Opening what looks like the drawer of an office filing cabinet, Gustavo Jimenez, a scientist at the Charles Darwin Foundation on the Galápagos, reaches inside, rummages around for a bit, and then pulls out not a report or a file, but a massive stuffed albatross. It’s about the size of a toddler, just one of hundreds of stuffed birds and animals in the foundation’s vertebrate collection.

We have already seen a stuffed Baltra Island iguana, a 4ft-long, scaly, dragon-like creature that was successfully brought back from near-extinction in the 1930s, but has the misfortune to live on one of the two islands that have an airport. About once a month, Jimenez receives a body that has been flattened by a bus or landed on by an aircraft.

Then there are the finches, the songbirds that inspired Charles Darwin to formulate the theory of evolution. It was the differing length of their beaks that helped lead him to the notion that they had evolved differently according to their environment. Now they are roadkill. “There are now so many people living in the highlands,” says Jimenez. “So many cars. It’s impossible to estimate how many are run over a year, but at least 10,000.” To put this in context, there are only just over 100 left of the most endangered type, the mangrove finch.

In the filing cabinets of life on these islands, the waved albatross – the only albatross to live in the tropics – is just another Galápagan hard-luck story: regularly caught up in fishing nets, it’s on the critically endangered species list with a “high risk of extinction in the wild”.

The collection is supposed to be a catalogue of life, but increasingly it looks more like one of death. Of species threatened. Disappearing. Missing. Of an entire ecosystem under threat. Because there is nowhere quite like the Galápagos. In every sense. For its profound isolation in the Pacific Ocean, its unique biodiversity – home to hundreds of endemic species – and for its pristine, untouched environment.

Except, as even a glance around the harbour of Puerto Ayora, the main town on the island of Santa Cruz, will show you, it’s no longer pristine. A filmy slick of oil shines on the surface of the water where hundreds of boats wait to receive the next intake of tourists. And beyond is a large town, a mess of shanty suburbs and half-finished hotels. The ground water is contaminated and there’s no proper sewerage. Dozens and dozens of Toyota pickups wait to ferry the tourists around.

What many people don’t realise is that the Galápagos, as well as being one of the most fragile environments on Earth, is also is one of the fastest-growing economies in South America. Per capita income is higher here than anywhere else in Ecuador. Nearly 40,000 people have made their home here, drawn by tourism, and with them have come hundreds of introduced species, invasive plants and an infrastructure that simply can’t cope.

For anyone who grew up watching David Attenborough and giant tortoises on Life on Earth, it’s a shock. This isn’t what Charles Darwin’s earthly paradise is meant to look like, although Noemi D’Ozouville, an earth scientist who lives in Puerto Ayora and studies freshwater dynamics, sighs when I say this. “That’s the thing with the stories about the Galápagos: it’s either paradise or paradise in crisis.”

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