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The Pacific coastal plain is overall rather narrow, whereas the Caribbean lowlands are very broad in the

north, tapering down as they reach the Panama border in the south. An important inland extension of the

Pacific slope is known as the Central Valley, ostensibly the watershed of the Tárcoles River, where slightly

higher elevations (mainly 1000–1400m) and cooler temperatures are more agreeable to human settlement

and where the capital city of San José is situated.

Costa Rica’s spine of mountain ranges, increasing in height from northwest to southeast, comprises

the Northern Mountains (including the Guanacaste and Tilarán Cordilleras, reaching 1600–2000m); the

Central Mountains (volcanic massifs reaching 2700–3400m and essentially ringing the Central Valley,

including the Poás, Barva, and Irazú Volcanoes); and the imposing wall of the Talamanca Mountains, which

continues into western Panama and reaches 3800m at Cerro Chirripó, the highest peak in Costa Rica.

Spurs projecting from the Pacific side of the Talamancas form parallel south coastal mountain ranges

that rise to about 1500m and enclose two interior valleys, El General Valley to the north and Coto Brus

Valley to the south, which drain out into the Pacific via the Térraba River.

Climate and Habitat

Costa Rica lies in the latitude of the northeasterly trade winds, which blow in across warm Caribbean

waters and bring rain throughout most of the year, helping make the Caribbean lowlands wet and green

year-round. All else being equal, lowland swamp forest and rainforest would cover these lowlands, but

all is not equal. Today, the Caribbean lowlands of Costa Rica constitute an environmental disaster akin

to the English countryside, and have been mostly cleared by humans for agriculture, particularly cattle,

sugar cane, pineapples, and bananas.

Many classic neotropical groups are well represented among birds typical of the original lowland

habitats, including parrots, toucans, motmots, puffbirds, jacamars, woodcreepers, antbirds, and manakins.

Some species are widespread, ranging from South America north to southern Mexico, such as Scaled

Pigeon, Great Potoo, Collared Aracari, Black-cheeked Woodpecker, White-necked Jacobin, and Great

Antshrike. Others are endemic to southern Central America (Honduras to Panama), such as Black-eared

Wood Quail, Snowy Cotinga, Streak-crowned Antvireo, Tawny-chested Flycatcher, and Black-throated

Wren. La Selva Biological Station, in the northern Caribbean lowlands, protects one of the few remaining

areas of lowland rainforest in Costa Rica.

Sadly, however, forest reserves such as La Selva Biological Station exist only as small, far-flung islands

in an expanding ocean of deforested and cut-over rolling lowlands, which, although deceptively green in

aspect, are often rather lacking in birds, thanks to pesticides or other unseen human forces. In some areas,

a few rainforest species of canopy and mid-levels—such as Short-billed Pigeon, Northern Mealy Amazon,

Slaty-tailed Trogon, and Southern Black-faced Grosbeak—seem able to persist, at least for now, in tree-

scattered agricultural and pasture lands, especially those with remnant forest corridors along watercourses;

but understory and ground-dwelling species, not so much.

Reaching the mountains, moisture-laden air from the Caribbean rises and cools, dropping more rain

and producing a very wet Caribbean foothill zone, where the steep terrain is not as amenable to agriculture

or settlement. This narrow zone is thus relatively well forested but conversely not as easy to access as the

lowlands. These humid foothill forests mark the northern limit for numerous species typical of the Andean

foothills of northwestern South America, such as Green-fronted Lancebill, Red-headed Barbet, Brown-

billed Scythebill, Red-faced Spinetail, Rufous-rumped Antwren, and Rufous-breasted Antthrush. They are

also home to several species endemic to Central America, such as Snowcap, Lattice-tailed Trogon, Black-

hooded Antthrush, Bare-necked Umbrellabird, Gray-headed Piprites, and Blue-and-gold Tanager. Braulio

Carrillo National Park, only a short distance north of San José, offers access to this rich habitat zone.

With increasing elevation, temperatures cool and a temperate highland flora takes over, including cloud

forest locally and, in the Central and Talamanca Mountains, extensive humid oak forest and bamboo. At

the highest and coolest elevations, forest gives way to an open, wet shrubby habitat known as páramo.

Long isolated from the highlands of northern Central America and eastern Panama, the highlands of Costa

Rica and adjacent Panama are a major center of avian endemism. Some of the endemics are common

and widespread, seen relatively easily, such as Fiery-throated and Volcano Hummingbirds, Prong-billed

Barbet, Sooty Thrush, Long-tailed Silky, Collared Whitestart, and Sooty-capped Bush-tanager. Others

are more local or elusive, including Silvery-throated Jay, Silvery-fronted Tapaculo, Ochraceous Pewee,

Timberline Wren, Wrenthrush, and Peg-billed Finch. Access to this high-elevation habitat is easily

achieved along the Pan-American Highway south of Cartago where it passes along the spine of Cerro

de la Muerte.