30/04/2020

Invertebrate of the Month: Lord Howe Island stick insect

This month our star invertebrate is the critically endangered Lord Howe Island stick insect

Hello, my name is Louiza and I am a legendary Lord Howe Island stick insect.

I was hatched and raised at Bristol Zoo Gardens, spending all 18 months of my life so far in Bug World living in my own exclusive room, so I have never met the other invertebrates. I need to be kept separate so that pathogens from them don’t get transferred to me. I am super rare - so rare, in fact, that I am registered as Critically Endangered by the IUCN Red List of Threatened Species™.

Since 1918, I was considered extinct. A ship ran aground on Lord Howe Island (my home) in the early 20th century and introduced black rats which saw us as a delicious snack and practically ate us to extinction. (We are wingless, which made fleeing ravenous rats rather difficult - it doesn’t help that we are a rather enticing meaty snack, weighing 20-25g per insect.) Miraculously, in 2001, twenty of us were discovered hiding under a Lord Howe Island Melaleuca plant on a volcanic spike known as Ball’s pyramid. Ball’s pyramid is the only location my family is still surviving on as it’s rat-fee. We are herbivores and we are fond of Melaleuca - you should give it a try some time. Though, as you are human, it’s probably not your cup of tea.

Two years later, two breeding pairs were transported to Melbourne Zoo. In 2013, other zoos such as Budapest and San Diego took eggs to assist with the breeding programme coordinated by Melbourne. Then, in 2015, more eggs were distributed to San Diego and Toronto. Bristol Zoo Gardens also received 299 eggs (my grandparents among them) from Melbourne Zoo, and became the first collection outside of Australia to successfully breed our species. I trust that Bristol Zoo Gardens will be excellent carers for my children. We will thrive once again.

Every time we mate, we lay 9-10 eggs and bury them in the ground where they remain until they hatch. Once hatched, the hatchlings tunnel to the surface and clamber to safety onto a branch. My daughter Lola recently hatched at Bristol Zoo Gardens; pride fills me as I watch her already being wise and performing behaviours to avoid predators. Currently, she is so small (approximately 2cm) compared to me (13cm) and she is a gorgeous pale green – though, as she moults and matures, she will get darker in colour until she is a glossy black with a reddish-brown tinge. 

Her light green colour helps her hide amongst the foliage, allowing her to remain well-hidden when predators are on the prowl. If she is spotted, she will do me proud and run like her life depends on it, because it does.

For the first few months of Lola’s life, I won’t encounter her as she will be active in the day and I much prefer to be nocturnal; but, as she gets older, she will gradually become nocturnal and I may get to say hello as we feed on the foliage of lucerne at night and shelter in our wooden box during the day.

Once Bristol Zoo Gardens has a substantially large population of us, they hope to be able to pass on eggs to other European collections to act as more ambassadors for our incredible species. I know that, with Bristol Zoo’s help, Lola can significantly contribute to this goal and help our species to thrive once again.

Thank you, Bristol Zoo Gardens!

Blog post written by Laura Thomas, placement student in Bug World.

We miss you and your support

Donate

We miss you and your support