What I am sure of: eggs are to be found in all 3 currently occupied NBs (NB-1, NB-3, and NB-4).
What I am unsure of: the total number of eggs in NB-1 and NB-4!
NB-1: Day # 2 of brooding: brooding continues with x eggs. I am 99.99...% sure that brooding has begung. This of course means that Sparrows indded do not sleep in the nest after having laid eggs. This is surprising, as I would have expected that like the Tits the female guards the eggs at night.
NB-3: Day # 5 of brooding: brooding continues with 9 eggs. The male brought food repeated number of times today. Once he even brought a worm which was so big that the female had difficulties in swallowing it and had to "spit" it out.
NB-4: Day # 2 of brooding: brooding continues with x eggs. The Great Tit is amazing at hiding her eggs when she leaves. I believe she does this due to the fact that the Sparrows are nesting close by. I see her moving significant amounts of nesting material to under her belly before she leaves and removing this same material when she returns. Hopefully I will manage to see the eggs soon.