Nature today | Dilemma: do we let the black grouse die out in the Netherlands or not?
In our country about the middle of the twentieth century, it is estimated that grouse. Today it is several dozen. The animals are only found on the Sallandse Heuvelrug and they are also having a hard time there. Since 2012, birds are brought from Sweden every year to keep the population going. The aim is for the species to survive on its own as soon as the living conditions have improved. How meaningful are those efforts?
The problem
As a project leader at Staatsbosbeheer, Corné Balemans is responsible for nature restoration on the Sallandse Heuvelrug. The biggest problem for the black grouse is excessive nitrogen deposition, he says: “That has acidified the soil. The soil must have an acidity of at least 4.5, but it is 2.8 – with cleaning vinegar.”
The result is that there are too few herbs and vital effects for the chicks. “The black grouse is an indicator species,” explains senior fauna ecologist Meta Rijks, who is responsible for reintroductions and additions at Staatsbosbeheer. “That contains all kinds of elements in the encompassing order, if it is to complete the life cycle. This animal shows you how the area is doing. Bird species have already disappeared and now threaten the black grouse. If the population of animals is too small, there is no longer a partner and the species dies out. We try to prevent that.”
Why add?
Getting grouse from Sweden saves us time until it is recovered. In 2021, the province of Overijssel decided to continue adding additions for another five years. Cost: 300,000 euros. Waste of money, find, because some of the animals are eaten by predators. Proponents believe that we can – possibly – keep the grouse. The Netherlands is also obliged to try to do so under European legislation for Natura 2000 areas. The ultimate responsibility for preserving the black grouse lies with the province of Overijssel. The bird is included as a target species in the Natura 2000 management plan, which means that the bird is currently protected.
Every spring, experts and volunteers travel to Sweden to catch. Mark Zekhuis, ecologist and co-author of the book ‘Gewilde Dieren’ about reintroductions, went along twice. “Catching early morning. The animals are examined by a veterinarian and released within 24 hours on the Sallandse Heuvelrug.” Do the birds get stressed from the transfer? Mark: “They certainly don’t like it, but I think it’s acceptable. In the back of the car I heard roosters bellowing to impress fellow species; a sign that they were hormone-driven rather than stress-driven.”
Is it safe to move animals?
Right after spawning are the vulnerabilities of grouse. They do not yet know the hiding places and when exploring the terrain they are easy prey. Meta: “After the first weeks, the numbers decrease rapidly and the origins participate in reproduction. That goes well, until the chicks are born and the food shortage presents itself. Chicks are dependent on insects in the first weeks, later they slowly switch to plant food. We examined and repaired it from malnutrition. A hen will survive if the hen finds one of the scarce spots sufficiently satisfied.”
Can you remove animals from their own environment and expose them to those risks? Meta: “We mainly select young, strong birds. In addition, the Swedish government is watching closely and we have again received a permit.” Corné sees the social discussion expanding in Sweden: “The first round we received a permit for five years, now it is two years.” For the population in Sweden, removing twenty to thirty animals per year is no problem, says Mark: “We do not see a decrease in numbers at the trapping sites. Thousands of grouse are shot every year in Sweden. But it is possible that the permit will not be renewed again, then we can look at cooperation with the Baltic states, healthy populations live there too.”
Why not accept extinction instead of reintroduction?
Would it be accepting for now that it is not accepted? “That has not yet been achieved anywhere in Europe,” says Meta. “It has to do with the behavior of the animals. If you release grouse in a place without conspecifics, they will fly in all directions and they will no longer meet. There is therefore no chance of reintroduction.” Mark agrees: “Newcomers need the knowledge of the animals present to survive.”
What happens in the meantime to recovery from the in-between?
Apply rock flour to dry sandy soils as effective measures against acidification. Of the 1 hectare of dry heathland on the Sallandse Heuvelrug, 300 hectares is 300 hectares of land, of which 200 hectares are being exported. The measure is not experimental. “Preliminary results in other nature reserves are positive,” says Corné. “But the signal only goes green when the long-term effects are known. And then the money has to be there too.”
Other measures on the Sallandse Heuvelrug include expanding the number of hectares of dry heathland and mowing, burning, chopping and small-scale turfing of heathland in order to get more variation in age and stratification of the plants. Trees are also used to create open terrain so that it is less preyed upon by predators. The latter arouses resistance: not everyone thinks felling trees to red a bird species is a good idea. Corné: “Understandably, as a result of the climate problem, more trees are indeed needed, but preserving biodiversity is also important. It is up to the government to make choices. What we can do is not better explained why change in the landscape is sometimes necessary and that after the tree felling phase it becomes different, but often also more beautiful and varied.”
Continue to add?
Remedial measures from slowing down, but only cutting emissions really helps. Corné: “Even if the government introduces source measures tomorrow, the consequences of excessive more useful targets will only diminish in six to ten years.” Mark is nicer: “rock dust you can measure in plants after three years, after that you can gradually expect more herb richness and therefore more insects.”
Although Corné sees signs of recovery in the heath landscape, the black grouse population is not yet growing. That is why Meta is happy that the province is continuing to add additions: “This bird belongs here.” Mark also welcomed the support of the province: “On the other hand, the government has until now given priority to companies that emit a lot of nitrogen. Then the mopping continues with the tap open. I hope we can make adjustments in time.”
Or else…?
Mark: “It may be too late for the black grouse. There are also provisions for the animal to become extinct. Our country is on the southern border of its maybe it’s getting too hot and too dry here. I believe that nature reserves should in principle be self-reliant. You don’t want to be dependent on humans for a long time. But it is man who has caused these problems. This project shows what nature restoration costs: if you destroy a lot, the bill is high. We owe it to ourselves to try to preserve the grouse. In addition, we can reduce the benefits of this project in protecting other vulnerable species, such as the skylark and the partridge.”
Even if we can’t make it, the investment is worth it, says Meta. “Many more species of the measures in the area, such as the nightjar, European stonechat, sand lizard and blue-winged grasshopper. Thanks to the basic conditions of the black grouse, we learn from being on the right track with nature restoration.”
Text and photos: State Forestry