By Jonas Waldenström
A week ago, this year’s duck hunting season started. Or harvesting, as some hunters would say. And it is really a harvest: it is estimated that around 180,000 Mallards are shot in Sweden alone. This in a country with only 10 million inhabitants. On top of that you may add Eurasian Teals and diving ducks such as Tufted Ducks. And the occasional Garganey, Gadwall and other more rare species – collateral damage in the cannonade.
Should we worry? Should we be angry? No, at least not today, and at least not in NW Europe. The image of a hunter as a trigger-happy mooron isn’t accurate – actually many hunters are conservationists. Biodiversity doesn’t come from nothing, it requires landowners that preserve or maintain land. In this case good breeding and stopover areas for ducks. Without the incentive for hunting, a lot of nice duck habitat wouldn’t exist today. And you can combine bird watching and bird hunting, two sides of the same coin.
On the other hand, hunting has consequences. For the individual (a dead duck can not reproduce) and for the population. Our data from Ottenby show that roughly 10 % of the Mallards we equip with a band will be shot. With a migratory species, a population that is breeding in some part of Europe may be harvested in another region. In our case, a fair proportion of the Mallards shot in E Sweden originate from Finland, Russia and the Baltic states and may continue migration to Denmark, Germany and the Netherlands. Each country with their sets of riffles.
For Mallards, it has been shown that hunting is not an additive mortality, but a compensated mortality at the population level. In other words, the death toll imposed by hunting reduces the population number, but this is in turn compensated by less mortality from other sources, or by higher breeding output of the remaining birds. Density-dependent population regulation, you can say.
It should be noted, as well, that a chunk of what is shot is released Mallards. You know the put-and-take industry in recreational fishing? This is something similar: estates where Mallards are breed and released, and where visiting hunters pay for hunting. Roughly 100,000 ducks in Sweden per year, and more than a million in France! Per year! Some of the domestic origin birds survive the onslaught and live to reproduce. As they have a different stock than wild Mallards, some researchers fear that they could affect the population genetic structure of Mallards in Europe. Some things can be observed already today: Mallards tend to be heavier now than 40 years ago, and have fewer lamellae in the upper mandible, presumably an adaption to a more coarse diet. Whether this really has to do with released ducks isn’t settled yet, but similar trends are not seen in Eurasian Teals – a species not reared for hunting purposes.
But one thing is clear: the start of the hunting season is also a major push for birds to start migrate in earnest. Especially evident is the movements of Eurasian Teals which tend to start the same morning as the hunting season starts. But, little ducky, you may run, but you can’t hide – hunting will continue along the migratory route and on the win