A weather regime dominated from the Caribbean Sea influences the Yalijux mountain range with an annual rainfall of 4,000 mm (160 in). In addition, the forest filters a high amount of water from the clouds, which is a main characteristic of cloud forest, an evergreen, very humid broadleaf forest. Chelemhá preserves pristine cloud forest with a mean canopy height of 30 m.
The cloud forest of Chelemhá typifies what many people in northern latitudes imagine as "jungle" - an impressive chaotic green. Epiphytes grow upon branches and trunks of giant trees. The exuberant development of mosses, ferns, orchids, bromeliads and other epiphytes is typical to tropical cloud forests. These plants form true gardens with ton-weighty charges upon huge branches. Oak (Quercus spp.) and a variety of wild Avocado (Lauraceae) are characteristic trees of the Chelemhá cloud forest. Some species of the latter family have small fruit, of approximately 2 cm in diameter, which is the Quetzal's main food. Single pine trees (Pinus sp.) grow on ridges and on naturally disturbed areas, like landslides. Elfin forest, a few meter tall scrub of Ericaceae plants, grows on the most wind-exposed ridges. Tree ferns (Cyatheaceae and Dicksoniaceae) and palms (Chamedorea spp.) are obvious parts of the cloud forest understory. The forest of Chelemhá is full of surprises. In the 1980ies a 3 meter tall shrub was discovered unknown to science. It was later described as Solenophora schleehaufii from the Gesneriaceae family (Weigend & Förther 2002).
Chelemhá is home to a diverse fauna. Large mammals of the Chelemhá cloud forest include Guatemalan Howler Monkeys (Alouatta pigra), Brocket Deer (Mazama americana), Collared Pecary (Tayassu tajacu), Paca (Agouti paca), Mexican Porcupine (Sphiggurus mexicanus), and Gray Fox (Urucyon cineroargentatus). The loud calls of the nocturnal Cacomistles (Bassariscus sumichrasti) are heard, and sometimes Kinkajous (Potos flavus) can be seen at night. Also top predators roam through the Chelemhá cloud forest. Footprints and scats of large cats such as the Puma (Puma concolor) and Jaguar (Panthera onca) have been recorded by the PROEVAL RAXMU Bird Monitoring Program.
The Quetzal (Pharomachrus mocinno) is the national bird of Guatemala, and it lives only in cloud forests. Many Guatemalans have never seen the bird. The Quetzal belongs to the trogon family (Trogonidae) and is one of the most spectacular birds of the continent. Adult males have extremely elongated uppertail coverts, which grow almost a meter long. During the breeding season, males perform spectacular display flights. They ascend from trees on the ridges with a kwa-kwa kwa-kwa ... call and undulating flight into the sky, before falling like green lightning and disappearing into the canopy. Males and females both incubate the eggs and take care of their young. After the breeding season, Quetzals migrate to lower altitudes.
The Mesoamerican cloud forests have been identified as hotspots of biodiversity and centers of endemism (Bibby et al. 1992). Birds such as Black-throated Jay (Cyanolyca pumilo), Highland Guan (Penelopina nigra), Green-throated Mountain-gem (Lampornis viridipallens), and Blue-throated Motmot (Aspatha gularis) live only in mountain ranges of northern Central America. The cloud forest of Chelemhá is home to 16 of these species.
Although birds are the best known animal group in Chelemhá, many aspects on their natural history remain to be discovered. Even more remains to be learned about other taxa including arthropods such as butterflies, beetles, grasshoppers, spiders and so on. Even species yet unknown to science can be expected in the cloud forest.
Bibby, C. J., N. J.Collar, M. J. Crosby, M. F. Heath, C. Imboden, T. H. Johnson, A. J. Long, A. J. Stattersfield, & S. J. Thirgood (1992): Putting biodiversity on the map: priority areas for global conservation. International Council for Bird Preservation, Cambridge, UK.
Richards, P. W. (1996): The tropical rain forest. Cambridge University Press, Cambridge.
Weigend, M. & H. Förther (2002): A revision of the Central American genus Solenophora (Gesneriaceae). Harvard Papers Bot. 7: 37-78.