Hello! I am thinking of providing a non-working chimney pot/ stack on my house roof for jackdaws to nest in. For long they have nested in a real chimney in the roof (fires are not lit) but almost yearly an adult or fledging falls down the stack to grate level in the summer, I assume when the birds' weight collapses the stick nest. Uninjured adults will simply use an open window to escape. But the tragedy is with the youngsters - too immature to fly and only lucky if they descend uninjured and right down to the hearth so I can then transport to a refuge.
My question: how deep and wide would the new " false" chimney, with a flat base at the stack top, need to be to encourage nesting in it? Once accommodated in the alternative home I could then get the real chimney pot capped off - saving bird lives. Thanks.
Definitely fit a cowl.
Often nest building will start in much colder times, and chimneys tend to warmer places, so you can't blame any bird for building a nest on an active chimney pot.
They are readily available, and without spikes from most good builders merchants.