In the last decade, two-thirds of the world’s forest elephants – found only in the rainforests of Equatorial Africa – have been slaughtered by ivory poachers.

Why the explosion in killing? Since 2000, more than 50,000 kilometres of roads have been bulldozed into this habitat, mostly by industrial loggers, inadvertently opening it up to poachers armed with powerful rifles and cable snares. The elephants simply have nowhere to hide any more.

Such ecological carnage is being repeated the world over. The last remnants of nature are in retreat – and it is roads and other infrastructure that are often the root cause.

In the Amazon and adjoining Andes mountains, are planned, each requiring a road network for the dams themselves and power lines to be built. Just the 12 proposed for the Tapajós river – one of the biologically richest parts of the Amazon – will lead to nearly by 2032, according to a recent study.

The Amazon also has 53,000 active mining leases, spanning more than a fifth of the river basin’s land area. New roads for mining and fossil-fuel projects are opening it up like a flayed fish – and with that a Pandora’s box of environmental problems, such as illegal deforestation and fires, poaching, illicit gold mining and rampant land speculation.

Feeding frenzy

And if you want to see the wilds of Africa, don’t delay. Africa is being transformed by a feeding frenzy of foreign mining investments. China is pouring over $100 billion per year into mining projects on the continent. India, Brazil, Canada, the US and Australia aren’t far behind. New roads and infrastructure are rapidly proliferating – including 29 massive “development corridors” that will criss-cross sub-Saharan Africa, opening up many wild and semi-wild areas to new pressures.

Worse may be to come. At a recent in Brisbane, Australia, the G20 nations – the largest economies on the planet – pledged to pour $60-70 trillion into new infrastructure across the world over the next 15 years. To put that into perspective, the estimated value of all existing infrastructure is around $50 trillion.

These are scary times for the environment. In my view, the G20’s pledge is far too ambitious and should be scaled back sharply. The projects that do go ahead must be managed very carefully, or their environmental consequences could be devastating.

My colleagues and I recently published that will make such projects ecologically safer (Current Biology, DOI: 10.1016/j.cub.2015.02.050). Ideas include “island” projects without new roads, with people and equipment flown in where possible, and avoiding upgrading dirt roads to deter activities such as illegal logging.

Let’s hope the G20 listens. Nobody is saying the world doesn’t need better infrastructure – especially developing nations trying to raise living and social standards. But the blast-ahead, business-as-usual model isn’t working. For our natural world, it threatens a fatal future.

The field of cryptobiology has produced some real laughs over the years – the Jersey devil and mothman are among my favourites – but occasionally it yields some bona fide discoveries, such as the okapi and coelacanth. So what are we to make of the startling news that the legendary yeti has been “discovered”?

The yeti is supposedly a giant ape-like creature that lives in the Himalayas. Those who claim to have seen it describe it as dark, shaggy, bipedal and extremely shy. Scores of trekkers and mountain climbers, including Everest conqueror Edmund Hilary, claim to have found footprints that are similar to a human’s but much bigger and broader.

Hair-raising match

The story of this putative discovery is big news because it is being attributed to a reputable scientist, geneticist Bryan Sykes from the University of Oxford. Sykes compared DNA from two hair samples found in the Himalayas to those from a variety of known animals. He reported that both were a 100 per cent match to an ancient polar bear jawbone from Svalbard, Norway, that is up to 120,000 years old. This was around the time that the polar bear was diverging from its closest relative, the brown or grizzly bear.

One of the hairs was collected from the remains of a “highly unusual” animal shot by a local hunter in northern India the 1970s. The other was found by a film crew 800 miles away in a forest in Bhutan in 2001. Given that the samples were found so far apart, Sykes proposes that a giant subspecies of polar bear (possibly one hybridised with the brown bear) could be alive and kicking in the high Himalayas. Indeed, he speculates, this might be the mythical yeti.

And from there a global media circus has erupted. In the UK, for instance, The Daily Telegraph is trumpeting that the ““. The Sydney Morning Herald reports that ““. The headlines get more frenzied on the blogosphere.

Stoking the fire

To be fair to the media, Sykes stoked the fire. For starters, his findings haven’t been published or survived the gauntlet of peer-review yet, although they have been submitted to a journal. They were announced by press release to publicise a TV documentary, ““, that will air in the UK on Sunday.

Curiously, back in 2001 when Sykes first tested the hair found in the forest, he told żěè¶ĚĘÓƵ “It’s not a bear, nor anything else that we’ve so far been able to identify.” It is not clear what has made him change his mind.

Sykes must be confident in his findings to take such a high-profile, high-risk tack, though I can’t help but be reminded of the media train wreck following Martin Fleischmann and Stanley Pons’s alleged discovery of cold fusion. For the sake of mainstream scientists everywhere, let us hope that Sykes is on solid ground and is treated more kindly.

żěè¶ĚĘÓƵs who search for obscure or supposedly extinct creatures are not getting the respect and recognition they deserve

LAST December an 8-second went viral. Shot in remote northern Tasmania, the blurry footage featured a long-tailed mammal trotting across a meadow with an oddly stilted gait. According to the film-maker, Murray McAllister, the animal was a Tasmanian tiger.

The Tasmanian tiger, or thylacine, is a wolf-sized marsupial predator that has been presumed extinct since the last known specimen died in Hobart zoo in 1936. Yet despite its apparent demise, reports of Tassie tigers refuse to die. Hundreds of sightings, many from seemingly credible observers, have been recorded, both in Tasmania and on the mainland.

When I saw the video there was something vaguely familiar about it. Then it hit me: the animal moved like a red fox. I’d raised a fox as a boy in the western US, and they have a peculiar way of trotting. Soon, others were saying the same thing. Then a faecal sample McAllister collected was analysed for its DNA: it was a red fox.

McAllister has been searching for the Tasmanian tiger since 1998. Though he might not describe himself as such, he is a cryptobiologist, a chaser of mythical, mysterious or supposedly extinct species. Cryptobiologists are a diverse lot, ranging from conventional scientists to eccentrics far from the mainstream. All share a dream of discovering elusive or unknown creatures unrecognised by conventional science – and with it their share of instant fame.

Everyone knows about fabled creatures like Nessie and Bigfoot, but cryptobiologists actually chase a far larger menagerie of exotic beasts which they collectively term “cryptids”. Some, like the Tasmanian tiger, clearly once existed. Others, such as giant vampire bats, conceivably might exist, having somehow escaped the attentions of conventional scientists. The third category, oddities such as the Jersey devil and the mothman, are strictly on the fringes.

The more credible side of the cryptobiology crowd can be a pretty serious lot. Some, such as tropical ecologist David Bickford of the National University of Singapore and Aaron Bauer, an evolutionary biologist and herpetologist at Villanova University in Pennsylvania, are respected mainstream scientists. Bickford has discovered a number of previously unknown species, including a bizarre lungless frog that lives only beneath waterfalls in Borneo.

The most committed cryptobiologists spend big sums of their own money to finance their quests. Being outside the realm of traditional science, they don’t usually have a choice. For example, the late Grover Krantz, a physical anthropologist at Washington State University, invested around $50,000 for a light aircraft, infrared heat detector and other expensive gear in a decades-long search for Bigfoot in the Pacific Northwest.

But for mainstream scientists, being a cryptobiologist isn’t easy. Some have paid for their efforts in more than money. Roy Mackal, a dedicated chaser of Nessie and mokele-mbembe, an aquatic dinosaur that supposedly lives in the Congo basin, was booted out of the biology department at the University of Chicago; few if any dispute that his cryptid-seeking was the chief cause. Others endure sneers from their colleagues, a loss of credibility and even academic isolation.

Why tolerate such treatment? “The search for the fringe and fanciful captivates many people,” says Mike Trenerry, a biologist with the Queensland Department of Environment and Resource Management who uses automatic cameras to search for rare beasts. “We want to believe there is more out there than what we already know about.”

“The search captivates people. We want to believe there is more out there than we already know”

And the truth, of course, is that even in the 21st century, the natural world is still brimming with mystery. Tropical biologists commonly find that half or more of the insect species they capture in the rainforest canopy are new to science. Undiscovered fish and other species are frequently found in the deep sea. Up to half of all the plant species in the Amazon are still scientifically undocumented.

Not all of the new discoveries are small or obscure. The Mindoro fruit bat, discovered in the Philippines in 2007, has a 1-metre wingspan. The same year saw the discovery of a in Australia and a large in South Africa.

And despite the misfire of the recent Tasmanian tiger video, there are many Lazarus species that have been rediscovered after having been presumed extinct. Until 1951, the Bermuda petrel had not been seen by scientists for 330 years. The Javan elephant, okapi, coelacanth, mountain pygmy possum, venomous Cuban solenodon and giant terror skink were also erroneously consigned to oblivion. The Laotian rock rat, discovered in 1996, is now the sole known representative of a rodent family that was thought to have vanished 11 million years ago. The Wollemi pine – the only known survivor of a 200-million-year-old plant family – was discovered in 1994 just a stone’s throw from Sydney, Australia.

It is the Lazarus species, perhaps more than any other cryptid group, that most inspire cryptobiologists. They give them hope by revealing that nature is still very much shrouded in uncertainty. From the coelacanth to the mountain pygmy possum, Cuban solenodon and giant terror skink, even dramatic species are sometimes wrongly presumed to have vanished.

So we should celebrate the intrepid efforts of cryptobiologists. Yes, they chase bizarre creatures and flit around the fringes of conventional science, but we ought to appreciate their adventurous spirit rather than be disdainful.