The Diet of the Pond BatMyotis dasycnemeand Its Seasonal Variation in a Forested Lakeland of Northern Poland

The diet of the Central European trawling vespertilionid, the pond bat Myotis dasycneme, was studied in a nursery roost in the postglacial lakeland of northern Poland , based on a very large (n = 1,725) sample of faecal pellets. This is only the third published dietary study of the species, considered to have a high conservation priority in Europe. Pond bats'prey was dominated by non-biting midges (Chironomidae — both imagines and pupae) and caddis flies (Trichoptera). However, the spectrum of prey was relatively broad, with 16 taxa, including 12 recorded for the first time in the diet of M. dasycneme. Frequency of occurrence (0%) of particular taxa varied through the season. 0% of caddis flies and non-biting midges in droppings were negatively correlated (rs= -0.75, P < 0.05); exceptionally high 0% of caddis flies, being larger (and presumably more profitable) prey, occurred in late June and July, coinciding with high energy demands of lactating females. No evidence of piscivory was revealed.