Autumn migration

Joe Sultana and Charles Gauci in their A New Guide To The Birds Of Malta, page 94, state that the turtle dove "in autumn passes in much smaller numbers" than it does in spring. Joe Aquilina St John (July 18) seems to think differently; who am I to say that the Maltese ornithologists Mr Sultana and Mr Gauci are right, and that Mr Aquilina St John is wrong!

Mr Aquilina St John also misquotes the Guide by saying that spring migrants take the direct route over Malta. I have not been able to find this information anywhere in the Guide and anyhow there is no direct route over Malta: we only get turtle doves at any season when these birds are diverted to the Maltese islands from their normal migration route for various reasons, but the direct route across the central Mediterranean is that from North Tunisia to Sicily, some 150 kilometres north-west of the Maltese Islands. Again, according to Mr Aquilina St John, "letting the birds pass through unharmed to their nesting grounds there will be more chicks (sic) maturing and flying over Malta in the autumn". Wrong again.

As things now stand, turtle doves that survive the slaughter of Maltese shooters carry on to Europe where they breed and multiply, they and their progeny then fly southwards to their wintering quarters, to return north in the following spring. Logically there should be a heavier passage of these bids on their way south following the breeding season - turtle doves could raise from four to six fledglings every season.

For the mathematically minded, say that for every 100 turtle doves flying over Malta, half of them are killed - a beautiful but impossible dream - 50 survivors would then fly off to the Continent and breed there.

Assuming a further 10 die from natural causes, the remaining 40 could raise from 160 to 240 young so that on their return journey there would be, allowing for natural wastage, from 180 to 260 turtle doves instead of the 100 spring migrating birds, and yet this is not the case because according to Mr Sultana and Mr Gauci in autumn it (the turtle dove) passes in much smaller numbers, something that every Maltese bird-killer could tell you.

A modicum of intelligence would suggest that because turtle doves disperse on their return journey southwards fewer birds are seen in autumn - just as I said in my previous letter.

If Mr Aquilina St John still cannot understand why autumn turtle dove shooting can never replace spring migration shooting, then I give up.