I think this technique counts as collage!
These are composite images of the flight-lines of birds. They are created by videoing the flying birds using a tripod then merging consecutive frames in whatever software works for you (I use Photoshop). If the birds are far away or their flight quite slow then every other frame or even fewer is enough. For the slowly drifting storks I think I used every 5 frames. There may be other ways to come up with similar results, such as taking photos with burst mode, but video works for me.
The idea came when watching these openbill storks thermalling to gain height. It's always lovely to watch them soaring in circles but I thought it would be really interesting to get a better idea of the paths they make across the sky so came up with this "multiple exposure" technique.
Getting the camera pointing in the right direction was the problem with the storks. Not only are they going higher, but the columns of rising air are also moving across the land making it hard to predict exactly where the birds are heading. It took lots of trial and error mixed with a bit of luck. With the swiftlets this was less of a problem as they zip around in all directions but they don't quite produce the aesthetic curves of storks' flight.
The skies above our garden usually have at least a few swiftlets trawling the air and they almost always manage to get in these flight-line composites even if the target was the storks. To test your birding skills there is also at least one swallow and one rock pigeon somewhere.
This last one below shows swiftlets around a "swiftlet condo", which is a purpose-built room or whole building designed to encourage swiftlets to nest inside. The saliva-nests are then harvested for the birds'-nest soup market, which can be very lucrative if you manage to get a big colony. To make this more likely the condo owners install loudspeakers blaring out the noise of chirping swiftlets to attract more of them. One coastal town near us is unbearable thanks to dozens of these loudspeakers competing with each other all day!
