Deimatic Behavior in Pleurodema Brachyops

Deimatic Behavior in Pleurodema brachy ops

MARCIO MARTINS, Departamento de Ecologia, Institulo Nacional de Pesquisas da Amazonia, Cnixa Posta/478, 69083 Manaus AM, Bra:,il .

Deimatic behavior consists of intimidating postures or actions that occur in animals '"hich cannot flee very fast, or which have been caught by a pursuing predator (Edmunds, 1981). Puffing up the body, ele vating the hindparts, and displaying bright colored marks, glands and eyespots are known deimatic dis plays in frogs (Sazima and Caramasc.h i, 1988). Pily salaemus ualtereri and Plrysalaemus deimaliCJJS puff up the body and display glands that resemble eyes when disturbed (Edmunds, 1981; Sazima and Caramaschi, 1988). Seven of 12 known species of Pleurodema have a pair of prominent lumbar glands; these glands are generaJly black with other contrasting colors (Duell man and Veloso, 1977). Cei and Espina (1957) reported on the deimatic behavior in Pleurodema thaul and Cei (1962, fig. 46) found it in Pleurodema bufonina. Duell man and Veloso (1977) did not observe this behavior in the other five spedes of Pleurodnna having lumbar glands (in cluding P. brachyops). During a study of the reproductive biology of frogs inhabiting the savanna in northern Brazil, I observed deimatic behavior in Pleurodema brachyo,vs under laboratory conditions. 306 NOTES

a b FIG. 1. P/eurodema brachyops with (a) body in1lated (at night in the field) and (b) body in1lated, hind parts elevated, and displaying noxious glands, eyespots, and bright colored markings (by day in laboratory). Glands are black with small white markings; area surrounding glands is black; bright colored markings are stippled. Dr.1wn from color diapo~itives.

Field observations we·re made in 1986 in temporary P. deimaticus (Sazima and Caramaschi, 1986), Pleuro a.nd permanent ponds in the savanna around Boa Vis dema Ihau l (Cei and Espina, 1957), and P. bufonina (Cei, ta (2"48'N, 60"12'W, 100m elev.), Roraima, Brazil. More 1962) exhibit all these dlsplays, but they lack bright than ten P. bracllyop; males collected in these ponds colored thzghs, which are found in other frogs in at n1ght were transported to the laboratory and tested which some of thl'se displays occur (e.g., D<·ndro/Jatcs .><>parately in a plastic chamber (50 x 4-0 x 8 em) the flavop;rtusand L:l'loJact.vlu..yrinthiru,, l. Suima, pers. foll owing morning. EaC'h frog was tested just once. comm.). Pll'llmdt·ma l•raclzyops is untque m presenting The tests consisted of inhjbiting escape by the frog all of these displays. Although the dcimatic behavior and stimulating it by tapping its back. of these frogs can be considered a complel> behavioral Pleurodema bracizyops in Boa Vista has a reticulated, pattern, its evolution may have occurred in relatively gray dorsum with smooth skin, lumbar glands black simple steps (Sazima and Caramaschi, 1986) as each wilh small white markings, surrounded by an area of of its components alone or in combination is found black. The inguinal region and h idden surfaces of tlw in several frog families (Bufonidae, Dcndrobatidae, thighs are bright orange. In the field at night, P. Leptodactylidae. and Sooglos.~idae; Cott, 1940. Cei and bruc/zyops males ned \\'ith a sequence of l>hort Jumps Espina, 1957; Cci, 1962; Bajger, J980; Sa.mna and Ca when approached. When caught and unabll' to jump, ramaschi, 1986; l. Sazima. pers. comm.; pers. obs.). The they inflated the body ell.posing only partially the observations presented here and the visual nature of lumbar glands and did not alter this posture when the deimatic displays observed in P. bracllyops suggest further stimulated (Fig. la). One juverule exhibited that these displays occur only by day. This could ex the same behavior after several trials, and also re plain the lack of observation of this behavior in nat maiJled immobile for a few seconds when 1 turned it ural field conditions (Duell man and Veloso. 1977: this upside down. I never found a P. /Jrachy''PS by day in paper). Although P. brachyops is a nocturnal breeding the field. ln the laboratory, all P. /Jraclzyops males tested species (Staton and Dixon, 1977; Hoogmoed and Gor e>.hlbited deimatic behavior when firstsh:nuJatcd (Fig. zula. 1979; pers. obs.), the combination of these five 1b). Their posture consisted of inflating the body and display components suggests that there is predation elevating the hjndparts, thus displaying the lumbar in possible diurnal activities and/ or in its ruurnal glands, the orange spots of the inguinal region and retreat. posterior surfaces of the thighs. The head was low ered a little and the eyes were open. Glandular se Acknowlerlgments.-l thank C. Morato de Carvalho crt:tions were not observo:d. When re-stimulated, the for the opportunity of working in RorJima,!. Sazima posture was enhanced and when not, the posture was for discussion and valuable suggestions, j.-M. Hero abandoned after a fcw S<>conds and the frog fled. for improving my English, and Convcruo CNPq/ The deimatic behavior observed in P. braclryops con INPA/ Governo de Roraima for financial support. sists of at least five types of displays: body inflation, hindparts elevation, noxious glands display, bright LlrrRAniRE CITED color display, and eycspots display. These disp l~ ys are known in other frogs and are considered to be BAJGER, J. 1980. Diversity of defensive responses in rnti midating to potential predators (for a review, see populations of fire toads (Bombi1111 bom/Jma and Bom Sazima and Caramaschi, 1986). Physalnemus llattrrcrl, bina utrri~gala). Herpetologicn 36: 133-137. NOTES 307

CE!, J. M. 1962. Batracios de Chile. Ed. Univ. Chile, Santiago. Pp. 1- 128 + i-cviii. ---, AND S. EsPINA. 1957. La vibracion sexual preventiva (" warning vibration" ) en Pleurodema chilenas. lnv. Zool. Chllenas 4:15-21. Carr, H. B. 1940. Adaptive coloration in an imals. Methuen, London . DUELLMAN, W . E ., AND A. VELOSO M. 1977. Phylog eny of P/eurodrma (Anura: Leptodactylidae): a bio geographic model. Occ. Pap. Mus. Nat. H ist. Univ. Kansas 64:1-46. EDMUNDS, M. 1981. Defensive behaviour. In D. Mcfarland (ed.), The Oxford companion to animal behaviour, pp. 121-129. Oxford Univ. Press, Ox ford. HOOCMOED, M. 5., .>u'ID S. J. GoRZ1.11.A 1979. Check list of the savanna inhabiting frogs o f the El Man teca region with notes on their ecology and de scription of a new species of treefrog (Hylidae, Anura). Zoo!. Meded . 54:183- 216. SAZJMA, I., AND U. CAR..o.MASCHJ . 1986. Descri~ao de Physa/aemus deimaticus, sp. n ., e observa~oe s sobre o comportamento deimatico em P. naltere·ri (Steindn.)-Anura, Leptodacty lidae. Rev. Bioi. 13:91- 101. STATON, M. A., ANO J. R. DIXON. 1977. The herpe tofauna of the Central Llanos of Venezuela: note worthy records, a tentative checklist and ecolog ical notes. J. Herpetol. 11:17- 24.

Accepted : 3 February 1988.