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