After writing the last post I went out and realised for the first time that there are no telephone wires, which may be one reason why I haven’t seen many swallows in the past. I'm sure there were wires and poles where I lived in Bradford (tram wire poles as well!), Wakefield, Newton Abbot and Leeds.
Let alone Ottawa. One of the best reasons for returning to England was the ugliness of North American towns, all -- as far as I recall -- disfigured by overhead lines, not only for telephones but power lines.