CR

Mariana Crow

Corvus kubaryi

Declining

Overview

The Mariana crow is a species of the crow family from the tropical Western Pacific. It is a glossy black bird about 15 inches (38 cm) long and known only from the islands of Guam and Rota.

The Mariana Crow faces severe population decline primarily due to introduced predators, particularly brown tree snakes that prey on eggs and nestlings. Habitat degradation from invasive plant species and human development has reduced suitable nesting sites, while the species' extremely small population size makes it vulnerable to stochastic events and genetic bottlenecks.

Threat summary

Habitat

The Mariana Crow inhabits native limestone forests, secondary forests, and forest edges on the islands of Guam and Rota in the Mariana Islands. It prefers areas with mature trees for nesting and foraging, particularly native species like Pisonia and Ficus.

Forest· majorMarine coastal/supratidal· majorRocky areas· major

Conservation measures underway

Species managementSpecies recoveryAwareness & communications

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Frequently asked questions

Why is Mariana Crow classified as Critically Endangered?
Mariana Crow is classified as Critically Endangered — facing an extremely high risk of extinction in the wild — because population sizes are very small, declining sharply, or restricted to a tiny range. The Mariana Crow faces severe population decline primarily due to introduced predators, particularly brown tree snakes that prey on eggs and nestlings. Habitat degradation from invasive plant species and human development has reduced suitable nesting sites, while the species' extremely small population size makes it vulnerable to stochastic events and genetic bottlenecks.
Where does Mariana Crow live?
Mariana Crow occurs in Guam, Northern Mariana Islands, and United States. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Mariana Crow?
The main threats to Mariana Crow are 1.1, 11.1, 2.1, and 8.1. The full IUCN-classified threat record for this species is detailed on the species page.

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