Other mammals Large mammals, such as primates, cattle, horses, some antelopes, giraffes, hippopotamuses, rhinoceroses, elephants, seals, whales, dolphins, and porpoises, generally are pregnant with one offspring at a time, although they may have twin or multiple births on occasion.
other mammals large mammals such as primates cattle horses some antelopes giraffes hippopotamuses rhinoceroses elephants seals whales dolphins and porpoises generally are pregnant with one offspring at a time although they may have twin or multiple births on occasion