A critically endangered Sumatran rhinoceros was born Saturday at an Indonesian sanctuary, only the fourth birth in captivity in more than a century, boosting survival hopes for the species, say conservationists. \"Ratu gave birth to a male baby at 00:45 (17:45 GMT Friday) on Saturday. Both the mother and the baby are all very well,\" conservationist Widodo Ramono, who works at a sanctuary on the southern tip of Sumatra island, told AFP. The last three in-captivity births for Sumatran rhinos took place in the United States at the Cincinnati Zoo in Ohio. The father of the new born, Andalas, was himself the first Sumatran rhino delivered in captivity in 112 years. He was born in September 2001, according to the zoo. Before Andalas, the latest Sumatran rhino born in captivity was in the Calcutta Zoo in India in 1889, according the Rhino Resource Center, a British reference website. Andalas was brought to Indonesia to mate with Ratu, a female who grew up in the wild but wandered out of the forest and now lives at the Sumatran Rhino Sanctuary in Way Kambas National Park. Sumatran rhinos have suffered a 50 percent drop in population numbers over the past 20 years, largely due to poaching and loss of tropical habitat. There are now believed to be fewer than 200 alive. Most reside in isolated pockets in Southeast Asia. \"Thank God, we are very grateful that all the delivery process went smoothly and naturally. We actually made some emergency preparation in case that Ratu need(ed) a surgery in delivering the baby,\" Indonesia forestry ministry\'s spokesman Masyhud said. \"It\'s really a big present for the Sumatran rhino breeding efforts as we know that this is a very rare species which have some difficulties in their reproduction,\" the ministry\'s spokesman said. Solitary and aggressive, the rhinos are rarely sighted in the wild and avoid even other members of their species except when females are ready to mate. \"This is the first birth of a Sumatran rhino at a sanctuary in Indonesia,\" he told AFP. \"Soon after the delivery, the mother began breastfeeding the baby,\" he added. The US-based International Rhino Foundation executive director Susie Ellis said in a press release, published on Friday before the birth, that a veterinary team would immediately harvest placental cells that can be used to generate stem cells. Stem cells have the potential to be useful for many purposes in the near future, including curing diseases and helping promote reproduction, it said. The head veterinarian Dedi Candra had closely monitored Ratu\'s pregnancy by weighing her weekly and conducting regular ultrasound exams, the release also said. Ratu and Andalas were paired in 2009 at the sanctuary, two years after Andalas was brought from the Cincinnati zoo for a breeding programme. The 12-year-old lost her first pregnancy after two months and her second after less than a month. She gave birth after a 16-month pregnancy. Poaching is one of the biggest killers of Sumatran rhinos, whose horns are reputed to have medicinal properties. But rhinos have also suffered from the destruction of their habitat. According to environmentalists, two million hectares of forests are lost every year in Indonesia. Andalas is the only remaining male Sumatran rhino at the Way Kambas sanctuary since Torgamba, another male, died last year. The sanctuary has three female Sumatran rhinos. Besides the Sumatran rhino, Indonesia is also the last refuge to the critically endangered Javan rhino, which conservationists believe number only 44, located in the Ujung Kulon National Park on the western-most tip of Java.