Wastewater Treatment Plant Effects on Foraging Ecology of Bats

The quality of water can have effects on insects, which would therefore have an effect on the bats as well. The area of study is the Cape Fear River Basin (CFRB) in North Carolina. The creeks where study was conducted are the North and South Buffalo Creek, because this is where the CFRB headwaters are and both receive point-source nitrogen effluent from the Wastewater Treatment Plants (WWTPs). The four species of bat that are common in Buffalo Creek are: red (Lasiurus borealis), big brown (Eptesicus fuscus), evening (Nycticeius humeralis), and eastern pipistrelle (Perimyotis subflavus).

Less common, but present, bats: silver-haired (Lasionycteris noctivagans), hoary ( L. cinereus), Brazilian free-tailed (Tadarida brasiliensis) and two myotis. The objective of the 2004-2005 study was to determine the prey availability and abundance, the bat community structure, and the bat foraging and commuting behavior at the sites below and above WWTPs. They predicted that the effect of WWTP effluent would be seen in P. subflavus but not E.

fuscus, L. borealis, or N. humeralis.

To gather information on insect abundance and diversity passive traps were used. The two traps used were emergence and malaise traps, and once the insect samples were collected they were stored in 80% ethanol to then be identified by order. To determine the presence of different bat species and their abundance, a Pettersson D240x was used to be able to record the frequencies of the bats flying over the study site. The authors were able to distinguish commuting calls for all species but E.

Get quality help now

Bella Hamilton

Verified

Proficient in: Animals

5 (234)

“ Very organized ,I enjoyed and Loved every bit of our professional interaction ”

+84 relevant experts are online

Hire writer

fuscus and L. noctivagans and could not distinguish the myotis species. To record the total bat activity, another Pettersson D240x was to record in real time to help count the total number of bat sequences that were recorded during the night. All sequences were analyzed by at least two people to ensure consistency in activity counts. Two Pettersson D240x bat detectors, and one emergence and Malaise trap were used at each site up- and downstream of the WWTP.

The results for 2004 insect collection was that there were 4629 insects caught over 31 nights, and in 2005 10,231 insects were caught over 26 nights. The most representative orders were Diptera, Lepidoptera, Coleoptera, Homoptera, Hymenoptera, Trichoptera, Odonata, and Orthoptera with the majority of the samples being from Diptera. In 2004 there were more insects upstream than downstream, and the same goes in 2005. There were more non-chironomid and chironomid Diptera upstream than there were downstream of the WWTPs in both years. In 2004 there were 19 nights of tim-expanded recordings, but due to an equipment failure only 12 nights could be used representing 386 echolocation sequences that did not contain feeding buzzes. In 2005 there were 22 nights of complete recordings with 671 echolocation sequences. The echolocation sequences from E. fuscus, N. humeralis, P. subflavus, L.cinereus, L. borealis, T. brasiliensis and 2 myotis were recorded in both years with the most abundant being E. fuscus, P. subflavus, and N. humeralis. In both 2004 and 2005