The Marail guan or Cayenne guan (Penelope marail ) is a species of bird in the family Cracidae, the chachalacas, guans, and curassows. It is found in Brazil, French Guiana, Guyana, Suriname, and Venezuela.
The Marail guan is 63 to 68 cm (2.1 to 2.2 ft) long. Males weigh 772 to 1,310 g (1.7 to 2.9 lb) and females 770 to 1,450 g (1.7 to 3.2 lb). The back, wings, and central tail feathers of the nominate subspecies are dark with a greenish olive gloss. The outer tail feathers are bluish black. Its throat and chest are dark with white speckles and the belly reddish brown. It has a red dewlap. P. m. jacupeba is slightly smaller, paler, and more a grayish brown.
The nominate subspecies of Marail guan is found from eastern Venezuela through the Guianas. P. m. jacupeba is found in northern Brazil north of the Amazon River and possibly in southeastern Venezuela, although not all authorities accept the latter. It mostly inhabits mature tropical forest though it can be found in secondary forest. In the Guianas and Brazil is favors terre firma forest with dense undergrowth. It is a bird of the lowlands, in Venezuela ranging between 100 and 600 m (330 and 1,970 ft) of elevation.
The Marail guan appears to be sedentary. A study in Suriname found territories ranged in size from 2 to 9 ha (4.9 to 22 acres).
The Marail guan forages singly or in groups of up to six, mostly in the canopy and lower levels of the forest but sometimes on the ground. Its diet is almost entirely fruits though insects are occasionally taken.
The Marail guan's breeding season varies within its range. It appears to span from October to February in the Guianas and extend further in Brazil. It builds a cup nest high in a tree fork and lays two or three eggs.
