Eckhart Kuijken

Up-to-date information on nature quality for environmental management in Flanders

Environmental management and nature conservation policy need up-to-date information on the state of the environment.

Implementation of the first adaptive management plan for a European migratory waterbird population: The case of the Svalbard pink-footed goose Anser brachyrhynchus

Abstract An International Species Management Plan for the Svalbard population of the pink-footed goose was adopted under the Agreement on the Conservation of African-Eurasian Migratory Waterbirds in 2012, the first case of adaptive management of a migratory waterbird population in Europe. An international working group (including statutory agencies, NGO representatives and experts) agreed on objectives and actions to maintain the population in favourable conservation status, while accounting for biodiversity, economic and recreational interests. Agreements include setting a population target to reduce agricultural conflicts and avoid tundra degradation, and using hunting in some range states to maintain stable population size. As part of the adaptive management procedures, adjustment to harvest is made annually subject to population status. This has required streamlining of monitoring and assessment activities. Three years after implementation, indicators suggest the attainment of management results. Dialogue, consensus-building and engagement among stakeholders represent the major process achievements.

Incidents of neckband icing and consequences for body condition and survival of pink-footed geese Anser brachyrhynchus

During cold spells in Denmark and The Netherlands in January–February 1996, and in Belgium in January 1997, ice buildup on plastic neckbands on pinkfooted geese Anser brachyrhynchus was observed, affecting 15–31% of the marked geese in the areas. Ice started to form at effective temperatures of approximately -5°C, but broke off after 1–6 days, despite temperatures remaining below the freezing point. During the subsequent months, there was no detectable difference in body condition, assessed by an abdominal profile index, of geese which had experienced no, light or heavy icing of neckbands, respectively. Furthermore, during the subsequent spring and autumn there was no significant difference in resighting rates of geese with and without neckband icing.

Highly dynamic wintering strategies in migratory geese: Coping with environmental change

Abstract When and where to move is a fundamental decision to migratory birds, and the fitness‐related costs and benefits of migratory choices make them subject to strong selective forces. Site use and migration routes are outcomes of opportunities in the surrounding landscape, and the optimal migration strategy may be conservative or explorative depending on the variability in the environment occupied by the species. This study applies 25 years of resighting data to examine development in winter migration strategy of pink‐footed geese divided among Denmark, the Netherlands and Belgium, and analyse potential drivers of strategy change as well as individuals’ likelihood to break with migratory tradition. Contrary with the general notion that geese are highly traditional in their winter site use, our results reveal that winter migration strategy is highly dynamic in this species, with an average annual probability of changing strategy of 54%. Strategy was not related to hunting pressure or winter temperature, but could be partly explained by a tracking of food resources in a landscape of rapid land use changes. The probability of individuals changing strategy from year to year varied considerably between birds, and was partly related to sex and age, with young males being the most likely to change. The annual probability of changing wintering strategy increased substantially from ≈40% to ≈60% during the study period, indicating an increasingly explorative behaviour. Our findings demonstrate that individual winter strategies are very flexible and able to change over time, suggesting that phenotypic plasticity and cultural transmission are important drivers of strategy choice in this species. Growing benefits from exploratory behaviours, including the ability to track rapid land use changes, may ultimately result in increased resilience to global change.