Antagonistic Behavior Between Evening Bats and Carpenter Ants Michael J. Bender1,*, Steven B. Castleberry1, Darren A. Miller2, and T. Bentley Wigley3 Abstract - We report on mist-net captures of three individual Nycticeius humeralis (Evening Bat) with anterior portions of Camponotus fl oridanus (Florida Carpenter Ant) attached by the mandibles. Based on head morphology, the ants were most likely alate queens captured as prey during the ants’ nocturnal mating fl ights. No similar interaction between evening bats and ants has previously been documented. Evidence of antagonism between bats and ants in the United States has rarely been reported. In the five cases we found reported in the literature, bats were collected with the head of a Camponotus sp. Mayr (carpenter ants) attached to their facial region. Handley (1956) concluded that such interactions occurred in fl ight when bats pursued ants as prey. Although the genus of ant is consistent, four bat species were involved in reported interactions. Two cases were noted for Eptesicus fuscus Beauvois (Big Brown Bat; Handley 1956, Wilson 1958), and one each for Tadarida brasiliensis I. Geoffroy (Brazilian Free-Tailed Bat; Ross 1961), Macrotus waterhousii Gray (Waterhouse’s Leaf-Nosed Bat; Ross 1961), and Pipistrellus hesperus H. Allen (Western Pipistrelle; Harris 1971). No interaction between Nycticeius humeralis Rafinesque (Evening Bat) and ants has been reported. In May 2007, in Decatur County, GA, we captured three Evening Bats with remains of ants attached. Herein we report on capture and observation of these individuals. Observation and Discussion. On May 29, 2007, while mist-netting over a small pond within a managed pine (Pinus spp.) forest landscape, we captured a pregnant Evening Bat with the anterior portions of two ants attached (Fig. 1). The ants were firmly attached by their mandibles to the right side of the bat’s head, with one attached at the base of the ear and the other near the eye. Both ants were missing the abdomen and the posterior part of the thorax. The posterior portions of the ants were presumably bitten off by the bat. Locations of attachment likely affected vision, hearing, and foraging efficiency. It is unlikely that the bat was able to groom the ants off because of the location and secure attachment. Upon release, the bat’s behavior did not suggest lasting effects from the attached and subsequently removed ants. On May 30, 2007, we captured two lactating Evening Bats with mist nets at a different pond within the same managed forest, approximately 4.5 km away from the previous pond, each with anterior portions of a single ant attached. We photographed one bat with an ant attached to the left cheek (Fig. 2). Location of ant attachment and photographs were not recorded for the second bat, but both ants were securely attached by their mandibles with the bodies removed just below the head. Both bats behaved normally upon removal of the ants and release. Ants were preserved and later tentatively identified as alate queen Camponotus fl oridanus Buckley (Florida Carpenter Ant). Identification was based on head morphology by John Pickering (University of Georgia) and Stefan Cover (Harvard University). The absence of complete specimens precluded us from identifying ants with absolute confidence or determining conclusively if the ants possessed wings at the time of interaction. Seasonal timing of bat captures and location of ant attachment support assumptions of aerial contact made previously by Handley (1956). Camponotus species, including Florida Carpenter Ants, are primarily nocturnal (Sharma et al. 2004, Suiter Notes of the Southeastern Nat u ral ist, Issue 8/1, 2009 179 180 Southeastern Naturalist Notes Vol. 8, No. 1 Figure 1. Adult female Nycticeius humeralis (Evening Bat) with anterior portions of two Camponotus fl oridanus (Florida Carpenter Ants) attached by the mandibles. Figure 2. Adult female Nycticeius humeralis (Evening Bat) with anterior portion of Camponotus fl oridanus (Florida Carpenter Ant) attached by the mandibles. 2009 Southeastern Naturalist Notes 181 2003) and exhibit aerial swarming and mating behavior in spring. However, it is also plausible, although unlikely, that this interaction occurred due to cohabitation of a tree cavity. Bats are capable of discriminating between food items based on palatability (Hristov and Conner 2005), size, and taxa (Agosta et al. 2003). Evening Bats rarely include hymenopterans as a major prey item (Whitaker 2002, Whitaker and Clem 1992), but ants may be consumed extensively by many bats, including Evening Bats, during periods of high abundance (i.e., swarming events; Carter et al. 2004). The aggressive nature and occasional injuries associated with consuming carpenter ants may not outweigh the benefits of a concentrated and abundant food source during swarming events. Acknowledgments. Funding was provided by Warnell School of Forestry and Natural Resources at the University of Georgia, the National Council for Air and Stream Improvement, Inc., and Weyerhaeuser Company. Research was conducted on property owned by International Paper Company, which also provided field housing and logistical assistance. We thank J. Pickering and S. Cover for assistance with ant identifications and A. Forsberg for field assistance. Literature Cited Agosta, S.J., D. Morton, and K.M. Kuhn. 2003. Feeding ecology of the bat Eptesicus fuscus: “Preferred” prey abundance as one factor infl uencing prey selection and diet breadth. Journal of Zoology, London 260:169–177. Carter, T.C., M.A. Menzel, B.R. Chapman, and K.V. Miller. 2004. Partitioning of food resources by syntopic Eastern Red (Lasiurus borealis), Seminole (L. seminolus) and Evening Nycticeius humeralis) Bats. American Midland Naturalist 151:186–191. Handley, Jr., C.O. 1956. Bat versus ant. Journal of Mammalogy 37:279. Harris, A.H. 1971. Pipistrellus hesperus (Chiroptera) versus ant. Southwestern Naturalist 15: 396–397. Hristov, N., and W.E. Conner. 2005. Effectiveness of tiger moth (Lepidoptera, Arctiidae) chemical defenses against an insectivorous bat (Eptesicus fuscus). Chemoecology 15:105–113. Ross, A. 1961. Notes on the food habits of bats. Journal of Mammalogy 42:66–71. Sharma, V.K., S.R. Lone, A. Goel, and M.K. Chandrashekaran. 2004. Circadian consequences of social organization in the ant species Camponotus compressus. Naturwissenschaften 91: 386–390. Suiter, D.R. 2003. Biology and management of carpenter ants. University of Georgia Cooperative Extension Service (CAES) Bulletin 1225:1–8. Whitaker, Jr., J.O. 2002. Prey selection in a temperate-zone insectivorous bat community. Journal of Mammalogy 85:460–469. Whitaker, Jr., J.O., and P. Clem. 1992. Food of the Evening Bat, Nycticeius humeralis, from Indiana. American Midland Naturalist 127:211–214. Wilson, N. 1958. Another instance of bat versus ant. Journal of Mammalogy 39:438. 1 Daniel B. Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602. 2Weyerhaeuser Company, PO Box 2288, Columbus, MS 39701. 3National Council for Air and Stream Improvement Inc., PO Box 340317, Clemson, SC 29634. *Corresponding author - benderm@warnell.uga.edu.