Strange behaviour

Whilst out on my rounds the day before, myself and my student witnessed the most bizarre behaviour in a bird. The crow started by dangling upside down on the wire coming from the telegraph pole, and then it zipwired along the wire, whilst dangling upside down!! We were gobsmacked!
The following day to this we were back in the same street, and this time I had a camera! Well we didn't see any zipwiring birds, but we did witness some of them dangling upside down - seemingly on purpose! Maybe they were just trying to view the world from a different perspective?
The extra photo shows the 'friends' that were sitting close to the upside down bird. They were very noisy, and one made a very odd sound. Totally bizarre!