Hi all,
There is a new blog on my site about the Welcome Swallows that were feeding on sub-surface prey (prey that was swimming more than 2 mm below the surface of the water and not breaking the water surface) at the Western Treatment Plant (Vic) in July 2012. It is more contentious, and not possible to prove from what I saw, but it is possible that the swallows were using their attenuated outer tail feathers to lure prey to the surface. If not that, it is possible they were attempting to shade the water where they were hunting.
The swallows moved from a near horizontal hovering position to a near vertical hovering position and peered at the water. In this raised position they would then lower to touch the tip of the attenuated outer tail feathers to the water, creating a ripple, then raise up and repeat the tail touch action, or alternatively return to a horizontal position whilst still intently watching the water surface. On some occasions the bird would drop and attack near where the tail had been touching, and other times the bird would rise and turn back without attacking.
Further observation is clearly needed on this matter but for whichever reason, attempting to block the sun or luring prey, the behaviour was intentional and repeated on numerous occasions by multiple members of the flock. Again, any feedback of similar sightings would be appreciated.
More details and a photo are at the link below.
cheers
