Some of the best-known conservation projects with which Fauna & Flora International (FFI) is associated have focused on large animals such as gorillas, elephants, rhinos, tigers and orang-utans. There are good reasons for this. These species are highly threatened, need large areas of habitat to survive, can be seen in many zoos, and are widely known and liked. They are thus first-rate 'flagship species' because they attract our attention to conservation. When we adequately protect substantial blocks of their habitat, and seek to reduce hunting and poaching pressures on them, then there is hope that these animals will be able to breed and persist. 

Of course, there are countless other animal and plant species living in those same habitats, but by protecting the large flagship species we are confident of conserving the whole array of species whose interactions make up their ecosystem. In this sense, these large animals are 'umbrella species'. 

But not every ecosystem containing highly threatened species is fortunate enough to benefit from the umbrella protection afforded by the presence of spectacular large mammals. A good example is limestone hills or 'karst' - those wonderful steep-sided and white rock hills that form some of the most beautiful and popular landscapes in Asia. What makes these areas particularly special is that many of them contain caves. 

The biodiversity of limestone ecosystems, both on the surface and inside the caves, is highly characteristic and restricted to these habitats; it doesn't include tigers and elephants. The limestone species are adapted to cope with the highly alkaline environment and exceedingly dry soil conditions over part of the year. Many species are confined to (or found primarily inside) the caves. Remarkably, some species are confined to a single hill or cave. With no charismatic large mammal as an umbrella species, they still need attention from conservationists. 

Dark Matter

Caves don't tend to be well-liked ecosystems, being extremely dark, often quite cramped, and slippery. And the beasts that live within them such as giant, long-legged centipedes, whip scorpions and hand-sized spiders can be the stuff of nightmares. Nevertheless, one's attitude towards them (and to the woodlice, millipedes, beetles and even cockroaches living alongside them) must surely be tempered by the knowledge that they exist in that place and that place only. Due to the extreme darkness, many specialist cave animals have evolved with no eyes, pigmentation or flying ability, instead developing long antennae and legs to compensate for their lack of sight. These sightless organisms include fishes, millipedes, spiders, shrimps and beetles. The cave environment is normally quite stable, so many species will perish quickly - and become extinct - if the prevailing conditions change. 

With no sunlight reaching into the dark interior, most of the energy that drives the cave ecosystems comes from the faeces or guano dropped by the bats and swiftlets that roost there. Like it or not, this guano and the fungus growing upon it become the base of cave food chains. 

Whip spider in a limestone cave in Kampot Province, Cambodia.

Credit: Jeremy Holden/FFI.

Cave-restricted species continue to be discovered in virtually every newly surveyed tropical limestone area, but Asia seems to be the richest hunting ground. Indeed, FFI-led surveys of one set of caves on Java, Indonesia, revealed no fewer than 40 invertebrate species that were new to science.

For over 15 years, FFI has been actively conserving some of the best limestone areas in Asia and thus protecting remarkable communities of invertebrates. Indeed, no other NGO has more experience and knowledge of karst systems and their conservation in Asia. Where it is possible to find a beautiful mammal that acts as a flagship species to protect the creep-crawlies beneath, we will do so - as with the limestone-restricted Tonkin snub-nosed monkey in Vietnam. But otherwise we need to find other ways to avoid extinctions. 

How can technology help us monitor (and possibly discover) those small cold-blooded critters that live in caves? Tony Whitten

Many of the invertebrate species most in need of conservation attention are little known, and very few have been assessed for the IUCN's Red List of Threatened Species. The FFI office in the David Attenborough Building, Cambridge now hosts the Secretariat of the IUCN Specialist Group on Cave Invertebrates (of which I am the co-chair) and securing a dramatic increase in the number of cave invertebrates assessed for the Red List is one of our urgent priorities. It is clear that the status of many limestone-restricted species is perilous (whether or not they have been formally assessed) and many have already gone extinct as a direct result of economic development, especially quarrying limestone for cement. 

This is where I call on the collective knowledge and creativity of the WILDLABS.NET community: How can technology help us monitor (and possibly discover) those small cold-blooded critters that live in caves? 

We, the IUCN Specialist Group on Cave Invertebrates, want to hear your ideas for technologies that can help us measure and monitor the biodiversity of these unique ecosystems in a non-destructive manner without us having to visit every day, or even every month. As you think of solutions, remember that this isn't a simple question of detecting movement in the dark; the technology needs to be able to detect cold blooded creatures that are likely at the ambient temperature exist against a warm backdrop with absolutely zero light. This means that simple camera traps, heat sensors or IR systems are likely not going to be appropriate, so we need to think outside the box. 

If you have an idea for how we might meet this challenge, join us in the Sensor Group and share your brilliant ideas. I look forward to an inspiring discussion!