Saving desert tortoises is a costly hurdle for solar projects

Stubborn does not come close to describing the desert tortoise, a species that did its evolving more than 220 million years ago and has since remained resolutely prehistoric.

Its slowpoke take on biological adaptation has exposed modern vulnerabilities. The persnickety reptile is today beset by respiratory infections and prone to disease. Its only defenses are the shell on its back and the scent of its unspeakably foul urine.

At the $2.2-billion BrightSource Energy solar farm in the Ivanpah Valley, the tortoise brought construction to a standstill for three months when excavation work found far more animals than biologists expected.

BrightSource has spent $56 million so far to protect and relocate the tortoises, but even at that price, the work has met with unforeseen calamity: Animals crushed under vehicle tires, army ants attacking hatchlings in a makeshift nursery and one small tortoise carried off to an eagle nest, its embedded microchip pinging faintly as it receded.

History has shown the tortoise to be a stubborn survivor, withstanding upheavals that caused the grand dinosaur extinction and ice ages that wiped out most living creatures. But unless current recovery efforts begin to gain traction, this threatened species could become collateral damage in the war against fossil fuels.