I would like to tell you something about Natuur 2000's bat conservation project "Fort Oelegem" at the village of Oelegem, 25 km East of Antwerpen (Flanders, Belgium).
Fort Oelegem is a concrete built fortress from the early 1900's. At that moment, military and political people in Europe were starting up the preparation of another new big war: World War I. Especially in France they were very eager to take revenge over the 1870 defeat of Napoleon III against the new German state, founded that same year. In little Belgium the government feared to become sandwiched between the country's two neighbouring powers of France and Germany, so it was decided to realise a "national refuge" for army and government in the harbour town of Antwerpen, the city to be surrounded by a circle of 33 fortresses and one of them being Fort Oelegem.

At the outbreak of WWI, the refuge idea appeared a lousy one: after one week "Battle of Antwerpen" (October 1914) Antwerpen felt, some fortresses were severely damaged but remote Fort Oelegem hardly took part in the battle and became for 4 years the home of a dozen pinhelmed German soldiers. As a matter of fact, after WWI and the development during this war of the mobile fortresses that are the tanks, the military importance of such a fort was over and out. Although Fort Oelegem still got "modernised" between 1920 and 1939, it did neither play a role in 1940 when a second world war resulted from the first. After 1950 the army lost for good its interest in the expensive military buildings surrounding Antwerpen, some of them were sold while the others slowly tumbled into oblivion and ruin...

Around that time, it was 1984, nearby living members of Natuur 2000 got the conviction that ruinous Fort Oelegem had become the perfect ersatz of a bat cave. Here indeed the three major conditions of a good hibernation site were fulfilled: (1) total quietness, (2) 100% humidity, (3) a constant cave temperature of just under 10°C. The Natuur 2000 EB was warned and these guys contacted some bigger nature conservation societies in Belgium, but unfortunately none was interested... So Natuur 2000 decided to take itself the initiative, by hiring the fortress from the Belgian state and organising it as a bat hibernation place.

In fact, the buildings are used by the bats from late September (when the evenings are becoming colder and the numbers of insects they feed on are declining) till late April (when the insects are back in the night air). The Fort Oelegem working group of Natuur 2000 started its annual bat counts in January 1985. They counted some 70 bats. Since then, there were countings every winter. In January 2012 more than 1000 bats were counted, amongst them 392 Daubenton's bats (Myotis daubentonii), 372 Natterer's bats (Myotis naterreri), 139 Whiskered/Brandt's bats (Myotis mystacinus/brandtii), 96 Geoffroy's bats (Myotis emarginatus), 13 Brown long-eared bats (Plecotus auritus). For such counting every room in the fort buildings is thoroughly scrutinized , you find the bats in all possible and impossible holes and other safe places in a sort of coma condition, their temperature, heart beating etc having been drastically lowered and being themselves that way extremely vulnerable for any disturbance.

As soon as the bats have left the buildings again, i.e. from May till September, Fort Oelegem becomes an instrument for nature education. The Fort Oelegem working group (all non paid volunteers) is busy then with receiving all kinds of touristic groups, nature conservation societies, youth movements etc and explaining the actual raison d'être of the fort and the ecological importance of bat conservation. We are of course participating in the European Bat Night every last weekend of August, but any group of people or family can ask for some bat detector guided bat observation on a dry summer evening. From 1984 till now some 60.000 visitors must have been visiting the monument or attending a bat night. All this has surely been helping to awake the public opinion in Flanders in favour of bat conservation The last years more fortresses of the "Antwerp Fort Ring" have been organised as bat reserves, making it during winter one of the major bat sites in Western Europe. Natuur 2000 is proud to have been a pioneer in this evolution...

So, if you once might come to Flanders being interested in fortresses and/or bats, don't hesitate and do contact Natuur 2000, we'll be glad to show us what keeps us busy at Oelegem !

Jo Orts

Working Group Fort Oelegem/Natuur 2000