Every lizard counts

“We’ve got a runner!” A blue-tailed skink the length of a birthday candle sits atop a stack of sticks and rocks, which in turn sits on top of the lizard’s perspex tank. Today is census day at Christmas Island National Park’s captive breeding facility, known as the Lizard Lodge, and I am supposed to be helping lizard keepers Kent and Renata with the population count. Instead, what I seem to be doing is releasing one of their precious, critically endangered lizards back into the wild.

It’s shockingly easy to lose a species. And when you’re down to a handful of individuals, they all count. The enclosures of the Lizard Lodge hold almost every blue-tailed skink and Lister’s gecko known to exist. There’s a much smaller breeding population at Sydney’s Taronga Zoo, but this facility, in the lizards’ native environment, represents their last, best hope for survival.

Christmas Island was once home to five endemic reptiles, but today it’s quite possible that only one of these species survives in the wild. Biennial island surveys – two months of hard slog by Parks Australia staff through the island’s dense, scratchy forests, over “pinnacles” of limestone in unrelenting, humid heat – have shown no sign of the forest skink, Lister’s gecko, blue-tailed skink or Christmas Island blind snake. The Christmas Island giant gecko still hangs on, but its numbers are also falling. The island’s reptiles are in crisis, and no one is entirely sure what’s killing them.

In the late 1990s scientists noticed that populations of the previously abundant forest skink were dropping off, and by 2003 they were only found in a few remote parts of the island. Five years later, this had declined to just one site. Perth Zoo lizard experts flew north to join Parks Australia staff on an expedition to capture both forest and blue-tailed skinks, in the hope of finding enough of them to start a breeding program. Two weeks’ work yielded 17 blue-tailed skinks, but only one forest skink. Later, two more forest skinks were captured. All three were female. Without males to fertilise them, the eggs they laid were useless. One by one the lizards died, leaving a single female, Gump, as the last hope for her species. Increasingly desperate searches for other forest skinks failed to find her a mate. In 2014, with minimal fanfare or recognition, Gump breathed her last, ushering Christmas Island’s forest skink into the record books as the first Australian reptile to go extinct since white colonisation.

The first part of today’s lizard census was in fact a lizard hunt, as the enclosures needed clearing so renovations could take place. It’s always hot in the Lizard Lodge; mosquitoes hang in the humid air, and the lizards are warm and fast. Each species is housed separately in a series of large, elongated perspex tanks, in populations graded by size and gender. We tackled the geckos first. They are about the size of clothes pegs, and the special pads on their toes allow them to run up the tank walls and then horizontally across the ceiling, making them quite the escape artists when the lids are off. Kent showed me how to grab the wriggling lizards, quickly but gently, and stuff them into ziplock bags.

“There’s meant to be 16 of them in this tank,” said Kent. “How many have we got?” I rifled through the bags. Often the count comes up one or two short. Perhaps they’ve escaped. Perhaps they’ve died and shrivelled to nothing in the heat. Perhaps their companions ate them. There’s no way of knowing.

What is known is that small-island populations are hit hard by introduced pests and diseases. Prior to the late 1880s, people rarely visited remote Christmas Island, and never permanently settled. But when people eventually did stay to mine the island’s phosphate, they brought with them a range of invasive hitchhikers. After millions of years evolving in isolation, the island’s endemic reptiles suddenly had company. Five new non-native reptiles arrived, among them the voracious wolf snake, as well as a cadre of other aggressors, including yellow crazy ants and giant centipedes.

The Lizard Lodge was built in 2014 as a safe place for the remaining lizards, with enclosures free from predation and carefully furnished to make the inhabitants feel at home. Within each tank are arranged sticks, rocks and sheets of bark for the lizards to lounge upon. There are also small wooden boxes, about the size of a deck of cards, crafted to mimic the nooks and crannies of the island’s porous limestone.

Looking into a fully stocked tank, you may see only one or two skinks, where 20 are known to live. To count them, we had to remove every piece of “furniture”, running our hands gently along each stick or bark fragment to ensure no lizards were hiding on the dark side of the wood. Something I apparently failed to do with sufficient diligence.

Kent, Renata and I ease our way towards the blue-tailed escapee, who leaps off the top of the sticks and onto the roof of an adjacent tank. After a minor scuffle, Kent scruffs the skink and drops it back into its enclosure. I breathe a sigh of relief. There are a dozen or more skinks still in the tank; they never sit still, making counting them an eye-bending experience. “I got 16,” says Renata. “I got 18,” I reply, and we have to count them half a dozen more times before we’re moderately confident.

The cleaning of the tanks is like an act of supplication, an apology to the lizards for our ecological sins. The skinks scuttle about, avoiding our ministrations as we rake through the husks of uneaten insects, sweeping clean the sandy soil. Once the dross is gone, the rebuilding begins. Stones, sticks, bark and lizard hides must be arranged just so. I find a meditative calm in this task, creating a Zen garden for reptile pleasure.

After lunching in the shade, watching huge robber crabs make off with our apple cores, Renata and I drive to the Christmas Island airport, to pick up some lunch for the lizards. We clear security, take the ute onto the grassy verge of the airstrip and hang a bug net on a long pole out each window. Renata puts her foot down and we hurtle along the runway, skimming the grass with our nets. At the end of each run, we jump out of the cab, cinch each net and shake the insects down to the bottom. Opening the net again, crickets the size of birds fly out – “too big for the lizards to eat anyway” – and we stuff the remaining bugs into large plastic jars. Back at the Lizard Lodge, I pour bugs down on the waiting lizards like a cargo cult god, and they smack their skinny lips in what looks suspiciously like reptilian joy.

And then I bring rain. I walk up and down the aisles brandishing a garden hose and spray down their rocks, their branches, their water dishes and sand, until they’re sodden in the late afternoon heat. By the morning all will have dried, and the daily cycle of lizard maintenance will begin again.