I heard this in the grounds of Avoca Handweavers Centre, Kilmacanogue, Wicklow. Whatever made it was moving through the tree canopy but I couldn't see it. There was a female blackbird on the ground feeding, almost oblivious to me, so I'm wondering if the call was a hungry juvenile? A passerby asked me if it was a squirrel, but I have no idea and we couldn't see anything.