Surveying food preference of the graylag goose (Anser anser) in foraging Grassland in Bojagh national park

The current study is aimed to determine diet and food preference of the graylag goose during the wintering season in wet Grassland of Bojagh National Park. Firstly, in order to identify the diet, droppings were gathered done during the first months of winter 2012 and 2013. Simultaneously, the scheme of quadrating was performed using 1 square meter plots with a distance of 50 meters between adjacent plots, located along three transects to identify the wet grassland vegetation. 53 dropping sample was collected Plants to determine preferable foods and it was compared with plants located in grassland after building their tissue epidermal. Then percentage of Relative Frequency of occurrence, Percentage occurrence and relative volume percentage for each food item in dropping samples was calculated, and also food preference was measured using Manly’s alpha. Results of graylag’s diet showed that the plant of Germaine family (Poaceae) is located at first stage of the species’s diet. After that, Medicago spp of family with the amount of %20/94 Relative Frequency of occurrence and %58/49 percentage of occurrence and %7.23 relative volume and Runculaceae with the amount of %12/16 Relative Frequency of occurrence and %33/96 percentage of occurrence and %3/33 relative volume respectively devoted the most amount of graylag species’s diet. On the other hand, the results of food preference showed that three food items preferable to the species were Poaceae, Eryngium caucasicum and with 0.237, 0.216 and 0.17 manly’s alpha respectively. The food items almost include plants with hemicryptophyte and therophyte life forms. Therefore, adapting management approaches such as maintenance of vegetation cover in the early stage of succession and integrated management of livestock grazing in order to maintain vegetation diversity of wet grasslands from in the invasion of undesirable tall plants in order to keep the guild of this migratory bird in bojagh national park are recommended.