Elephant mother Tonga, left, and half-sister Mongu stand next to the one day-old and yet unnamed female elephant calf at the Schoenbrunn zoo in Vienna, Austria, on Thursday, Sept. AP Photo/Hans Punz VIENNA (AP) - Vienna's Schoenbrunn Zoo is reporting the first live birth of an elephant through artificial insemination using frozen sperm. Zoo veterinarian Thomas Voracek calls the birth of the female calf on Wednesday evening "a milestone." It's relatively common for elephants to be impregnated using artificial insemination, but Voracek said Thursday that using frozen sperm successfully is an important contribution to the preservation of the species. That's because the method allows sperm to be used over a longer period. The zoo says the sperm came from Steve, a wild bull elephant at the Phinda game reserve in South Africa's Kwazulu-Natal province. The baby's mother, Tonga, has been at the zoo in Vienna since 1998.