Zomerganzen - Summering geese management and population counts in Flanders, Belgium

Dataset type

Deze dataset bevat primaire waarnemingsgegevens voor soorten.

Beschrijving

Zomerganzen - Summering geese management and population counts in Flanders, Belgium is a sampling event dataset published by the Research Institute for Nature and Forest (INBO). The dataset contains over 3,700 sampling events, carried out since 2009, mostly in the months June and July. The data are compiled from different summering geese related projects, but most data were collected through fieldwork within the framework of the EU co-funded Interreg projects INVEXO http://www.invexo.eu) and RINSE (www.rinse-europe.eu). Since 2015, data collection is funded by INBO. The dataset includes close to 5,000 presence occurrences, as well as over 15,000 absence occurrences. The sampling protocol for the majority of the occurrences are simultaneous counts. Here, the number of individuals of different geese species in a fixed set of areas is determined. Counts are performed within the same weekend to avoid double counting. Simultaneous counts were organised yearly since 2008 and take place the first weekend after July 15, the best period for monitoring the summering population of geese. These counts are performed by professional INBO employees as well as experienced birdwatchers from Natuurpunt using a standardized field protocol. Data are recorded in a citizen science portal http://waarnemingen.be/waarnemingen_projecten.php?project=231). However, The dataset also comprises opportunistic field observations from the same portal outside this period. Furthermore, data are derived from management actions, such as fertility reduction (egg shaking and pricking), the use of Larsen traps (for Egyptian goose), and the execution of moult captures. Here, the individuals in the dataset were actually removed from the environment. The aim of the data collection is management follow-up and evaluation. Consequently, caution is advised when using these data for trend analysis, distribution range calculation, niche modeling or other. Issues with the dataset can be reported at https://github.com/LifeWatchINBO/data-publication/tree/master/datasets/zomerganzen-events We strongly believe an open attitude is essential for tackling the IAS problem (Groom et al. 2015). To allow anyone to use this dataset, we have released the data to the public domain under a Creative Commons Zero waiver http://creativecommons.org/publicdomain/zero/1.0/). We would appreciate it however if you read and follow these norms for data use http://www.inbo.be/en/norms-for-data-use) and provide a link to the original dataset https://doi.org/10.15468/a5ubtp) whenever possible. If you use these data for a scientific paper, please cite the dataset following the applicable citation norms and/or consider us for co-authorship. We are always interested to know how you have used or visualized the data, or to provide more information, so please contact us via the contact information provided in the metadata, opendata@inbo.be or https://twitter.com/LifeWatchINBO.

Geografische beschrijving

In the initial stages, data from the simultaneous counts of summering geese were gathered at the level of the two westernmost provinces in Flanders (West Flanders, East Flanders), as these were considered in the Invexo and RINSE project's area. These are provincies with high numbers of summering geese, with several species under management (greater Canada goose, Egyptian goose, greylag goose). Here, a set of counting areas with confirmed presence of geese was selected and maintained as the sample study area over the years. Since 2014, management has been upscaled to other provinces. Therefore, counts are organised at the level of the whole Flanders region since.

Doel

Impact scoring for established non-native birds in Europe has shown Canada goose (Branta canadensis) to have the highest environmental, economic (agricultural damage) and social impact of all non-native birds species. Among the ecological effects are overgrazing, fouling, trampling of vegetation such as reed beds and meadows, bioturbiation of oligitrophic fens and pathogen transmission. Also, geese cause agricultural damage and nuisance in recreational areas. Management of invasive geese in the region (western Flanders, eastern Flanders, Zeeuws-Vlaanderen) was, until recently, mainly done by egg pricking and hunting. Within the framework of the EU co-funded Interreg projects Invexo and RINSE, the coordination of egg pricking and hunting was enhanced and additional moult captures (n=131) were performed on a larger cross-border scale. Moult captures were very successful for Canada geese, with a total of 7829 caught between 2010 and 2013. Greylag geese (Anser anser), although comparable in density, tended to move away from catching sites during the moulting season. In relation to density, catch success for feral goose (Anser anser f. domestica) was high. Barnacle geese (Branta leucopsis) moult later and were therefore only caught in very low numbers. The reported numbers of Canada geese culled by hunters also increased in the same period with over 7000 birds shot per season. The overall impact of the combined management efforts was assessed by annual simultaneous counts of the geese populations in the region using a fixed sample of counting areas. Trends in the average number of geese per municipality and per year were modelled using gee-GLMs. This showed a significant decrease in the number of Canada and feral goose since the beginning of the projects. In East Flanders, where moult captures were applied most intensively, a significant yearly decrease was noted. Here, the modeled decline was in line with the trend in the absolute numbers of Canada geese which showed a 40 % reduction since 2010. For the species caught in high numbers, the impact was significant over four years, and related to catch effort. Although suggesting a link between moult captures and population numbers this approach would assume other management efforts to be evenly applied over the project area, which was not the case. Moreover, the absolute number of geese in the entire area hardly decreased in the last year. Recent research indicates that Canada geese disperse over large distances within Europe, blurring effects of a local action over the years. Goose captures were performed within the EU co-funded Interreg Invexo http://www.invexo.eu) (2010-2012) and the Interreg 2Seas project RINSE http://www.rinse-europe.eu) (2012-2014), which seeks to improve awareness of the threats posed by INNS, and the methods to address them. Future work will be to upscale management and implement adaptive management backed by population models and thorough monitoring. This requires continued investment in prevention, awareness raising and generating public support.

Gegevenskwaliteit

The fieldwork is performed by skilled volunteer birdwatchers, often working together within local bird clubs. The NGO Natuurpunt http://natuurpunt.be) supports the majority of these bird clubs and volunteers, and thereby delivers an important contribution to the project. Quality control on the data was performed by Natuurpunt Studie vzw. Additionally, all the data was validated by experts from the Research Institute for Nature and Forest (INBO).

Methoden

To allow reliable comparisons between years and areas, the counts are aimed for maximum standardization. Not all areas are counted every year. The aim is a yearly coverage of 65% of the areas. Trend calculations based on these census data therefore requires taking into account area and year effects.

Type inhoud

Omvat: Puntvoorkomstengegevens.

Bronvermelding

Devisscher S, Adriaens T, Brosens D, Huysentruyt F, Driessens G, Desmet P (2021): Zomerganzen - Summering geese management and population counts in Flanders, Belgium. v1.6. Research Institute for Nature and Forest (INBO). Dataset/Samplingevent. https://doi.org/10.15468/a5ubtp

Rechten

To the extent possible under law, the publisher has waived all rights to these data and has dedicated them to the Public Domain (CC0 1.0). Users may copy, modify, distribute and use the work, including for commercial purposes, without restriction.

Gedigitaliseerde records

Metadata voor het laatst bijgewerkt op 2025-06-23 11:56:21.0