Antarctic Penguins Part 7

When the chicks are small they are kept completely covered by the parent who sits on the nest. They grow, however, at an enormous rate, gobbling vast quant.i.ties of food as it is brought to them, their elastic bellies seeming to have no limit to their capacity (Fig. 59); indeed, when standing, they rest on a sort of tripod, formed by the protuberant belly in front and the two feet behind.

I weighed a chick at intervals for some time, and this was the astonis.h.i.+ng result:

Ounces

The egg 456 The chick when hatched 300 Five days old 1300 Six " 1575 Eight " 2475 Nine " 2850 Eleven " 3775 Twelve " 4250

To see an Adelie chick of a fortnight's growth trying to get itself covered by its mother is a most ludicrous sight. The most it can hope for is to get its head under cover, the rest of its body being exposed to the air; but the downy coat of the chick is close and warm, and suffices in all weathers to protect it from the cold. Fig. 60 ill.u.s.trates what I have said very well, whilst Fig. 61 shows a mother with a chick twelve days old.

Whilst the chicks are small the two parents manage to keep them fed without much difficulty;(6) but as one of them has always to remain at the nest to keep the chicks warm, guard them from skuas and hooligan c.o.c.ks, and prevent them from straying, only one is free to go for food.

Later on, however, two other factors introduce themselves. The first of these is that the chick's downy coats become thick enough to protect them from cold without the warmth of the parent; and the second that as the chicks grow they require an ever-increasing quant.i.ty of food, and at the age of about a fortnight this demand becomes too great for one bird to cope with. At this time it is still necessary to prevent the chicks from straying and to protect them from the skuas and "hooligans," and so to meet these two demands a most interesting social system is developed.

The individual care of the chicks by their parents is abandoned, and in place of this, colonies start to "pool" their offspring, which are herded together into clumps or "creches," each of which is guarded by a few old birds, the rest being free to go and forage.

(6) Fig. 62.

[Ill.u.s.tration: Fig. 60. A TASK BECOMING IMPOSSIBLE (Page 95)]

It is quite likely that if a chick which has escaped from its own creche joins another creche it will get fed there, as it seems hardly possible for the adults to recognize the individuals of so large a gathering and to detect a stranger should one turn up, but there is good reason to believe that the old birds work for their own creches only, and remain faithful to them for the rest of the season, because, as they make their way across the rookery, laden with the food they are bringing from the sea, it is sadly common to see them pursued by strayed and starving youngsters, plaintively piping their prayers for a meal; and these appeals are always made in vain, the old birds turning a deaf ear to the youngsters, who at last, weary and weak, give up the pursuit, and in the end fall a prey to the ever-watchful skuas. Further evidence is found in the fact that the chicks at the very back of the rookery and up at the top of the Cape are just as well nourished as those nearer the water, who are constantly pa.s.sed by a stream of food-laden parents.

Twice already I have mentioned that strayed chicks fall a prey to "hooligan" c.o.c.ks. These hang about the rookery often in little bands. At the beginning of the season there are very few of them, but later they increase greatly, do much damage, and cause a great deal of annoyance to the peaceful inhabitants. The few to be found at first probably are c.o.c.ks who have not succeeded in finding mates, and consequently are "at a loose end." Later on, as their numbers are so greatly increased, they must be widowers, whose mates have lost their lives in one way or another.

Many of the colonies, especially those nearer the water, are plagued by little knots of "hooligans," who hang about their outskirts, and should a chick go astray it stands a good chance of losing its life at their hands. The crimes which they commit are such as to find no place in this book, but it is interesting indeed to note that, when nature intends them to find employment, these birds, like men degenerate in idleness.

Some way back I made some allusion to the way in which many of the penguins were choosing sites up the precipitous sides of the Cape at the back of the rookery. Later I came to the conclusion that this was purely the result of their love of climbing. There was one colony at the very summit of the Cape,(7) whose inhabitants could only reach their nests by a long and trying climb to the top and then a walk of some hundred yards across a steep snow slope hanging over the very brink of a sheer drop of seven hundred feet on to the sea-ice.

(7) Fig. 70.

[Ill.u.s.tration: Fig. 61. ADeLIE WITH CHICK TWELVE DAYS OLD (Page 96)]

During the whole of the time when they were rearing their young, these mountaineers had to make several journeys during each twenty-four hours to carry their enormous bellyfuls of euphausia all the way from the sea to their young on the nests--a weary climb for their little legs and bulky bodies. The greater number who had undertaken this did so at a time when there were ample s.p.a.ces unoccupied in the most eligible parts of the rookery.

I have mentioned that large ma.s.ses of ice were stranded by the sea along the sh.o.r.es of the rookery. These fragments of bergs, some of them fifteen to twenty feet in height, formed a miniature mountain range along the sh.o.r.e. All day parties of penguins were to be seen a.s.siduously climbing the steep sides of this little range. Time after time, when half way up, they would descend to try another route, and often when with much pains one had scaled a slippery incline, he would come sliding to the bottom, only to pick himself up and have another try. (Fig. 63.)

Generally, this climbing was done by small parties who had clubbed together, as they generally do, from social inclination. It was not unusual for a little band of climbers to take as much as an hour or more over climbing to the summit. Arrived at the top they would spend a variable period there, sometimes descending at once, sometimes spending a considerable time there, gazing contentedly about them, or peering over the edge to chatter with other parties below.

Again, about half a mile from the beach, a large berg some one hundred feet in height was grounded in fairly deep water, accessible at first over the sea-ice, but later, when this had gone, surrounded by open water. Its sides were sheer except on one side, which sloped steeply from the water's edge to the top.

From the time when they first went to the sea to feed until the end of the season, there was a continual stream of penguins ascending and descending the berg. As I watched them through gla.s.ses I saw that they had worn deep paths in the snow from base to summit. They had absolutely nothing to gain by going to all this trouble but the pleasure they seemed to derive from the climb, and when at the top, merely had a good look round and came down again.

[Ill.u.s.tration: Fig. 62. A COUPLE WITH THEIR CHICKS (Page 96)]

When the birds were arriving at the rookery I watched for those who were to nest up the cliff, and several times saw birds on arriving at the rookery make for the heights without any hesitation, threading their way almost in a straight line through the nests to the screes at the bottom of the cliff, and up these to one or other of the paths leading up its side. Probably these had been hatched there, or had nested there before, and were making their way to their old haunts, but my notes on their nesting habits go to show that the c.o.c.ks, at any rate, cannot keep to the same spot during successive years. It is the hen who chooses the site, and stays on it, as I have shown, until a mate comes to her, and wins her, very often only after defeating many other compet.i.tors.

The waste of life in an Adelie rookery is very great, and is due to the following causes:

The eggs.

Skuas.

c.o.c.ks fighting among the nests.

Floods from thaw water.

Death of parents.

Snow-drifts.

Landslides.

The young chicks.

Skuas.

Landslides.

"Hooligan" c.o.c.ks.

Getting lost.

Death of parents.

Adults.

Sea-leopards.

Landslides.

Snow-drifts.

In the above lists I have made no mention of the wanton depredations committed--owing to the licence given to ignorant seamen--by expeditions which visit the Antarctic from time to time, but as these visits are made at rare intervals, they cannot greatly affect the population.

[Ill.u.s.tration: Fig. 63. ADeLIE PENGUINS HAVE A STRONG LOVE OF CLIMBING FOR ITS OWN SAKE (Page 99)]

Some of the items in my list require explanation. The screes at the foot of the cliff at Cape Adare are perhaps the most thickly populated part of the rookery. As the thaw proceeds, boulders of different sizes are continually falling down the cliff, some of them for many hundreds of feet before they finally plunge in among the nests on the screes, doing terrible damage, and often rolling some distance out into the rookery.

At other times, owing to the bursting out of thaw water which has been dammed up at the top of the cliff, large landslides are caused which bury many hundreds of nests beneath them. In fact, these screes on which the nests are built have been formed by these landslides taking place from year to year, and no doubt form the graves of thousands upon thousands of former generations. One of these slides took place whilst we were at the rookery, doing terrible damage. A crowded colony of Adelies were nesting just below, and the avalanche pa.s.sed right through and over them, causing the most sad havoc. We found hundreds of injured and dying, some of them in a pitiable condition. Several were completely disembowelled, others had the whole skin of their backs torn down and hanging behind them in a flap, exposing the bare flesh. Dozens had broken or dislocated legs and flippers.

The worst feature was that many were buried alive beneath the snow, or pinned down to the ground by ma.s.ses of basalt. Twice I saw one flipper sticking out of the snow, moving dismally, and dug out in each case a badly injured bird which would have lingered perhaps for days, because loose snow does not always suffocate, owing to the amount of air contained in its interstices, and to the fact that diffusion takes place through it very readily. Several of us spent a long time in killing with ice-axes those that seemed too badly injured to recover.

It was remarkable to see the way in which all the nests which had escaped the avalanche, however narrowly, were still sat upon by their occupants, as if nothing had happened. Also I saw several badly injured birds sitting on their eggs, some of them soaked in blood, so that they looked like crimson parrots. The amount of bloodshed must have been great, as the snow was dyed with blood in all directions. As a cascade of water followed the avalanche, and continued for some hours, spreading out into little rivers among the nests, many were being deluged, and some of the penguins actually were sitting in the running water, in a vain attempt to keep warm their drowned chicks and spoiled eggs.

Sometimes, digging at hazard in the drifted snow, I came on birds that had been deeply buried, and though they were held down and kept motionless by the weight of the snow covering them, most of them were alive, and I have no doubt many dozens died a lingering death in this way. Such as had merely suffered broken flippers or legs, I spared, and the next day nearly all of these seemed to be doing well. One bird I found sitting on two eggs which were in the middle of a rivulet of water, so I lifted them out and put them on dry ground close by, but the parent would have nothing to do with them after this.

[Ill.u.s.tration: Fig. 64. ADeLIES ON THE ICE-FOOT]

A feature of the above scene, which one could not help noticing, was that however badly a penguin was injured it was never molested by the others, as is almost invariably the rule among other birds, including their near neighbours the skuas. I have seen a sick skua hunted continuously for over an hour by a mob of its own kind who would not allow it to settle on the ice for a moment's rest.

Another item of my list requiring explanation is "snow-drifts."

During both spring and summer there are occasional snowstorms, and during these the birds sit tight on their nests, sometimes being covered up by drift. As a rule the bird on the nest keeps a s.p.a.ce open by poking its head upwards through the snow, but sometimes it becomes completely buried. Air diffuses so rapidly through snow that death does not take place by suffocation, and the bird can live for weeks beneath a drift, sitting on its nest in the little chamber which it has thawed out by its own warmth. Generally after a few hours the snow abates and settles down sufficiently to expose the nest once more, but sometimes a breeze springs up which is not strong enough to blow the snow away, but simply hardens the surface of the drift into a crust which lasts for several weeks, and the birds are imprisoned in consequence. Then little black dots are seen about the surface of the drift, which are the heads of penguins thrust through their breathing holes.

On one such occasion I witnessed an interesting little incident. An imprisoned hen was poking her neck up through her breathing hole when her mate spied her and came up. He appeared to be very angry with her for remaining so long on the nest, being unable to grasp the reason, and after swearing at her for some time he started to peck at her head, she retaliating as far as her cramped position would allow. When she withdrew her head, he thrust his down the hole till she drove it out again, and as this state of things seemed to be going on indefinitely, I came up and loosened the crust of snow which imprisoned her, on which she burst out, and seemed glad to do so. She was covered with mire, having for many days been sitting in a pool of thaw water which had swamped her nest and evidently spoilt the eggs. When I put her back on the nest, she sat there for some time, but eventually they both deserted. I should say that some hundreds of nests were spoilt in this way.

[Ill.u.s.tration: Fig. 65. ADeLIES ON THE ICE-FOOT]

As I photographed the above incident at intervals, different stages are seen on Figs. 67 to 69.

I have mentioned that eggs got lost owing to c.o.c.ks fighting among the nests. When hens are incubating the eggs they never leave the nest under any circ.u.mstances until relieved by their mates, being most reliable and faithful to their charge. They squabble continually with their nearest neighbours, whom they seem to hate, but only retaliate on those within reach, using their bills only to peck at each other's heads without s.h.i.+fting their position.

The c.o.c.ks, however, are less dependable. Starting a quarrel in the same way as the hens do, their militant instincts soon became aroused, on which they are apt to jump up and start a furious fight with flippers, staggering to and fro over their nests, and very often spilling the eggs, which are lost in consequence. On certain occasions I was able to interfere between the combatants, and replace the eggs, on which they would return to their domestic duties and seem to forget the incident. A good many eggs must have been lost in this way during the season.

Late in the season an occurrence took place for which I have never been able to find any explanation. Occasionally I had noticed that the penguins had crowded together more than usual on the ice-foot, mult.i.tudes of them standing for hours without any apparent purpose. A good idea of this scene may be got from the frontispiece.

One morning Mr. Priestley came into the hut and told me that "the penguins were drilling on the sea-ice," and that I had better come and look at them. I went with him to the ice-foot, and this is what we saw.