This is the Lord Howe Island stick insect, or Dryococelus australis.

It is a large, flightless insect, with sturdy legs that enable it to run quickly. Nymphs are a pale green, becoming uniformly black at maturity, often with a reddish-brown tinge. The body is relatively plump for members of this order, and generally smooth and shiny. The intersegmental membranes between the joints are pale grey. Females can grow up to 20 cm long, the males are slightly smaller.

Stick insects are unique in that their 6 legs move completely independently of each other, and are not operated by a centralised control system.

This species is thought to display some degree of pair bonding, which is extremely unusual for an insect. Males and females will sleep beside each other, with their legs intertwined. Females are also capable of reproduction without males, essentially producing clones of themselves.

After hatching, they grow rapidly, and have a lifespan of just 12 to 18 months.

In their natural habitat on Lord Howe Island - a volcanic remnant 15 square kilometers in size in the Tasman Sea - they have been reported to live colonially in the hollows of trees, in groups up to several hundred strong.

This species is, however, currently one of the rarest insects on the planet, with fewer than 50 individuals remaining in the wild.

In fact, it was considered extinct soon after the accidental introduction of the black rat (Rattus rattus) to Lord Howe Island in 1918. The rats found the insect and the island’s other trusting creatures an easy catch, and multiplied quickly. The last sighting of this species on Lord Howe was in 1920. In 1921, a resident of the island reported that the cacophony of bird calls in the lush forest had all but stopped - just 3 years after the black rats’ establishment. Within a decade, the rat had directly caused the disappearance of five species of birds, and two species of snails. Two other species of birds were brought to the edge if extinction, and are currently critically endangered.

Amazingly, in 2001, three individuals of the insect were discovered on Ball’s Pyramid, a tall, sheer volcanic sea stack 23 kilometers offshore from Lord Howe Island. Ball’s Pyramid sustains little life. It is nearly completely free of vegetation, apart from a few shrubs (Melaleuca howeana) which survive in a crevice where fresh water seeps from the rocks below. It was on one of these shrubs that the stick insect population was found, sharing the plant with two pairs of nesting seabirds. This seemingly inhospitable environment is a far cry from the green, moist rainforest of Lord Howe Island, and it isn’t clear how the insects came to be there, or how they managed to survive. On such an exposed site, one strong storm could have destroyed the entire colony.
A further investigation revealed a total of 24 individuals in this small area of Ball’s Pyramid. Two pairs were removed in 2004, and a captive breeding program was set up. The breeding program was very successful - there are now more than 13,000 Lord Howe Island stick insects in zoos worldwide.

In 2019, Lord Howe Island underwent the largest and most complex rodent eradication program ever attempted, which involved the shielding of the 207 extant native bird species - as well as the 382 human inhabitants - from the poisonous bait. Conservationists are constantly on the lookout for signs of rodent life. If the island is still rat-free in 2021, the Lord Howe Island stick insect will be reintroduced to its native habitat, 100 years after its disappearance.