New Caledonian crow

New Caledonian crows live on islands in the Pacific Ocean, east of Australia.

They live in forests and in open places with trees.

New Caledonia is a group of islands in the Pacific Ocean, about 1,200 kilometers east of Australia. The crow lives on the biggest island, Grande Terre, and on the nearby island of Maré, where people brought it.

The crows are common in all kinds of forest on Grande Terre. They also live in open savanna with niaouli trees and on farmland. They usually live in pairs or small family groups, sometimes up to 30 birds together.

The IUCN (2018) lists the species as endemic to New Caledonia, a French territory, and introduced to the neighboring island of Maré in the Loyalty Islands. The Oxford group describes New Caledonia as lying about 1,200 kilometers east of Australia, with a main island, Grande Terre, of about 16,000 square kilometers.

Kenward and colleagues (2004) report the crows as common throughout the range of forest types on Grande Terre, and also found in niaouli savanna and agricultural areas. Groups range from pairs to about 30 birds, most often small; larger groups may be temporary gatherings of several family groups.

New Caledonian crows eat insects, grubs, snails, nuts and fruit.

They use their stick tools to pull fat grubs out of holes in dead trees.

New Caledonian crows eat many kinds of food: insects and their grubs, snails, nuts, fruit, seeds, flowers and sometimes other birds' eggs.

Their tools are used for insects and other small creatures that hide. Some tools fish big beetle grubs out of tunnels deep inside dead wood. Others reach small animals under bark and in cracks. Like many crows, they also hide food to eat later and drop snails or nuts to crack them.

Kenward and colleagues (2004), citing earlier naturalists, list insects and their larvae, snails, nuts, fruit, seeds, flowers and other birds' eggs. Tool use appears to be directed exclusively at invertebrates and falls into two classes: tools for extracting large cerambycid (longhorn beetle) larvae that bore deep into wood, and tools for small invertebrates under bark and in crevices (Hunt and Gray 2002).

How much of the diet comes from tool use is not yet known. Food caching and dropping snails or nuts to break them, behaviors seen in many corvids, have also been documented in this species.

These crows make two kinds of tools.

They bend twigs into hooks, and they cut spiky leaves into strips. In a lab, a crow named Betty bent a wire into a hook!

Wild New Caledonian crows make hook tools from twigs and cut tools from the edges of pandanus leaves, which have rows of thorns. The leaf tools are made in several steps. In a big survey, scientists found three different leaf-tool designs, and different areas of the island used different designs.

In a study published in 2002, scientists at Oxford tested a crow named Betty. When she had only a straight wire to reach some food in a little bucket at the bottom of a tube, she bent the wire into a hook and lifted the bucket out. She did it again and again in later tests.

Hunt and Gray (2003) documented 5,550 pandanus tools from 21 sites and found three designs, wide, narrow and stepped, with continuous, overlapping distributions; they propose these arose by cumulative change from a common origin, a hypothesis about animal culture that remains under study. The Oxford group describes pandanus tools, made in a series of steps, as the most sophisticated animal tools yet discovered (Hunt 2000, 2004).

In the laboratory, Weir, Chappell and Kacelnik (Science, 2002) reported that a female, Betty, bent straight garden wire into hooks to lift a food bucket from a vertical tube, repeatedly and with several techniques. The Oxford group notes this was the first time an animal was seen making a new tool for a specific task without extended trial-and-error learning.

There are many New Caledonian crows.

They are not in danger now. They need their forests, so it is important to keep the forests safe.

The New Caledonian crow is not in danger: scientists list it as Least Concern, and its numbers seem steady. It is common in many parts of its island home.

Still, it lives only on a few islands, and the clearing and damage of New Caledonia's forests is a threat to it. Some crows live in protected areas such as Rivière Bleue Park.

BirdLife International's 2018 assessment for the IUCN Red List (assessed 9 August 2018) lists the species as Least Concern: despite a possibly restricted range, the population is believed to be large, the species is described as common in parts of its range, and the trend is suspected to be stable.

The IUCN names clearance and degradation of New Caledonia's forests as a threat. No specific conservation measures have been put in place, but populations occur in protected areas such as Rivière Bleue Park.