EN
Although the importance of cattle grazed pasture to foraging bats has already been well documented, the relative importance of cattle dung compared with the cattle themselves is largely unknown. This was investigated by comparing two adjacent fields: a current and a recent area of organic cattle-grazed pasture in England. The cattle were exchanged between fields during each of two separate observation periods in June and July 2005, one of eight evenings and the other of ten. Hand-held detectors were used to record time-expanded bat passes simultaneously from comparable positions within each field for 150 minutes after sunset. In addition, two separate observation periods (one of three evenings and the other of four) was used to investigate bat activity over and away from cattle within the same field. In general, bat activity was statistically greater within the field containing cattle than in the field without cattle (paired t-test, t21 = 3.97, P < 0.001). Within the field containing cattle, bat activity was greater over cows than away from them (paired t-test, t6 = 2.48, P < 0.05). It is therefore suggested that cattle, rather than dung are the primary attractant for foraging bats. Specifically, the difference in bat activity between the fields with and without cattle was statistically significant for Eptesicus serotinus (paired t-test, t21 = 4.14, P < 0.001), Pipistrellus pipistrellus (paired t-test, t21 = 3.23, P < 0.01) and Myotis (Dunn's test, Z = 2.99, P < 0.01) bats. Management recommendations include keeping cattle within bat foraging areas, minimizing the use of anthelminthic avermectin-based drugs for cattle, and maintaining woodland/trees within and around cattle-grazed pasture.