Pesticide risk assessment for birds and mammals
Whinchat Saxicola rubetra
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- Time of year Food type % of diet (by number)
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5.1.9 Whinchat Saxicola rubetraGeneral information The whinchat occurs in open areas, from semi-dry heathlands and clear cut forest to humid meadows and edges of marshes with suitable perches such as fences, bushes and tall weeds. It may be found all over the Zone although its occurrence in Denmark is now rather sparse. Whinchat populations have declined strongly across Western and Central Europe during recent decades (BirdLife International 2004); e.g. in Denmark the average annual decline during 1981-2011 was as high as 5.56 % (Heldbjerg & Lerche-Jørgensen 2012). Northern and eastern populations have apparently fared better (Table 5.), maybe partly as a result of large-scale abandonment of arable land in the Baltic States during the 1990s. In Finland the farmland population has been more or less stable at least since the early 1980s (Tiainen et al. 1985, 2008, 2012a,b), probably due to a still heterogenous landscape structure. Table 5.. Population size and trends of whinchat (breeding population) in the Nordic and Baltic countries. Sources: BirdLife International/European Bird Census Council (2000), BirdLife International (2004), Ottosson et al. (2012).
* Farmland populations have been more or less stable since at least the early 1980s (Tiainen et al. 2008, 2012b). Whinchats are long-distance migrants that winter in tropical Africa. They arrive at the breeding grounds mainly during May and depart in August-September. Breeding begins soon after arrival in May, or in early June in the northern part of the Zone. Whinchats are usually single-brooded in Northern Europe, but re-layings occur in case of nest loss, implying that breeding activities may take place until mid-July (Glutz von Blotzheim & Bauer 1988). Agricultural association In Western and Central Europe, whinchats are mainly associated with extensively managed grassland types, especially extensively grazed pasture and hay meadows which are not mown before July. Intensively managed grassland and arable crops are avoided, although exceptional breedings have been recorded in cereal, potato and clover fields (Cramp 1988, Glutz von Blotzheim & Bauer 1988). Whinchats seem to occur more frequently in arable or mixed farmland in North Europe. In a Latvian study, the species was strongly associated with abandoned fields (Aunins et al. 2001). In Finland the CAP set-asides, and since 2008 the environmental fallow scheme, has favoured the whinchat, which also benefits on eutrofication of verge vegetation of larger drainage ditches (Herzon et al. 2011, Tiainen et al. 2012a). In Norway whinchats were frequently recorded in cereal fields from mid-summer until the onset of autumn migration (Hage et al. 2011). Population densities in northern Europe are mostly between 0.1 and 1.3 pairs per 10 ha (Glutz von Blotzheim & Bauer 1988). Body weight Body weight of both sexes mostly 14–19 g (Snow & Perrins 1998). Mean body weight (16.5 g) may be used for risk assessment. Energy expenditure No species specific data available, therefore calculated allometrically using the equation for passerine birds in accordance with the formula in Appendix G of the EFSA Guidance Document (EFSA 2009). Diet The diet in Europe consists almost exclusively of invertebrates. A few seeds also occur in the diet and berries are taken during autumn migration. Hunts from perch, flying to and taking prey mainly from ground or in vegetation (Cramp 1988). Adult diet is mainly insects and is often dominated by Coleoptera, Hymenoptera and/or Diptera, but also Orthoptera, Dermaptera, Heteroptera and Lepidoptera (imagines and larvae) occur frequently. Other animal food items occurring in adult diet are spiders, snails and Oligochaeta (Glutz von Blotzheim & Bauer 1988). Quantitative studies of adult diet are apparently few; in a Ukranian study 98 % of the food items were insects, mainly Coleoptera (70 %) (n = 14 stomachs, Kusmenko 1977 cited by Glutz von Blotzheim & Bauer 1988). Nestling diet has been studied in Poland and Switzerland. In the Polish study the most common food items in diet were adult Lepidoptera (24.8 % by number), Lepidoptera and Symphyta larvae (15.9 %), Tipulidae (14.5 %) and Orthoptera (12.8 %) (Steinfatt 1937 cited by Glutz von Blotzheim & Bauer 1988). The results of the Swiss study are summarized in Table 5.. Table 5.. Whinchat nestling diet in two areas of canton Waadt, Switzerland (Labhardt cited by Glutz von Blotzheim & Bauer 1988).
1 almost exclusively Symphyta larvae 2 mainly larvae. Risk assessment The whinchat is relevant for the following crop scenarios:
Based on the studies summarized above, the diet may be assumed to consist of 75 % foliar arthropods and 25 % ground-dwelling arthropods. Following pre-harvest desiccation with herbicides, the crop in most cases will be wilted, and associated foliar arthropods will be gone, within one week. The proportion of foliar arthropods in diet will therefore be strongly reduced; Table 5.. Table 5.. Estimated diet composition of whinchats feeding in cereal fields at different stages.
Interception shall be considered for ground-dwelling arthropods, as appropriate for the growth stage in question. There are no species-specific data allowing a refinement of PT. Directory: media media -> Applications to Drill media -> Unicef voices of Youth Chat Theme: Children and aids nigeria and Zimbabwe 13 October 2006 Background media -> Tsunami Terror Alert: Voices of Youth media -> Biblical Eschatology Presentation by: D. Paul Beck May 4, 2016 Ground Rules media -> Guide to completing the collection using the Omnibus system media -> The milk carton kids media -> Events Date and Location media -> The Gilded Age: The First Generation of Historians by H. Wayne Morgan University of Oklahoma, April 18, 1997 media -> Analysis of Law in the United Kingdom pertaining to Cross-Border Disaster Relief Prepared by: For the 30 June 2010 Foreword media -> Cuba fieldcourse 2010 Download 2.61 Mb. Share with your friends:
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