The form of signature on this cast dates its original model to the specific period 1846-57, when, to distinguish them from those models whose editions were controlled by Émile Martin, Barye was signing new works, to be edited by his own atelier, with both initials. In both versions of Aigle tenant un héron (the first showing the eagle's head turned to the right, see Poletti & Richarme, 2000, A183, p. 328), Barye has re-used the position of the bird first seen in his 1839 work, Ocelot emportant un héron (see lot 157). Both versions of Aigle tenant un héron appear for the first time in the 1857-8 catalogue. This present cast of the second version almost certainly dates from the 1860s and appears to the upper left of the Royer portrait of Eduardo Guinle (see p. 12 in this catalogue). After Barye's death, the model was edited with great success by Barbedienne.