Little is known about the behaviors of Crested Eagle other than nest observations and limited foraging observations.

Foraging behavior has rarely been observed, but prey is seemingly taken while in flight (Julliot 1994). In contrast to Harpy Eagle (Harpia harpyja), Crested Eagle regularly soars, either in pairs or solitary; this is generally assumed to be a foraging behavior (Wetmore 1965, Bierregaard 1994). In two specific instances, Crested Eagle behavior in taking juvenile tamarins has been reported: 1) a tamarin was taken while in flight after the eagle was seen soaring overhead (attack in exposed canopy at height of twenty meters). 2) The tamarin was taken in flight, but the eagle was seen perched about ten meters from the feeding tree before the attack (attack in sub-canopy at height of 13 meters) (Vasquez and Heymann 2001). In other observations, Crested Eagles have often been seen perched on tall roosts for long periods, possibly watching for prey (Bierregaard 1994). Most attacks on prey are in forest interior.

There is little data on territoriality for Crested Eagle. Pairs may have a range of over 100 km², but there is no evidence that pairs defend these ranges (Galetti et al. 1997). Threat displays by juveniles and brooding females towards passing vultures may or may not indicate territoriality (Whitacre et al. 2002). Thiollay (1989) estimated a density of 4 individuals/100 km² in French Guiana. Galletti et al. (1997) reports Crested Eagles from multiple locales that are characterized by a minimum area of 320 km² of continuous forest. Galletti et al. (1997) also suggest that each pair of Crested Eagles may have a home range of more than 100 km².

Little is known about courtship. Bierregaard (1984) witnessed that copulation is brief (less than ten seconds) and seems to occur in the nest. After copulation, the male hopped from perch to perch in the nest tree and gave a single high pitched whistle, but no other courtship was displayed.

Solitary, except when breeding.

No information.