I am a potter (work with ceramics), and I thought I would try and build a bird house out of clay.
I have a wooden bird house in the yard and had swallows in them, but in recent years I feel that the sparrows have kicked them out.
The question(s) I am hoping you can help me with pertains to the size of the hole. If I wanted to try and attract the swallows and deter the sparrows is there a hole size I should consider?
I live in Calgary, Alberta Canada. Attached is a photo I took of the birds I am wanting to attract (living in my wooden house)
Also, I note that the swallows typically cling to the side of the house. If it is made of ceramic that will be difficult for a bird to cling too, as their claws will not be able to penetrate the clay body. I could texture the area around the hole, or I could put a peg that goes through the wall so it sticks out on both sides (bird can use it to get in and out). Do swallows like bird pegs (stands)?
Thanks for any opinions. I appreciate it.