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

A black and white Christmas

“The pandas are coming!” announced Edinburgh Zoo’s press office on Monday morning. The reason, I discovered, was not to proclaim the transfer of seminal fluid from male to female panda (cause for celebration as that might be), but because the Royal Zoological Society of Scotland (RZSS) finally has a date set for the long-awaited arrival of a pair of giant pandas. When the FedEx Panda Express touches down in Edinburgh on Sunday, Tian-Tian and Yang-Guang will be the first giant pandas to set foot in Britain for 17 years. I’ve thought a lot – probably too much – about giant