SPECIES

Olive Oropendola Psarocolius bifasciatus Scientific name definitions

Harold F. Greeney
Version: 2.0 — Published June 10, 2022

Behavior

Introduction

Further study would help to foster a better understanding of this social bird; its general behavior and habits are not known to differ much from other oropendolas (183, 4, 34, 3, 189).

Locomotion

Flight

The Olive Oropendola is usually seen high in or above the canopy flying over with heavy, easily audible wingbeats (33).

Self-Maintenance

Preening

Preening is not known to differ from other oropendola species. The bill is used to preen and smooth feathers (see below).

Agonistic Behavior

Males are known to be aggressive towards each other, particularly during the breeding season, and may also act aggressively towards caciques or other species of oropendolas attempting to nest nearby (192, 5). Aggressive interactions at a canopy termite swarm included interactions between two Olive Oropendolas, and between an Olive Oropendola and Spix's Guan (Penelope jacquacu) (194). See also Sexual Behavior and Breeding: Brood Parasitism.

Sexual Behavior

Mating System and Operational Sex Ratio

Although it has not been specifically documented, the Olive Oropendola is presumed to be a highly polygynous species, based on observations of male behaviors and nest clustering within colonies (2, 192, 5). The sex ratio of breeding adults within colonies suggests a harem polygynous mating system, with ratios as high as seven females per male (2, 192).

Courtship, Copulation, and Pair Bond

Based on observations of subspecies yuracares in southern Venezuela, Rodríguez-Ferraro (192) described the phenology of nesting behaviors at two colonies. Early in the breeding season, and while females are building, males spend the majority of daylight hours resting, displaying, or preening from a from a preferred perch within the colony tree. This perch may be contested by other males. Once females approach nest completion and prepare to lay eggs, the males’ rate of display increases dramatically and tends to take place at the nest site rather than from the perch they occupied during early nest construction.

Jaramillo and Burke (2) summarized the observations of Rodríguez-Ferraro on Venezuelan colonies, describing the changes in general activity that was subsequently published by Rodríguez-Ferraro (192). Most of these observations were supported by observations at Bolivian colonies (5).

From Jaramillo and Burke (2):

“Colony activity is high during the nest-building and chick-feeding stage, but declines noticeably during the incubation stage. At times, an oropendola colony may appear almost deserted while incubation is underway. Males are always present at the colony, and observations suggest that one of the males is dominant and spends most of his time at the colony. During the receptive period of the females, the dominant male is seldom away from the colony. Other males will display near the colony tree, but these are driven off by this male if they approach too closely. Attendance by other males appears to be highest during the nest-building stage. Copulations do not occur at the colony; this may allow males other than the dominant male access to mate with the females. Females forage singly, or in groups, and often in the company of lone males. Males do not consort with other males during the breeding season and are usually encountered foraging alone if they are not accompanying females.”

While on their chosen perch, or later while standing on or near a nest within their colony, males perform a bowing display that accompanies their song (3, 4, 187). This display is similar to that of other oropendolas. Based largely on the observations of Rodríguez-Ferraro (192) at two yuracares colonies in Venezuela, Jaramillo and Burke (2) describe the display as follows. “[The male] bends down and bows his head deeply, while drooping the rapidly vibrating wings. He culminates the display by bending forward more dramatically and cocking the tail upwards as the rump feathers are raised; the final liquid gurgle part of the song is given at this point. In 'less extreme' displays, the wings are not flapped. There is no audible wing noise while displaying.”

Social and Interspecific Behavior

Degree of Sociality

Although it appears that the Olive Oropendola forages, breeds, and assorts most frequently in small monospecific groups, at least on occasion, it will join large heterospecific feeding flocks of other oropendolas (particularly Green Oropendola (Psarocolius viridis)), caciques, and jays (126, 2), and is sometimes found roosting with other oropendola species on river islands (34). It has been documented in mixed-species breeding colonies with other icterids, including Red-rumped Cacique (Cacicus haemorrhous) (192), Yellow-rumped Cacique (Cacicus cela)) (178, 5), Selva Cacique (Cacicus koepckeae) (195), and Crested Oropendola (Psarocolius decumanus) (5). See also Breeding: Nest Site.

Recommended Citation

Greeney, H. F. (2022). Olive Oropendola (Psarocolius bifasciatus), version 2.0. In Birds of the World (B. K. Keeney, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.olioro1.02