From extinction to survival: the journey of the Lord Howe stick insect

The Lord Howe stick insect, considered one of the rarest invertebrates in the world, has been saved from extinction thanks to joint conservation efforts by Melbourne Zoo and San Diego

On the gloved hands of Kyle Kassel, a keeper at the San Diego Zoo, moves the Lord Howe Island stick insect, nicknamed the “tree lobster” for its impressive size of nearly 8 inches. This brave little creature, once declared extinct, now symbolizes an extraordinary battle for survival. How is it possible that an invertebrate, considered the rarest in the world, has become a beacon of hope for conservation?

From the brink of extinction to a conservation success story

The Lord Howe Island stick insect, known as one of the rarest invertebrates globally, was nearly wiped out due to rats accidentally introduced to the island in 1918. However, a fortunate discovery on Ball’s Pyramid in 2001 sparked an ambitious conservation program. The Melbourne Zoo, with its expertise in invertebrate care, played a pivotal role in rescuing and breeding these insects from just two individuals named Adam and Eve.

Thanks to intensive breeding methods and the dedication of the zoo team, the population has grown to about 500 individuals. In 2017, a new female was introduced to increase genetic diversity, and now the San Diego Zoo is also contributing successfully to the conservation effort.

The importance of invertebrate conservation and the challenges faced

Despite receiving less attention than vertebrates, invertebrates like the Lord Howe Island stick insect play crucial roles in ecosystems as pollinators, predators, and decomposers. Captive breeding programs, like those conducted in Melbourne and San Diego, are vital for saving declining populations and restoring their vital functions.

However, the success of these programs depends on the availability of viable habitats and the acceptance of local communities. The story of the Lord Howe Island stick insect shows how challenging and delicate the reintroduction process can be. The removal of rats from the island in 2019 has set the stage, but reintroduction requires careful consultation with residents, many of whom have never lived with these insects.

Keeping insects in captivity poses problems such as inbreeding and rapid evolution. The Melbourne Zoo has observed evolutionary changes in captive-bred insects, such as reduced eye size and fewer olfactory receptors, which could compromise their survival in the wild. Additionally, managing hundreds of invertebrates requires significant resources, including the necessary plants to feed them.

Moreover, preparing local communities for reintroduction is crucial. On Lord Howe Island, educating the population about the ecological benefits of stick insects is a priority to ensure a successful reintroduction. Cristina Venables, the island’s environmental manager, is working to raise awareness among the inhabitants and involve them in caring for the insects.

At their current habitat in the San Diego Zoo, the Lord Howe Island stick insects live in optimal conditions that replicate the climate of their native island. Here, a team of 13 keepers takes care of the insects, alongside other invertebrates like tarantulas, mantids, and horseshoe crabs. This controlled environment has allowed the population to reach about 400 individuals, a tangible sign of the success of the conservation program.

Source: NYTimes