The London Zoo began their annual head count of animals in residence earlier this week.
Though the zoo keeps their records updated continually, licensing requirements mandate an annual count, which usually takes zoo workers a week to complete.
Last year's count included 712 species with nearly 18,500 critters in total.
The results of the count are submitted to the International Species Information System (ISIS) so the information can be shared with other zoos. The database also helps determine the goals of worldwide conservation and breeding programs for endangered animals.