I am trying to unravel the mystery of a bluebird box that has suffered nestling deaths for two consecutive years. When the box was cleaned out after fledging, more than one was found dead in the box. The dead nestlings would have been at least 10 days old. One time it was 3 out of 6; another time 2 out of 5.
My question is whether HOSP would kill some but not all of the babies. When we had a HOSP attact our box there were 4 eggs in the nest. It did not get them all the first time, but returned and ruined them all. Would a HOSP kill only some but not all? I am wondering if others have had experiences that might shed some light on this mystery.
I am considering moving the box to a different location.
Cari, was it monitored regularly? I’m asking since those dead babies weren’t found until after the others fledged. Did they have any signs of an attack? I think it’s possible that a HOSP might do that. Normally I think he’d kill them all so that he could have the box. It could have been chemicals.
After the babies were banded I did not open the box. My understanding is that after 13-14 days old you risk the nestlings trying to fledge too early.
But I visited the box often, offering mealworms to an overworked Papa, and took photos of the noisy nestlings poking their heads through the opening and demanding more. There were definitely noisy little ones in that box, so I didn’t think it wise to open it.
I have high hopes that three of the five banded fledged on schedule.
Meanwhile, as I noted on another thread “Banding Bluebirds”, we moved the box and located a trap near the original site.