The Herpetological Journal

pp.65-71

Authors: Russell J. Hall And Paula F. P. Henry

Abstract: Growing concern about the decline of certain amphibian populations and for conservation of amphibians and reptiles has led to renewed awareness of problems from pesticides. Testing amphibians and reptiles as a requirement for chemical registration has been proposed but is difficult because of the phylogenetic diversity of these groups. Information from the literature and research may determine whether amphibians and reptiles are adequately protected by current tests for mammals, birds, and fish. Existing information indicates that amphibians are unpredictably more resistant to certain cholinesterase inhibitors, and more sensitive to two chemicals used in fishery applications than could have been predicted. A single study on one species of lizard suggests that reptiles may be close in sensitivity to mammals and birds. Research on effects of pesticides on amphibians and reptiles should compare responses to currently tested groups and should seek to delineate those taxa and chemicals for which cross-group prediction is not possible. New tests for amphibians and reptiles should rely to the greatest extent possible on existing data bases, and should be designed for maximum economy and minimum harm to test animals. A strategy for developing the needed information is proposed. Good field testing and surveillance of chemicals in use may compensate for failures of predictive evaluations and may ultimately lead to improved tests.

pp.72-76

Authors: John Davenport, Timothy J. A Ndrews And Giles Hudson.

Abstract: At 30±1°C, caimans (Caiman crocodilus) ate a mean satiation ration of 8.2% body weight. Mean total gut clearance time (TGCT) was 1 36 h; mean gastric emptying time (GET) was 97 h. These data indicate that caimans eat considerably less food than salt-water crocodiles ( Crocodylus porosus) of similar size, not because their meal size was less, but because they take much longer to process food. Assimilation efficiencies for protein, energy (cals) and dry mass were 9 1 .8%, 68.2% and 62.0% on a diet of sheeps' hearts and 90.2%, 69.2% and 64.7% in caimans fed on fish. These efficiencies are all significantly lower than those found in salt-water crocodiles. Hard particulate material is retained within the stomach by a powerful pyloric sphincter, but caimans appear not to eat gastroliths deliberately. Evidence is presented to show that polyunsaturated fatty acids (PUFAs), especially 22:5co3, are assimilated and incorporated into tissues. Fish-fed caimans showed more 20:5co3 and 22:6co3 in their tissue than liver-fed animals. It has previously been suggested that species of the Family Crocodylidae (believed to be of largely marine ancestry) can assimilate PUFAs while members of the Family Alligatoridae (probably of prolonged freshwater ancestry) cannot. The results of this study deny this clearcut distinction and indicate that any differences in lipid metabolism amongst crocodillians are likely to reflect ecological considerations rather than taxonomic patterns.

pp.77-81

Authors: John B. Iverson

Abstract: The relationships between maximum total and maximum freshwater turtle species richness versus twelve environmental factors hypothesized to be correlated with richness were examined for 42 river drainage basins on five continents. The only highly significant correlate was annual rainfall. Latitude, temperatures, and basin area and discharge were not significantly correlated with species richness. These results are interpreted in light of current theoretical determinants of species diversity.

pp.82-85

Authors: R. S. Oldham And M. J. S. Swan.

Abstract: Fourteen adult common frogs (Rana temporaria) and 40 common toads (Bufa bufo) were forced fed with 2.5 g radio transmitters. The transmitters lodged in the stomach and were regurgitated after 2 to 13 days in the frog and 2 to 38 days in the toad. They did not significantly affect either feeding rates or mass fluctuations of the toads. Reception range was up to 1 00 m and battery life 33 to 47 days. Twenty three toads tracked on a daily basis during the summer showed displacement of between 0 and 1 08 m, animals commonly staying in one place for several days.

pp.86-89

Authors: AUGUSTO FOA1 , GIANLUCA TOSINI2 AND ROGER AVERY

Abstract: Adult ruin lizards, Podarcis sicula, at a study site near Pisa, Italy, were seen during all months of 1988, but in significantly reduced numbers in January, February, November and December. The length of the diel period during which individuals were observed varied from 2-3 h in mid-winter to 14 h in July and August. High activity, defined as any one-hour period of the day during which the total number of lizards observed over three days of observation in any month was greater than the 95% confidence limits for the overall mean, was bimodal from April to October inclusive. Bimodality in the activity pattern was particularly pronounced in the hottest months, as low activity, when numbers observed were lower than the C.L. for the overall mean, occurred during the central hours of the day ( 1200- 1400 h) in July and August. Low activity was also recorded at the beginning and end of the active period in all months from February to November. The diel cycles of juveniles (lizards less than 6 months old) appeared to be less structured than those of adults.

pp.90-93

Authors: J. M. R. Baker

Abstract: The relationship between body size and fecundity in female smooth newts (Triturus vulgaris) was examined by counting the numbers of eggs oviposited, to resolve several controversies. First, whether body size is positively correlated with fecundity. Second, whether ovarian oocyte counts represent the numbers of ova oviposited by females in any particular year. In addition, the hypothesis that body size is positively related to the rate of ovipositon was tested. Female body size was positively correlated with clutch size and rate of oviposition. Numbers of ova oviposited by individuals were of a similar order of magnitude to the estimates of clutch size obtained from ovarian oocyte counts in previous studies. A median oviposition rate of 7.2 ova per day was recorded during the oviposition period.

pp.94-98

Authors: J. Alan Holman

Abstract: Pleistocene deposits at Selsey, West Sussex, thought to represent Substage II of the lpswichian Interglacial Age, have yielded five herpetological taxa: Bufo bufo, Bufo calamita, Rana sp., Emys orbicularis, and Natrix natrix. This is the earliest British record of Bufo calamita and extends its temporal range in Britain back about 1 05,000 years. The presence of Emys orbicularis indicates that mean July temperatures in Britain were probably at least two degrees Celsius warmer than today. The anurans and the pond tortoise indicate the presence of a lotic wetland situation The anurans (outside of the breeding season) and the grass snake could have lived in a grassy area near the wetland.

pp.99-101

Authors: Wolfgang Woster, Satoko Otsuka, Roger S. Thorpe And Anita Malhotra

pp.101-103

Authors: Massimo Capula And Luca Luiselli