Toronto

Toronto Zoo giant panda breeding attempt fails

Er Shun the giant panda did not get pregnant following an insemination in April.

Er Shun was inseminated in April

Er Shun came to the Toronto Zoo from China last year.

One of the star giant pandas at the Toronto Zoo failed to get pregnant following a breeding attempt.

Er Shun was artificially inseminated in April, an attempt the zoo says led to "early signs" of a possible giant panda cub.

But urinary hormone tests, ultrasounds and even behavioural observations show she didn't produce a cub.

Er Shun is one of two pandas on loan to Canada from China.

Officials at the zoo say there isn't a pregnancy test for the endangered animals but they still plan to share their research internationally to help breeding efforts.

Pandas have just a single chance each year when they can breed — a window lasting one to three days.