1000 of beavers of Lonjsko Polje

As I travel to work every day and I'm interested in everything, I see a variety of changes taking place along the rail track. So one day, crossing the bridge, I saw a big tree growing on the shore of a stream, with about half a meter no bark. First I thought that the bark was peeled by deers or wild boars or even wild rabbits.Then I remembered that they don’t peel an old tree but only the young trees, and they love the fruit trees most.

Since I love fishing, and I often go to the Lonjsko polje and to the River Ilova, I remember the beavers who have often made me company. Especially last few years.

From a colleagues of fishermen, I heard that a couple of beavers were released in Lonjsko polje ten years ago. So I went to the Internet and found out that the beavers in Croatia died out at the beginning of the twentieth century but they were imported again into Croatia in the nineties of the last century.

It was an international project called "THE BEAVER IN CROATIA".

Before releasing the beavers in Croatia, experts from Germany and Croatia selected the most suitable place for beavers. A few potential locations, among which some were along the rivers Česma, Lonja and Drava. They have choosen the most suitable place; the forest Žutica, near Ivanić Grad, 40 km away from Zagreb.

So on April 20, 1996, the first two beavers were released in the forest Žutica. Male and female. Since it is not easy to catch these animals, by 1998 the beavers were brought and released into Žutica forest 9 times. 47 beavers were brought from Bavaria to the forest Žutica in these three years, and 24 were females.

In late '97, 29 beavers were also brought and released in the sleeves of the Drava river. And a year later, 9 more beavers were released in the forest Česma. By the end of that year, the number of beavers was tripled, which proved that they were completely domesticated in Croatia. Today, it is estimated that there are about 5 to 6 thousand individuals, about half of which remained in Croatia, while the rest of them live along the Sava and Drava rivers and their tributaries or crossed into Slovenia, Bosnia and Herzegovina, Hungary and even Austria .

I recently watched an agricultural show in wich the apple plantation owner complained that the beavers destroyed over 2 000 apple fruit trees.The beaver is a protected animal species and so there is an issue. I suppose that some professional environmental impact analysis and risk assessment related to it should have be done when the beavers were brought to Croatia. It seems that not much attention have been paid to that problem so today there are too much beavers. The owners of plantations and the Croatian Forests have problems because the beavers destroy the trees in these lowland forests. In the forests near the Lonjsko polje there are plenty of water, many small streams and swamps, and this is area where the beavers live. Croatian Waters has also problem because the beavers clog draining channels, streams and block them with trees and branches.

And so we also come to the conclusion that HŽ Infrastruktura could soon have problems with the beavers. My rail track passes by the edge of the Lonjsko polje through the perennial forests where the beavers live. One beaver already noticed that this place was a very convenient place to make his home and began to demolish a large tree by the river. And I recognized the potential problem and the risk to our rail infrastructure. However, this tree is not big enough to destroy the rail track if it falls on it, but what if the beaver find another big enough tree along the river? So if he bites a bit of tree every day, one day the tree will fall, and the question is whether it will fall into the stream as the beaver wants or somewhere else.

So hypothetically there is a possibility to fall on the rail track. If this happens, it will damage the contact network and cause traffic jam, and possibly an extraordinary problem with big consequences. If the tree does not fall on the rail track but in the stream, the problem will occur later when the water level rises due to the dam, and in case of heavy rain the rail track may be flooded.

The problem with the tree falling on the rail tracks has so far been most often on the mountain rail tracks, in Gorski kotar and in Lika, because it is difficult to ensure that the trees are not near the rail tracks because of such a configuration of terrain. But if the beavers continue to breed, it is possible that similar problem will appear on lowland rail tracks, especially those which go through the woods. The beaver is a very diligent animal; it demolishes trees to make a home but also for recreation and teeth grinding. Simply, in its nature it is to demolish the trees and to gnaw them. Up to now, he had ruined them in the Lonjsko polje, in the wild, so that was not too bad for anyone.

Obviously the beaver is approaching more and more in civilization, near the road, and also near rail tracks. Since the protected species can not be killed, that should be somehow regulated by the state. So, along with all the problems we have on the rail tracks, and systematically neglecting the railway infrastructure from all the governments that have been in the past, the bad rail tracks conditions that result with speed reducing, reducing the number of passengers, reducing the cargo, we also have now an issue with beavers.

20 years ago, when beavers were imported into Croatia, the problems were probably not recognized.

Apart from the beavers we imported, we also have our local "beavers" who are inclined to demolish and construct dams to build their homes. But they are not too much sympathetic and they are doing a lot of damage. Nevertheless, in our society there is increasing awareness of the need to deal with risk management. This is what the European Union directive calls for, so we have to fit it into our laws and regulations. So today we have good tools for identifying possible risks. And in HŽ Infrastructure there is also a Risk Management Guide, but not to identify the benefits of identifying, assessing and managing risks. That's why it would be good to start systematically managing the risks in our company. If we did not think about it about twenty years ago, then we have to think about it today.

Author: Mario Dautović