We took this photograph last year in the Pantanal, Brazil. It shows two Jabiru Storks sleeping in their nest while the stars rotate overhead. The camera was positioned so that the southern celestial pole was behind the nest and an exposure time of 40 minutes was used to capture the star trails. The tree was illuminated by a single lamp placed about 100m away.
The southern celestial pole can be located by identifying the Southern Cross constellation and following it down about four and a half cross-lengths. In the Northern Hemisphere, you can find the north celestial pole by pointing your camera at the North Star. You can find out more about locating the celestial poles here.
Will, this is a gorgeous photo… not my favorite of yours (as you suggest on twitter :)), but it is really inventive. It is quite amazing that those birds stayed in the same spot for that long! Great fore-thought on using the star trails as a way to highlight your subject. Beautiful!
Really cool shot and an interesting bit of background information to go with it