Pesticide risk assessment for birds and mammals
Selected focal species 5.1Birds
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5Selected focal species5.1Birds5.1.1 Bean goose Anser fabalisGeneral information The bean goose (subspecies A. f. fabalis) breeds in small numbers (few thousand) within the taiga zone of Norway, Sweden and Finland. The main breeding areas are in Russia where it is replaced by the more numerous subspecies rossicus within the tundra zone. Main wintering areas (both subspecies) are in Germany and the Netherlands but some 30-40,000 birds (mainly fabalis), or c. 10 % of the European wintering population, usually winter in Denmark and southern Sweden (BirdLife International 2004). Occurrence in other parts of the Zone is chiefly on passage during spring and autumn (Table 5.). Table 5.. Population size and trends of bean goose (wintering population) in the Nordic and Baltic countries. ”–”: not present. Source: BirdLife International 2004.
* See text for migrant numbers. Departure from the breeding grounds is usually late August to mid-September, with arrival in winter quarters from late September to early October, but passage may occur throughout October (Cramp & Simmons 1977). Numbers in Sweden peak in September-October (Nilsson 2004). Further dispersal towards southwest may occur during cold spells. In eastern Denmark, most bean geese arrive during December-January, indicating cold flight from Swedish wintering areas. The bean geese depart from the wintering areas from mid-March, with spring numbers in Sweden usually peaking during April (Nilsson 2004). From the beginning of May most birds have left for the breeding grounds. The number of bean geese staging in Sweden in autumn varies in different years from 40,000 to 80,000 individuals (Nilsson 2004), with a peak in October (Wallin and Millberg 1995). In spring the number of staging birds is much lower (Nilsson and Persson 1984) and the birds also stay for a shorter period of time compared to autumn. Agricultural association Bean geese use agricultural land for foraging during migration. In a Swedish study, bean geese were found using mainly autumn sown cereals and stubbles in September-October (Axelsson 2004). Stubbles were used mostly in September with a shift towards cereals later in the month (Axelsson 2004). In early autumn (before 10 October) 8 % of the geese were found on autumn sown cereals (Nilsson and Persson 1984), while in late October 60 % of the geese in the study area were found on this habitat (Gezelius 1990). In spring (March-April) the bean geese are mainly found in cereal fields. It is reasonable to assume that the crop type used by foraging geese also constitutes the main nutritional intake. Body weight Body weight (subspecies fabalis) ♂ 2690–4060 g, ♀ 2220–3470 g (Snow & Perrins 1998). Mean body weight of the smaller sex (♀: 2845 g) may be used for risk assessment. Energy expenditure No specific studies of energy demands have been conducted on bean goose, but see below for studies on the closely related pink-footed goose. Because no species-specific data are available, daily energy expenditure may be calculated allometrically using the equation for non-passerine birds in accordance with the formula in Appendix G of the EFSA Guidance Document (EFSA 2009). The allometric equation gives an estimate of the energy required for subsistence but does not allow for pre-migratory fattening in spring. Using the allometric equation therefore leads to an underestimation of the energy demand in spring, especially in April (cf. pink-footed goose). It should be noticed, though, that the bean geese wintering in Fennoscandia (including Denmark) mainly breed within the Russian taiga zone; hence their journey towards the breeding grounds is shorter and the possibilities for feeding en route and after arrival to the breeding area are probably better than in the pink-footed goose. Therefore the need for pre-migratory fattening is assumed to be less pronounced in the bean goose. Diet The feeding during migration and in the winter quarters is performed on arable and pasture land, and especially in late autumn (from mid-October) cereals are predominantly used (Nilsson and Persson 1984; Axelsson 2004). The main diet is various green plant material and, if available, wheat, rape, and peas (Nilsson and Persson 1984; Axelsson 2004). Also feeds on newly sown grain (cf., e.g., Danish/Swedish/German name “seed goose”). Risk assessment The bean goose is relevant for the following crop scenarios:
In any case it may be assumed that within the treated area, the birds feed entirely on the treated crop or seed (PD = 1). A body weight of 2845 g and a Daily Energy Expenditure (DEE) of 1412 kJ/day (from the allometric equation) may be used in risk assessment. For birds feeding on freshly drilled seeds, a DEE of 1412 kJ/day is equivalent to an intake of 108 g seed/day (fresh weight) 6. However, this is almost certainly an underestimate of the actual intake of birds feeding on new-sown spring cereals (cf. the studies referred below for pink-footed goose). A FIR of 225 g seed/day (fresh weight), as used in the pink-footed goose, will probably also represent the worst case situation for bean goose. There is no species-specific information allowing a refinement of PT. PT information from other Anser species, e.g. greylag goose Anser anser, may in principle be extrapolated to cover bean goose (Å. Berg pers. comm.). However, the available data on greylag goose (Prosser 2010) do not distinguish between active and inactive time and are therefore not considered suitable for risk assessment. The relevance of reproductive risk assessment is doubtful as the bean goose does not breed in agricultural areas within the Zone. In any case, reproductive risk assessment will only be relevant for applications performed shortly before departure in spring, i.e. in April. 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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