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Milwaukee, WI, United States

Turk P.A.,Avila University | Wyszynski N.N.,University of Tennessee at Knoxville | Powell R.,Avila University | Henderson R.W.,Section of Vertebrate Zoology

Gymnophthalmus pleii and G. underwoodi (Gymnophthalmidae) occupy xeric woodlands along the western coast of Dominica, whereas Sphaerodactylus fantasticus fuga (Sphaerodactylidae) is a dwarf gecko found in more mesic microhabitats in the same general area. We studied population densities and desiccation rates of all three species in order to determine relationships between lizard sizes, rates of water loss, and habitat associations at two different sites. Populations of all three species appear to be allopatric. Mean population density estimates were 1,338.0 ± 385.1 G. pleii/ha (0-3,440/ha) at Cabrits National Park and 127.0 ± 127.0 G. underwoodi/ha (0-1,270/ha) and 1,210.0 ± 823.0 S. fantasticus fuga/ha (0-7,650/ha) at Batali Beach. The desiccation rate for G. pleii, which occupies the most xeric habitats, was significantly lower than those for both other species. The rates for G. underwoodi, of which only juveniles were examined, and S. fantasticus fuga did not differ significantly, and both occurred in similar habitats. As predicted, smaller lizards in all three species lost water faster than larger lizards. © 2010 Deutsche Gesellschaft für Herpetologie und Terrarienkunde e.V. (DGHT). Source

Pauers M.J.,Section of Vertebrate Zoology | Mckinnon J.S.,East Carolina University
Current Zoology

Sexual selection is widely viewed as playing a central role in haplochromine cichlid speciation. Hypothetically, once divergent mate preferences evolve among populations of these fishes, reproductive isolation follows and the populations begin to behave as different species. Various studies have examined patterns of assortative mating among species and sometimes populations, but few have examined variation in directional preferences, especially among populations of the same species. We investigated mate choice behavior in two populations of Labeotropheus fuelleborni, a Lake Malawi endemic. We test whether mating preferences between populations are based on the same traits and in the same direction as preferences within populations. We examine the potential contributions of two classes of trait, color patterns and behaviors, to reproductive isolation. When females chose between either two males of their own population, or two from another, female preferences were generally similar (for the female population) across the two contexts. Mate choice patterns differed between (female) populations for a measure of color, but only modestly for male behavior. In a separate experiment we simultaneously offered females a male of their own population and a male from a different population. In these trials, females consistently preferred males from their own population, which were also the males that displayed more frequently than their opponents, but not necessarily those with color traits suggested to be most attractive in the previous experiment. Thus directional preferences for chroma and related aspects of color may be important when females are presented with males of otherwise similar phenotypes, but may play little role in mediating assortative mating among populations with substantially different color patterns. A preference for male behavior could play some role in speciation if males preferentially court same-population females, as we have observed for the populations studied herein [Current Zoology 58. © 2012 Current Zoology. Source

Pauers M.J.,Section of Vertebrate Zoology | Pauers M.J.,University of Wisconsin - Milwaukee | McMillan S.A.,University of Wisconsin - Milwaukee

The Lake Malawi cichlid genus Labeotropheus has been a source of confusion among biologists and taxonomists. Although unique populations of both L. fuelleborni and L. trewavasae exist throughout the lake, these populations have not been elevated to species, despite taxonomists doing so for populations within other Lake Malawi cichlids. One reason for this oversight is the supposed consistent differences in morphology between Labeotropheus species; since, where they co-occur, L. fuelleborni is always deeper-bodied than L. trewavasae, it is thought that all deep-bodied populations of Labeotropheus are L. fuelleborni, and the slender ones are L. trewavasae. Using geometric morphometrics, we analyze 18 populations of Labeotropheus and show that body shape varies among populations, and does not always fall into a deep-body/slender-body dichotomy. These differences in body shape are not related to geographical distance among populations, but are possibly related to the type of habitat in which the populations are found. Further, head shape is extremely variable among populations, and we find two locations where there is convergence in head shape between sympatric L. fuelleborni and L. trewavasae. Our results suggest that the morphological criteria applied to the Labeotropheus are not accurate, and hamper the recognition of Labeotropheus biodiversity. © 2014, Springer International Publishing Switzerland. Source

Bentz E.J.,Feather River College | Bentz E.J.,Oregon State University | Rodriguez M.J.R.,University of Puerto Rico at Mayaguez | John R.R.,University of California at Santa Cruz | And 2 more authors.
Herpetological Conservation and Biology

The slopes above Chatham Bay on Union Island, St. Vincent and the Grenadines, support one of the last mature secondary forests in the Grenadines. The characteristics of the forest allow it to support a unique herpetofauna that includes four small crevice- and litter-dwelling reptilian species (Gonatodes daudini, Bachia heteropa, Sphaerodactylus kirbyi, and Typhlops tasymicris). We examined population sizes and densities, activity periods, microhabitat use, thermal biology, and water loss rates of these four presumably syntopic species to better understand these poorly known species and the unique ecological system of the forest floor on which they depend. Our findings show that G. daudini, S. kirbyi, and B. heteropa are present in the ~37-ha area of forest above Chatham Bay at a ratio of approximately 2:1:12, respectively, and tentatively estimated total population sizes are about 6,600 G. daudini, 3,200 S. kirbyi, and 39,000 B. heteropa. Each of the four species was found to exploit separate microhabitats based on specific needs for cover, moisture, and thermal environments. The conditions necessary for these species to thrive apparently are available only in relatively mature forest situated to receive and hold moisture. This unique assemblage and the forest that supports it are under severe and imminent threat from exotic mammals and development, and the preservation of the area above Chatham Bay should be a high conservation priority of regional governmental agencies and non-governmental organizations. Source

Rodriguez M.J.R.,University of Puerto Rico at Mayaguez | Bentz E.J.,Feather River College | Bentz E.J.,Oregon State University | Scantlebury D.P.,University of Rochester | And 5 more authors.
Journal of Herpetology

Typhlops tasymicris was known previously from only two specimens, both immature females collected on Grenada in 1968. In June 2010, we rediscovered the species on Union Island, St. Vincent and the Grenadines, where we encountered five individuals (and captured four) on the forested slopes above Chatham Bay. The new specimens agree closely with the two previously reported individuals for all scale characters and coloration, but they differ in sizes and proportions. At least two of the new specimens are adults, but all seem to be females. This first record of a typhlopid snake in the Grenadines suggests a greater range than indicated by the earlier specimens. Although suitable habitat occurs nowhere else on Union Island, the species could occur elsewhere in the Grenadines where relatively mature forests persist. DNA sequence data clearly show a closer affinity with South American species than with any West Indian congeners. © 2011 Society for the Study of Amphibians and Reptiles. Source

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