FOOD OF WATER PIPIT NESTLINGS, ANTHUS-SPINOLETTA SPINOLETTA, IN CHANGING ENVIRONMENT

Food of water pipit nestlings, Anthus spinoletta spinoletta, in Jeseni ky mountains (north Moravia) was studied using a neck-ring method, 718 of the prey items observed. Diptera (36.5%), Lepidotera (22.4%) and H omoptera (21.6%) were the predominant food types. Average body length of the prey was 8.3 mm (1.2-27.0 mm). The total diversity of food (H = 3.741) and equitability (J = 0.767) decreased during rainy weather, w hen the number of Lepidoptera caterpillars and Scatophagidae imagos in creased. I thus hypothesise that the permanent accessibility and conce ntration of food sources at ground level facilitate successful reprodu ction, thus affecting the evolution of adaption in water pipit, which does not have to employ different foraging strategies in changing envi ronment.