I first got to know these birds when I moved to Sweden a number of years ago and I am fascinated with them. They pair bond and gather in (sometimes) huge flocks at the end of the day. Heaven help anyone who has parked their car under the tree they choose!
Superstitions attached to these birds:
1. A jackdaw settling on the house - an omen of death
2. In some cultures, a jackdaw on the roof - a new arrival
3. Seeing one jackdaw - bad omen
In Milan Kundera's The Book of Laughter and Forgetting, Kundera notes that Hermann Kafka, father to Franz Kafka, had a sign in front of his shop with a jackdaw painted next to his name, since kavka means jackdaw in Czech. (Source: Wikipedia)