Night Migration Mysteries Revealed

A recent study conducted by researchers from the Illinois Natural History Survey and the University of Illinois has resulted in statistical data to prove that during their nocturnal migration birds fly together in loose flocks. This is the first conclusive data that confirms what many ornithologists and bird-watchers have suspected for some time.

Researchers have spent decades attempting to unlock the mysteries of the nocturnal migration of birds. Considering the size of a bird and the altitude at which it flies, together with the fact that it is nighttime, this has proven to be very difficult. Previous studies have indicated that, although migrating birds may have been flying tens of meters apart, they nonetheless stayed together by flying at the same speed and at approximately the same altitude. However, these studies have not provided convincing proof to support this assertion. Even if a study could establish that the birds were in fact traveling together, there was no way of knowing if this flight pattern was intentional.

The new research project, which has been conducted by professor of animal biology, Ronald Larkin together with Robert Szafoni, analyzed bird-flight data which had been collected by Larkin by means of a low-power-density tracking radar during the 70s and 80s. This radar works by pointing a narrow cone, referred to as a “pencil-beam”, at any target within range. The target, in this case a bird, appears as an echo on the radar screen. With a flip of a switch, the radar locks on the target and tracks it while recording data with regard to the target’s distance from the radar, as well as its altitude and direction of flight. Moreover, the radar provides data which can be used to calculate the frequency of the target bird’s wing beats.

Once the radar has locked onto a bird and is tracking its flight, if another bird appeared in the radar’s beam, the radar operator could switch back and forth between the two birds and thereby track the flight details of both birds simultaneously. Upon analyzing dozens of sets of data, researchers came to the conclusion that a significant number of tracked birds were flying at the same speed, same altitude and in the same direction, even though some of the pairs were more than 200 meters apart.

Ongoing research continues to reveal that birds are fascinating creatures with astounding abilities – and no doubt bird-lovers everywhere agree.