Social Behaviour of the Dwarf Gecko Sphaerodactylus Vincenti Vincenti on St

Social behaviour of Sphaerodactylus vincenti vincenti

SALAMANDRA 44 1 15-22 Rheinbach, 20 February 2008 ISSN 0036-3375

Social behaviour of the dwarf gecko Sphaerodactylus vincenti vincenti on St. Vincent, Lesser Antilles

Martha A. Marcum, Michael A. Powell, Alexander J. Muensch, Helen F. Arnold & Robert Powell

Abstract. In June 2006, we staged male/male (m/m), male/female (m/f), and female/female (f/f) (seven each) interactions between pairs of Sphaerodactylus vincenti vincenti (Sphaerodactylidae) from St. Vin- cent, West Indies, and evaluated 23 types of behaviours. Behavioural repertoires diff ered signifi cantly between types of interactions. Six individual behaviours occurred signifi cantly more frequently in at least one type of interaction: crouch, gular-infl ation, and antiparallel-positioning more in m/m than in m/f, tongue-fl ick and rooting more in f/f than either m/m or m/f, and head-turn more in f/f than in m/f encounters. Female/female interactions consistently included the greatest number of behaviours that could be construed as being aggressive, although attack, the most egregious agonistic behaviour documented, occurred at almost equal frequencies in both types of consexual interactions. Th e most consistently observed pattern (found in all three combinations of interactions) began with stare, followed by signaling from a distance, approach or attack, contact, and fi nally withdrawal. Some display/approach sequences were performed with a “limp”. In intersexual encounters, males would initiate an approach from behind or alongside a female, moving toward her tail, and lick-sniffi ng her there. Th e female would then allow the male to mount or, more frequently, violently tail-wave and withdraw. Key words. Squamata, Sphaerodactylidae, Sphaerodactylus vincenti vincenti, St. Vincent, social behaviour.

Introduction Sphaerodactylus vincenti vincenti (Fig. ) is the only species of dwarf gecko on St. Vin- Dwarf geckos in the genus Sphaerodactylus cent and is an island endemic. Other subspe- are small, voiceless lizards that may be active cies of S. vincenti occur on the Martinique, by day, night, or during crepuscular periods St. Lucia, and Dominica island banks (Stein- (Leuck et al. 988, Steinberg et al. 2007). berg et al. 2008). Sphaerodactylus v. vincen- Th e systematic literature on West Indian ti is a relatively large sphaerodactyl, with a species of Sphaerodactylus is abundant, but maximum snout-vent length (SVL) of 40 that concerned with behaviour of Caribbean mm, and is found in leaf litter, bromeliads, (Leuck et al. 988, Regalado 997, 2003) and under rocks and rotten logs (Schwartz and speciﬁ cally Lesser Antillean (Wissmann & Henderson 99), particularly in mesic et al. 2005) dwarf geckos lags far behind, with areas (Steinberg et al. 2007). only ﬁ ve of the over 80 species known to occur in the region (Powell et al. 996) hav- ing received more than cursory examination. Materials and methods According to the few detailed studies, visual signals are a primary means of sex recogni- In June 2006, we collected four groups of tion, although geckos in general appear to 6-0 geckos in a densely shaded area with rely heavily on olfactory cues (e.g., Dial & thick (> 5 cm) mango (Mangifera sp.) leaf lit- Schwenk 996). ter in the Botanical Garden in Kingstown,

St. Vincent. We observed and videotaped 2 with a paper towel substrate, and misted con- intraspeciﬁ c interactions: seven male/male, tainers twice a day for the duration of captivi- seven female/female, and seven male/female ty. Containers were kept outside on a covered encounters. All animals were released at the porch at ambient temperatures and humidity, site of capture aft er a maximum of three days and were washed thoroughly with soap and in captivity. warm water for each new inhabitant to elimi- We sexed geckos and measured SVL to the nate the possibility of chemical distractions. nearest 0. mm. Individuals were housed in Aft er the settling period, we placed two 6 x 9 x 0-cm plastic cages and circular plas- selected geckos into a washed and dried 2 tic containers with screened lids. In order to x 4 x 3-cm plastic cage with a fresh, white calm and acclimate geckos prior to each in- paper substrate cut to ﬁ t the bottom of the teraction, we isolated them by placing paper cage. Each individual participated in a maxi- between neighbouring cages for a period of mum of three encounters. No animals were at least 20 minutes. We provided each gecko used more than once per day and no pairs

Fig. 1. Adult male (top) and female Sphaerodactylus vincenti vincenti from the Botanical Garden, Kingstown, St. Vincent, showing some of the colour and pattern variation observed in these geckos. Despite the diﬀ erences evident in these two individuals, S. v. vincenti is not sexually dimorphic, with variation in dorsal and ventral ground colours, colour of the iris, and distinctiveness of pattern elements found in both males and females. Sexes of all lizards used in this study were determined by the presence (males) or absence of enlarged escutcheons. Th ese lizards reach estimated population densities to 5625/ha in moist, shaded leaf-litter (Steinberg et al. 2007).

16 Social behaviour of Sphaerodactylus vincenti vincenti were repeated. Every interaction was taped other animal), on wall (individual climbed on a video-recorder that simultaneously re- the wall of the cage), and rooting (individual corded our audio observations, which were touched nose to the substrate). supplemented with notes by at least two ob- We noted other behaviours observed by servers. We later reviewed the video record- D.S. Steinberg (pers. comm.) that included: ings to obtain a more detailed analysis and gular-pumping (a series of throat infl ations more descriptive data set. As in Wissmann et and defl ations), gular-infl ation (individual al. (2005), we began recording each individ- maintains an engorged throat sac for a peri- ual’s behavioural repertoire, which included od of time), and antiparallel-positioning (in- notations of behavioural sequences, from the dividuals are parallel to one another but fac- time that one lizard initiated a behaviour or ing opposite directions). We modifi ed the lat- assumed a position directed toward the oth- ter to include variations of head positioning er. We ceased recording aft er 5 minutes of at the neck or side of the other animal. We inactivity following any interactions or af- believe that redefi ning this behaviour is ap- ter 20 minutes of total inactivity had passed propriate because each head placement was since the introduction. accompanied by licking and/or sniffi ng and Behaviours were characterised as in Re- therefore seemed to serve the same purposes galado (997, 2003) and Wissmann et al. of attaining information and sexual identifi - (2005) and included: approach (individual cation (Regalado 2003). moved toward the other animal at a normal We combined two behaviours that were pace), withdrawal (individual moved away identifi ed separately by Wissmann et al. from the other animal), stiff (legs extended (2005), as it was diffi cult to distinguish be- posteriorly, sometimes with body tilted to- tween lick (individual tongue fl icks at the ward the opponent, almost always accompa- other animal) and sniff (individual touches nied by arched back and head pointed down), the other animal with its snout without lick- crouch (individual rested its legs alongside ing), labeling the combined behaviour lick- the body while keeping its trunk close to the sniff . We divided raised-tail (Wissmann et al. substrate and head held above the substrate), 2005) into three behaviours distinguished by head-turn (stationary individual assumes duration and extent: raised-tail A (elevated a 45-90° angle between head and long axis tail curved upward), raised-tail B (tail elevat- of the body, oft en alternating the direction ed at the base and center making an arc with of fl exion to the opposite side of the body), the tip pointed down), raised-tail C (tail is tongue-fl ick (rapid extension and retraction fl at on the substrate with only the tip curved of tongue), head-bob (up and down move- upward). ment of the head, noted from the beginning We observed and added one behaviour to the end of a series), and stand (individu- (attack: rapid charge followed by a bite) that al lift ed body partially away from substrate was not noted in any of the previous studies. while stationary). We analysed our data using Statview 5.0 Additional behaviours drawn from Wiss- (SAS Inst., Cary, North Carolina); for all mann et al. (2005) included: stare (individu- tests, α = 0.05. al looked intently at the other animal), walk (individual moved around without appearing to interact with the other animal), tail-wave Results (tail waved or wagged quickly and rhythmi- cally from side to side, noted from beginning Repertoires of behaviours (Table ) diff ered to the end of a series), touch (part of one in- signifi cantly between types of interaction dividual’s body touched the other animal), (contingency test, df = 23, χ2 = 44.82, P < mount (individual climbed on top of the 0.000), but when we compared individual

17 Martha A. Marcum et al. types of behaviours, the only signifi cant dif- Tab. 1. Frequencies of behaviours exhibited by ference was in the occurrence of antiparallel- Sphaerodactylus vincenti vincenti during male/ positioning (ANOVA, df = 2, F = 3.93, P = male (MM), male/female (MF), and female/female (FF) interactions. See text for distinctions between 0.04). Pairwise comparisons (Fisher’s PLSD) “raise-tail A”, “raise-tail B”, and “raise-tail C”. revealed the following signifi cant diff erences: crouch between male/male and male/female Behaviour MM MF FF interactions (P = 0.03), head-turn between fe- approach 92 50 79 male/female and male/female interactions (P withdrawal 95 49 77 = 0.04), tongue-fl icks between female/female and male/female interactions (P = 0.005) and stiff 6 6 44 between female/female and male/male inter- stare 06 63 7 actions (P = 0.004), rooting between female/ walk 74 25 54 female and male/female interactions (P = crouch 5 4 25 0.04) and between female/female and male/ tail-wave 64 53 53 male interactions (P = 0.04), gular-infl ation head-turn 42 73 48 between male/female and male/male interac- tongue-fl ick 5 6 56 tions (P = 0.02), and antiparallel-positioning head-bob 5 52 2 between male/female and male/male interac- lick-sniff 77 29 47 tions (P = 0.0). stand 30 30 26 Although diff erences were not always sig- touch 6 9 0 nifi cant, certain behaviours occurred substantially more frequently than others. Males on-wall 2 3 9 in same-sex interactions approached and rooting 3 4 36 withdrew more frequently than individuals gular-pumping 78 34 70 in male-female interactions. Males in same- mount 2 5 0 sex interactions head-turned more than an- gular-infl ation 57 5 39 imals in intersexual interactions. Stiff , stare, antiparallel-positioning 0 0 6 walk, head-bob, lick-sniff , and gular-pump- attack 3 2 4 ing occurred least frequently in male/female raise-tail A 54 25 38 interactions. Raised-tail A occurred less fre- raise-tail B 7 3  quently in male/female interactions than in raise-tail C 3 5  male/male interactions. raise-tail total 74 2 50

Discussion & Crews 2004) or gekkonid species that are vocal (e.g., Marcellini 974, 977a, 977b). Studies of lizards’ social behaviours have Also, studies of sphaerodactylid geckos in the shown them capable of various behavioural genus Gonatodes oft en concern species that postures, sequences, and degrees of sociality, are more arboreal than litter-dwelling (e.g., but reptilian behaviours appear to be speciﬁ c Ellingson et al. 995). In addition, many re- to the ecological setting (Brattstrom 974). cent studies of behaviours in geckos address Consequently, comparisons of sphaerodactyl foraging rather than social behaviours (e.g., behaviours with those of other lizards, even Werner et al. 2006). other geckos, may be inappropriate, particu- However, Demeter & Marcellini (98), larly because many studies of social behav- in a study of courtship and aggressive be- iours in geckos address those of eublephar- haviours of captive Gonatodes vittatus, in- ids (e.g., Greenberg 943, Dial & Sch- dicated that their observations were similar wenk 996, Cooper & Steele 997, Sakata to those described for other diurnally active

18 Social behaviour of Sphaerodactylus vincenti vincenti geckos. Also, their results supported obser- may be used to establish dominance. Only vations (e.g., Stamps 977) and studies (e.g., one mount lasted for more than a few sec- Greer 967, Kastle 964) of diurnal species onds in an intersexual interaction and, in indicating that females exhibit a high degree that encounter, we observed no copulation. of aggressive behaviour — as appears to be Th is probably is attributable to the fact that the case for species of Sphaerodactylus (Re- males mounted only non-gravid females, and galado 997, 2003, Wissmann et al. 2005). four of seven females in inter-sexual encoun- As in this study, sample sizes were oft en small, ters were gravid. rendering statistically based distinctions be- Lick-sniffi ng occurred in conjunction with tween smaller groups, such as between grav- antiparallel-positioning on 3 occasions. In id and non-gravid females, impossible. Also, that position, the presumably dominant indi- the available data for Sphaerodactylus are in- vidual lick-sniff ed up and down the other liz- capable of determining the extent to which ard’s back, moving between the neck, trunk, behavioural repertoires vary between species and tail. Th is would usually provoke the pre- or to what extent such repertoires are stere- sumptive submissive to withdraw, ending the otypical of the species studied or of the ge- encounter. nus as a whole. However, that very paucity of As Regalado (997) observed in S. ele- information provides tantalizing glimpses of gans, crouch occurred more frequently dur- interactions that may be every bit as complex ing male/male interactions than in male-fe- as those known to occur in iguanian lizards. male interactions, and usually was used by Hereaft er, we restrict comparisons to submissive animals, suggesting that this be- those with other species in the genus Sphaer- haviour was a component of agonistic en- odactylus. Twelve of 23 behaviours occurred counters. Similarly, according to Regalado primarily in male/male interactions, suggest- (997), head-turning was “agonistic … Such ing that they may be components of agonistic head orientation reveals the infl ated throat behavioural sequences in S. vincent vincen- to the antagonist”. Our study found most in- ti. For example, antiparallel-positioning was stances of this behaviour in consexual inter- common in male/male interactions, but was actions. Head-turn was the most frequently not observed in male/female interactions. observed behaviour in our trials. D.S. Steinberg (pers. comm.) observed an- Tongue-fl icks were more abundant in fe- tiparallel-positioning in two of three male/ male/female interactions than either male/ female encounters in S. macrolepis, and sur- female or male/male interactions. Lick- mised that it might serve as a mechanism ing behaviours may be used in vomerolfac- for gathering information used by females tion and pheromone detection/sex identifi - to evaluate males during courtship. In con- cation (Regalado 997), although Dial & trast, in our study, males would initiate an ap- Schwenk (996), for example, indicated that proach from behind or alongside the female olfaction, rather than vomerolfaction, may (and females oft en positioned themselves be more important in geckos. Tongue-fl ick- facing away from males), always moving to- ing the substrate (i.e., rooting) to determine ward her tail, and lick-sniffi ng her there. Th e the sex of a conspecifi c would seem less ag- female would then allow the male to mount gressive and intrusive than licking. Rooting or, more frequently, violently tail-wave and may be used for identifi cation, obviating a withdraw. potentially more hostile and energetically Rigourous tail-waves preceded withdraw- costly behaviour, suggesting that females in als, which Regalado (997) also observed in same-sex interactions attempted to avoid es- S. elegans. Mounting occurred twice during calated encounters more than sphaerodactyls male/male interactions, suggesting that this in other situations. behaviour is not only for copulation, but also Males in same-sex interactions displayed

19 Martha A. Marcum et al. gular infl ation signifi cantly more frequent- gular-pumping, stiff , raised-tail, and head- ly than animals in male/female encounters. bob as singular acts or in various combina- Th is behaviour appears to be a “modifi er” tions. Signaling or staring sometimes oc- when performed in combination with other curred with the two individuals positioned displays, and a “low level agonistic behaviour, in an antiparallel orientation, bodies curved probably signaling awareness of conspecifi c toward one another in a “c” shape, but with proximity” when performed by itself (Re- varying degrees of space separating them. galado 2003). Females in same-sex interac- Approach oft en followed along a curved tions also used gular infl ation more frequent- pathway toward the other lizard; Regalado ly than either sex in intersexual encounters. (2003) noted that stiff oft en was performed Other presumably agonistic behaviours along a “roundabout path toward a conspe- that occurred substantially less frequently in cifi c”. At times, approach evolved into attack. intersexual encounters were stiff , head-bob, Contact occurred by sniff -licking or biting, lick-sniff , and gular-pumping. Conversely, in the case of an attack, until one of the indi- presumed submissives oft en raised their tails viduals chose to withdraw, which thus termi- (A), an action most commonly seen in male/ nated the sequence. Conversely, a withdraw- male interactions, perhaps correlating with al could also transform into a signaling dis- the higher frequencies of approaches found play or another approach, restarting the pat- in that type of encounter. Head-bobbing was tern. In this way, dominance passed back and the second most frequently observed behav- forth between individuals until one yielded. iour, and both stiff and head-bob have been For the majority of encounters, however, one frequently seen in other Sphaerodactylus (Re- animal would dominate interactions by ini- galado 997). Lick-sniff seems to be an ago- tiating this pattern of behaviour with an ap- nistic behaviour in the context of same-sex proach or display, and remain dominant until interactions, but may also be a means of ap- the end of the interaction. peasement in courtship (Regalado 2003). A display observed by Regalado (2003) Our observations were similar to those in S. nicholsi and in four instances during our of Wissmann et al. (2005) and Regalado study was a display/approach sequence per- (997, 2003) in that female/female interac- formed with a “limp”. Th e dominant animal tions oft en were aggressive. Attack, the most lift ed the front leg closest to the conspecifi c egregious agonistic behaviour documented, and folded it against the body. Th is was fi rst however, occurred almost equally in both performed with a stationary head-bob and types of consexual interactions, with four at- then while approaching, giving the appear- tacks in female/female encounters and three ance of a limp. Th e folded leg occurred in in male/male interactions. Female/female combinations of behaviours similar to non- interactions also generated the greatest fre- limping approaches. quencies of head-bobs and stare. We noted another recurring combination Th e most consistent behavioural pattern of behaviours 44 times: approaching individ- (found in all three types of interactions and uals synchronised head-bobs with tail-wav- performed by both sexes) began with stare, ing. Th e tip of the tail twitched rapidly in followed by signaling from a distance (some- time with each up-and-down movement of times animals would skip this element), ap- the head. Individuals displayed this sequence proach or attack, contact, and fi nally with- from a stationary signaling stance, during an drawal. Th is sequence varied somewhat approach, or both. Th e tail-twitch sometimes among individuals, but followed the same evolved into a larger tail-wave or whipping general pattern. Individuals stared while movement when the displaying individual head-turning from one side of the body to closely approached the other lizard or when the other, and signaled with gular-infl ation, “provoked” by some sort of agonistic behav-

20 Social behaviour of Sphaerodactylus vincenti vincenti iour. Th ese synchronous head-bobs and tail- the grounds of the Botanic Garden. Protocols were waves occurred in sequences of as many as 53 approved by the Avila University Animal Care and repetitions. Use Committee. Fieldwork was funded by a grant Repertoires of behaviours apparently are from the National Science Foundation (U.S.A.) to Robert Powell (DBI-0242589). shared by both sexes of S. vincenti vincenti and the congeners that have been studied. Frequencies of behaviours varied considera- References bly among sexes and types of interactions, but agonistic behaviours were signifi cantly more Brattstrom, B.H. (974): Th e evolution of reptil- abundant during consexual interactions. ian social behavior. – American Zoologist, 4: Sphaerodactyls can occur in remarkably high 35-49. densities (Rodda et al. 200, Steinberg et Cooper, W.E., Jr. & L.J. Steele (997): Pheromo- al. 2007), possibly resulting in intense com- nal discrimination of sex by male and female petition for resources (e.g., space), which, in Leopard Geckos (Eublepharis macularius). – turn, may have led to the evolution of terri- Journal of Chemical Ecology, 23: 2967-2977. torial and aggressive behaviours. Intersexu- Demeter, B.J. & D.L. Marcellini (98): Court- al encounters, on the other hand, were rela- ship and aggressive behavior of the Streak Liz- tively docile, suggesting that females are not ard (Gonatodes vittatus) in captivity. – Herpe- coaxed into receptivity by aggressive males. tologica, 37: 250-256. We found many diff erences in frequen- Dial, B.E. & K. Schwenk (996): Olfaction and cies of behaviours in diff erent types of inter- predator detection in Coleonyx brevis (Squa- actions to be substantial but not signifi cant, mata: Eublepharidae), with comments on the indicating that larger sample sizes might re- functional signifi cance of buccal pulsing in veal stronger trends. Certain combinations of geckos. – Journal of Experimental Zoology, 276: 45-424. behaviours, all of which varied to some degree, also are suggestive of trends that might Ellingson, J.M., L.J. Fleishman & E.R. Loew (995): Visual pigments and spectral sensitiv- be confi rmed with additional research. How- ity of the diurnal gecko Gonatodes albogularis. ever, these data should help establish a foun- – Journal of Comparative Physiology, 77: 559- dation upon which further investigations 567. can build: research capable of characteris- Greenberg, B. (943): Social behavior of the ing predictable sequences of behaviours and Western Banded Gecko, Coleonyx variegatus. their corresponding functions so that we may – Physiological Zoology, 5: 0-22. achieve a more thorough understanding of Greer, A.E. (967): Th e ecology and behavior of social interactions and idiosyncrasies of this two sympatric Lygodactylus geckos. – Breviora, ubiquitous genus of West Indian geckos. 268: -9. Kastle, W. (964): Verhaltungsstudien an Tag- geckonen der Gattungen Lygodactylus und Acknowledgements Phelsuma. – Zeitschrift für Tierpsychologie,2 : 486-507. Leuck, B.E., K.W. Hughes & H.Y. Cheng (998): David S. Steinberg helped collect geckos. Rob- Social displays of experimentally paired dwarf ert W. Henderson and John S. Parmerlee, Jr. geckos (Sphaerodactylus clenchi). – Journal of reviewed an early draft of this paper. Permits to Herpetology, 24: 46-48. conduct research on St. Vincent were issued by the Department of Forestry, St. Vincent and the Gren- Marcellini, D.L. (974): Acoustic behavior of the adines. Brian Johnson, Director, Department of gekkonid lizard, Hemidactylus frenatus. – Her- Forestry, Cornelius Richards, Amos Glasgow, petologica, 30: 44-52. and especially FitzGerald Providence facilitat- Marcellini, D.L. (977a): Acoustic and visual ed our eff orts. Nigel Weeks, Director of National display behavior in gekkonid lizards. – Ameri- Parks, granted permission to conduct research on can Zoologist, 7: 25-266.

21 Martha A. Marcum et al.

Marcellini, D.L. (977b): Th e function of a vo- Schwartz, A. & R.W. Henderson (99): Am- cal display of the lizard Hemidactylus frenatus phibians and Reptiles of the West Indies: De- (Sauria: Gekkonidae). – Animal Behaviour, 25: scriptions, Distributions, and Natural History. 44-47. – Gainesville, Florida (Univ. Florida Press). Powell, R., R.W. Henderson, K. Adler & H.A. Stamps, J.A. (977): Social behavior and spacing Dundee (996): An annotated checklist of patterns in lizards. – pp. 265-334 in Gans, C. West Indian amphibians and reptiles. – pp. 5– & D.W. Tinkle (eds.): Biology of the Reptil- 93 + 8 pls. in Powell, R. & R.W. Henderson ia, Vol. 7, Ecology and Behavior A. New York, (eds.): Contributions to West Indian Herpetol- New York (Academic Press). ogy: A Tribute to Albert Schwartz. – Ithaca, Steinberg, D.S., S.D. Powell, R. Powell, J.S. New York (Soc. Study Amphib. Rept. Contrib. Parmerlee, Jr. & R.W. Henderson (2007): Herpetol., Vol. 2). Population densities, water-loss rates, and di- Regalado, R. (997): Social behavior of the Ashy ets of Sphaerodactylus vincenti on St. Vincent, Gecko (Sphaerodactylus elegans Macleay): West Indies. – Journal of Herpetology, 4: 330- Repertoire and sex recognition. – Herpetologi- 336. cal Natural History, 5: 4-52. Steinberg, D.S., J.L. Hite, R. Powell & R.W. Regalado, R. (2003): Social behavior and sex Henderson (2008): Sphaerodactylus vincen- recognition in the Puerto Rican Dwarf Gecko ti. – Catalogue of American Amphibians and Sphaerodactylus nicholsi. – Caribbean Journal Reptiles: in press. of Science, 39: 77-93. Werner, Y.L., H. Takahashi, Y. Yasukawa & H. Rodda, G.H., G. Perry, R.J.R.J. Rondeau & J. La- Ota (2006): Factors aﬀ ecting foraging behav- zell (200): Th e densest terrestrial vertebrate. iour, as seen in a nocturnal ground lizards, Go- – Journal of Tropical Ecology, 7: 33-338. niurosaurus kuroiwae kuroiwae. – Journal of Sakata, J.T. & D. Crews (2004): Developmental Natural History, 40: 439-459. sculpting of social phenotype and plasticity. Wissmann, S.M., R.L. Hensley, R.R. Powell & J.S. – Neuroscience & Biobehavioral Reviews, 28: Parmerlee, Jr. (2005): Social behaviour in the 95–2. dwarf geckos Sphaerodactylus sabanus and S. sputator fromfrom St.St. Eustatius,Eustatius, NetherlandsNetherlands Anti-Anti- lles. – Salamandra, 4: 45-50.

Manuscript received: 22 January 2007 Authors’ addresses: Martha A. Marcum, Department of Biology, University of North Florida, Jack- sonville, Florida 32224, USA; Michael A. Powell, Department of Political Science, Truman State University, Kirksville, Missouri 63501, USA; Alexander J. Muensch, Department of Biology, Avila University, Kansas City, Missouri 64145, USA; Helen F. Arnold, Department of Biology, Arkansas State University–Beebe, Beebe, Arkansas 72012, USA; Robert Powell, Department of Biology, Avila University, Kansas City, Missouri 64145, USA.