Early Friday morning, January 30 the Houston Zoo welcomed the birth of a bouncing baby boy Masai giraffe. â€œHe was born around 6:30 a.m. and by 7:50 a.m. he was standing on his own,â€ Giraffes are the tallest living terrestrial animal. The average male giraffe can reach a height of about 17 feet tall and can weight up to 3,000 pounds. The average female giraffe can reach a height of 15 feet tall. The average gestation period for Masai giraffes is 14 months.