Homerange area |
Lek area - the spatial protection unit |
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In the Scandinavian population, home range of individual great snipes span from approx. 0.18 km2 to 0.97 km2, on average approx. 0.42 km2 (Höglund and Robertson 1990). More accurate telemetry studies conducted in Poland using GPS loggers indicate a more patchy utilisation of the space used by males, which in combination with the in-season dispersion observed in some males, causes difficulties in determining the size of the actual individual home range using methods commonly used in ecology like MCP8 or KED9. The size and shape of the individual home range depends also on the availability and stability of feeding grounds during the breeding season. Some males, especially in the later breeding period (the 3rd decade of May and the 1st and 2nd decade of June) can forage even up to 12 km away from the lek (M. Korniluk - unpublished data). It is believed that this phenomenon is associated with the disappearance of appropriate feeding grounds closer to the lek. Great snipe feeding grounds outside the lek area were most often located in extensively grazed or mowed wet meadows. Feeding areas had very often traces of wild boar activities, which may indicate the great importance of these animals in the formation of great snipe feeding grounds, especially in suboptimal biotopes. It is presumed that the actual size of individual home range in Poland may be larger than in the Scandinavian population, which is probably due to the use of different types of habitats and their lower stability and poorer food resources.
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In spatial terms, active conservation of places where the great snipe occurs should refer to the lek area, which can be defined as the area used by males and females from a given lek during several breeding seasons. This area includes a lek arena and surrounding habitats for feeding and nesting. As shown by telemetry studies carried out in Poland on two leks in Biebrza and Narew valleys, the majority of great snipe locations are within a radius of up to about 1 km from the lek, with the largest number of feeding birds recorded up to 500 m (M. Korniluk - unpublished data) .
The lek area in bog habitat at Biebrza valley covered an area of about 110 ha, while in the mineral part of the upper Narew valley it was about 160 ha (M. Korniluk - unpublished data). The size and extent of the area used by great snipes vary between years and depend on many factors. These include: the size of the lek (number of males), spatial conditions (share of grassland, width of the valley, etc.), availability and quality of suitable habitats (type and intensity of use as well as abundance of invertebrates) and hydrological conditions (areas with appropriate humidity). In the years with more stable and favourable habitat conditions, the size of the lek area is smaller than in unfavourable years. |
Following the precautionary principle and due to the need to supplement the knowledge of the size of the lek area, it is proposed to adopt the area of up to 1 km from the lek as the target area for dedicated conservation measures, consisting in shaping habitats in accordance with species requirements and maintaining a higher priority for areas closest to the lek site. All activities that may adversely affect the conservation status of the species and its habitats within this area should be treated as detrimental for the great snipe site
GPS positions from the vicinity of the lek area obtained from telemetry monitoring of males in upper Narew valley in 2013-2015 and the lek area determined using two different methods for 95% of the position. The polygons with different methods and intensities of use are marked with colours
