He came back! Not for long, but he was back. The intruder that unsettled 33(11) yesterday was actually the former co-owner of this nest. At one point he even landed on the nest for a few seconds, mantled and then flew off again.
Seconds after 28 left, 33 then landed on the nest. Throughout these goings-on, Maya sat on a nearby perch, uninterested.
Even though 33 had previously chased him off his own nest and took over, 28 has not given up completely. He obviously still has a bond with this nest, and with Maya, who would have chased him away had she not wanted him there.
Will he return again?