SPARROWS IN THE NURSERY

The sparrow, as every Anglo-Indian knows, is a bird that goes about

dumping down nests in _sahibs’_ bungalows. It is greatly assisted in this

noble work by the native of India, who has brought to the acme of

perfection the art of jerry-building. In the ramshackle, half-finished

modern bungalow the rafters that support the ceiling never, by any

chance, fit properly into the walls. There are thus in every room a

number of cracks, holes, and crevices in which the sparrows love to nest.

As a matter of fact, these are not at all safe nesting places. Apart from

the fact that the nest is liable to be pulled down at any moment by an

angry human being, the situation is dangerous, because there is nothing

to prevent a restless young bird from falling out of the nest and thus

terminating a promising career. A few days ago a servant brought me a

baby sparrow that had fallen out of a nest in the pantry. I always feel

inclined to wring the neck of any sparrow that fate has put within my

grasp, for I have many a score to pay off against the species. Upon this

occasion, however, I felt mercifully inclined, so took the young bird,

which was nearly covered with feathers, and offered it bread soaked in

milk. This it swallowed greedily. When the youngster was as full up

inside as the Hammersmith ’bus on a wet day, I told the bearer to put it

in the cage in which my amadavats dwell. When I left for office I

directed the man to feed the new arrival. On my return in the evening the

bearer informed me that the young hopeful had declined its food. Now, a

young sparrow refuses to eat only when it is stuffed to the brim. It was

thus evident that its parents had found it out and were feeding it, in

spite of the fact that the nest from which it came was in the pantry on

the east side of the house, while its new quarters were in the west

verandah.

The next day a second sparrow fell out of the nest in the pantry and was

also consigned to the amadavats’ cage. At bed-time that night I took a

look at the birds, and found that the two young sparrows had tucked

themselves snugly in the seed tin! The next morning a third sparrow from

the same nest was brought to me; it was put in the cage along with its

brethren. As my office was closed on the day in question, I had the cage

placed in front of my study window. I could thus watch the doings of the

latest additions to my aviary. The hen sparrow does the lion’s share of

the feeding; she works like a slave from morning to night. At intervals,

varying from one to ten minutes, throughout the day she appears with a

beakful of food, which consists chiefly of green caterpillars.

It is the custom to speak of the sparrow as a curse to the husbandman.

The bird is popularly supposed to live on grain, fruit, seedlings, and

buds—those of valuable plants by preference. There is no denying the fact

that the sparrow does devour a certain amount of fruit and grain, but, so

far from being a pest, I believe that the good it does by destroying

noxious insects far outweighs the harm. Adult sparrows frequently feed on

insects. I have watched them hawking flies in company with the swifts,

and the skill displayed by the “spadger” showed that his was no ’prentice

hand at the game.

Sparrow nestlings in the early stages are fed almost exclusively on

caterpillars, grubs, and insects. As there are usually five or six baby

sparrows in a brood, and as these have appalling appetites, they must

consume an enormous number of insects. Let us work out a little sum. We

may assume that the sparrow brings at least three caterpillars in each

beakful of food she carries to her brood. She feeds them at least fifteen

times in the hour, and works for not less than twelve hours in the day. I

timed the sparrows in question to commence feeding operations at 5.30

a.m., and when I left the bungalow at 6 p.m. the birds were still at it.

Thus the hen sparrow brings in something like 540 insects _per diem_ to

her brood. She feeds them on this diet for at least twenty days, so that

the brood is responsible for no less than 10,000 insects, mostly

caterpillars, before its units are ready to fend for themselves.

According to Hume, the sparrow in India brings up two broods in the year.

I should have doubled this figure, since the species appears to be always

breeding. But it is better to understate than exaggerate. We thus arrive

at the conclusion that the hen sparrow destroys each year over 20,000

insects, mostly injurious, in the feeding of her young. Add to this

number those she herself consumes, those the cock eats, and those he

brings to the nest, and you have a fine insect mortality bill.

The movements of the mother bird when feeding her young are so rapid that

it is not easy to determine what it is she brings to the nest, even

though the objects hang down from her beak; the same applies to the cock.

In order to make quite certain of the nature of the food she was

bringing, I sought, by frightening her, to make her drop a beakful;

accordingly, at one of her visits I tapped the window-pane smartly just

as she was about to ram the food down the gaping mouth of a young bird.

She flew off chirruping with anger and alarm, but kept her bill tightly

closed on the food she was carrying. As the parents had to feed the young

ones through the bars of a cage the process required some manipulation,

and, in spite of its care, the bird sometimes dropped part of its burden;

but, almost before I had time to move, it had dashed down to the ground

and retrieved it. However, by dint of careful watching I managed to bang

the window immediately after the hen had dropped something of a dark

colour. Having frightened her away I rushed outside and found that the

object in question was part of a sausage-shaped sac containing a number

of tiny green grubs. After a few minutes the hen returned with her beak

full. Her fright had made her suspicious, so she perched on the verandah

trellis-work and looked around for a little. Nine times she flew towards

the cage, but on each occasion her courage failed her, to the intense

disgust of her clamouring brood. At the tenth attempt she plucked up

sufficient courage to feed the young birds.

At a subsequent visit she dropped a caterpillar, and I frightened her

away before she could retrieve it. I found it to be alive and about an

inch in length.

On another occasion I saw her ramming something black down the throat of

a young hopeful. Frightening her away, I went outside and found the

youthful bird making valiant attempts to swallow a whole mulberry. But it

was not often that she gave them fruit; green caterpillars formed quite

nine-tenths of what she brought in; the remainder was composed chiefly of

grubs, with an occasional grasshopper or moth. As the young grew older

the proportion of insect food given to them diminished until, when they

were about twenty-two days old, their diet was made up principally of

grain.

The day on which the third young sparrow was put into the cage was a warm

one, so at 2 p.m., when the shade temperature was about 115°, I brought

the cage into the comparatively cool bungalow, for the sake of the

amadavats. The cock sparrow witnessed the removal of the cage and did not

hesitate to give me a bit of his mind. In a minute or so the hen returned

with her beak full of green caterpillars. When she found the cage gone,

she, too, expressed her opinion of me and of mankind in general in no

uncertain terms. It was the last straw. Earlier in the day I had removed

one of the baby sparrows from the cage and placed it in a cigar-ash tray

outside the cage. The hen had affected not to notice that anything had

happened, and fed it in the ash-tray as though she were unconscious of

the removal. When, however, the whole cage and its contents disappeared

it was quite useless for her to pretend that nothing was wrong, so she

treated me to her best “Billingsgate.”

After the cage had been inside for about three-quarters of an hour the

young “spadgers” began to feel the pangs of hunger, and made this known

by giving vent to a torrent of chirrups which differed in no way from

those that make the adult so offensive. All that the poor mother could do

was to answer from the outside. I felt, that afternoon, that I was paying

off with interest some of my score against the sparrow.

The next day I did not take the cage into the bungalow, because I wanted

to ascertain whether sparrows feed their young throughout the day, or

whether they indulge in a noonday siesta. They kept it up, at their

respective rates, throughout the day, although the thermometer in the

shade must have risen to 115°. After the hen had disburdened herself of

the food she brought, she would perch for a moment on the trellis, and

pant with open beak as though she were thoroughly exhausted.

I have long been trying to ascertain how birds in the nest obtain the

liquid they require. Do the succulent caterpillars, on which young

sparrows are fed, provide them with sufficient moisture, or do the

parents water them? Although I spent several hours in watching those

sparrows, I am not able to answer the question satisfactorily. I placed a

bowl of water on the ground near the cage, hoping that this would tempt

the hen bird to drink, and that I should see her carry some of the liquid

to her offspring. But she took no notice of the water. She certainly used

to come to the cage sometimes with her beak apparently empty, and yet

insert it into the open mouth of a young one. Was she then watering the

nestling, or did her beak hold some small seeds that did not protrude? It

seems incredible that unfledged birds exposed to the temperature of an

Indian summer require no water; nevertheless, I never actually saw any

pass from the crop of the parents to those of the youngsters.

THE CARE OF YOUNG BIRDS

AFTER THEY LEAVE THE NEST

It has been urged as an objection to the Darwinian theory that Natural

Selection, if that force exists, must tend to destroy species rather than

cause new ones to come into being. Nearly all birds leave the nest before

they are fully developed. When they first come out of the nursery they

have attained neither their full powers of flight nor complete skill in

obtaining food. Every young bird, no matter how fine a specimen it be,

leaves the nest an inexperienced weakling, and can therefore stand no

chance in competition with the fully grown and experienced members of the

species. Natural Selection takes an individual as it finds it and pays no

attention to potentialities.

That such an objection should have been urged against the theory of

Natural Selection is proof of the fact that naturalists are inclined to

forget that, with many, if not all, species of birds, the duties of the

parents towards their offspring by no means cease when the young birds

leave the nest.

The parent birds, in many cases, continue to feed their young long after

these are apparently well able to fend for themselves. This fact is not

sufficiently emphasised in books on natural history. On the other hand,

such works lay stress upon the fact that in many species of birds the

parents drive their offspring away from the place of their birth in order

that the numbers of the species in the locality shall not outgrow the

food supply. How far this is a general characteristic of birds I do not

know. What I desire to emphasise is that the driving-away process, when

it occurs, does not take place until some time after the young have left

the nest. The fact that the parent birds tend the young long after they

have left the nest, and even after they are fully capable of holding

their own in the struggle for existence, disposes of the above-cited

objection to the theory of Natural Selection. Nature is so careful of the

young warriors that she prolongs the instinct of parental affection

longer than is absolutely necessary. So important is it that the young

should have a fair start in life that she errs on the safe side.

It is common knowledge that foster-parents feed cuckoos when these have

grown so large that, in order to reach the mouth of their spurious babes,

the little foster-mothers have to perch on their shoulders.

The sight of a tiny bird feeding the great parasite is laughable, but it

is also most instructive. It demonstrates how thoroughly bird mothers

perform their duties.

Crows tend their young ones for weeks after they have left the nest. I

have had ample opportunity of satisfying myself as to this.

It was my custom in Madras to breakfast on the verandah. A number of

crows used to assemble daily to watch operations and to pick up the

pieces of food thrown to them. They would go farther when the opportunity

occurred, and commit petty larceny.

The crows were all grey-necked ones, with the exception of two belonging

to the larger black species. But these latter are comparatively shy

birds, and consequently used to hang about on the outskirts of the crowd.

Among the grey-necked crows was a family of four—the parents and two

young birds. Every day, without fail, they used to visit the verandah;

the two young birds made more noise than all the rest of the crows put

together. They were easily recognisable, firstly, by their more raucous

voices, and, secondly, by the pink inside of the mouth. When I first

noticed them they were so old that, in size, they were very nearly equal

to the mother. Further, the grey of the neck was sharply differentiated

from the black portions of the plumage, showing that they had left the

nest some time ago.

Unfortunately I did not make a note of the day on which they first put in

an appearance. I can, however, safely say that they visited my verandah

regularly for some weeks, during the whole of which time the mother bird

fed them most assiduously. It was ludicrous to see the great creatures

sidle up to mamma when she had seized a piece of toast, and open their

red mouths, often pecking at one another out of jealousy.

They were obviously well able to look after themselves; their flight was

as powerful as that of the mother bird, yet she treated them as though

they were infants, incapable of doing anything for themselves.

At the beginning of the cold weather I changed my quarters, so was not

able to witness the break-up of the crow family. Probably this did not

occur until the following spring, when nesting operations commenced.

The feeding of the young after they have left the nest and are full-grown

is not confined to crows.

I was walking one morning along a shady lane when I noticed on the grass

by the roadside a bird which I did not recognise. It was a small

creature, clothed in black and white, which tripped along like a wagtail.

It had no tail, but it wagged the hind end of its body just as a

sandpiper does. While I was trying to identify this strange creature, a

young pied wagtail came running up to it with open mouth, into which the

first bird popped something. I then saw that the unknown bird was simply

a pied wagtail (_Motacilla maderaspatensis_) which had lost her tail! The

young bird was fully as large as the mother, and having a respectable

tail, which it wagged in a very sedate manner, looked far more imposing.

The parts of the plumage which were black in the mother were brownish

grey in the young bird. The white eyebrow was not so well defined in the

youngster as in the adult, while the former had rather more white in the

wing, but as regards size there was nothing to choose between the two.

The young bird remained in close attendance on the mother. It was able to

keep pace with her as she dashed after a flying insect. It ran after her

begging continually for food. The mother swallowed most of the flies she

caught, but now and again put one into the mouth of the young bird, but

she did so very severely, as if she were saying, “You are far too old to

be fed; it is no use to pretend you cannot catch insects, you are a

naughty, lazy, little bird!” But the lackadaisical air of the young one

expressed more plainly than words: “Oh, mother, it tires me to chase

insects. They move so fast. I have tried, but have caught so few, and am

very hungry.”

For several minutes the young wagtail followed the mother; then something

arrested its attention, so that it tarried behind its parent. The mother

moved away, apparently glad to be rid of the troublesome child for a

little. Then she suddenly flew off. Presently the young wagtail looked

round for its mother, and I was interested to see what would happen when

it noticed that she had flown away. My curiosity was soon satisfied.

Directly the young bird perceived that the mother had gone, it set itself

most philosophically to catch insects, which it did with all the skill of

an old bird, turning, twisting, doubling, with the elegance of an

experienced wagtail.

I describe these two little incidents, not as anything wonderful, but as

examples of what is continually going on in the world around us.

The parental instinct is probably developed in some birds more than in

others, but I believe that in all cases the affection of a bird mother

for her young persists long after they have left the nest, and for some

time after they are fully capable of looking after themselves.

Birds are born with many instincts, but they have much to learn both

before and after they leave the nest. It is not until their education is

complete, until the mother bird has taught them all she herself knows,

until they are as strong or stronger than she, that the young birds are

driven away and made to look after themselves.

[Illustration: THE INDIAN ADJUTANT. (LEPTOPTILUS DUBIUS)]

Birds of the Plains · 第 9 / 60 题