Intology – Intelligent Technology News
Computers Technology Internet Arts Business Science Sports

According to a research published in Integrative and Comparative Biology journal, birds don’t fly alone when migrating at night.

Some birds, at least, keep together on their migratory journeys, flying in tandem even when they are 200 meters or more apart.

The research by animal biology professor Ronald Larkin and his colleagues from University of Illinois and the Illinois Natural History Survey confirms what many ornithologists and observers had long suspected that birds fly together in loose flocks during their nocturnal migration.

Previous studies sometimes very strongly suggested that the birds were flying tens of meters apart and yet somehow keeping together. But the evidence for this was indirect and suggestive. For the first time the researchers took a fresh look at bird-flight data Larkin had collected in the 1970s and ’80s using Korean War-era low-power-density tracking radar. The radar directs microwaves in a narrow cone – a “pencil-beam” that can be pointed at virtually any target within range.

It detects and records the discrete flight details of two birds at a time.

According to Larkin:

If there is a bird target here, you can see it on the radar display as an echo. You throw a switch and it locks onto the target, it tracks the target, and wherever the bird flies, the radar points at it.

The radar kept track of a target’s distance (from the radar), altitude and direction of travel over time. It also provided data used to calculate the frequency of a target’s wing beats. Since the radar could also track flying insects and other arthropods, the wing beat data would be important for distinguishing birds from bugs.

Determining whether two birds were actively traveling together was tricky. Larkin said:

Even back in the 1970s it hit me that you can have two birds flying absolutely parallel in the same direction and at the same height, but they can be flying at such a different speed that one of them gains on the other and they’re just, you know, automobiles passing on the expressway. They’re simply taking the same route and not keeping together.

After analyzing dozens of trials, the researchers determined that a significant proportion of the pairs of birds they had tracked were flying at the same altitude, at the same speed and in the same direction. Some of these birds were quite far apart, more than 200 meters away from each other – a distance of nearly two football fields  – and yet they were traveling together.

It also demonstrated that the birds were following their own course and were not simply being blown along by the wind.

In this research Larkin was joined by Robert Szafoni a natural heritage biologist.