Table 1.

Population sizes according to Species360 of 737 species that had captive breeding recommended as of 2015 by IUCN as part of their conservation strategy

Population size	# of species	% of total species (n = 737)
500+	25	3
100–499	81	11
50–99	57	8
1–49	145	20
0	271	37
Unclear due to taxonomy	158	21