Interesting observation here. Freehold in Lancaster hosts some 50 or more pairs of jackdaws that nest in the mostly redundant chimney pots. It is a very successful colony. There is however territorial friction and a nest close to us was destroyed by a more dominant pair. The debris was ignored and after 2 weeks we swept it up. I would have expected a random collection of sticks but when I examined the pile this was not the case. There appears to be a carefully collected or adapted set of 5 or 6 lengths of twig to assemble the nest. interested to know if anyone else has observed this….