if his throat would split."

As the children looked up they saw a fine bird with a curved beak, rusty-brown back, and light breast streaked with black, who was clinging to a slender spray, jerking his long tail while he sang.

"It seems as if I could almost hear the words he says," said Rap.

"Birds sing in many different tones," said the Doctor. "The Thrasher's song is like some one talking cheerfully; the Meadowlark's is flute-like; the Oriole's is more like clarion notes; the Bobolink bubbles over like a babbling brook; while the dear little brown striped Song Sparrow, who is with us in hedge and garden all the year, sings pleasant home-like ballads."

"There are some birds that Olive told me can't sing a bit," said Nat, "but only call and squeak. How do they ask their mates to marry them?"

"All birds have alarm cries, and a call-note that serves the same purpose as a song, although it may not seem at all musical to us. We are naturally more interested in that order of birds whose voices are the most perfectly developed. These not only sing when they are courting, but all the time their mates are sitting upon the eggs, and until the young are ready to fly."

"Why do birds always build nests in spring?" asked Nat.

"I think because there is more for them to feed the little ones with, than when it gets to be hot and dry," said Rap, "and it gives them time to grow big and strong before winter comes, when they must go away."

"Quite right, Rap, and it also gives the parents a chance to shed the old feathers that have been worn by rubbing on the nest, grow a new, thick, warm coat for winter, and rest themselves before they set out on their autumn journey. Do you remember what I told you that rainy day in my study about this moulting or changing of feathers?"

"Yes, I do," said Rap and Nat together. "Most birds have two coats a year, and the male's is the brighter," continued Nat eagerly, proud to show that he remembered. "The one that comes out in the spring is the gayest, so that his mate shall admire him and when this coat comes he sings his very best and--"

"Stop and take breath, my boy," laughed the Doctor; "there is plenty of time. Why do we think that the male has the gayest feathers--do you remember that also?"

"No, I've forgotten," said Nat.

"I remember," cried Rap; "it is to please the female and because she sits so much on the nest that if her feathers were as bright as the male's her enemies would see her quicker, and when the little birds hatch out they are mostly in plain colors too, like their mother."