Part 31

The coast of Colombia faces on the Pacific Ocean and the Caribbean Sea, and is divided by the Isthmus of Panama into two completely separated parts. The Pacific coast-line, omitting minor convolutions, has a length of about 500 m., while that of the Caribbean is about 700 m. The former has been of slight service in the development of the country because of the unsettled and unhealthy character of the coast region, and the high mountain barriers between its natural ports and the settled parts of the republic. There are only two commercial ports on the coast, Tumaco and Buenaventura, though there are several natural harbours which would be of great service were there any demand for them. The rivers Mira, Patia and San Juan permit the entrance of small steamers, as also some of the smaller rivers. The larger bays on this coast are Tumaco, Chocó, Magdalena, Cabita, Coqui, Puerto Utria, Solano, Cupica and Octavia--some of them affording exceptionally safe and well-sheltered harbours. The Caribbean coast of Colombia has only four ports engaged in international trade--Barranquilla, Cartagena, Santa Marta and Rio Hacha. There are some smaller ports on the coast, but they are open only to vessels of light draft and have no trade worth mention. Barranquilla, the principal port of the republic, is situated on the Magdalena, and its seaport, or landing-place, is Puerto Colombia at the inner end of Savanilla Bay, where a steel pier 4000 ft. long has been built out to deep water, alongside which ocean-going vessels can receive and discharge cargo. The bay is slowly filling up, however, and two other landing-places--Salgar and Savanilla--had to be abandoned before Puerto Colombia was selected. The pier-head had 24 ft. of water alongside in 1907, but the silt brought down by the Magdalena is turned westward by the current along this coast, and may at any time fill the bay with dangerous shoals. The oldest and best port on the coast is Cartagena, 65 m. south-west of Barranquilla, which has a well-sheltered harbour protected by islands, and is connected with the Magdalena at Calamar by railway. The next best port is that of Santa Marta, about 46 m. east-north-east of Barranquilla (in a straight line), with which it is connected by 23 m. of railway and 50 m. of inland navigation on the Ciénaga de Santa Marta and eastern outlets of the Magdalena. Santa Marta is situated on a small, almost landlocked bay, well protected from prevailing winds by high land on the north and north-east, affording excellent anchorage in waters free from shoaling through the deposit of silt. The depth of the bay ranges from 4½ to 19 fathoms. The town stands at the foot of the Sierra Nevada de Santa Marta, which restricts the area of cultivatable land in its immediate vicinity, and the enclosing high lands make the climate hot and somewhat dangerous for foreigners. Since the development of the fruit trade on the shores of the Caribbean sea and Gulf of Mexico by an important American company, which owns a large tract of land near Santa Marta devoted to banana cultivation, and has built a railway 50 m. inland principally for the transportation of fruit, the trade of the port has greatly increased. The population of this region, however, is sparse, and its growth is slow. The fourth port on this coast is Rio Hacha, an open roadstead, about 93 m. east of Santa Marta, at the mouth of the small river Rancheira descending from the eastern slopes of the Sierra Nevada de Santa Marta. It has little trade, and the undeveloped, unpopulated state of the country behind it affords no promise of immediate growth. There are other small towns on the coast which are ports for the small vessels engaged in the coasting and river trade, but they have no international importance because of their inaccessibility to ocean-going steamers, or the extremely small volume of their trade. The Gulf of Uraba is a large bight or southerly extension of the Gulf of Darien. It receives the waters of the Atrato, Bacuba, and a number of small rivers, and penetrates the land about 50 m., but has very little commercial importance because of the unhealthy and unsettled character of the neighbouring country, and because of the bar across its entrance formed by silt from the Atrato. The Gulf of Morosquillo, a broad shallow indentation of the coast south of Cartagena, receives the waters of the Rio Sinú, at the mouth of which is the small port of Cispata. Between the mouth of the Magdalena and Santa Marta is the Ciénaga de Santa Marta, a large marshy lagoon separated from the sea by a narrow sand spit, having its "boca" or outlet at its eastern side. There is some traffic in small steamers on its shallow waters, which is increasing with the development of fruit cultivation on its eastern and southern sides. It extends inland about 31 m., and marks a deep indentation of the coast like the Gulf of Uraba.

_Geology._--The geology of Colombia is very imperfectly known, and it is only by a comparison with the neighbouring regions that it is possible to form any clear idea of the geological structure and succession. The oldest rocks are gneisses and schists, together with granite and other eruptive rocks. These are overlaid by sandstones, slates and limestones, alternating with porphyries and porphyrites sometimes in the form of sheets, sometimes as breccias and conglomerates. Cretaceous fossils have been found abundantly in this series, but it is still possible that earlier systems may be represented. Coal-bearing beds, possibly of Tertiary age, occur in Antioquia and elsewhere. Structurally, the four main chains of Colombia differ considerably from one another in geological constitution. The low Cordilleras of the Chocos, on the west coast, are covered by soft Quaternary sandstones and marls containing shells of extant species, such as still inhabit the neighbouring ocean. The Western Cordillera is the direct continuation of the Western Cordillera of Ecuador, and, like the latter, to judge from the scattered observations which are all that are available, consists chiefly of sandstones and porphyritic rocks of the Cretaceous series. Between the Western and the Central Cordilleras is a longitudinal depression along which the river Cauca finds its way towards the sea. On the western side of this depression there are red sandstones with coal-seams, possibly Tertiary; the floor and the eastern side consist chiefly of ancient crystalline and schistose rocks. The Central Cordillera is the direct continuation of the Eastern Cordillera of Ecuador, and is formed chiefly of gneiss and other crystalline rocks, but sedimentary deposits of Cretaceous age also occur. Finally the Eastern branch, known as the Cordillera of Bogotá, is composed almost entirely of Cretaceous beds thrown into a series of regular anticlinals and synclinals similar to those of the Jura Mountains. The older rocks occasionally appear in the centre of the anticlinals. In all these branches of the Andes the folds run approximately in the direction of the chains, but the Sierra de Santa Marta appears to belong to a totally distinct system of folding, the direction of the folds being from west to east, bending gradually towards the south-east. Although volcanoes are by no means absent, they are much less important than in Ecuador, and their products take a far smaller share in the formation of the Andes. In Ecuador the depression between the Eastern and Western Cordilleras is almost entirely filled with modern lavas and agglomerates; in Colombia the corresponding Cauca depression is almost free from such deposits. In the Central Cordillera volcanoes extend to about 5° N.; in the Western Cordillera they barely enter within the limits of Colombia; in the Cordillera of Bogotá they are entirely absent.[1]

_Climate._--Were it not for the high altitudes of western Colombia, high temperatures would prevail over the whole country, except where modified by the north-east trade winds and the cold ocean current which sweeps up the western coast. The elevated plateaus and summits of the Andes are responsible, however, for many important and profound modifications in climate, not only in respect to the lower temperatures of the higher elevations, but also in respect to the higher temperatures of the sheltered lowland valleys and the varying climatic conditions of the neighbouring plains. The republic lies almost wholly within the north torrid zone, a comparatively small part of the forested Amazonian plain extending beyond the equator into the south torrid zone. The great Andean barrier which crosses the republic from the south to north acts as a condenser to the prevailing easterly winds from the Atlantic, and causes a very heavy rainfall on their eastern slopes and over the forested Amazon plain. High temperatures as well as excessive humidity prevail throughout this region. Farther north, on the open llanos of the Orinoco tributaries, the year is divided into equal parts, an alternating wet and dry season, the sun temperatures being high followed by cool nights, and the temperatures of the rainy season being even higher. The rainfall is heavy in the wet season, causing many of the rivers to spread over extensive areas, but in the dry season the inundated plains become dry, the large rivers fed by the snows and rainfall of the Andes return within their banks, the shallow lagoons and smaller streams dry up, vegetation disappears, and the level plain becomes a desert. The northern plains of the republic are swept by the north-east trades, and here, too, the mountain barriers exercise a strongly modifying influence. The low ridges of the Sierra de Perijá do not wholly shut out these moisture-laden winds, but they cause a heavy rainfall on their eastern slopes, and create a dry area on their western flanks, of which the Vale of Upar is an example. The higher masses of the Sierra Nevada de Santa Marta cover a very limited area, leaving the trade winds a comparatively unbroken sweep across the northern plains until checked by the Western Cordillera, the Panama ranges and the Sierra de Baudo, where a heavy precipitation follows. Farther south the coast ranges cause a very heavy rainfall on their western slopes, which are quite as uninhabitable because of rain and heat as are the coasts of southern Chile through rain and cold. The rainfall on this coast is said to average 73 in., though it is much higher at certain points and in the Atrato Valley. As a result the coastal plain is covered with swamps and tangled forests, and is extremely unhealthy, except at a few favoured points on the coast. High temperatures prevail throughout the greater part of the Magdalena and Cauca valleys, because the mountain ranges which enclose them shut out the prevailing winds. At Honda, on the Magdalena, 664 ft. above sea-level, the mean temperature for the year is 82° F., and the mercury frequently rises to 102° in the shade. These lowland plains and valleys comprise the climatic tropical zone of Colombia, which is characterized by high temperatures, and by excessive humidity and dense forests, an exception to the last-named characteristic being the open llanos where dry summers prevail. Above this tropical zone in the mountainous regions are to be found all the varying gradations of climate which we are accustomed to associate with changes in latitude. There are the subtropical districts of the valleys and slopes between 1500 and 7500 ft. elevation, which include some of the most fertile and productive areas in Colombia; the temperate districts between 7500 and 10,000 ft., the cold, bleak and inhospitable _paramos_ between 10,000 and 15,000 ft., and above these the arctic wastes of ice and snow. The temperate and subtropical regions cover the greater part of the departments traversed by the Eastern Cordillera, the northern end of the Central Cordillera, the Santa Marta plateaus, and the Upper Cauca Valley. They include the larger part of the white population and the chief productive industries of the country. There is no satisfactory record of temperatures and rainfall in these widely different climatic zones from which correct averages can be drawn and compared. Observations have been made and recorded at Bogotá and at some other large towns, but for the greater part of the country we have only fragmentary reports. The mean annual temperature on the eastern plains, so far as known, ranges from 87° F. on the forested slopes to 90° and 91° on the llanos of the Meta and Arauca. On the Caribbean coastal plain it ranges from 80° to 84°, but at Tumaco, on the Pacific coast, within two degrees of the equator, it is only 79°. At Medellin, in the mountainous region of Antioquia, 4950 ft. above sea-level, the mean annual temperature is 70°, and the yearly rainfall 55 in., while at Bogotá, 8563 ft., the former is 57° and the latter 44 in. At Tuquerres, near the frontier of Ecuador, 10,200 ft. elevation, the mean annual temperature is said to be 55°. The changes of seasons are no less complicated and confusing. A considerable part of the republic is covered by the equatorial belt of calms, whose oscillations divide the year into a wet and dry season. This division is modified, however, by the location of mountain ranges and by elevation. In the Amazon region there is no great change during the year, and on the northern plains the so-called dry season is one of light rains except where mountain ranges break the sweep of the north-east trades. The alternating wet and dry seasons are likewise to be found on the Pacific coastal plain, though this region is not entirely dry and vegetation never dries up as on the _llanos_. Above the lowland plains the seasons vary in character according to geographical position and elevation. The two-season division rules in the departments of Santander and Antioquia, but without the extremes of humidity and aridity characteristic of the eastern plains. Farther south, at elevations between 800 and 9500 ft., the year is divided into four distinct seasons--two wet and two dry--the former called _inviernos_ (winters) and the latter _veranos_ (summers). These seasons are governed by the apparent movements of the sun, the winters occurring at the equinoxes and the summers at the solstices. The _sabana_ of Bogotá and neighbouring districts are subject to these changes of season. At higher altitudes long, cold, wet winters are experienced, with so short and cold a summer between them that the bleak _paramos_ are left uninhabited except by a few shepherds in the short dry season.

_Fauna._--The geographical position of Colombia gives to it a fauna and flora largely characteristic of the great tropical region of the Amazon on the south-east, and of the mountainous regions of Central America on the north-west. At the same time it is rich in animal and plant types of its own, especially the latter, and is considered one of the best fields in South America for the student and collector. The fauna is essentially tropical, though a few species characteristic of colder regions are to be found in the higher Andes. Of the Quadrumana there are at least seventeen distinct species, and this number may be increased after a thorough exploration of the forested eastern plains. They are all arboreal in habit, and are to be found throughout the forested lowlands and lower mountain slopes. The carnivora are represented by seven or eight species of the Felidae, the largest of which are the puma (_Felis concolor_) and the jaguar (_F. onca_). These animals, together with the smaller ocelot, have a wide geographical range, and are very numerous in the valley of the Magdalena. Two species of bear and the "coatí" (_Nasua_) represent the plantigrades and inhabit the mountain slopes, and, of Pachydermata, the peccary (_Dicotyles_) and "danta" or tapir (_Tapirus_) have a wide distribution throughout the lowland and lower plateau forests. The Colombian tapir is known as the _Tapirus Roulini_, and is slightly smaller than the Brazilian species (_T. americanus_). There are deer in the forests and on the open savannahs, the rabbit and squirrel are to be seen on the eastern slopes of the Andes, and partly amphibious rodents, the "capybara" (_Hydrochoerus_) and "guagua" (_Coelogenys subniger_), are very numerous along the wooded watercourses. The sloth, armadillo, opossum, skunk and a species of fox complete the list of the more common quadrupeds so far as known, though it is certain that a careful biological survey would discover many others. The large rivers of Colombia and the lakes of the lowlands are filled with alligators, turtles, and fish, and several species of fish are highly esteemed by the natives as food. The saurians are represented on land by several species of lizard, some of them conspicuous for their brilliant colouring, and by the large "iguana," whose flesh is considered a great delicacy. Among the ophidians, which include many harmless species, are the boa-constrictor, rattlesnake, the dreaded _Lachesis_ and the coral snake. The "manatee" (_Manatus americanus_) is found in the Atrato and other large Colombian rivers.

In bird and insect life Colombia is second only to Brazil. The condor, which inhabits the higher Cordilleras, is peculiar to the whole Andean region, and is the largest of the Raptores. Among other members of this order are the eagle, osprey, vulture, buzzard, kite and hawk, with about a dozen species in all. Parrots and paroquets are numerous everywhere in the tropical and subtropical regions, as also the gorgeously coloured macaw and awkward toucan. The largest class, perhaps, is that formed by the astonishing number of water-fowl which throng the shallow lagoons and river beaches at certain seasons of the year. They are mostly migratory in habit, and are to be found in many other countries. Among these are the large white crane and small crane, the blue heron, the snowy-white egret, the roseate spoonbill (_Platalea ajaja_), stork, bittern and many species of ducks. The largest and most conspicuous member of this interesting family is the _Mycteria americana_, the gigantic stork so frequently seen in the Amazon valley, and even more numerous about the lagoons of northern Colombia. One of the best game-birds of the forest is the "crested curassow" (_Crax alector_), sometimes weighing 12lb, which feeds on arboreal fruits and rarely comes to the ground. Colombia also possesses many species of the beautiful little humming-bird, among which are the tiny _Steganura Underwoodi_ and the sword-bill, _Docimastes ensiferus_, which were found by Mr Albert Millican on a bleak _paramo_ 12,000 ft. above sea-level. One of the most interesting birds found in the country is the "weaver-bird" (_Cassicus persicus_), which lives in colonies and suspends its long, pouch-like nest from the end of a horizontal branch of some high, isolated tree. In regard to insects, what has been said of Brazil will apply very closely to Colombia. Mosquitoes, butterflies, spiders, beetles and ants are infinitely numerous, and some of the species are indescribably troublesome.