October 25, 2014 Edition 1
The Mercury (subscription), South Africa
At last people are talking sense about the plight of the barn swallows at the Mount Moreland roosts (The Mercury October 19).
In the past even some ornithologists have been heard to say that the swallows don’t matter, but put in the context that the roost accommodates at least 13% of the known population makes the threat to the roost, if Dube Tradeport goes ahead, an international crisis.
I have been monitoring the swallows since 1992. There are two roost sites at Mount Moreland, one on each side of the village. The mitigation for phase one of the tradeport was that the majority of any storm water run-off would go through the smaller wetland, but nobody from the Institute of Natural Resources, who are meant to be doing the EIA, had checked whether any swallows roost there. They do.
I think the estimate of three million birds could be very low. We know that between 700 000 and two million birds come in to roost on any one night (and that does not include the birds on the other side of the village). What we don’t know is how many of these are resident or just passing through.
My hypothesis is that the roost is more a “motel” than a residential hotel. If my thoughts are correct, and I base them on the fact that the numbers each night vary greatly, then the actual number passing through the roosts each year could be 10 times higher than the three million suggested.
With regard to air strikes, I don’t think that 18gm of barn swallow, even if consumed in large numbers, is going to have much effect on a modern jet engine which is designed to withstand much larger birds.
