By Zahra Khaliq A wildlife park is celebrating the birth of a critically endangered Black Rhino calf – one of the rarest mammals on earth. The award-winning Yorkshire Wildlife Park (YWP) in Doncaster saw its first birth in history when mum Najuma, 7, reached the end of her 15-month long pregnancy and gave birth to a male calf. The baby rhino, already weighing 73 kilos, was welcomed on January 16, marking a significant event as international conservation efforts continue to protect the species through the efforts of zoos and wildlife parks, as well as in the wild. The calf has spent his first f…