Richard Franz

Use of PVC Pipe Refugia as a Sampling Technique for Hylid Treefrogs

Abstract We used retreats made from white polyvinyl chloride (PVC) pipes to capture hylids and determined how pipe design and placement influenced the frequency with which hylids used pipes as retreats. Pipes were hung vertically in trees on three sites in north-central Florida. Pipes were checked twice weekly for 10 mo during which 788 individuals of four species (Hyla squirella, H. cinerea, H. femoralis and H. gratiosa) were captured, with 2658 recaptures. Retreats on hardwoods were used significantly more than retreats on pines, and retreats hung at 2 m and 4 m aboveground were used significantly more than retreats at 0 m. Long and T shaped retreats (both 60 cm long) were used significantly more than short (30 cm) retreats. Retreats capped on the bottom with water inside and 3.81 cm in diameter were used more frequently than retreats of the same diameter that were either capped on the top or not capped and retreats 1.75 cm in diameter with no cap.

Exceptionally well preserved late Quaternary plant and vertebrate fossils from a blue hole on Abaco, The Bahamas

We report Quaternary vertebrate and plant fossils from Sawmill Sink, a “blue hole” (a water-filled sinkhole) on Great Abaco Island, The Bahamas. The fossils are well preserved because of deposition in anoxic salt water. Vertebrate fossils from peat on the talus cone are radiocarbon-dated from ≈4,200 to 1,000 cal BP (Late Holocene). The peat produced skeletons of two extinct species (tortoise Chelonoidis undescribed sp. and Caracara Caracara creightoni) and two extant species no longer in The Bahamas (Cuban crocodile, Crocodylus rhombifer; and Coopers or Gundlachs Hawk, Accipiter cooperii or Accipiter gundlachii). A different, inorganic bone deposit on a limestone ledge in Sawmill Sink is a Late Pleistocene owl roost that features lizards (one species), snakes (three species), birds (25 species), and bats (four species). The owl roost fauna includes Rallus undescribed sp. (extinct; the first Bahamian flightless rail) and four other locally extinct species of birds (Coopers/Gundlachs Hawk, A. cooperii/gundlachii; flicker Colaptes sp.; Cave Swallow, Petrochelidon fulva; and Eastern Meadowlark, Sturnella magna) and mammals (Bahamian hutia, Geocapromys ingrahami; and a bat, Myotis sp.). The exquisitely preserved fossils from Sawmill Sink suggest a grassy pineland as the dominant plant community on Abaco in the Late Pleistocene, with a heavier component of coppice (tropical dry evergreen forest) in the Late Holocene. Important in its own right, this information also will help biologists and government planners to develop conservation programs in The Bahamas that consider long-term ecological and cultural processes.

Respiration rates, ATP turnover and adenylate energy charge in excised gills of surface and cave crayfish

Abstract 1. 1. Respiration rates, ATP turnover and adenylate concentrations of excised gills were determined in three closely related surface and cave species of the crayfish genus Procamburus. 2. 2. Significantly lower gill tissue respiration rates and longer ATP turnover times were associated with the subterranean crayfish species. 3. 3. Respiration values of gill tissue were not correlated with body size, experimental temperature or oxygen tension of the original habitat. 4. 4. Adenylate energy charge (ATP + 1 2 ADP/ATP + ADP + AMP) values were similar in gill tissues of the three crayfish studied, even though O2 consumption ranged from 3.22 to 0.45 μl/hr/mg and ATP turnover times ranged from 0.40 to 4.23 sec. 5. 5. These data indicate that gill tissue respiration rates in the species examined appear to result from adaptations associated with habitat conditions and food availability.

Effects of deer feeders, habitat and sensory cues on predation rates on artificial turtle nests

Abstract We used artificial nests modeled after those of Trachemys scripta, a wide-ranging freshwater turtle species, to evaluate the effects of deer feeders, habitat type and visual and olfactory cues on nest predation in northern Florida. Nests were placed at lake sites with and without deer feeders, and in three habitat types: road, edge and forest. Overall nest mortality due to predators was high (89%). Nest survival was 5.5 times higher at lakes without deer feeders than at those with feeders. Among habitat types, survival was highest at road nests (23%), while survival rates at forest (4%) and edge nests (6%) were lower than that at road nests. No significant difference in survival was detected with respect to the presence of visual or olfactory cues. Our results suggest that deer feeders reduce recruitment in freshwater turtle populations, and that generalizations regarding the negative impacts of roads should be made cautiously, in a taxon and site-specific fashion.

Tropical ancient DNA reveals relationships of the extinct Bahamian giant tortoise Chelonoidis alburyorum

Ancient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands. We have reconstructed the near-complete mitochondrial genome of an extinct giant tortoise from the Bahamas (Chelonoidis alburyorum) using an approximately 1 000-year-old humerus from a water-filled sinkhole (blue hole) on Great Abaco Island. Phylogenetic and molecular clock analyses place this extinct species as closely related to Galápagos (C. niger complex) and Chaco tortoises (C. chilensis), and provide evidence for repeated overseas dispersal in this tortoise group. The ancestors of extant Chelonoidis species arrived in South America from Africa only after the opening of the Atlantic Ocean and dispersed from there to the Caribbean and the Galápagos Islands. Our results also suggest that the anoxic, thermally buffered environment of blue holes may enhance DNA preservation, and thus are opening a window for better understanding evolution and population history of extinct tropical species, which would likely still exist without human impact.

Discovery of a population of Orinoco crocodile Crocodylus intermedius in Southern Venezuela

Abstract A viable population of the Orinoco crocodile Crocodylus intermedius was located on the Rio Caura, State of Bolivar, Venezuela. Prior to this discovery, the species was considered to be nearly extinct in the wild. The history of this discovery, and the populations distribution and future are discussed.

A relict population of the mottled sculpin,Cottus bairdi, from the Maryland coastal plain

A population of mottled sculpin,Cottus bairdi, in the central Delmarva Peninsula (Nanticoke drainage) is the only record of this species from the Atlantic Coastal Plain. Examination reveals that specimens have characteristics of bothC. bairdi and the problematicC. girardi. The presence of other Piedmont indicator-species in this general area suggest a relict Piedmont community.