Monitoring report breeding birds in the Grenspark
Countless species feel at home in Grenspark Kalmthoutse Heide. To have a good insight into the life of the fauna and flora of the nature reserve, an ambitious monitoring plan has been drawn up. The populations of various animal groups and plants are closely monitored and the trends are used to shape efficient management. This allows timely intervention when a species is struggling and further works that pay off.
In 2023, breeding birds in the Grenspark were scrutinised. More specifically, it focused on the situation in five zones, located in the eastern part of the area: the Nol, the Stappersven, the Boterbergen, the Ster and the Markgraaf. Eight enthusiastic volunteers went out several times to find out which birds were breeding or not and how many territories they owned. The monitors focused on 53 species of interest, determined among others according to Natura2000 guidelines, supplemented by 30 other birds of interest.
Photo pied flycatcher: An Meert
After the fieldwork, the data were analysed by Rudi Delvaux, who compared the current status with information from previous counts in 2008, 2013, 2018 and 2020 and a comprehensive report was written. Although the results should be interpreted with caution, some positive stories stood out, often thanks to successful management. Unfortunately, in addition, a number of breeding birds fared somewhat less well.
Strong risers
A first group of species were the birds that were definitely breeding in the Grenspark Park in 2023. This can include the eagle owl, which is very fine news for Europe's largest owl species. Furthermore, the bluethroat, among others, did very well. The number of territories of this striking little bird doubled from 7 to 14 between 2020 and 2023, which could well be explained by the wet spring last year. The success of the pied flycatcher was along the same lines, with an increase from 19 territories in 2018 to 38 territories in 2023. This may be due to its ability to respond well to caterpillar supply, as these prey are increasingly available earlier due to climate change.
For quite a few certain breeding birds, management also played an important role in their positive trends. For instance, the removal of rhododendron, the creation of more open space and a larger area of natural woodland resulted in an increase in the number of territories of fitis, collared redstart, woodlark, stonechat, tree pipit and great spotted woodpecker.
A final bird that the volunteers found breeding evidence of in 2023, as well as an increasing number of territories, is the Canada goose. This is bad news, however, as this goose is an invasive alien species that causes nuisance and damage.
Stable figures
Some breeding birds were more conservative, with figures that have been more or less stable for several years, such as the pied flycatcher, black tit and black woodpecker. Since the first two do experience a decline outside the Grenspark and the number of territories of the black woodpecker was low, it is important to monitor these species closely.
Special attention should also be paid to species that, although breeding in 2023, had fewer and fewer territories, e.g. the apple finch, the great thrush and the lapwing. These birds can respectively be helped by more deciduous and mixed forests, more open areas in the forests and less intensive agriculture.
A second group of species in the analysis were birds seen during the breeding season, but which the monitors could not say for sure whether they were actually breeding. Cautiously positive news came from the middle spotted woodpecker and the golden oriole. Both beautiful species are slowly re-establishing themselves in a small number of territories, but for little woodpecker and golden oriole it is therefore likely to be a while yet. The same goes for the cuckoo. Given its steep national decline and the importance of the Grenspark for this iconic species, mapping its territories deserves extra attention. However, this is easier said than done, because although the calls of overflying males are very recognisable, they cover quite long distances and are difficult to track.
Declining trend
Among the species that did not breed with certainty, there were also some that unfortunately had a negative trend. For instance, only 1 territory of the greenfinch was found, while this beautiful finch occupied at least 6 in 2018. This is in line with the general Flemish situation and one possible explanation is the deadly disease 'the yellow'. In the case of the fire goldcrest, then again, the drop from 7 territories in 2018 to 2 in 2023 is probably due to the loss of spruce trees, trees where this little bird likes to hang out, due to the lettering. Despite the fact that the related goldcrest equally prefers coniferous forests, the letter-setter seems to have less impact on the number of its territories, but breeding cases could not be identified by the monitors either.
Finally, there were 16 species on the volunteers' list that were unfortunately neither breeding nor territorially observed. Some, such as the mattock, have probably disappeared from the region for good. It is not all doom and gloom, however, some birds carry a message of hope. The impressive marsh harrier and the elegant kestrel are seen more and more, and although the snipe last had a territory in the surveyed area in 2013, it did have a successful year in the other part of the Grenspark.
Want to know more about the breeding birds in Grenspark Kalmthoutse Grenspark Kalmthoutse Heide? Then be sure to read the full report on the 2023 breeding bird inventory. That detailed text gives a clear overview of all species surveyed and was made possible thanks to the hard work of Bram Vogels, Bert Goyens, Herman Jacobs, Jean Jordaens, Thijs Nouws, Jos Jacobs, Marc Van Aerde, Wouter Vanwesenbeeck and Rudi Delvaux.