umber-bird, a stork-like bird about the size of a raven, which leads
a quiet, nocturnal life in the forest, and builds an enormous nest,
one of the most remarkable built by any bird. These nests are usually
placed at but a short distance from the ground, in forks of the trunk,
or on any thick boughs of the lower part of the crown that are strong
enough to bear them; for they exceed the nests of the largest birds of
prey in circumference and weight, being often from one and a half to
two yards in diameter and not much less in height, and consisting of
fairly thick branches and twigs, which are neatly stuck together or
mortared with clay. If one does not happen to notice how the umber-bird
slips out and in one would never imagine that these structures were
hollow, but would rather take them for the eyrie of a bird of prey,
especially as eagles and horned owls frequently nest on the top of
them. But when one has seen the real owner enter, and has inspected
the nest closely, one finds that the interior is divided into three
compartments, connected by holes which serve as doors, and further
observation reveals that these three compartments answer the purpose of
hall, reception or dining room, and brooding-chamber. This last room,
the farthest back, is slightly higher than the rest, so that if any
water should get in it can flow away; but the whole structure is so
excellently built that even heavy and long-continuing showers of rain
do very little damage. Within the brooding-chamber, on a soft cushion
of sedge and other materials, lie the three, four, or five white eggs
on which the female sits; in the middle chamber the male meantime
stores up all sorts of provisions, a bountiful supply of fish, frogs,
lizards, and other dainties which he has caught, so that his mate can
choose from these stores, and has only to reach forward to satisfy her
hunger; in the entrance chamber the male stands or sits, whenever he
is not busy hunting for food, to keep guard and to cheer his mate with
his society, until the growing offspring take up the whole attention of
both.[52]
The association of umber-bird and eagle or horned owl is not a solitary
instance of friendly companionship on the part of birds belonging
to different species and totally unlike in their habits. On the
broad, fan-like leaves of the magnificent duleb-palm, which stand out
horizontally from the trunk, the nests of the dwarf peregrine falcon
and the guinea-dove often stand so close together that the falcon could
easily grasp one of his neighbour’s young ones. But he does not touch
them, for he is only accustomed to attack birds on the wing, and thus
the little doves grow up in safety beside the little falcons, and the
parents of both often sit peacefully beside each other, near their
respective nests.[53]
Another palm gave me an opportunity of observing birds whose brooding
surprised and fascinated me greatly. Round a single tom-palm there
flew, with constant cries, small-sized swifts, nearly related to our
own swifts, and my attention was thus directed to the tree itself. On
close observation I saw that the birds frequently repaired between the
leaves, and I then discovered on the grooves of the leaf-stalks light
points which I took to be nests. I climbed the tree, bent one of the
leaves towards me, and saw that each nest, which was made chiefly of
cotton, was plastered firmly in the angle between the stalk and the
midrib of the leaf, cemented by salivary secretion, after the method
usually followed by swifts. But the hollow of the nest appeared to me
so flat that I wondered how the two eggs could remain lying when the
leaf was shaken by the wind. And it must have shaken with the slightest
breath, not to speak of the storms which often raged here! Carefully I
reached out my hand to take out the eggs; then I saw with astonishment
that the mother had glued them firmly to the nest. And as I examined
newly-hatched, tiny, helpless young birds, I saw, with increasing
astonishment, that they, too, were attached to the nest in the same
way, and were thus secured from falling out.
[Illustration: Fig. 32.--Long-tailed Monkeys.]
Apart from the birds, which continually attract the naturalist’s
attention by their omnipresence, beauty, vivacity and nimbleness, as
well as by their songs, or rather cries; apart also from the very
numerous lizards and snakes, or the abundant insects, even a careful
observer can see very little of the other denizens of the primeval
forest, and especially little of its mammals. But one can hardly
fail to see a band of long-tailed monkeys, for the liveliness and
restlessness characteristic of these and of all the African monkeys is
sure to bring them sooner or later before the most unobservant eye, and
their continual gurgling noises must reach the ear; yet one may pass
within a few yards of most of the other mammals without having any idea
that they are near. The great majority of the mammals inhabiting the
primeval forest become active only after sundown, and return to their
lairs before daybreak; but even those which are active and busy in full
sunlight in the morning and evening are by no means so easily seen as
might be imagined, for the thickness of the forest stands them in good
stead. A European with whom I hunted in the primeval forest said to
me: “Did you see that leopard that bounded from me towards you a few
minutes ago? I could not shoot for I had not my gun in order; but you
must have seen him.” He was wrong; I had not seen the great beast, so
dense was the undergrowth in the forest. Where it is less dense another
fact has its importance: the colour-resemblance between the mammals and
their surroundings. The grayish lemur, which sits or sleeps huddled
up high up on a branch spun over with lichens, resembles a knob or
protuberance so clearly and convincingly that its form is only made
out when the sportsman, taught by former experience, uses his glass
and observes it keenly; the bat, which hangs high up in the crown of
another tree, also looks like an outgrowth or a withered leaf; even the
spotted skin of the leopard may be a faithful mimicry of the dry leaves
and flowering euphorbias, and I myself once had to advance with cocked
rifle to within fifteen paces of a bush in which a leopard had taken
shelter before I could distinguish the animal from his surroundings.
The same holds true of the forest antelopes, and indeed of all the
mammals, and they know that this is so.[54] Not everywhere, but here
and there throughout the forest, and then always abundantly, there
lives a little antelope, the bush or Salt’s antelope. It is one of
the most charming of all ruminants, most gracefully built, not bigger
than a fawn a few days old, and of a foxy, gray-blue colour. It lives
with a mate in the thickest undergrowth of the forest, choosing for
its lair or habitual resting-place a bush which is branched and leafy
to the ground, and thence treading out narrow paths in all directions
through the thicket. I have often shot the animal; but at first it
escaped me as it escapes all the travellers and sportsmen who make
its acquaintance. I could never see it except when, if startled, it
flew past me like an arrow. “Look, sir, there, in front of you in the
nearest bush is a little antelope; it is down there in the gap between
the two thickly-leaved branches,” whispered my native guide in my ear.
I strained every nerve, penetrated every part of the bush with my gaze,
and saw nothing but branches and leaves, for the graceful legs had
become twigs, the head and body a leafy bough. But the sportsman’s eye
becomes accustomed in time even to the primeval forest. When one has
become familiar with the dainty creature’s habits, one learns to find
it as well as the sharp-sighted natives do. Its acute hearing warns
it of the approach of a man long before he can see any trace of its
presence. Scared by the rustle of heavy human footsteps it starts up
from its lair, takes a few steps forwards, and steps into some gap from
which to see what happens. Like a bronze statue it stands stiff and
motionless, without even moving an ear or turning an eye, but looking
and listening; the leg which was raised to step onwards remains in that
position, not a sign betrays life. Now is the time for the sportsman to
raise his gun quickly, take aim and shoot; a moment later the cunning
antelope has gained the cover of a neighbouring bush at a single bound,
or has bent slowly down and crept away so quietly that scarcely a leaf
stirs, scarcely a blade of grass moves.
[Illustration: Fig. 33.--Salt’s Antelope (_Antilope Saltiana_).]
The primeval forest thus presents a succession of varied pictures
to the traveller’s eye. If one has learnt to see, and attempts to
understand, one finds more in every part of the forest at every season
than one can master. But one does not see the same things at every
spot, and at every season. Here, where spring lasts only a few weeks,
and summer and autumn are counted by days, the long reign of winter
sets in directly after the rainy season, just as in the steppe, and the
full, rich, overflowing life of animals and plants is crowded into a
very short time. As soon as the birds have finished brooding they begin
to migrate; as soon as the mammals have exhausted the food-supply in
one part of the forest they betake themselves to another. Consequently
one meets different animals in the same spot at different times,
or at least one sees different aspects of animal life. The river,
for instance, becomes animated in proportion as the forest becomes
depopulated.
While the river is high, one does not see much of the animals which
live in and about the water. All the islands are deeply buried under
the water, the banks are likewise flooded, and the birds which usually
inhabit them are crowded out for the time. And if a crocodile should
raise his head and part of his scaly back above the water, he must be
close to the boat if one sees him at all. Strictly speaking, there
remain only the hippopotamuses, which are comparatively abundant in
some parts, the birds flying about over the water, and perhaps a few
diving-birds to prove that any higher vertebrates live in and about
the river. But, when the rain has ceased, the river falls, and all
the islands, sand-banks, and the river-banks themselves stand out
once more. The scene is changed also as far as the animal world is
concerned. The hippopotamuses retire to the deepest parts of the
river, associating in troops sometimes of considerable strength, and
making themselves very conspicuous as they come to the surface to
breathe, each breath being inhaled with a snort which can be heard a
long way off. During the day they land on islands or sand-banks to
rest or stretch themselves in the sun, and they can then be seen from
a distance of more than half a mile. The crocodiles eagerly enjoy a
pleasure they had to forego while the river was high, that of sunning
themselves for hours in the heat of the day. To this end they creep
out about mid-day on a flat, sandy island, fall heavily with an
audible plump on the sand, open their formidably-toothed jaws wide,
and sleep till evening; there may be ten, twenty, or thirty of them
on a single sand-bank. Now the sand-banks, both river-banks, and the
shores of the larger islands are covered with flocks of birds whose
numerical strength is most impressive. For, by this time of year most
of the native shore-birds and swimming-birds have ended their brooding
labours, and frequent the shores of the river with their young to
enjoy, while they are moulting, the abundant and easily-procured food.
About the same time, too, the migratory birds from the north arrive to
pass the winter here. The last-named are also to be found in every part
of the primeval forest, but are not nearly so much in evidence there
as by the river, whose banks and islands are covered by the largest
and most conspicuous species. It may even happen that the available
space by the river is too small, the rich supply of food insufficient
for the number of claimants. Thus every space is more than fully
occupied, every promising hunting-ground is visited by thousands, every
sleeping-place even is fought over. For three days I sailed, in an
excellent boat and with a very good wind, up the White Nile, and during
the whole long journey both banks were uninterruptedly covered with a
gay and motley throng of littoral and aquatic birds. In the midst of
the forests about the Blue Nile one can see a similar sight. Extensive
sand-banks are completely covered by gray and demoiselle cranes,
but they only serve these winter visitors as resting, sleeping, and
moulting places, from whence they fly out every morning into the steppe
in search of food, returning about mid-day to drink, bathe, dress
their feathers, and to spend the night, though they are in continual
danger from the crocodiles. Regularly about mid-day they are joined by
several crowned cranes whose visit always causes lively excitement,
for they are, if not better, at least more ardent dancers than the
other cranes, and on their arrival they never fail to exhibit their
skill, and thus to incite the others to rivalry. On the same sand-banks
one may often see tantalus-ibises, magnificent stork-like birds, with
rosy-white plumage and brilliant rose-red wings, which take possession
of the extreme edge of the island or the neighbouring damp places. In a
good light they literally glow, and they are at all times beautiful,
contrasting wonderfully with the light gray cranes, and decorating
the whole neighbourhood. Splendid giant or saddle-billed storks step
proudly along the shores; ugly, but curiously-formed marabous walk up
and down with an air of dignity; glittering, open-bill storks stand in
large companies; giant and great white herons wade about in search of
fish; and everywhere standing and lying, swimming and diving, grazing
and grubbing, cackling and chattering are thousands of Spur-winged,
Egyptian, and other geese, widow and pintail ducks, African darters,
ibises, curlews, sandpipers, dunlins, redshanks, and many more, a
motley throng which decorates the stream even more than the tantalus
ibises. But, in addition to all those mentioned, some of whom are
constantly coming and going, there fly terns and gulls, sand-martins
and bee-eaters, while splendid sea-eagles wheel in circles high up in
the air.
[Illustration: Fig. 34.--Crocodile and Crocodile-birds (_Pluxianus
ægyptius_).]
There are some members of this bird-fauna, so rich in every respect,
who have to wait till the water is at its lowest before they can begin
to brood, for, when the river is full, they are quite unable to find
such nesting-places as they desire. Among these is a running bird,
prettily and gaily coloured, clever and vivacious by nature, which was
well known to the ancients as the Crocodile-bird or the Trochilus of
Herodotus. Of it the old historian relates, as Pliny repeats on his
authority, that it lives in true friendship with the crocodile. And
this old story is no fable, as one might be inclined to suppose, but
is based on solid facts, which I have myself been able to verify.[55]
The crocodile-bird, whose image is so often represented on the ancient
Egyptian monuments, and stands for U in the hieroglyphic alphabet,
occurs in Egypt and Nubia, but nowadays it seems to be only in the
Soudan that it discharges, on the crocodile’s behalf, those sentinel
duties for which it was famous among the ancient peoples. But the
service it renders is not to the crocodile alone, but to all other
creatures who are willing to take advantage of its watchfulness.
Observant, inquisitive, excitable, clamorous, and gifted with a
far-reaching voice, it is well fitted to serve as watchman to all less
careful creatures. No approach, whether of beast of prey or of man,
escapes its suspicious observation; every sailing-boat or rowing-boat
on the river attracts its attention; and it never fails to tell of
its discovery in loud cries. Thus it brings under the notice of all
the other creatures who share its home or resting-place the unusual
occurrence, enabling them either to find out for themselves if there
is really any danger, or to make good their escape on the strength of
its warning. Thus it discharges the duties of a sentinel. Its friendly
relations with the crocodile can hardly be called mutual, for to credit
the crocodile with friendship is going rather far. Certainly the
reptile treats the bird as a harmless creature, but this is not out of
any benevolence, but simply because he has a thorough knowledge and
a correct estimate of his partner. And as to the bird, it is at home
on the sand-banks where the crocodile is wont to rest, and has been
from its youth accustomed to the monster; it busies itself about him
and associates itself with him, as if he were the master and itself
the servant. Without hesitation it hops on his back as he rests;
without apprehension it approaches his gaping jaws to see if there be
perchance a leech sucking his lips, or if there be some morsel of food
sticking between his teeth; and without misgiving it darts off with
either. All this the crocodile quietly allows, for doubtless he has
learned by experience that he cannot get at the ever watchful, agile,
and clever little rogue. I once saw a crocodile-bird having a meal
along with a screaming sea-eagle off a fish, which the latter had
caught and borne to a sand-bank. While the eagle, which held its booty
firmly in its talons or stood upon it, was breaking off pieces of the
flesh, the parasite at the lordly bird’s table kept at a respectful
distance; but as soon as the eagle raised its head to swallow, the
crocodile-bird ran forward, seized one of the prepared fragments, and
was off again to his old position, there to enjoy his stolen goods.
Not less astonishing than this self-possessed audacity is the way in
which the crocodile-bird hides its eggs from prying eyes. For long I
searched in vain for the nest. When the brooding period set in was
readily enough discovered by dissecting a specimen which I killed; and
that the bird must nest on the sand-bank I was already convinced from
my observation of its mode of life. But it was in vain that I searched
their favourite spots; not a hint of a nest could I find. At last I
observed a pair, one sitting on the ground, the other busying itself
round about; I brought my field-glass to bear upon the sitting bird and
made straight for it. As I came near it rose, hastily scraped some sand
together, and flew off, uttering its usual cry, but without any other
signs of excitement. I was not diverted from my purpose, but advanced
carefully, keeping the exact spot always in view. But even when I
reached the place I could see no nest, and it was not till I noticed a
slight unevenness in the sand, and dug carefully with my fingers, that
I found what I sought, two eggs most deceptively like the sand in their
colour and markings. Had the mother-bird been allowed more time than I
gave her, it is not likely that I should ever have noticed the slight
unevenness in the sand.
Even richer, if that be possible, than the fauna of the river, and at
any rate more diverse, is that to be found at the proper season on
the shores and surface of all the lakes and larger water-pools which
lie within the forest and are filled either by the spring rains or
by the full floods of the river. Surrounded by the forest, and not
unfrequently so thickly hedged round that one cannot reach them without
great difficulty, and more immediately fringed by a scarcely less rich
vegetation of canes and reed-thickets, where the papyrus and the lotos
still flourish, these rain-lakes, or _Fulat_ as the natives call them,
afford most excellent resting-stations and breeding-places for the most
diverse kinds of beasts and birds.
Their safe seclusion pleases even the hippopotamus so well that it
seeks them out as fit places where to bring forth and suckle, tend and
rear its young, safe from dangerous intruders, and without trouble as
to food, which the water supplies in abundance. Wild hogs and buffaloes
are also attracted to the luxuriant fringe of vegetation and to the
creeks which gradually pass into swamp and bog. To all the thirsty race
of antelopes the quiet pools afford welcome supplies. On the surface
thousands of pelicans gather in the evenings, and fish greedily before
they go to roost on the tall trees near by; all day long the darters
dive; many ducks and geese swim about, both native species and those
which have come from the north to these comfortable winter-quarters;
in the creeks and shallows the giant-herons and the beautiful little
bush-herons secure rich booty at small cost of exertion; countless
hosts of little birds are sheltered among the green, sappy herbage of
the shore, and many other shore-and water-birds find resting-places and
build their nests on the overtowering trees of the forest.
It is no wonder, then, that these lakes should periodically swarm with
birds; and it is likewise plain that such great wealth of booty must
also attract all sorts of enemies. The smaller birds are followed by
the falcons and owls, the larger birds by the eagle and horned owl, the
mammals by the fox and jackal, the leopard and the lion. Sometimes,
too, an army of voracious locusts coming in from the steppe falls upon
the fresh green girdle around such a lake and ravages it in a few
days, devouring all the leaves. Or one should rather say threatening
to devour, for at such a time the assemblage of birds becomes even
larger than before. From far and near they come flocking--falcons
and owls, ravens and rollers, francolins and guinea-fowl, storks and
ibises, coots and ducks. Every bird that ever eats insects now confines
itself exclusively to the pertinacious visitors. Hundreds of kestrels
and lesser kestrels, which are then in these winter-quarters, sweep
over the invaded forest, and swoop down upon the locusts, seizing
and devouring them, with scarce an interruption in their flight.
Ravens, rollers, hornbills, ibises, and storks pick them off the
branches of the trees and shake down hundreds which fall victims to
the guinea-fowl, ducks, and other birds waiting underneath. Harriers
and chanting hawks circle around the trees on which the “defoliating”
insects soon take the place of the leaves that were. Even the sedate
marabous and saddle-billed storks do not disdain to avail themselves
of booty whose abundance compensates for the paltry size of the
individual victims. All this bustle greatly enhances the liveliness of
a scene which is at no time dull, and makes the lake more than ever a
rendezvous of the most diverse forms of life.