...and some remain with many questions unanswered....
The curious observer might have noticed that the young Tree Sparrows left the nest. To be exact they left at around 11 am on the 24th of May. The Blue Tits in NB-3 left between 7:30 and 11 am on the 26th of May.
After the Tree Sparrows left, I thought I should remove the nest (I had read something along the lines: remove the nest due to potential flees etc.) and so I removed it. On second thoughts, however decided to reinsert the nest. Considering effort which had gone into building it, I thought, that perhaps the sparrows would not want to build a second one. And so I reinserted the nest. I agree, it is not really a non-interference policy which I am following. It is difficult to decide what is best and given that observing them is already interference per se, given that building a house which removes natural reproduction areas and living in said house is also interference, I no longer know if it is at all non-hypocritical to say: observe is not interference but intervention is interference.
I am digressing.
At any rate I reinserted the nest and well today there have been visits. I have not yet been able to establish the nature of the visitor, but will be able to do so later.
Interestingly enough after the Tree Sparrows left, they were gone. Completely gone. I have not yet seen another Tree Sparrow since they left. I wonder where they are. I wonder if the parents led the young ones to feeding grounds in the fields, or in the woods, or near the river. I have no idea. The Great Tits last year could still be seen after 1 month of their leaving the nest. The differences between the species are intriguing!
I will be posting some videos of both the Tree Sparrows and Blue Tits in the next couple of days.