Some of the reasons that affect the abundance of wildlife, and the quality of biodiversity are for example the seasons of the year (rainy or dry “periods" in the tropics), migrations, behaviour, breeding season, natural barrers, environmental changes (fires, deforestation) and many others, but surely  there is something always present to the naturalist and is that almost any species “rare” or “common” can show up unexpectedly anywhere to anybody. The following list is only a breef idea of what we considerer some uncommon or highly localized species, and it´s based entirely on personal opinions and trips records. (Include only the three bioregions mentioned in this work).

Guacamaya Verde  /   Military Macaw:    (With a small colony of 8 individuals in Rio Frío area, Southern Maracaibo Lake. First sightings by Angel Ulloa & Alan Highton in 1994) 

Toucan Pico Verde  /  Keel-billed  Toucan:   (Common in Central América. Known in Venezuela only in Perijá Mountains and Santa Rosa Mountains near Casigua, Zulia State. Pers. Obs.)

Colibrí Coludo Verde  /  Green-tailed  Trainbearer:   (Not seen.Known in Venezuela  from a single specimen in the BMNH, colected by A.Goering in Mérida region. Phelps. 1979) 

Perico Multicolor  /  Rusty-faced Parrot:   (Some probable sightings in Sierra Nevada de Mérida.Known by peasants when we show the Field Guide.Páramo El Carrizal.Reported in Tamá) 

Oso Frontino  /  Spectacled Bear:   (Exceptionaly rare to see, with very  few confirm sightings in Venezuela,Thomas Swenson. Pers. Com. And Isaac Goldstein. Pers. Com)

Perro de Monte  /  Bush Dog:   (The rarest canidae in Venezuela. Few sightings.Omar Linares 1998.There is a skin in a restaurant in El Vigia City. Mérida State. Pers. Obs.) 

Gato de Monte  /  Tigrillo, Oncilla:   (People call Tigrito or Tigrillo two similar species, but this is the smallest Venezuelan cat and according with the specialists is the rarer.) 

Manatí del Orinoco  /  Orinocan Manatee:   (Common in the past.Under threat of extinction by hunting and destruction of habitat. A small population still remaining in Southern  Maracaibo) 

Armadillo Gigante  /  Giant Armadillo: (Partialy extincted in some regions.Habitat degrading and hunting.There is a carapace in a house in the lower Paguey River. Pers. Obs.) 

Ranas Arlequin  /  Atelopus Frogs:   (Many species are considered nearly extincted and many others offitialy extincted, like A. mucubajiensis. The reason of it still unknown) 

Laucha  /  Laucha:  (Most of the native species of fish in the high Andes are nearly extincted by the introduction of Trouts from North América in the late 50’s)