Chapter IV: Part II: Domestic Life of the Adelie Penguin (1)
Laying and incubation of the eggs : The Adelies' habits in the water : Their games : Care of the young : The later development of their social system.
On November 3 several eggs were found, and on the 4th these were beginning to be plentiful in places, though many of the colonies had not yet started to lay.
Let me here call attention to the fact that up to now not a single bird out of all those thousands had left the rookery once it had entered it. Consequently not a single bird had taken food of any description during all the most strenuous part of the breeding season, and as they did not start to feed till November 8 thousands had to my knowledge fasted for no fewer than twenty-seven days. Now of all the days of the year these twenty-seven are certainly the most trying during the life of the Adelie.
With the exception, in some cases, of a few hours immediately after arrival (and I believe the later arrivals could not afford themselves even this short respite) constant vigilance had been maintained; battle after battle had been fought; some had been nearly killed in savage encounters, recovered, fought again and again with varying fortune. They had mated at last, built their nests, procreated their species, and, in short, met the severest trials that Nature can inflict upon mind and body, and at the end of it, though in many cases blood-stained and in all caked and bedraggled with mire, they were as active and as brave as ever.
When one egg had been laid the hen still sat on the nest. The egg had to be continually warmed, and as the temperature was well below freezing-point, exposure would mean the death of the embryo.
In order to determine the period between the laying of the two eggs, I numbered seven nests with wooden pegs, writing on the pegs the date on which each egg was laid. The result obtained is shown on page 53.
The average interval in the four cases where two eggs were laid being 3.5 days.
No. 7 nest was that of the hen which I mentioned as having waited for so long for a mate, and the lateness of the date on which the first egg appeared may have resulted in there being no other.
+------------+--------------+---------------+-------------+
| | Date of | Date of | |
| | appearance | appearance | Interval |
| | of first egg | of second egg | |
+------------+--------------+---------------+-------------+
| No. 1 nest | Nov. 14 | -- | Only 1 laid |
| | | | |
| No. 2 nest | Nov. 13 | Nov. 16 | 3 days |
| | | | |
| No. 3 nest | Nov. 14 | Nov. 17 | 3 days |
| | | | |
| No. 4 nest | | | |
| | | | |
| No. 5 nest | Nov. 12 | Nov. 16 | 4 days |
| | | | |
| No. 6 nest | Nov. 8 | Nov. 12 | 4 days |
| | | | |
| No. 7 nest | Nov. 24 | -- | Only 1 laid |
+------------+--------------+---------------+-------------+
The only notes I have on the incubation period are that the first chick appeared in No. 5 nest on December 19 (incubation period thirty-seven days) and in No. 7 nest on December 28 (incubation period thirty-four days).
The skuas had increased considerably in numbers by November 4, and frequently came to the scrap-heap outside our hut. Here were many frozen carcasses of penguins which we had thrown there after the breasts had been removed for food during the past winter. The skuas picked the bones quite clean of flesh, so that the skeletons lay white under the skins, and it was remarkable to what distances they sometimes carried the carcasses, which weighed considerably more than the skuas themselves. I found some of these bodies over five hundred yards away.
A perpetual feud was carried on between the penguins and the skuas. The latter birds come to the south in the summer, and make their nests close to, and in some cases actually among, those of the penguins, and during the breeding time live almost entirely on the eggs, and later, on the chicks. They never attack the adult penguins, who run at them and drive them away when they light within reach, but as the skuas can take to the wing and the penguins cannot, no pursuit is possible.
The skuas fly about over the rookery, keeping only a few yards from the ground, and should one of them see a nest vacated and the eggs exposed, if only for a few seconds, it swoops at this, and with scarcely a pause in its flight, picks up an egg in its beak and carries it to an open space on the ground, there to devour the contents. Here then was another need for constant vigilance, and so daring did the skuas become, that often when a penguin sat on a nest carelessly, so as to leave one of the eggs protruding from under it, a lightning dash from a skua would result in the egg being borne triumphantly away.
The bitterness of the penguins' hatred of the skuas was well shown in the neighbourhood of our scrap-heap. None of the food thrown out on to this heap was of the least use to the penguins, but we noticed after a time that almost always there were one or more penguins there, keeping guard against the skuas, and doing their utmost to prevent them from getting the food, and never allowing them to light on the heap for more than a few seconds at a time. In fact, a constant feature of this heap was the sentry penguin, darting hither and thither, aiming savage pecks at the skuas, which would then rise a yard or two into the air out of reach, the penguin squalling in its anger at being unable to follow its enemy. At this juncture the penguin would imitate the flying motion with its flappers, seeming instinctively to attempt to mount into the air, as its remote ancestors doubtlessly did, before their wings had adapted themselves solely to swimming.
Close to the scrap-heap there was a large knoll crowded with penguins' nests, and it was this knoll that provided the sentries. Very rarely did one of these leave the heap until another came to relieve it as long as there were skuas about, but when the skuas went the penguins left it too. When the skuas returned, however, and without the lapse of a few seconds, a penguin would be seen to detach itself from the knoll and run to guard the heap. That some primitive understanding on this matter existed among the penguins seems to me probable, because whilst there were generally one or two guarding the heap, there was never a crowd, the rest of the knoll seeming quite satisfied as long as one of their number remained on guard.
In describing the Cape Adare rookery I mentioned the fact that the pebbles entering into the formation of the beach are basaltic, and therefore of a dead black shade. The result of this is that as the sun's altitude increases, heat is absorbed readily by the black rock, through that clear atmosphere, and the snow upon it rapidly melts.
For a long time the penguins at their nests had satisfied their thirst by eating the snow near them, but as this disappeared, they suffered greatly, as was made evident by the way they lay with beaks open and tongues exposed between them. (Fig. 30.) As time went on the cocks started to make short journeys to the drifts which still remained in order to quench their thirst, but the hens stuck manfully, or rather "henfully" to their posts, though some of them seemed much distressed. Later, those cocks which had nested in the centre of the rookery had quite long journeys to make in order to find drifts, a very popular resort being that which had formed in the lee of our hut, and all day streams of them came here to gobble snow. Once a cock was seen to take a lump of snow in his beak and carry it to his mate on the nest, who ate it.
Mr. Priestley tells me that when he was at Cape Royds in 1908 he saw cocks taking snow to hens on their nests. This procedure would seem to be different to the parental instinct which governs the feeding of the young, and it seemed to show that the cock realized that the hen must be thirsty and in need of the snow, and kept this fact in mind when he was away from her. Another point to note is that the occurrence was a very rare and, in fact, exceptional one.
When conditions arose which were new to their experience the penguins seemed utterly unable to grasp them.
As an example of this, we had rigged a guide rope from our hut to the meteorological screen, about fifty yards away, to guide us during blizzards. This rope, which was supported by poles driven into the ground, sagged in one place till it nearly touched the ground. At frequent intervals, penguins on their way past the hut were brought to a standstill by running their breasts into this sagged rope, and each bird as it was caught invariably went through the same ridiculous procedure. First it would push hard against the rope, then finding this of no avail, back a few steps, walk up to it again and have another push, repeating the process several times. After this, instead of going a few feet further along where it could easily walk under the rope, in ninety per cent. of cases it would turn, and by a wide detour walk right round the hut the other way, evidently convinced that some unknown obstacle completely barred its passage on that side. This spectacle was a continual source of amusement to us as it went on all day and every day for some time.
As penguins' eggs are very good to eat and a great luxury, as well as being beneficial to men living under Antarctic conditions, we collected a large number, which we stowed away to freeze. To collect these eggs we used to set off, carrying a bucket, and walk through the knolls. As we picked our way, carefully placing our feet in the narrow spaces between the nests, we were savagely pecked about the legs, as in most positions at least, these birds could reach us without even leaving the nest, whilst very often the mates standing near them would sail in at us, raining in blows with their flippers with the rapidity of a maxim gun.
To search for eggs it was necessary to lift up the occupant of each nest and look beneath her. If she were tackled from front or flank this was a painful and difficult business, as she drove at the intruder's hands with powerful strokes of her sharp beak, but we found that the best way to set about the matter was to dangle a fur mit in front of her with one hand, and when she seized this quickly slip the other behind her, lifting her nether regions from the nest, and at the same time pushing her gently forward. Immediately she would drop the fur mit, and sticking her beak into the ground push herself backward with a determined effort to stay on the nest. So long as the pressure from behind was kept up she would keep her beak firmly fixed in the ground, and could be robbed at will.
The egg abstracted, she was then left in peace, on which she would rise to her feet, look under her for the egg and, finding that it was gone, ruffle her feathers, and, trembling with indignation, look round for the robber, seemingly quite unable to realize that we were the guilty ones. This is typical of the Adelie's attitude towards us. We are beyond their comprehension, and fear of us, anger at us, curiosity over us, although frequently shown, are displayed only for a fleeting moment. In a few minutes she might forget about the incident altogether and quietly resume her position on the empty nest, but very often she would violently attack any other bird who might happen to be standing near, and thus as we filled our buckets we left a line of altercation in our wake. This, however, was not long lived, and affairs soon settled down to their normal state, and I believe that in about one minute the affair was completely forgotten. The penguin, indeed, is in its nature the embodiment of all that man should be when he explores the Antarctic regions, ever acting on the principle that it is of no use to worry over spilt milk.
The comparative size of the penguin's egg is shown in some of my photographs. Ninety-six eggs averaged 4.56 ounces apiece. They vary in size from about 6.45 cm. to 7.2 cm. in length, and from 5.0 cm. to 5.5 cm. in breadth, on an average. Both ends are nearly equally rounded, and of a white chalky texture without, and green within. This green colour is plainly shown by transmitted light.
When the two have been laid the sitting bird places them one in front of the other. The rearmost egg is tucked up on the outspread feet, the foremost lies on the ground, and is covered by the belly of the bird as it lies forward upon it. (Fig. 31.) By many of the birds a strong inclination to burrow was displayed, and they seemed very fond of delving in the soft shingle ledges that were to be found on some parts of the beach. They did this ostensibly to get small stones for their nests, but certainly burrowed deeper than they need have done, and occasionally squatted for some time in little caves that they made in this way. I noticed the same thing in the drifts when they went to eat snow, and thought at times that they were going to make underground nests, but they never did so, though some of the little shingle caves would have made ideal nesting sites.
By November 7, though many nests were still without eggs, a large number now contained two, and their owners started, turn and turn about, to go to the open water leads about a third of a mile distant to feed, and as a result of this a change began gradually to come over the face of the rookery. Hitherto the whole ground in the neighbourhood of the nests had been stained a bright green. This was due to the fasting birds continually dropping their watery, bile-stained excreta upon it. (The gall of penguins is bright green.) These excreta practically contained no solid matter excepting epithelial cells and salts.
The nests themselves are never fouled, the excreta being squirted clear of them for a distance of a foot or more, so that each nest has the appearance of a flower with bright green petals radiating from its centre. Some of the photographs show this well, especially Fig. 30. Even when the chicks have come and are being sat upon by the parents, this still holds good, because they lie with their heads under the old bird's belly and their hindquarters just presenting themselves, so that they may add their little decorative offerings, petal by petal! Now that the birds were going to feed, the watery-green stains upon the ground gave place to the characteristic bright brick-red guano, resulting from their feeding on the shrimp-like euphausia in the sea; and the colour of the whole rookery was changed in a few days, though this was first noticeable, of course, in the region of those knolls which had been occupied first, and which were now settled down to the peaceable and regular family life which was to last until the chicks had grown.
As this family life became established, law and order reigned to some extent, and there was a distinct tendency to preserve it, noticeably on those knolls which had so settled down, and I think the following most surprising incident bears evidence of what I have said. I quote word for word from my notes on November 24, 1911:
"This afternoon I saw two cocks (probably) engaged in a very fierce fight, which lasted a good three minutes. They were fighting with flippers and bills, one of them being particularly clever with the latter, frequently seizing and holding his opponent just behind the right eye whilst he battered him with his flippers.
"After a couple of minutes, during which each had the other down on the ground several times, three or four other penguins ran up and apparently tried to stop the fight. This is the only construction I can put on their behaviour, as time after time they kept running in when the two combatants clinched, pushing their breasts in between them, but making no attempt to fight themselves, whilst their more collected appearance and smooth feathers were in marked contrast to the angry attitudes of the combatants.
"The fight, which had started on the outskirts of a knoll crowded with nests, soon edged away to the space outside, and it was here that I (and Campbell, who was with me) saw the other penguins try to stop it. The last minute was a very fierce and vindictive 'mill,' both fighting with all their might, and ended in one of them trying to toboggan away from his opponent; but he was too exhausted to get any pace on, so that just as he got into the crowd again he was caught, and both fought for a few seconds more, when the apparent victor suddenly stopped and ran away. The other picked himself up and made his way rapidly among the nests, evidently searching for one in particular.
"Following him, I saw him run up to a nest near the place where the fight had begun. There was a solitary penguin waiting by this nest, which was evidently new and not yet completed, and without eggs. The cock I had followed, ruffled and battered with battle, ran up to the waiting bird, and the usual side-to-side chatter in the ecstatic attitude began and continued for half a minute, after which each became calmer, and I left them apparently reconciled and arranging stones in the nest.
"This incident was after the usual nature of a dispute between two mates for a hen, but the pacific interference of the other birds was quite new to my experience. That it was pacific I am quite convinced, and Campbell agreed with me that there was no doubt of it. All the nests round about had eggs under incubation, and the pair in question must have been newcomers."
On returning home I was glad to find that Mr. Bernacchi, who landed at Cape Adare with the "Southern Cross" expedition, says in his account (p. 131) that he also saw penguins interfering and trying to stop others from fighting.
Owing to our having several snowfalls without wind, and to the action of the sun on the black rock, which I have mentioned already, the rookery became a mass of slush in many places, and in some of the lower-lying parts actually flooded. In some of these low-lying situations penguins had unwarily made their nests, and there was one particular little colony near our hut which was threatened with total extinction from the accumulation of thaw water. As this trickled down from the higher ground around them, the occupants of the flooded ground exerted all their energies to avert this calamity, and from each nest one of its tenants could be seen making journey after journey for pebbles, which it brought to the one sitting on the nest, who placed stone after stone in position, so that as the water rose the little castle grew higher and higher and kept the eggs dry. One nest in particular I noticed which was as yet a foot or so clear of the water and on dry ground; but whilst the hen sat on this, the cock was working most energetically in anticipation of what was going to happen, and for hours journeyed to and from the nest, each time wading across the little lake to the other side, where he was getting the stones.
This scene, which I photographed, is depicted on Fig. 33. In the right-hand corner of the picture the cock is seen in the act of delivering another stone to the hen who is waiting to receive it, whilst some of the nests are actually surrounded by water. Fig. 34 shows another nest, rising like a little island from a thaw pool, the eggs being only just above water.
Some time ago I mentioned that there were penguins of weak individuality who allowed others to rob them of their stones, and this was in some cases very noticeable on the flooded ground, and there were one or two nests here which had been almost entirely removed by thieving neighbours.
To quote again from my notes.
"November 10. This evening I saw a hen penguin trying to sit on a nest with two eggs. The nest had no stones, and was scooped deeply in the ground in a slush of melting snow, so that the eggs were nearly covered with water. The poor hen stood in the water and kept trying to squat down on the eggs, but each time she did so, sat in the water and had to get up again. She was shivering with cold and all bedraggled.
"I took the two eggs out of the nest, and Browning and I collected a heap of stones (partly from her richer neighbours!) and built the nest well up above the water. Then I replaced the eggs, and the hen at once gladly sat on them, put them in position, and was busily engaged in arranging the new stones round her when we left."
One day, when the season was well advanced, I saw a violent altercation taking place between two penguins, one of which was in possession of a nest in a somewhat isolated position. The other evidently was doing his utmost to capture the nest, as whenever he got the other off, he stood on it. There were scarcely any stones in the nest, which contained one egg. I think from the way they fought that both were cocks.
For two reasons I make special mention of the occurrence, first, because of all the fights I ever saw this was the longest and most relentless, and, secondly, because the nest being in such an isolated position it seemed curious that there could be any mistake about its ownership. Such, however, seemed to be the case, and hour after hour, during the whole day, they fought again and again.
After each bout of a few minutes both birds became so exhausted that they sank panting to the ground, evidently suffering from thirst and at the limit of their endurance. Sometimes one captured the nest, sometimes the other, but after several hours of this, one of them began to show signs of outlasting the other, and kept possession. For long after this, however, the other returned repeatedly to the attack.
I fetched my camera and photographed the birds as they fought (Fig. 36). As time went on, the weaker bird took longer and longer intervals to recover between his attacks, lying on his breast, with his head on the snow and eyes half closed, so that I thought he was going to die. Each time he got to his feet and staggered at his enemy, the latter rose from the nest and met him, only to drive him back again. When I saw them at about 10 P.M. (it was perpetual daylight now) both were lying down, the victor on the nest, the vanquished about five yards off. The next day one bird remained on the nest and the other had gone, and I do not know what happened to him.
In the course of a walk through the rookery considerable diversity in the choice of nesting sites was to be noticed. The general tendency is for the penguins to build their nests close together (within a foot or two of one another) on the tops of the rounded knolls, the lower levels being left untenanted.
The most thickly populated districts were to be found on the screes immediately below the cliffs. These screes having been formed in the first instance by the falling of fragments due to weathering of the cliff, their substance is still added to, little by little, as time goes on, and therefore many are killed annually by falling rocks, as is mentioned elsewhere, but weighing against this danger is the advantage the cliff offers as a shelter from the E.S.E. gales. The same applies to the nesting sites up the cliff, but I am convinced that only the love of climbing can account for the extraordinary positions chosen by some of the birds. Some of the nests are so difficult of access that their occupants, on their way to them, may be seen sliding backwards down the little glazed snow-slopes several times before they accomplish the ascent, whilst in other places they have to jump from one foothold to another along the almost perpendicular cliff.
Even up these heights a tendency to grouping is seen, though there are a fair number of individuals who, seeming to seek seclusion, make their nests at some distance from the others. I noticed this in some places along the shore, too, where solitary nests were to be seen on isolated patches of shingle.
When I visited Cape Royds in 1911 I found a couple nesting alone in a cove known as "Black Sand Beach," some half mile from the rookery there. Such isolation as this, however, is very unusual, and was quite a departure from the regular custom of the species.
In some places at Cape Adare, large rocks some two or three feet in height stood about the rookery. Whenever the summit of one of these was accessible, a pair built their nest upon it,(4) though how they managed to keep up there during the gales was a matter for wonder, but the proud possessors of the castle evidently had a delight in their lofty position. One nest had been made on an old packing-case left by the expedition which wintered there in 1894, and several nested among the weathering bones of the seals that had died on the beach.
(4) Fig. 37.
Although the greatest care had been taken by nearly all in the choice of sites that would be on dry ground when the thaw came later in the season, yet a few hens had gone to the other extreme, and with greatest stupidity chosen their site right down in the hollows where they were absolutely certain to be flooded later on. These stupid ones are thus prevented from rearing their young, and so selection keeps the wiser for future generations, and eliminates the less intelligent from the community, though perhaps some of these learn by experience, and next year use more discrimination in choosing their nesting place.
Some of the colonies--in fact, most of them--were orderly and well arranged, and later in the season distinctly peaceful. Others, however, presented a less respectable appearance. There was one in particular, close to our hut, which could only be described as a slum of the meanest description. All through the season there was more fighting in this colony than anywhere else, and so remarkable was this, that we christened the locality "Casey's Court" and the name stuck for the rest of the year.
The nests had fewer stones than elsewhere, and were more untidily made, and when the eggs came, owing to the constant fighting that went on, most of them got spilt from the nests or broken, and very few chicks were hatched in consequence, the mortality among them also being so great that of the whole colony of some hundred nests, I do not think more than forty or fifty chicks at most reached maturity. The explanation of this state of things lay, I believe, in the fact that our hut and its curtilage deflected the stream of penguins on their way past the spot from the water to the back of the rookery, so that a constant stream of them passed through "Casey's Court," upsetting the tempers of the inhabitants so that they became disorderly. In addition to this, there was a fairly big thaw pool and much miry ground near by, so that the inhabitants were generally covered with mud and very disreputable to look at.
During the fasting season, as none of the penguins had entered the water, they all became very dirty and disreputable in appearance, as well may be imagined considering the life they led, but now that they went regularly to swim, they immediately got back their sleek and spotless state.
From the ice-foot to the open water, the half mile or so of sea-ice presented a lively scene as the thousands of birds passed to and fro over it, outward bound parties of dirty birds from the rookery passing the spruce bathers, homeward bound after their banquet and frolic in the sea. So interesting and instructive was it to watch the bathing parties, that we spent whole days in this way.
As I have said before, the couples took turn and turn about on the nest, one remaining to guard and incubate while the other went off to the water.
On leaving their nests, the birds made their way down the ice-foot on to the sea-ice. Here they would generally wait about and join up with others until enough had gathered together to make up a decent little party, which would then set off gaily for the water. They were now in the greatest possible spirits, chattering loudly and frolicking with one another, and playfully chasing each other about, occasionally indulging in a little friendly sparring with their flippers.
Arrived at length at the water's edge, almost always the same procedure was gone through. The object of every bird in the party seemed to be to get one of the others to enter the water first. They would crowd up to the very edge of the ice, dodging about and trying to push one another in. Sometimes those behind nearly would succeed in pushing the front rank in, who then would just recover themselves in time, and rushing round to the rear, endeavour to turn the tables on the others. Occasionally one actually would get pushed in, only to turn quickly under water and bound out again on to the ice like a cork shot out of a bottle. Then for some time they would chase one another about, seemingly bent on having a good game, each bird intent on finding any excuse from being the first in. Sometimes this would last a few minutes, sometimes for the better part of an hour, until suddenly the whole band would change its tactics, and one of the number start to run at full tilt along the edge of the ice, the rest following closely on his heels, until at last he would take a clean header into the water. One after another the rest of the party followed him (Fig. 38), all taking off exactly from the spot where he had entered, and following one another so quickly as to have the appearance of a lot of shot poured out of a bottle into the water. The accompanying photograph presents this last scene.
A dead silence would ensue till a few seconds later, when they would all come to the surface some twenty or thirty yards out, and start rolling about and splashing in the water, cleaning themselves and making sounds exactly like a lot of boys calling out and chaffing one another.
So extraordinary was this whole scene, that on first witnessing it we were overcome with astonishment, and it seemed to us almost impossible that the little creatures, whose antics we were watching, were actually birds and not human beings. Seemingly reluctant as they had been to enter the water, when once there they evinced every sign of enjoyment, and would stay in for hours at a time.
As may be imagined, the penguins spent a great deal of time on their way to and from the water, especially during the earlier period before the sea-ice had broken away from the ice-foot, as they had so far to walk before arriving at the open leads.
As a band of spotless bathers returning to the rookery, their white breasts and black backs glistening with a fine metallic lustre in the sunlight, met a dirty and bedraggled party on its way out from the nesting ground, frequently both would stop, and the clean and dirty mingle together and chatter with one another for some minutes. If they were not speaking words in some language of their own, their whole appearance belied them, and as they stood, some in pairs, some in groups of three or more, chattering amicably together, it became evident that they were sociable animals, glad to meet one another, and, like many men, pleased with the excuse to forget for a while their duties at home, where their mates were waiting to be relieved for their own spell off the nests.
After a variable period of this intercourse, the two parties would separate and continue on their respective ways, a clean stream issuing from the crowd in the direction of the rookery, a dirty one heading off towards the open water, but here it was seen that a few who had bathed and fed, and were already perhaps half-way home, had been persuaded to turn and accompany the others, and so back they would go again over the way they had come, to spend a few more hours in skylarking and splashing about in the sea.
In speaking of these games of the penguins, I wish to lay emphasis on the fact that these hours of relaxation play a large part in their lives during the advanced part of the breeding period. They would spend hours in playing at a sort of "touch last" on the sea-ice near the water's edge. They never played on the ground of the rookery itself, but only on the sea-ice and the ice-foot and in the water, and I may here mention another favourite pastime of theirs. I have said that the tide flowed past the rookery at the rate of some five or six knots. Small ice-floes are continually drifting past in the water, and as one of these arrived at the top of the ice-foot, it would be boarded by a crowd of penguins, sometimes until it could hold no more. (Fig. 39.) This "excursion boat," as we used to call it, would float its many occupants down the whole length of the ice-foot, and if it passed close to the edge, those that rode on the floes would shout at the knots of penguins gathered along the ice-foot (Fig. 40) who would shout at them in reply, so that a gay bantering seemed to accompany their passage past the rookery.
Arrived at the farther end, some half a mile lower down, those on the "excursion boat" had perforce to leave it, all plunging into the tide and swimming against this until they came to the top again, then boarded a fresh floe for another ride down. All day these floes, often crowded to their utmost capacity, would float past the rookery. Often a knot of hesitating penguins on the ice-foot, on being hailed by a babel of voices from a floe, would suddenly make the plunge, and all swim off to join their friends for the rest of the journey, and I have seen a floe so crowded that as a fresh party boarded it on one side, many were pushed off the other side into the water by the crush.
Once, as we stood watching the penguins bathing, one of them popped out of the water on to the ice with a large pebble in its mouth, which it had evidently fetched from the bottom. This surprised me, as the depth of the sea here was some ten fathoms at least. The bird simply dropped the stone on the ice and then dived in again, so that evidently he had gone to all the trouble of diving for the stone simply for the pleasure of doing it. Mr. J. H. Gurney, in his book on the gannet, says they (gannets) are said to have got themselves entangled in fishing-nets at a depth of 180 ft. and that their descent to a depth of 90 ft. is quite authentic, so that perhaps the depth of this penguin's dive was not an unusual one.
The tide at the open water leads where they bathed ran a good six knots, but the Adelies swam quite easily against this without leaving the surface.
In the water, as on the land, they have two means of progression. The first is by swimming as a duck swims, excepting that they lie much lower in the water than a duck does, the top of the back being submerged, so that the neck sticks up out of the water. As their feet are very slightly webbed, they have not the advantages that a duck or gull has when swimming in this way, but supplement their foot-work by short quick strokes of their flippers. This they are easily able to do, owing to the depth to which the breast sinks in the water.
The second method is by "porpoising."
This consists in swimming under water, using the wings or "flippers" for propulsion, the action of these limbs being practically the same as they would be in flying. As their wings are beautifully shaped for swimming, and their pectoral muscles extraordinarily powerful, they attain great speed, besides which they are as nimble as fish, being able completely to double in their tracks in the flash of a moment. In porpoising, after travelling thirty feet or so under water, they rise from it, shooting clean out with an impetus that carries them a couple of yards in the air, then with an arch of the back they are head first into the water again, swimming a few more strokes, then out again, and so on.
I show a photograph of them doing this (Fig. 49).
Perhaps the most surprising feat of which the Adelie is capable is seen when it leaps from the water on to the ice. We saw this best later in the year when the sea-ice had broken away from the ice-foot, so that open water washed against the ice cliff bounding the land. This little cliff rose sheer from the water at first, but later, by the action of the waves, was under-cut for some six feet or more in places, so that the ledge of ice at the top hung forwards over the water. The height of most of this upper ledge varied from three to six feet.
Whilst in the water the penguins usually hunted and played in parties, just as they had entered it, though a fair number of solitary individuals were also to be seen. When a party had satisfied their appetites and their desire for play, they would swim to a distance of some thirty to forty yards from the ice-foot, when they might be seen all to stretch their necks up and take a good look at the proposed landing-place. Having done this, every bird would suddenly disappear beneath the surface, not a ripple showing which direction they had taken, till suddenly, sometimes in a bunch, sometimes in a stream, one after the other they would all shoot out of the water, clean up on to the top of the ice-foot. (Figs. 41 and 42.) Several times I measured the distance from the surface of the water to the ledge on which they landed, and the highest leap I recorded was exactly five feet. The "take off" was about four feet out from the edge, the whole of the necessary impetus being gained as the bird approached beneath the water.
The most important thing to note about this jumping from the water was the accuracy with which they invariably rose at precisely the right moment, the exact distance being judged during their momentary survey of a spot from a distance, before they dived beneath the water, and carried in their minds as they approached the ice. I am sure that this impression was all they had to guide them, as with a ripple on the water, and at the pace they were going, they could not possibly have seen their landing-place at all clearly as they approached it, besides which, in many cases, the ledge of ice on which they landed projected many feet forwards from the surface, yet I never saw them misjudge their distance so as to come up under the overhanging ledge.
During their approach they swam at an even distance of about three or four feet beneath the surface, projecting themselves upwards by a sudden upward bend of the body, at the same time using their tail as a helm, in the manner well shown in one of my photographs, in which one of the birds is seen in the air at the moment it left the water, the tail being bent sharply up towards the back.
Their quickness of perception is shown very well as they land on the ice. If the surface is composed of snow, and so affords them a good foothold, they throw their legs well forward and land on their feet, as shown in Figs. 41 and 42, but should they find themselves landing on a slippery ice-surface, they throw themselves forward, landing on their breasts in the tobogganing position as shown in Fig. 43.
The Adelies dive very beautifully. We did not see this at first, before the sea-ice had gone out, because to enter the water they had only to drop a few inches, but later, when entering from the ice terraces, we constantly saw them making the most graceful dives.
At the place where they most often went in, a long terrace of ice about six feet in height ran for some hundreds of yards along the edge of the water, and here, just as on the sea-ice, crowds would stand near the brink. When they had succeeded in pushing one of their number over, all would crane their necks over the edge (Fig. 44), and when they saw the pioneer safe in the water, the rest followed.
When diving into shallow water they fall flat (Figs. 45, 46, and 47), but into deep water, and from any considerable height, they assume the most perfect positions (Fig. 50) and make very little splash. Occasionally we saw them stand hesitating to dive at a height of some twenty feet, but generally they descended to some lower spot, and did not often dive from such a height, but twelve feet was no uncommon dive for them.
The reluctance shown by each individual of a party of intending bathers to be the first to enter the water may partly have been explained when, later on, we discovered that a large number of sea-leopards were gathered in the sea in the neighbourhood of the rookery to prey on the penguins. These formidable animals, of which I show some photographs, used to lurk beneath the overhanging ledges of the ice-foot, out of sight of the birds on the ice overhead. (Fig. 51.) They lay quite still in the water, only their heads protruding, until a party of Adelies would descend into the water almost on top of them, when with a sudden dash and snap of their great formidable jaws, they would secure one of the birds.
It seemed to me then, that all the chivvying and preliminaries which they went through before entering the water, arose mainly from a desire on the part of each penguin to get one of its neighbours to go in first in order to prove whether the coast was clear or not, though all this manoeuvring was certainly taken very lightly, and quite in the nature of a game. This indeed was not surprising, for of all the animals of which I have had any experience, I think the Adelie penguin is the very bravest. The more we saw of them the fonder we became of them and the more we admired their indomitable courage. The appearance of a sea-leopard in their midst was the one thing that caused them any panic. With dozens of these enemies about they would gambol in the sea in the most light-hearted manner, but the appearance of one among them was the signal for a stampede, but even this was invariably gone through in an orderly manner with some show of reason, for, porpoising off in a clump, they at once spread themselves out, scattering in a fan-shaped formation as they sped away, instead of all following the same direction.
As far as I could judge, however, the sea-leopards are a trifle faster in the water than the Adelies, as one of them occasionally would catch up with one of the fugitives, who then, realizing that speed alone would not avail him, started dodging from side to side, and sometimes swam rapidly round and round in a circle of about twelve feet diameter for a full minute or more, doubtless knowing that he was quicker in turning than his great heavy pursuer, but exhaustion would overtake him in the end, and we could see the head and jaws of the great sea-leopard rise to the surface as he grabbed his victim. The sight of a panic-stricken little Adelie tearing round and round in this manner was a sadly common sight late in the season.
Sea-leopards are no mean customers and should be treated with caution. Commander Campbell and I used to hunt them from a little Norwegian pram (a species of dinghy) which we rowed quietly up and down close under the ice-foot, shooting at the sea-leopards with a rifle when we saw their heads above water.
One day we had an interesting little adventure. We had shot and killed one, a fine bull about ten feet long, which had sunk to the bottom in some five fathoms. Having just pulled away from him, we were about ten yards from the ice-foot, when another very large sea-leopard overtook us, swimming from the direction of the dead bull. It passed under the pram, bumping against the keel in doing so. When about ten yards ahead of us it turned and made straight back for us, but as we were bows-on to it, it came right alongside the boat, churning up the water and wetting us. At this moment it turned on its side, its right fore-flipper beating the surface and its belly towards us, and was just starting to rear its head up when we both lunged at it with our paddles, and so pushed the little boat away from it. This brought us alongside the ice-foot, from which Campbell got a shot at it half a minute later, and wounded it in the neck. The moment after we lunged at it with our paddles it dived, then reappeared ten or fifteen yards off, rearing its head out of the water, and it was at this moment that Campbell shot it. After this it reappeared several times at the surface, but drifted away with the tide and we lost it.
The sea-leopard has not a reputation for attacking men in boats, and this one may have been actuated by curiosity merely, but in favour of its meaning to attack us were, first, that it came to us straight from the direction of the dead bull we had shot, and secondly, that it seems hardly likely that after bumping against our keel, mere curiosity could have tempted it to come back and try to look over the gunwale! As a rule we had to drift very quietly along when hunting sea-leopards, as the slightest sound frightened them away.
All that we could do to protect our friends was to shoot as many of these sea-leopards as possible but though we may have made some difference, there were always many about.
Some idea of the depredations committed by these animals may be gathered from the fact that in the stomach of one which we shot I found the bodies of eighteen penguins, in various stages of digestion, the beast's intestines being literally stuffed with the feathers remaining from the disintegration of many more. Photographs of these animals are seen in Figs. 52, 53, and 54.
Though the actual presence of a sea-leopard put the Adelies to confusion, causing them to "porpoise" madly away for a few hundred yards, yet once away from the immediate neighbourhood of the arch enemy, they appeared to think no more of him, and behaved as though there were no further need for anxiety, though probably they kept a sharp look-out nevertheless. Evidence goes to show that the sea-leopard is the only living enemy, excepting man, that threatens the life of the adult Adelie penguin.
One day, as I watched some hundreds of Adelies bathing in an open lead, suddenly the back of an enormous killer-whale (_Orca gladiator_) rose above the surface as it crossed the lead from side to side, appearing from beneath the ice on one side and disappearing beneath it on the other. To my surprise, not the slightest fear was shown by the birds in the water. Had this beast been a sea-leopard, there would have been a stampede, and every bird have leapt from the water on to the sea-ice. On this evidence I formed the opinion that in all probability killer-whales do no harm to Adelie penguins; later I saw it confirmed, when a school of killers shaved close past several floes that were crowded with Adelies, and made not the least attempt to get at them, as they might so easily have done by upsetting the floes. Very probably this is because the agile bird can escape with such ease from the ponderous whale, and fears it no more than a terrier fears a cow, though he thinks twice before coming within reach of its jaws.
When the sea-ice had gone out, leaving open water right up to the ice-foot, a ledge of ice was left along the western side of the rookery, forming a sort of terrace or "front," with its sides composed of blue ice, rising sheer out of the water to a height of some six feet or more in places. From this point of vantage it was possible to stand and watch the penguins as they swam in the clear water below, and some idea was formed of their wonderful agility when swimming beneath the surface. As they propelled themselves along with powerful strokes of their wings, they swerved from side to side to secure the little prawn-like euphausia which literally swarm everywhere in the Antarctic seas, affording them ample food at all times. Their gluttonous habits here became very evident. They would gobble euphausia until they could hold no more, only to vomit the whole meal into the water as they swam, and so enlightened start to feast again. As they winged their way along, several feet beneath the surface, a milky cloud would suddenly issue from their mouths and drift slowly away down stream, as, without the slightest pause in their career, they dashed eagerly along in the hunt for more.
When a penguin returned to his mate on the nest, after his jaunt in the sea, much formality had to be gone through before he was allowed to take charge of the eggs. This ceremony of "relieving guard" almost invariably was observed.
Going up to his mate, with much graceful arching of his neck, he appeared to assure her in guttural tones of his readiness to take charge (Fig. 55). At this she would become very agitated, replying with raucous staccato notes, and refusing to budge from her position on the eggs. Then both would become angry for a while, arguing in a very heated manner, until at last she would rise, and, standing by the side of the nest, allow him to walk on to it, which he immediately did, and after carefully placing the eggs in position, sink down upon them, afterwards thrusting his bill beneath his breast to push them gently into a comfortable position. After staying by him for a little while, the other at length would go off to bathe and feed.
The length of time during which each bird was away varied considerably, but a "watch bill" was kept of one particular pair with the following result:(5)
(5) This "watch-bill" was kindly kept for me by Mr. Priestly on his
meteorological rounds, the nests being near the thermometer screen.
Nov. 14. Egg laid. Hen sitting.
Nov. 27. A cock seen to join the hen for the first time since the 14th. He took her place on the nest. This was the first day on which any red guano was seen about the nest.
Dec. 10. The hen returned between 8 P.M. and 10 P.M., having been absent since November 27. Fresh red guano: the first for many days.
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Antarctic Penguins: A Study of Their Social HabitsChapter IV: Part II: Domestic Life of the Adelie Penguin (1)
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