Coracopsis vasa (Shaw, 1812)

Taxonomic Identification

The greater vasa parrot, Coracopsis vasa (Shaw, 1812), has an uncertain breeding season that is most likely between October and December.

Breeding Biology Sexual Dimorphism

This species has a very unusual breeding biology and mating system: females are 25% larger than males and are physically dominant.

Mating System

Greater vasa parrots live in loose, polygynandrous groups, where each female has at least 3 to 8 sexual partners.

Male Copulatory Anatomy

Males of this species have re-evolved a phallus, and copulations can last up to 90 minutes.

Copulation Duration Categories

Copulations occur in two length categories: short, lasting 1 to 3 seconds, and long, with an average duration of 36 minutes.

Copulatory Tie Trait

Long copulations involve a copulatory tie, a trait most commonly seen in mammals such as canids and felids.

Copulatory Tie Mechanism

During a copulatory tie, the male and female cannot physically separate during mating, caused by swelling and the internal structure of the penis within the female’s body—this structure may be barbed or lined with small hooks in some species.

Female Brooding Morphology

During brooding and chick-rearing, females shed their head feathers and develop bright orange skin.

Female Nest-Perched Song

They also sing complex songs from perches close to their nests.

Male Food Provisioning

These behaviors attract males, who approach and regurgitate food that the female accepts while she is off the nest.

Female Nest Territory Defense

During this period, females also defend a territory around their nest against other females.

Madagascar Habitat Preference

In Madagascar, the greater vasa parrot is more common in areas of dry deciduous forest.

Congeneric Habitat Comparison

This differs from the closely related lesser vasa parrot, which is more common in the humid forests along Madagascar’s east coast.

Flock Feeding Behavior

Greater vasa parrots feed in large, noisy flocks.

Diet Composition

Their diet includes wild berries, fruits, nuts, seeds, and cultivated crops such as maize, millet, and rice.

Nocturnal and Roosting Behavior

These parrots are active on moonlit nights; at other times, they roost in large noisy flocks in the canopies of large trees.

Flock Lookout Role

One individual in the flock acts as a lookout to warn other group members of danger.

Captive Tool Use Observation

Greater vasa parrots held at Lincolnshire Wildlife Park have been recorded using grinding technology, marking the first time this behavior has been observed in a non-human animal.

Grinding Behavior Mechanics

The birds were observed holding date stones and pebbles in their beak to grind calcium-rich dust from seashells.

Grinding Behavior Temporal and Sex Patterns

This grinding behavior occurs most frequently just before the breeding season, and males were observed performing it more often than females.

Grinding Behavior Functional Hypothesis

A possible explanation for this pattern is that females need extra calcium to build eggshells, and males provide this calcium to females via regurgitated food.