Third time lucky? Adelaide Zoo staff again are full of hope the giant pandas Wang Wang and Funi will mate this year.
There are signs they are within weeks of the brief breeding season.
Dr David McLelland of Adelaide Zoo said both were showing positive behavioural signs.
"A lot more amorous behaviour towards each other and to the keepers as well and a lot more climbing up trees, from Funi especially," he said.
Since their arrival from China three years ago, the pandas have been kept in separate enclosures.
A five-day reunion will take place with the critical reproductive opportunity lasting just 36 hours, giving little time for romance.
"There is a very small window of opportunity and we need to do everything we can to identify that so can take advantage of the limited time we've got," Dr McLelland said.
Two mating attempts have failed but, this year, to increase the chance of a pregnancy, Funi will be artificially inseminated.
A reproductive expert has flown in from China to assist and scientists at Adelaide's Repromed Fertility Clinic are tracking when Funi will ovulate.
"We're working around the clock with urine samples and we're able to look at her oestrogen and progesterone levels and track from there the optimal time she's about to ovulate," Dr Deirdre Zander-Fox explained.
Zoo staff said a combination of natural breeding and artificial insemination was common practice in China and zoos around the world to achieve a successful birth.
Whether mating is a success will not be known for some time as the gestation period is about five months and keepers will only know if Funi is pregnant about two weeks before a birth.
Similar to kangaroos, pandas are able to delay pregnancy if the conditions are unsuitable for a birth.
Vets at Adelaide Zoo are using several unconventional methods to try to get Wang Wang and Funi in the mood for love.
Senior panda keeper Simone Davey told of using essential oils.
"They absolutely love essential oils and so we've been offering Wang Wang his favourite oils to see if he gets excited," she said.
Animal lovers are keeping their fingers crossed that a spark of love will be ignited this breeding season, while the experts remain cautious but optimistic.