From my work at the Centre for Animal movement research
at the Biology department in Lund, I have learnt about amazing aerial accomplishments in the bird world. For example, the great snipe that can make up to 6800 km nonstop flights when migrating, or the common swift that spends almost it's entire life on the wing - even eating and sleeping.
Ravens are no famous long distance migrants, but when it comes to flight acrobatics, they must be among the top birds. Maybe that is partly due to their playfulness - chasing each other with incredible speed, dropping items from high altitude and then rapidly dive to cach them again, or rolling and spinning in the sky. (See for example: http://farm3.staticflickr.com/2774/4356856066_84943edf39.jpg
Ten years ago, ravens were rarely seen in this area, but in recent years, the raven population in southern Sweden has increased, and now we have lots of wild raven visiting. Likely, our ravens attract some of them - especially the vagrants, young ravens who has not yet paired up. But for the last two yeas, a raven pair has breed no less than 600 metres from our aviaries, and during breeding season, we can hear the chicks beg for food and the adults communicating with each other and our ravens.
It is with mixed emotions we watch them fly over us, as it somehow stresses the limits and boundaries of our own aviaries. It is a comfort, though, that the ravens in our aviaries quite often fly themselves out of breath. Including the runway, the aviary complex streches about 35 metres, and while play chasing they just fly through the runway, makes a quick circle, and then back through the runway and into the next aviary. Or, they just bump into one of the big rafters with their feet - similar to a swimmer's turn - and immediately fly off again.
It is a special experience, walking through the runway as one of the ravens are passing, just centimetres above you head.