It is well known that the founding strategies of the “Nature” Directives of the European Union, namely the “Birds” and “Habitat” Directives, focus on habitat management as a tool to halt the degradation of the environment and wildlife. However, many bird species continue to decline across Europe. A study published in the Journal of Applied Ecology (McMahon BJ, S. Doyle, A. Gray, SBA Kelly, SM Redpath, 2020 - European bird declines: Do we need to rethink approaches to the management of abundant generalist predators? Journal of Applied Ecology . DOI: 10.1111 / 1365-2664.13695) verified the role of predation in determining the decline of bird populations and whether it was necessary to reconsider the approach to management of generalist predators.
Trends in bird populations and variations in their distribution in Europe, Great Britain and Ireland were analyzed to see if they reflected the abundance gradient of generalist predators (mainly fox and corvids). It was investigated whether ground-nesting bird species, considered more vulnerable to predation (Newton, 1993; Fletcher et al., 2010; Roos et al., 2018; Ludwig et al., 2019), were in greater decline than in species with other nesting strategies. The authors also compared species listed in Annex I of the Birds Directive, for which Member States are obliged to adopt habitat management strategies, with non-listed species, for which no similar measures are envisaged. Across Europe, 74% of ground-nesting bird species have been found to be in decline, compared to 41% for other species. This is particularly evident in Great Britain, where the model indicates 66% to 31%, and in Ireland, 71% to 20%.
Ground-nesting species are therefore significantly more likely to continue to decline than other species. Furthermore, the results are consistent with the thesis that the decline in populations of these birds is at least in part related to the greater abundance of generalist predators. In Great Britain, ground-nesting species were less likely to be in decline if they were listed in Annex I (habitat protection), however, in Europe and Ireland the inclusion of Annex I species has not been shown to be in able to reduce the problems associated with the ground nesting strategy of the species. The study concludes that current EU legislation is clearly insufficient to counter the widespread decline in ground-nesting birds, and this is happening in Europe, Ireland and even Great Britain. Ignoring the role of generalist predators in this phenomenon in modern rural environments can lead to further declines and losses of bird populations and species across Europe.
There is therefore an urgent need for large-scale experiments to test causality in the impact of generalist predators on ground-nesting bird species in different landscapes. There is also a need to step up habitat improvement measures for the most vulnerable species, notably those that nest on the ground, but as landscape changes will only happen in the long term, in the meantime, if we are to safeguard and enhance nesting birds. on land, it is necessary to reconsider the control of widespread generalist predators, at least until rural landscapes are adequately restored. An increase in opportunistic predators, such as corvids, foxes, some gulls, various ardeidae as well as wild boar has been documented for some time also in Italy.
The conclusions of the article can therefore be, in our opinion, extended to a large part of the Italian territory, where there are species that nest on the ground of both hunting and conservation interest, including various phasianids (eg partridge, rock partridge, quail) , the lapwing, the lark, the tottavilla, some ducks and even the hare. It is no coincidence that the International Action Plan on waders nesting in wet grasslands, including the lapwing, provides precisely for the control of these predators as a priority strategy to restore the species to a favorable conservation status at European level. Unfortunately, we do not see institutional initiatives in Italy that follow up on these European indications, just as we continually verify the difficulties for public administrations in proceeding with the effective control of generalist predators.