SummaryA wide variation was observed in hepatic bilirubin‐IX‐α undine diphosphate (UDP) glu‐curonyl, glucosyl and xylosyl transferase activities among yellow rat snakes, pin fish, chickens, turkeys, sea turtles, alligators, nutria and rats. Lower hepatic enzyme activities were observed in fish, snakes, turtles, and avian species with intermediate enzyme activities present in the livers of nutria and alligators. Hepatic glycosyltransferase activities were greater in the biliverdin‐excreting species which are known to excrete readily an exogenous bilirubin load. Hepatic enzyme activities and the biliary transport maxima of bilirubin‐IX‐α are close