Drawing conclusions about bird migration

In his article (May 21) Paul Portelli claims that he observed a larger than usual number of Caspian Terns this year, and says this was no coincidence but a result of the spring hunting ban imposed by the European Court of Justice. He further states that an "excited and incredulous" public told him about herons and raptors they had never seen before, again implying that this was due to the ban. Now, even if he saw more Caspian Terns this spring, Mr Portelli gives no proof for concluding that this was due to the hunting ban. The reason/s may be totally different from what he thinks, and I shall explain why.

Maltese hunters do not go hunting for terns in spring (or any other season), since their only quarry in spring are turtle-doves and quails. The shooting of terns is anyway illegal, and, therefore, a hunting ban on turtle-doves and quails is irrelevant for the terns. Those with a rudimentary knowledge of ornithology know that terns are predominantly coastal birds and rarely venture inland. On these islands they are mainly seen close to the shore along the Eastern seaboard which incidentally is the most urbanised, and they can be sighted further offshore from other parts of Malta, where they are out of range from guns.

It is a fact that bird migration numbers vary from year to year owing to various factors. Therefore, whereas this season Caspian Terns migrated in larger numbers close to the Maltese shores, next year could be a completely different story, even if a hunting ban is enforced once more. A typical example is the migration of certain broad-wing species recorded from the Tirat Zvi station in Northern Israel. In one particular year some species were observed in their thousands, but the next year the same species were seen only in double-digit numbers. Now, as far as can be ascertained, hunting is not permitted in Israel. Therefore, the reason behind the irregularity of the migration pattern in that country is definitely not hunting. The same phenomenon happens regularly in Malta as every ornithologist who observed Maltese bird migration over a number of years will tell you.

I look forward to Mr Portelli's weekly contributions, but I wish to suggest that he pays a little more attention and refrain from drawing gratuitous conclusions that hold no water with knowledgable observers of the local bird scene.