Final assignment case 6 – Animal Ecology
Nest site selection by meadow birds – in the South of the province of Utrecht
Introduction The Netherlands is an important country for meadow birds. The Dutch grasslands harbour relatively high proportions of European populations of several meadow bird species, but many breeding populations are declining. Meadow birds are birds that mainly breed on agricultural grasslands. Wader and duck species dominate the meadow bird community. The six main species are Lapwing ( Vanellus vanellus ), Black tailed Godwit ( Limosa limos a), Redshank ( Tringa totanus ), Oystercatcher ( Haematopus ostralegus ), Ruff ( Philomachus pugnax ) and Snipe ( Gallinago gallinago ).
Figure 1. Four meadow bird species: Lapwing, Black-tailed Godwit, Redshank and Oystercatcher.
Breeding success is an important factor in reassuring the survival of a species. In the Netherlands the breeding populations of many meadow birds are declining. The Black tailed Godwit, the Redshank, the Ruff and the Snipe are threatened in their existence in the Netherlands. Furthermore, the Netherlands has an international responsibility for the Black tailed Godwit and the Oystercatcher.
The Dutch government introduced meadow bird management to protect the meadow birds by establishing meadow bird agreements. On fields with meadow bird agreements, farmers have to keep soil structure and groundwater level intact and agricultural activities have to be postponed. Despite of this there is still a negative trend in the number of breeding pairs. Research in this field has been proven that meadow bird agreements do not result in higher settlement densities of breeding pairs and fields with meadow bird agreements need to be located preferentially in areas of high quality from a bird’s point of view.
Factors influencing the quality of a meadow area need to be examined, to decide whether it could be an attractive breeding habitat for meadow bird species. There is however not enough knowledge about the criteria that meadow birds use to select their nest sites, to be able to select high quality fields for meadow bird agreements. Therefore, it could happen that fields with meadow bird agreements have a low quality. Geographic information system (GIS) tools could help to discover which criteria meadow birds use in their nest site selection. When these criteria are known, guidelines should be developed that could help decision makers to choose high quality fields for meadow bird agreements.
Objective The main objective of this study is to explore the influence of soil variables (groundwater level and soil fauna) and small landscape elements (fences, poles, trees and houses) on meadow bird territory choice.
Detailed research objectives:
1. Analyze the spatial relationships between the soil variables obtained from sample points (food abundance, groundwater level) and meadow bird territory locations. 2. Analyze the influence of small landscape elements (trees, fences) and human activity (houses) on meadow bird territory locations.
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Hypothesis
1. Meadow birds prefer habitats with a high groundwater level and a high soil fauna. 2. Meadow birds avoid nesting near elements that could serve as perches for avian predators and elements with human activity.
Study area
Figure 2 . Location of the study area in the Netherlands. Figure 3 . Study area.
The study area is situated in Vianen, a municipality in the province of Utrecht (Fig. 2). The study area exists of 100 hectares of agricultural grasslands and some arable lands (Fig. 3). Along the main road in the study area are many houses and trees and some street furniture. Fences, poles, barbed wire and canals often demarcate the parcels of grassland and arable land.
Steps • Explore the available datasets (spatial and tabular content, resolution, map projection…etc.). • Create a data action model for your research on hypothesis 1 and hypothesis 2. • Implement both data action models in ArcGIS. • Draw conclusions out of maps and tabular information. • Be critical to the available data and the working method.
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