Study Of Foraging Strategies Of Rhinolophus Ferrumequinum On Lepidoptera Insects In Summer

Rhinolophus ferrumequinum has been marked as an endangered species in Europe andhas been listed as an LR/nt species into IUCN Red List of Threatened Species. Study offoraging strategies of R.ferrumequinum is one of major fields in bats study. Foragingstrategies of R.ferrumequinum were studied in the summer at Ji'an city, including diet (mainlyLepidoptera insects), foraging tactics and changes of echolocation calls in different states, etc.The results were as follows: 1. The diet of graeater horseshoe bats in the summer was consisted of Lepidoptera(75% bynumber),Coleoptera(6%),Hymenoptera(5%),Homoptera(5%)andDipterainsects(3%),togetherwith6%unidentifiedinsects.Lepidopterainsectsincluded11families,morethan 30 species of moths,such as Noctuidae(relative number percentage of Lepidopterainsects36.6%),Sphingidae(24.1%),Geometridae(13.4%)and Limacodidae(9.5%). Thelength of forewings ranged from 5—40mm(99.5%) and 60—65mm(0.5%). The result ofPearson correlation analysis showed that foraging of Rhinolophus ferrumequinum might beselective, not random. 2. Foraging tactics mostly included two ways: aerial hawking during the period of thepeak of insects activity and flycatching during the insects' non-peak activity period. Groundgleaning was not observed. Insects by captured in the air were small (winglength 5-20mm)through observing and measuring, while insects captured by flycatching were large (10-40mmand 60 -65mm). The bats never ate larger insects in flight; instead, they perched themselvesfrom a high place (top of the wire netting), selectively dismembered prey items and ate highnutritional parts (heads and abdomens), while discarding wings, antennas, etc (mainly wings). 3.Echolocation calls of R.ferrumequinum were (FM)/CF/FM type in flying and hangingstates. Duration time and interval time of pulse were decreased aburtly when the bats wereapporaching prey items, at the same time, terminal FM became more significant. Foragingbuzz was emitted at the moment of capturing. Echolocation calls almost disappeared aftercapturing prey items in 50ms.There were some difference in echolocation calls parameters indifferent states, such as repetition rate of pulse in flying was higher than inhanging(t=3.57,P<0.05);domain frequency in flight was lower than inhanging(t=-4.35,P<0.05);duration time and interval time of pulse in flight were lower than inhanging(t=-29.12,P<0.05;t=-33.03,P<0.05, respectively); duty cycle of the former was higherthan the latter(t=13.47,P<0.05).