The Dusky Nightjar is a dark-plumaged highland nightjar. In Costa Rica it nests at forest edges and occurs in high elevations of the Central Volcanic and Talamanca ranges and other highlands.
Adult males are dark slate-gray with rufous spots. Females are lighter and more rufous, with a smaller or absent throat band and no white in the tail; juveniles are rufous above.
It uses montane forest edges and canopy openings. In Costa Rica it lays one egg directly on leaf litter under grass on sloping ground. It is solitary and sedentary.
The single egg laid in Costa Rica is matte chalk-white. Breeding is recorded in February or March–April.
Adult males have white tips on the three outer pairs of tail feathers. Females lack white in the tail.
An extinction-risk assessment has not been added yet.