Black Guan (Chamaepetes unicolor)

About Black Guan (Chamaepetes unicolor)

• Kingdom: Animals
• Phylum: Chordates
• Class: Birds
• Order: Turkey-like birds
• Family: Chachalacas, Guans, and Curassows

This taxon occurs in the Talamancan montane forests, an ecoregion situated along the mountainous spine of the Cordillera Talamanca within Costa Rica and Panama. These forests represent one of Central America’s most intact habitats. The steep slopes, remoteness and relatively cool temperatures have limited the impact of agriculture and human development in most of this area.

This region exhibits considerable floral and faunal species diversity, many of which taxa are endemic. Over 30 percent of the ecoregion's flora, including over 10,000  vascular and 4000 non-vascular plant species, are endemic to this area, as are a number of fauna species. Nearly 75 percent of original forest cover remains intact, with forty percent protected by national and international parks.

The rainfall and temperature in this area of Central America is a direct result of the elevation and orientation north or south side of the mountain range. The average temperature and rainfall for this part of Costa Rica varies from 25°C and 2000 millimetres (mm) at the Caribbean Sea level to –8° C and >6000 mm at the highest peaks including Cerro Chirripo, the highest point in southern Central America at 3820 m. The high humidity and precipitation (which averages between 2500 and 6500 mm annually), steep slopes, and cool temperatures have limited agricultural and urban development, making these highland moist forests one of Central America's most intact ecosystems.

The forest habitats of this ecoregion include Atlantic slope "aseasonal" rainforest, Pacific slope seasonally dry but mostly evergreen forest, and "perpetually dripping cloud forest" on the mountain tops, above approximately 1500 m. The high annual rainfall, wind-blown mist, and frequent presence of clouds, probably the most outstanding characteristic of these montane forests, produce a lush, dense forest with a broken canopy and high species diversity. Abundant epiphytes cover tree branches, and tree ferns are common. Dominant tree groups include the Lauraceae family, especially in the northern section of the ecoregion, and endemic oaks (Quercus spp.), especially in the south. The unique oak forest stands in this ecoregion are characterized by majestic, tall trees (up to 50 m tall), heavily dominated by two species: Quercus costaricensis and Q. copeyensis, while Magnolia, Drymis, and Weinmannia are also important tree elements. The understory is characterized by the presence of several species of dwarf bamboo (Chusquea). Higher peaks and ridges exposed to moisture-laden trade winds support an elfin, or dwarf forest characterized by thick mats of bryophytes covering short, dense gnarled trees.

Seismically induced phenomena, volcanism, and landslides (triggered by torrential rains or earthquakes) are the major natural disturbances influencing the montane forest units within the Talamancan Range. The resulting steep slopes and nutrient-deficient soils insure that this ecoregion harbors some of the most intact in Central America. The La Amistad International Park, one of the largest reserves in Central America, consists of over 400,000 hectares of relatively intact montane forest. These larger blocks of intact forest are essential for preserving remnant populations of harpy eagles (Harpia harpyja) and they protect breeding grounds of threatened and endangered birds endemic to the highland forests of this ecoregion, such as: resplendent quetzal (Pharomacrus mocinno), three-wattled bellbird (Procnias tricarunculata), bare-necked umbrellabird (Cephalopterus glabricollis), and black guan (Chamaepetes unicolor). The first three of these birds migrate seasonally to lower elevations, demonstrating the importance of not only maintaining intact highland habitats but also connecting them to neighboring intact middle and lower elevations. In fact, over 65 (or over ten percent) of the bird species found here migrate altitudinally.

The Atlantic middle elevations also contain some of the most rare species of  butterflies Central America, as well as some of the world's highest butterfly species richness. Populations of crested eagle and painted parakeet were recently discovered in Cerro Hoya on the Azuero Peninsula.