The overarching goal of this project was to estimate the summer population size of the Greylag Goose in Denmark. By recruiting new volunteers, including hunters, to participate in the Greylag Goose count, our aim was to achieve better coverage and to produce a model for future population estimates.
In total, we succeeded in recruiting 96 volunteers, of which 2/3 were hunters, adding up to 195 participants (99 from the NOVANA network participated).
Based on the count data, a total of ~141,000 Greylag Geese were present in Denmark during early August. Of these, 23,032 Greylag Geese were counted by the newly recruited volunteers, 106,606 were reported by the NOVANA network and an additional 11,479 were extracted from DOFbasen.
We expect the total to be representative, yet a minimum estimate, as not all suitable sites were covered. Considering the fact that Greylag Goose is numerous and widespread in Denmark throughout the year, we expected the national count to be a challenging task. However, we consider the project successful, not least because we succeeded in involving a significant number of new volunteers, where the majority wish to be involved in future projects. Furthermore, we are pleased to be able to provide an estimate of the Danish summer population of Greylag Goose, as this is an important piece of the international puzzle related to the management of the NW/SW European population of Greylag Goose.
The final project report can be found here: https://dce.au.dk/fileadmin/dce.au.dk/Udgivelser/Notater_2023/N2023_01.pdf
We count greylag geese in Denmark in the weekend 6-7. August 2022 to be able to calculate the size of the summer population of greylag geese in Denmark. The census is coordinated by researchers at Aarhus University and is carried out in collaboration with the Danish Hunters' Association and a large network of nature enthusiasts.
Data will be used by the international goose platform in connection with the management of greylag geese. The aim is to maintain the European population of greylag geese in favorable conservation status while addressing the growing ecological and socio-economic challenges as well as ensuring sustainable hunting. Due to various challenges on the migration route, the stock is divided into two administrative units, namely the Nordic (migratory) and the Dutch-Belgian-German (stationary). A prerequisite for being able to manage the stock at management unit level is that the stock is calculated when the units are separated, ie. during the breeding season and before the autumn migration starts. Therefore, the preparation of national inventories is initiated in all the north-western European countries (inventories are already available in the Netherlands, Germany and Belgium). The inventory also includes a description of how the summer monitoring is best carried out in the future in connection with regular inventories in the NOVANA program.
At present and in the absence of better management, the population is managed based on a simple, but inadequate modelling tool (Johnson, F & Koffijberg, K. 2021). This method has first and foremost proven to be uncertain and does not take into account that the population is divided into two management units. There is therefore an increased risk that the population targets for the two units will not be achieved.
In the International working group under EGMP, it has therefore been decided that a more reliable decision-making tool should be ready for use in June 2023.
The EGMP Data Centre under the auspices of Aarhus University has just received a grant from the Jægernes Naturfond (the Hunters' Nature Foundation) for the preparation of a decision-making tool in the period 1 January 2022 -31 May 2023. However, a prerequisite for the decision-making tool to be able to set optimal and sustainable hunting quotas for each management unit is that the population size for each management unit can be calculated. Such a status can only be made in the summer, when the geese are divided into management units, i.e. after the breeding period and before migration starts. At present, such a population status is not available for each management unit, but for management Unit 2 (MU2) most of the data was collected in 2021.
The purpose of this project is to quantify the Danish breeding population of greylag geese in 2022.
The calculation is based on counts in the field and a subsequent modeling of the many data. The project will be completed in 2022.
The NW/SW European population of greylag geese, which includes the Danish breeding birds, has increased more than seven-fold since the 1980s. Among other things, this has resulted in increasing conflicts with agriculture and increased risks to air safety. At the same time, the species is important hunting game in most countries where it is found. Therefore, in 2018 an international management plan was drawn up under the Waterfowl Agreement (AEWA) European Goose Management Platform (EGMP) with the overall objective of maintaining the population in favorable conservation status while, at the same time, dealing with the growing ecological and socio-economic challenges and ensuring sustainable hunting.
The plan sets the overall strategic framework for joint European management of the population, including the measures that it will require to achieve this goal.
A key element is the establishment of an internationally coordinated population management program, which includes monitoring plans, analyses of the effects of hunting and regulation on the population as well as a decision-making model for the possible determination and coordination of hunting quotas as per the adaptive management developed for the pink-footed goose.
Here, it is important to note that the NW/SW European population is divided into two management units (MU1 and MU2) (Figure 1). On the one hand, there is a migratory unit that breeds in Norway, Sweden, Denmark and Finland and winters in the Netherlands, Belgium, Denmark, Sweden, France, Spain and Portugal, and on the other hand a unit consisting of resident birds in Germany, the Netherlands, Belgium and France. Each unit has its own population goal, and each unit must therefore be managed as an independent unit. As the two units overlap in distribution during the winter months, it is also important to take this into account. This particularly applies to the wintering places in the Netherlands.
