The effects on feeding of single and aggregated Bufo crucifer tadpoles were tested for 24 h in experimental pens in the field. Single tadpoles ate significantly lower amounts of cyanophytes (Cyanophyta) and heterotrophs than grouped tadpoles. Diatoms (Chrysophyta) and other algae (Chlorophyta, Euglenophyta and Pyrrophyta) were eaten in similar amounts by individuals from both treatments. In general, diets of aggregated and single tadpoles were similar in both diversity of taxa and proportions of different taxa. However, the reduction of cyanophytes and heterotrophs in the diet of isolated tadpoles might lead to some disadvantage through development if these food items are important to the required nutrient balance of B. crucifer.