The western slopes of the Andes fall away to the coastal region, beginning with a large, fertile lowland river plain that extends for around 150km to a range of hills, which rise up to around 900m and form a ridge about 20km inland from the sea.

 

The coastal lowlands have a very warm climate , with temperatures fluctuating between 25°C and 31°C (77-88°F) throughout the year. Here, the humid rainy season runs from December to May, though the dry season is still fairly muggy. The north of the region is generally much wetter throughout the year than the south coast, which barely receives any rainfall during the dry season. At the coast itself, the climate is heavily influenced by oceanic currents, which from May to December are responsible for keeping temperatures down and skies overcast. From June to August, particularly between the northern Guayas and the southern Manabí provinces, the coast is shrouded in thick mist and illuminated by a grey light that leaches everything else of colour.

The northern coastal region was once thickly forested, and included within it the Chocó bioregion , an area of extraordinary biodiversity extending up into Colombia. When the Andes were formed, the Chocó region in the west was cut off from the Amazon rainforests to the east. Since then, these highly humid western forests survived the ravages of the Ice Ages and followed an evolutionary path that diverged from that of their eastern counterparts, and it's thought that anywhere between one-fifth to a half of the 9000 estimated plant and animal species here are endemic, such as the glorious scarlet-and-white tanager, the rufous-crowned antpitta, and the banded ground cuckoo.

Unfortunately, in Ecuador less than five percent of the Chocó forests (which include coastal mangrove forests) have survived the twentieth century. Since the 1950s, the destruction started apace with new roads leading to unplanned colonization and rapid deforestation . The region's fertility has given it the dubious honour of being the most intensively farmed area in Ecuador with banana, rice, cacao, coffee and sugar-cane plantations. The latest threat to the Chocó comes from oil-palm plantations , which in a matter of years have felled about 100,000 hectares of native forests, much of it primary growth. More than twenty animal species are in danger of extinction in the Chocó.

The southern coastal area forms part of the Tumbesian bioregion that continues down into Peru. Originally, much of this distinctive landscape comprised dry tropical forests , suited to the arid southern climate, but almost all of this habitat has now been cleared for agriculture, save a few pockets such as at the Parque Nacional Machalilla and the Bosque Protector Cerro Blanco. Trees and spiny shrubs, such as acacias and cacti grow in abundance, as do some otherwise disappearing native tree species, such as balsam and tillo colorado , long coveted for their fine wood. Plants in the region have adapted to the desert-like environment and many trees, such as the ceiba, lose their leaves when water is scarce during the height of the dry season (July-Oct). Fewer birds live here than in the wet forests, but there are a significant number of range-restricted, endangered species endemic to this area, such as the grey-backed hawk, the ochre-bellied dove and the saffron siskin. Mammals include mantled howler monkeys, capuchins, coatimundi, ocelots and pumas.

Long, empty beaches fringe about one-third of Ecuador's 2000km of coastline , the rest comprising mangrove swamps, marshes, sandy cliffs, river deltas and estuaries. Mangrove trees , which grow in shallow salt or brackish waters, are found especially along quiet shorelines and in estuaries. The most common type in Ecuador is the red mangrove, so named because of its reddish wood, and like all mangroves it has a convoluted mass of arching roots, which support it in the unstable sandy shoreline soils and are exposed at low tide. The mangroves form forests and build up rich organic soil in the knotted network of their roots and branches, supporting a range of other plants and wildlife. Frigate birds, boobies and brown pelicans nest amongst the tangled branches and many types of fish, molluscs and crustaceans make their homes in the protective shelter of the roots.

Mangroves play an essential role in the ecology of coastal areas, but much of Ecuador's mangrove treasury has been squandered, cut down to make way for the construction of profitable shrimp farms - only a few patches have been conserved. Around San Lorenzo near the Colombian border, the Reserva Ecológica Cayapas-Mataje harbours the tallest mangrove forest in the world (some over 64m) as well as lovely coconut forests, teeming bird colonies and rare mammals such as the miniature tree sloth. Ecuador's other national mangrove reserve, Manglares Churute , south of Guayaquil, is home to flamingoes, pelicans and occasionally bottle-nosed dolphins.