Spiky yellow blog

Wednesday 25th June 2014

I was lucky enough to catch up with a Spiky yellow woodlouse (Pseudolaureola atlantica) whilst on St Helena. This crazy isopod looks more like a toy than a real species, but seeing them was a real treat as it is one of the world’s rarest creatures.

Spikies are highly endangered – only found on St Helena and nowhere else in the world, they are restricted to very specific areas of habitat. Until recently, the total population size was thought to be about 50 but then a satellite population was found. This looks to have nearly doubled the population.

Whilst a doubling in population size is fantastic news, when you compare this to other, more high profile endangered species such as the Mountain gorilla (population size approximately 880), the Black rhino (population sized around 4,000 individuals) and the Sumatran elephant (population around 2,500 individuals) it is abundantly clear how rare the poor spiky is. Action is really needed.

I have mentioned in my previous blogs that much of the original habitat that covered the island has gone, either grazed into oblivion, cut for timber or outcompeted by invasive species like the New Zealand flax. This has had a huge impact on the Spiky. It lives in the Cloud Forest which originally would have covered many of the high ridges on the island but now exists in tiny fragmented pockets. The area at High Peak where the main Spiky population can be found is about half the size of a tennis court, if that. It is tiny. At High Peak the Spikies can be found scuttling about on the ferns underneath the Black cabbage tree, the canopy of the trees creating a lovely, squelchy, humid atmosphere.

In theory it should be possible to boost the population by protecting and expanding the area of habitat that remains. However, this is St Helena and restoring the habitat is really difficult! Not only is the site about 20 metres from a cliff edge, it is also on a 45 degree slope which is battered by the trade winds coming off of the Atlantic. As the Black cabbage tree does such a good job retaining moisture it is difficult for re-colonisation to occur outside of the woodland as the soil dries out easily due to the wind and sun. Re-planting is one option, but again without the closed woodland canopy to offer some protection to the seedlings, success is difficult. Spiky yellow woodlouse (Pseudolaureola atlantica) (c) Alice Farr

Whilst the situation for the Spiky is undoubtedly serious there is a plan and awareness is growing. The St Helena National Trust is working hard to make sure they are not lost. To offer some protection for the regenerating seedlings they have rigged up a shelter which offers protection from the punishing sun and Atlantic winds. They are re-planting the Black cabbage and other native species to try and increase the forest and are also looking at captive breeding of the Spikies. Buglife is supporting the work where we can – we helped with the shelter and are working with the Trust on the captive breeding programme.

After reading this you may think that this is a lot of effort for one, tiny species, or that money could be spent on conservation work with wider benefits – it’s lucky the Spiky looks so good! On closer inspection there are huge benefits to this work. Safeguarding and expanding the precious fragments of Cloud Forest on St Helena is of major conservation benefit. Increasing this forest will help many other endemic species, not just invertebrates but the lichens, mosses and trees that are still in danger of extinction.