LONDON, Aug. 11 (Xinhua) -- Just a week old, and a baby Eastern black rhino is proving a big star attraction with visitors to Chester Zoo in northern England.

With the new arrival becoming the 11th rhino calf to be born, the zoo revealed its scientists carefully monitor rhino dung to discover the best time to introduce a potential mom to a male partner for mating.

Born as amazed zoo visitors watched, just days later the calf was venturing to the outside to play for the first time, rolling and frolicking in sand under the watchful eye of doting mom, Malindi.

The little youngster spent around an hour running around and rolling in sand before returning to mom's side and heading off for a much-deserved nap.

Earlier this week the zoo was named by official tourism agency VisitEngland as the second most popular paid for attraction after the Tower of London.

Tim Rowlands, curator of Mammals at the zoo said: "Malindi has bonded very well with her new calf during these important early days and, as an experienced mom, is doing a great job once again. The calf has bundles of energy and keepers will soon choose a name that perfectly matches his big personality."

Most rhino births typically happen during the quiet of night, but the calf was born to experience just before 1 p.m. on July 31 in front of surprised onlookers at the zoo.

The Eastern black rhino is listed as critically endangered and experts fear as few as 650 remain in the wild.

Chester Zoo is fighting for the survival of Eastern black rhino and has long supported conservation efforts in the wild to try and protect black rhinos and continues to fund, and provide expertise, to numerous sanctuaries in Africa.

The zoo's director general, Dr Mark Pilgrim, is responsible for managing the European breeding program for the Eastern black rhino

Ground-breaking science by a team at Chester Zoo team has contributed to the zoo's successful black rhino breeding program.

Zoo researchers have spent several years carefully monitoring the hormone levels of their resident female rhinos in a bid to discover the best time to introduce them to a potential partner. These hormone levels are monitored by analyzing rhino dung.