Iron retention was studied in rats (Rattus norvegicus), doves (Streptopelia d. decaocto) and two species of mynahs (Acridotheres t. tristis and Gracula r. religiosa) fed two different pelleted diets (88.5 and 567.9mg Fe/kg diet). The doves and rats served as species that are not susceptible to iron storage, whereas the mynahs are known to develop iron overload frequently. The retention was calculated after measuring the uptake and elimination of a single dose of radioactive iron ((59)Fe) using whole-body counting. It was hypothesized that the mynahs would retain more iron than the rats and doves, and that after dietary iron challenge the mynahs would downregulate iron retention less effectively. It is concluded that mynahs have much higher iron uptake and retention than doves, but a similar uptake to that in rats. The four studied species are able to downregulate iron retention, the doves being the most efficient. It is suggested that at least part of the susceptibility to iron overload in mynahs is related to a high iron absorption from the intestines regardless of body iron stores, which is comparable with the situation of hereditary haemochromatosis in man.