Mf. Robinson et Re. Stebbings, FOOD OF THE SEROTINE BAT, EPTESICUS-SEROTINUS - IS FECAL ANALYSIS A VALID QUALITATIVE AND QUANTITATIVE TECHNIQUE, Journal of zoology, 231, 1993, pp. 239-248
The diet of Eptesicus serotinus was investigated by faecal analysis an
d the validity of this technique as a means of obtaining reliable quan
titative results was assessed. Knowledge of what the bats cat will all
ow predictions of which habitats contribute most prey. Three male sero
tines were kept in captivity during the months of July and August 1991
and fed known quantities of identified insects. With captive E. serot
inus the remains of prey appeared within 33 min of first bite and cont
inued to appear for up to 32 h after consumption. Scales from two Noct
ua pronuba moths consumed were contained in 59 subsequent droppings. S
imilarly, fragments of three beetles, Geotrupes stercorarius, were con
tained in 28 subsequent faeces. Analysis of the faeces of free-living
bats revealed insects from seven orders. Coleoptera were found to be p
resent in 96.1% of the droppings examined; the next most frequently fo
und order was Lepidoptera, occurring in 14.7%. The beetles were mostly
associated with hay meadows (Amphimallon spp. and Melolontha spp.), o
r grazed pasture (Aphodius spp. and Geotrupes spp.). Quantitative dete
rmination of prey eaten is not possible owing to the large number of t
he droppings shown to contain the remains of marker insects and the lo
ng period over which they are produced.