Hazards to animal navigation

Navigation failures of homing pigeons
Disruption of birds' innate tracking systems
More than 2,000 homing pigeons disappeared for unknown reasons in one day during two races held in the USA. Out of 1,800 birds in a 320-kilometre race from New Market, Virginia, to Allentown, Pennsylvania, about 1,500 vanished. And in a 240-kilometre race from western Pennsylvania to suburban Philadelphia, 700 out of 900 pigeons were missing. The few birds that returned were exhausted and it was obvious that they had been flying lost for hours.

In 2000 in the UK, it was estimated that only 7,5 percent of homing pigeons were killed by raptors out of the 52 percent that failed to find their way home. The rest get lost or fly into pylons.

1. In a homing pigeons race, the birds are expected back in their lofts within a few hours. It is not unusual to lose a few birds during a race - a hungry hawk, for example, might snag a few racers. But to lose several hundred or thousand of them is beyond understanding.

2. There is something in the air. To lose this many is just unbelievable.

3. It is hard to explain why pigeons get lost, because no one knows exactly how homing pigeons do what they do.

4. One theory is that the homing pigeons' disappearance may have something to do with cellular phone activity. It's widely accepted that the pigeons use electromagnetic fields to help them navigate, and cellular phone calls might interfere with that.

5. Sunspots can send the pigeons off course.

6. With each passing day the chances that the birds will survive are decreasing. Unlike wild pigeons, these speeding machines don't know how to feed themselves in the wild and are easy prey.

7. Pigeon races should be held in parts of the country where peregrine falcons and other raptors are scarce.

(J) Problems under consideration