Why don’t pandas have more sex?

It’s true. Male pandas have such teensy winkies that many humans trained in the ways of sexing bears have mistaken boy pandas for girl pandas. Female pandas have a reproductive window so fleeting – just a day or two a year – that even if a male panda were to erect his little soldier, it would be unlikely to see any action. Based on these two observations, many people like to imagine that pandas are sexually inadequate, a species that would surely be extinct were it not for the supportive role played by humans. The truth about pandas and sex

Tian Tian, maybe definitely not

It is now virtually certain that Tian Tian, the female giant panda at Edinburgh Zoo, is no longer pregnant. Following artificial insemination in April, the zoo has been tracking Tian Tian’s hormone levels. The one to watch is progesterone. At around the time of ovulation, there is a small rise, with levels remaining roughly constant for several months. At this stage, the embryo is fertilized but is not developing. Then, some 60 to 100 days later, progesterone levels jump again from around 250 ng to 2500 ng (per gram of faeces) and the embryo begins to divide. In a press

Lonesome George has relatives

Lonesome George might be have passed away but he’s still making the news. Less than six months after his death, with his carapace still interred in a Galapagos freezer, it appears he may not have been the last of his kind after all. There is now clear evidence of giant tortoises with Pinta ancestry on another island in the archipelago. In a forthcoming study, geneticists from Yale University identify 17 hybrid tortoises with various combinations of Pinta genes on the nearby island of Isabela. The existence of these Pinta-like tortoises came to light by chance when an initial sample of

Lonesome George and the late Lord Devon’s helmet

On Monday, when news of Lonesome George’s death began to reach editors around the world, I was asked to write his obituary for the Guardian. As I had already sent in one to Nature, they sensibly got the very excellent John Vidal to do it instead. John’s done a pretty good job and he generously cites my book Lonesome George: The Life and Loves of a Conservation Icon. I was, however, very puzzled to read that I’d reported that “George was irresistibly attracted to the late Lord Devon’s wartime helmet, presumably because it resembled the shell of a young tortoise.”