Few cases of adoption have been reported in solitary breeding raptors, and in owls adoption has only been reported in two species. Here we report four cases of brood-switching of juvenile Tengmalm’s Owls (Aegolius funereus), recorded during and after the post-fledging dependence period using radio-telemetry, and a case of three orphaned siblings (one nestling and two fledglings) originally from one nestbox successfully fostered to another one. A possible evolutionary context of the brood-switching is discussed.