3 Jan 2013

Chester Zoo’s Endocrinology Technician, Rebecca Purcell, analyses samples of giant panda urine to look for vital clues in helping counterparts at Edinburgh Zoo in their attempts to breed the species


Our hormone experts, who are based in the UK’s only endocrinology laboratory specialising in studying hormone levels in wildlife, have been tasked by counterparts in Scotland to predict exactly when giant panda Tian Tian will be fertile.

And a hormone “crossover” – a rise in oestrogen levels and a sharp drop in progesterone – has now been spotted following weeks of daily tests; meaning the time is now close.

Chester Zoo’s Scientific Manager Dr Sue Walker said:

“It is well known that Edinburgh is home to giant pandas but perhaps less well known, is that two hundred and forty miles away here in a lab in Cheshire, we’re playing a key role in their attempts to breed cubs.”

Endocrinology Technician, Rebecca Purcell, added:

“Every day for the last month, samples of Tian Tian’s urine have been couriered from Edinburgh to Chester. We’ve then been performing a series of tests on the samples, looking specifically for changes in certain hormone concentrations.

“In particular we’ve been testing for levels of two hormones – oestrogen and progesterone. By tracking those, it enables us to predict when we think she will ovulate and thus, be the ideal time for her to be introduced to the male Giant Panda, Yang Guang.

“Finding this optimum time to put the pandas together is crucial in giving them the best possible chance of a successful mating.

“We’ve now seen a vital crossover in the levels of oestrogen and progesterone and so we now believe that time to be very close.”

Using hormone monitoring to predict oestrus is vital in giant pandas. Females only come into season once a year for approximately 36 hours. Introductions can only be made when the female is fully receptive to the male, otherwise they may fight and injure each other or the male may waste valuable energy in failed mating attempts.

Chester Zoo’s scientific input into its own breeding programmes has seen great success in recent times. A baby Eastern black rhino, a species classed as critically endangered in the wild where less than 650 are thought to remain, was born last month. A second black rhino, two baby Asian elephants and an okapi have also all arrived in the last six months.