birds, such as the thrushes, warblers, tits, shrikes, flycatchers,
starlings, crows, wagtails, larks, and finches. These families are
all more or less abundant in the tropics; but there are a number
of other families which are almost or quite peculiar to tropical
lands and give a special character to their bird-life. All the
peculiarly tropical families are, however, confined to some definite
portion of the tropics, a number of them being American only, others
Australian, while others again are common to all the warm countries
of the Old World; and it is a curious fact that there is no single
family of this great order of birds that is confined to the entire
tropics, or that is even especially characteristic of the tropical
zone, like the cuckoos among the Picariæ. The tropical families of
passerine birds being very numerous, and their peculiarities not
easily understood by any but ornithologists, it will be better to
consider the series of fifty families of Passeres as one compact
group, and endeavour to point out what external peculiarities are
most distinctive of those which inhabit tropical countries.
Owing to the prevalence of forests and the abundance of flowers,
fruits, and insects, tropical and especially equatorial birds
have become largely adapted to these kinds of food; while the
seed-eaters, which abound in temperate lands where grasses cover much
of the surface, are proportionately scarce. Many of the peculiarly
tropical families are therefore either true insect-eaters or true
fruit-eaters, whereas in the temperate zones a mixed diet is more
general.
One of the features of tropical birds that will first strike the
observer, is the prevalence of crests and of ornamental plumage
in various parts of the body, and especially of extremely long
or curiously shaped feathers in the tails, tail-coverts, or
wings of a variety of species. As examples we may refer to the
red paradise-bird, whose middle tail-feathers are like long
ribands of whalebone; to the wire-like tail-feathers of the king
bird-of-paradise of New Guinea, and of the wire-tailed manakin
of the Amazons; and to the long waving tail-plumes of the whydah
finch of West Africa and paradise-flycatcher of India; to the
varied and elegant crests of the cock-of-the-rock, the king-tyrant,
the umbrella-bird, and the six-plumed bird-of-paradise; and to
the wonderful side-plumes of most of the true paradise-birds. In
other orders of birds we have such remarkable examples as the
racquet-tailed kingfishers of the Moluccas, and the racquet-tailed
parrots of Celebes; the enormously developed tail-coverts of the
peacock and the Mexican trogon; and the excessive wing-plumes of
the argus-pheasant of Malacca and the long-shafted goatsucker of
West Africa.
Still more remarkable are the varied styles of coloration in the
birds of tropical forests, which rarely or never appear in those of
temperate lands. We have intensely lustrous metallic plumage in the
jacamars, trogons, humming-birds, sun-birds, and paradise-birds;
as well as in some starlings, pittas or ground-thrushes, and
drongo-shrikes. Pure green tints occur in parrots, pigeons, green
bulbuls, greenlets, and in some tanagers, finches, chatterers, and
pittas. These undoubtedly tend to concealment; but we have also the
strange phenomenon of white forest-birds in the tropics, a colour
only found elsewhere among the aquatic tribes and in the arctic
regions. Thus, we have the bell-bird of South America, the white
pigeons and cockatoos of the East, with a few starlings, woodpeckers,
kingfishers, and goatsuckers, which are either very light-coloured
or in great part pure white.
But besides these strange, and new, and beautiful forms of bird-life,
which we have attempted to indicate as characterising the tropical
regions, the traveller will soon find that there are hosts of
dull and dingy birds, not one whit different, so far as colour is
concerned, from the sparrows, warblers, and thrushes of our northern
climes. He will however, if observant, soon note that most of
these dull colours are protective; the groups to which they belong
frequenting low thickets, or the ground, or the trunks of trees.
He will find groups of birds specially adapted to certain modes
of tropical life. Some live on ants upon the ground, others peck
minute insects from the bark of trees; one group will devour bees
and wasps, others prefer caterpillars; while a host of small birds
seek for insects in the corollas of flowers. The air, the earth,
the undergrowth, the tree-trunks, the flowers, and the fruits,
all support their specially adapted tribes of birds. Each species
fills a place in nature, and can only continue to exist so long as
that place is open to it; and each has become what it is in every
detail of form, size, structure, and even of colour, because it has
inherited through countless ancestral forms all those variations
which have best adapted it among its fellows to fill that place,
and to leave behind it equally well adapted successors.
_Reptiles and Amphibia._--Next to the birds, or perhaps to the
less observant eye even before them, the abundance and variety of
reptiles form the chief characteristic of tropical nature; and the
three groups--Lizards, Snakes, and Frogs, comprise all that, from
our present point of view, need be noticed.
_Lizards._--Lizards are by far the most abundant in individuals
and the most conspicuous; and they constitute one of the first
attractions to the visitor from colder lands. They literally swarm
everywhere. In cities they may be seen running along walls and up
palings; sunning themselves on logs of wood, or creeping up to the
eaves of cottages. In every garden, road, or dry sandy path, they
scamper aside as you walk along. They crawl up trees, keeping at
the further side of the trunk and watching the passer-by with the
caution of a squirrel. Some will walk up smooth walls with the
greatest ease; while in houses the various kinds of Geckos cling
to the ceilings, along which they run back downwards in pursuit of
flies, holding on by means of their dilated toes with suctorial
discs; though sometimes, losing hold, they fall upon the table or
on the upturned face of the visitor. In the forests large, flat,
and marbled Geckos cling to the smooth trunks; small and active
lizards rest on the foliage; while occasionally the larger kinds,
three or four feet long, rustle heavily as they move among the
fallen leaves.
Their colours vary much, but are usually in harmony with their
surroundings and habits. Those that climb about walls and rocks are
stone-coloured, and sometimes nearly black; the house lizards are
grey or pale-ashy, and are hardly visible on a palm-leaf thatch, or
even on a white-washed ceiling. In the forest they are often mottled
with ashy-green, like lichen-grown bark. Most of the ground-lizards
are yellowish or brown; but some are of beautiful green colours,
with very long and slender tails. These are among the most active
and lively; and instead of crawling on their bellies like many
lizards, they stand well upon their feet and scamper about with the
agility and vivacity of kittens. Their tails are very brittle; a
slight blow causing them to snap off, when a new one grows, which
is, however, not so perfectly formed and completely scaled as the
original member. It is not uncommon, when a tail is half broken, for
a new one to grow out of the wound, producing the curious phenomenon
of a forked tail. There are about 1,300 different kinds of lizards
known, the great majority of which inhabit the tropics, and they
probably increase in numbers towards the equator. A rich vegetation
and a due proportion of moisture and sunshine seem favourable to
them, as shown by their great abundance and their varied kinds at
Para and in the Aru Islands--places which are nearly the antipodes
of each other, but which both enjoy the fine equatorial climate in
perfection, and are alike pre-eminent in the variety and beauty of
their insect life.
Three peculiar forms of lizard may be mentioned as specially
characteristic of the American, African, and Asiatic tropical zones
respectively. The iguanas of South America are large arboreal
herbivorous lizards of a beautiful green colour, which renders
them almost invisible when resting quietly among foliage. They are
distinguished by the serrated back, deep dew-lap, and enormously
long tail, and are one of the few kinds of lizards whose flesh is
considered a delicacy. The chameleons of Africa are also arboreal
lizards, and they have the prehensile tail which is more usually
found among American animals. They are excessively slow in their
motions, and are protected by the wonderful power of changing their
colour so as to assimilate it with that of immediately surrounding
objects. Like the majority of lizards they are insectivorous,
but they are said to be able to live for months without taking
food. The dragons or flying lizards of India and the larger Malay
islands, are perhaps the most curious and interesting of living
reptiles, owing to their power of passing through the air by means
of wing-like membranes, which stretch along each side of the body
and are expanded by means of slender bony processes from the first
six false ribs. These membranes are folded up close to the body
when not in use, and are then almost imperceptible; but when open
they form a nearly circular web, the upper surface of which is
generally zoned with red or yellow in a highly ornamental manner.
By means of this parachute the animal can easily pass from one
tree to another for a distance of about thirty feet, descending at
first, but as it approaches its destination rising a little so as
to reach the tree with its head erect. They are very small, being
usually not more than two or three inches long exclusive of the
slender tail; and when the wings are expanded in the sunshine they
more resemble some strange insect than one of the reptile tribe.
_Snakes._--Snakes are, fortunately, not so abundant or so obtrusive
as lizards, or the tropics would be scarcely habitable. At first,
indeed, the traveller is disposed to wonder that he does not see
more of them, but he will soon find out that there are plenty;
and, if he is possessed by the usual horror or dislike of them, he
may think there are too many. In the equatorial zone snakes are
less troublesome than in the drier parts of the tropics, although
they are probably more numerous and more varied. This is because
the country is naturally a vast forest, and the snakes being all
adapted to a forest life do not as a rule frequent gardens and come
into houses as in India and Australia, where they are accustomed
to open and rocky places. One cannot traverse the forest, however,
without soon coming upon them. The slender green whip-snakes glide
among the bushes, and may often be touched before they are seen.
The ease and rapidity with which these snakes pass through bushes,
almost without disturbing a leaf, is very curious. More dangerous
are the green vipers, which lie coiled motionless upon foliage,
where their colour renders it difficult to see them. The writer has
often come upon them while creeping through the jungle after birds
or insects, and has sometimes only had time to draw back when they
were within a few inches of his face. It is startling in walking
along a forest path to see a long snake glide away from just where
you were going to set down your foot; but it is perhaps even more
alarming to hear a long-drawn heavy slur-r-r, and just to catch a
glimpse of a serpent as thick as your leg and an unknown number of
feet in length, showing that you must have passed unheeding within
a short distance of where it was lying. The smaller pythons are
not however dangerous, and they often enter houses to catch and
feed upon the rats, and are rather liked by the natives. You will
sometimes be told, when sleeping in a native house, that there is
a large snake in the roof, and that you need not be disturbed in
case you should hear it hunting after its prey. These serpents no
doubt sometimes grow to an enormous size, but such monsters are
rare. In Borneo, Mr. St. John states that he measured one twenty-six
feet long, probably the largest ever measured by a European in the
East. The great water-boa of South America is believed to reach the
largest size. Mr. Bates measured skins twenty-one feet long, but the
largest ever met with by a European appears to be that described
by the botanist, Dr. Gardner, in his _Travels in Brazil_. It had
devoured a horse, and was found dead, entangled in the branches
of a tree overhanging a river, into which it had been carried by
a flood. It was nearly forty feet long. These creatures are said
to seize and devour full-sized cattle on the Rio Branco; and from
what is known of their habits this is by no means improbable.
_Frogs and Toads._--The only Amphibia that often meet the traveller’s
eye in equatorial countries are the various kinds of frogs and
toads, and especially the elegant tree-frogs. When the rainy season
begins, and dried-up pools and ditches become filled with water,
there is a strange nightly concert produced by the frogs, some of
which croak, others bellow, while many have clanging, or chirruping,
and not unmusical notes. In roads and gardens one occasionally
meets huge toads six or seven inches long; but the most abundant
and most interesting of the tribe are those adapted for an arboreal
life, and hence called tree-frogs. Their toes terminate in discs,
by means of which they can cling firmly to leaves and stems. The
majority of them are green or brown, and these usually feed at
night, sitting quietly during the day so as to be almost invisible,
owing to their colour and their moist shining skins so closely
resembling vegetable surfaces. Many are beautifully marbled and
spotted, and when sitting on leaves resemble large beetles more than
frogs, while others are adorned with bright and staring colours;
and these, as Mr. Belt has discovered, have nauseous secretions
which render them uneatable, so that they have no need to conceal
themselves. Some of these are bright blue, others are adorned with
yellow stripes, or have a red body with blue legs. Of the smaller
tree-frogs of the tropics there must be hundreds of species still
unknown to naturalists.
_Mammals--Monkeys._--The highest class of animals, the Mammalia,
although sufficiently abundant in all equatorial lands, are those
which are least seen by the traveller. There is, in fact, only
one group--the monkeys--which are at the same time pre-eminently
tropical and which make themselves perceived as one of the aspects
of tropical nature. They are to be met with in all the great
continents and larger islands, except Australia, New Guinea, and
Madagascar, though the latter island possesses the lower allied form
of Lemurs; and they never fail to impress the observer with a sense
of the exuberant vitality of the tropics. They are pre-eminently
arboreal in their mode of life, and are consequently most abundant
and varied where vegetation reaches its maximum development. In
the East we find that maximum in Borneo, and in the West African
forests; while in the West the great forest plain of the Amazon
stands pre-eminent. It is near the equator only that the great
Anthropoid apes, the gorilla, chimpanzee, and orang-utan are found,
and they may be met with by any persevering explorer of the jungle.
The gibbons, or long-armed apes, have a wider range in the Asiatic
continent and in Malaya, and they are more abundant both in species
and individuals. Their plaintive howling notes may often be heard
in the forests, and they are constantly to be seen sporting at the
summits of the loftiest trees, swinging suspended by their long
arms, or bounding from tree to tree with incredible agility. They
pass through the forest at a height of a hundred feet or more, as
rapidly as a deer will travel along the ground beneath them. Other
monkeys of various kinds are more abundant and usually less shy;
and in places where fire-arms are not much used they will approach
the houses and gambol in the trees undisturbed by the approach of
man. The most remarkable of the tailed monkeys of the East is the
proboscis monkey of Borneo, whose long fleshy nose gives it an
aspect very different from that of most of its allies.
In tropical America monkeys are even more abundant than in the
East, and they present many interesting peculiarities. They differ
somewhat in dentition and in other structural features from all
Old World apes, and a considerable number of them have prehensile
tails, a peculiarity never found elsewhere. In the howlers and the
spider monkeys the tail is very long and powerful, and by twisting
the extremity round a branch the animal can hang suspended as easily
as other monkeys can by their hands. It is, in fact, a fifth hand,
and is constantly used to pick up small objects from the ground.
The most remarkable of the American monkeys are the howlers, whose
tremendous roaring exceeds that of the lion or the bull, and is to
be heard frequently at morning and evening in the primeval forests.
The sound is produced by means of a large, thin, bony vessel in
the throat, into which air is forced; and it is very remarkable
that this one group of monkeys should possess an organ not found
in any other monkey or even in any other mammal, apparently for
no other purpose than to be able to make a louder noise than the
rest. The only other monkeys worthy of special attention are the
marmosets, beautiful little creatures with crests, whiskers, or
manes; in outward form resembling squirrels, but with a very small
monkey-like face. They are either black, brown, reddish, or nearly
white in colour, and are the smallest of the monkey tribe, some of
them being only about six inches long exclusive of the tail.
_Bats._--Almost the only other order of mammals that is specially
and largely developed in the tropical zone is that of the Chiroptera
or bats; which becomes suddenly much less plentiful when we pass
into the temperate regions, and still more rare towards the colder
parts of it, although a few species appear to reach the Arctic
circle. The characteristics of the tropical bats are their great
numbers and variety, their large size, and their peculiar forms
or habits. In the East those which most attract the traveller’s
attention are the great fruit-bats, or flying-foxes as they are
sometimes called, from the rusty colour of the coarse fur and the
fox-like shape of the head. These creatures may sometimes be seen
in immense flocks which take hours to pass by, and they often
devastate the fruit plantations of the natives. They are often five
feet across the expanded wings, with the body of a proportionate
size; and when resting in the daytime on dead trees, hanging head
downwards, the branches look as if covered with some monster fruits.
The descendants of the Portuguese in the East use them for food,
but all the native inhabitants reject them.
In South America there is a group of bats which are sure to attract
attention. These are the vampyres, several of which are blood-sucking
species, which abound in most parts of tropical America and are
especially plentiful in the Amazon Valley. Their carnivorous
propensities were once discredited, but are too well authenticated.
Horses and cattle are often bitten, and are found in the morning
covered with blood; and repeated attacks weaken and ultimately
destroy them. Some persons are especially subject to the attacks
of these bats; and as native huts are never sufficiently close to
keep them out, these unfortunate individuals are obliged to sleep
completely muffled up, in order to avoid being made seriously ill
or even losing their lives. The exact manner in which the attack
is made is not positively known, as the sufferer never feels the
wound. The present writer was once bitten on the toe, which was found
bleeding in the morning from a small round hole from which the flow
of blood was not easily stopped. On another occasion, when his feet
were carefully covered up, he was bitten on the tip of the nose,
only awaking to find his face streaming with blood. The motion of
the wings fans the sleeper into a deeper slumber, and renders him
insensible to the gentle abrasion of the skin either by teeth or
tongue. This ultimately forms a minute hole, the blood flowing from
which is sucked or lapped up by the hovering vampyre. The largest
South American bats, having wings from two to two-and-half feet in
expanse, are fruit-eaters like the Pteropi of the East, the true
blood-suckers being small or of medium size and varying in colour in
different localities. They belong to the genus _Phyllostoma_, and
have a tongue with horny papillæ at the end; and it is probably by
means of this that they abrade the skin and produce a small round
wound. This is the account given by Buffon and Azara, and there
seems now little doubt that it is correct.
Beyond these two great types--the monkeys and the bats--we look in
vain among the varied forms of mammalian life for any that can be
said to be distinctive of the tropics as compared with the temperate
regions. Many peculiar groups are tropical, but they are in almost
every case confined to limited portions of the tropical zones, or
are rare in species or individuals. Such are the lemurs in Africa,
Madagascar, and Southern Asia; the tapirs of America and Malaya;
the rhinoceroses and elephants of Africa and Asia; the cavies and
the sloths of America; the scaly ant-eaters of Africa and Asia;
but none of these are sufficiently numerous to come often before
the traveller so as to affect his general ideas of the aspects of
tropical life, and they are, therefore, out of place in such a
sketch of those aspects as we are here attempting to lay before
our readers.
_Summary of the Aspects of Animal Life in the Tropics._--We will
now briefly summarize the general aspects of animal life as
forming an ingredient in the scenery and natural phenomena of the
equatorial regions. Most prominent are the butterflies, owing to
their numbers, their size, and their brilliant colours; as well as
their peculiarities of form, and the slow and majestic flight of
many of them. In other insects, the large size, and frequency of
protective colours and markings are prominent features; together with
the inexhaustible profusion of the ants and other small insects.
Among birds the parrots stand forth as the pre-eminent tropical
group, as do the apes and monkeys among mammals; the two groups
having striking analogies, in the prehensile hand and the power
of imitation. Of reptiles, the two most prominent groups are the
lizards and the frogs; the snakes, though equally abundant, being
much less obtrusive.