Endangered Species Act:

One species in particular received widespread attention—the whooping crane. The species' historical range extended from central Canada South to Mexico, and from Utah to the Atlantic coast. Unregulated hunting and habitat loss contributed to a steady decline in the whooping crane population until, by 1890, it had disappeared from its primary breeding range in the north central United States. It would be another eight years before the first national law regulating wildlife commerce was signed, and another two years before the first version of the endangered species act was passed. The whooping crane population by 1941 was estimated at about only 16 birds still in the wild.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What was the estimated population of the whooping crane in 1941?
16 birds