Cocos Finch

The Cocos finch, or Cocos Island finch (Pinaroloxias inornata), presents itself as a modestly adorned bird, the sole representative of its genus and a unique outlier among Darwin's finches, as it is not native to the Galápagos Islands. This bird, approximately 12 cm in length and weighing around 12.5 g, is characterized by its black decurved pointed bill, an adaptation for its diet of berries and insects.

Identification Tips

Male Cocos finches are predominantly black, with feathers covering the tail, breast, nape, and crown. Their beaks remain black throughout the year, a trait that distinguishes them from their Galápagos counterparts. Females, on the other hand, exhibit a lighter brown hue with a speckling of black feathers extending from the breast to the flank and rump, and a contrasting milky white belly. The young are similar in appearance but are noted for their yellow bills.

Habitat

The Cocos finch is endemic to the lush, rainforest-clad Cocos Island, a Pacific gem located some 580 km southeast of Costa Rica. Its preferred habitats include Hibiscus thickets, closed-canopy forests, and woodland areas.

Distribution

This bird's range is confined to the 30 km² of Cocos Island, where it has not been observed to venture beyond.

Behaviour

Cocos finches exhibit a generalist approach to life, yet individuals may develop specialized foraging behaviors, a trait hypothesized to be learned through observation of their peers. This behavioral plasticity allows them to adapt to various ecological niches without morphological changes.

Song & Calls

The vocal repertoire of the Cocos finch includes a "buzzy" sound with a high-pitched terminal note. The call may start with a "djirr" and end with a "tiew," or alternatively, it may feature a high-pitched "phzzzz."

Breeding

Breeding season peaks around January to February, although nesting can occur throughout the year. Nests are crafted from lichen and dry moss, typically containing two brown-spotted white eggs, and are placed at the end of tree branches.

Similar Species

There are no similar species on Cocos Island, as the Cocos finch is the sole member of its genus in this location.

Diet and Feeding

The Cocos finch's diet consists primarily of berries and insects. Individual birds may exhibit unique foraging behaviors, which are not linked to age, sex, or morphological differences but rather to learned behaviors from conspecifics.

Conservation status

The Cocos finch is classified as Least Concern by the IUCN, with an estimated population of 6,000-15,000 individuals. The species benefits from the natural reserve status of Cocos Island, which limits human disturbance and has a low predation rate, contributing to a stable population.