The Herpetological Journal

pp.1-8

Authors: S. M. Siddeek And R. M. Baldwin

Abstract: We applied the stage-class matrix model to published data to investigate the population growth rate of Oman female green turtles (Chelonia mydas) under different simulated biological and fishery conditions. Juveniles dominated the stable stage-class population vector. Juveniles and adults contributed most to the potential reproductive output. The present total fishing deaths consisted of approximately 2280 hunted and 2000 accidentally drowned (in fishing nets) female turtles. The model suggested a maximum hunting quota of approximately 1 43 females to maintain a stable population. In addition to protecting eggs and hatchlings, reduction in the juvenile mortality significantly increased the population growth rate. Simulated reduction in the current annual 4280 female fishing deaths to 268 produced a positive population growth rate within feasible stock parameter values. Previous studies have indicated a size at first maturity below 85 cm curved carapace length (CCL). Thus, restricting the number of hunting and accidental drowning deaths to less than 268 females and enforcing a minimum size limit of 85 cm CCL in the traditional turtle fishery appeared necessary to reverse the population decline. More studies on stock abundance, sex composition, stage specific growth, survival, and reproductive rates are needed to refine the model.

pp.9-14

Authors: R. Marquez And J. Bosch

Abstract: The advertisement calls of the recently described species of midwife toad (Alytes dickhilleni) are described, and a characteristic audiospectrogram and waveform of the call are presented. We also provide numerical data about the spectral and temporal features of the calls. Information about calling behaviour and the relationship between call parameters, size, and temperature are provided as well.

pp.15-19

Authors: Ricardo Reques And Miguel Tejedo

Abstract: The most striking social behaviour in urodele tadpoles is overt aggression against conspecific or heterospecific larvae that may result in harmful injuries, predation or cannibalism. In this study we analysed under laboratory conditions aggressive behaviour in fire salamander, Salamandra salamandra, larvae. The aims of our study were: ( 1) to analyse the function of visual and movement displays in the context of agonistic behaviour; (2) to examine whether relative body size between individuals influences the frequency of aggressive interactions; and, (3) to determine the effect of larval density on the frequency of these aggressive interactions. The analysis of patterns that preceded a direct act of aggression (i.e. lunge or bite) revealed that the initiator of the contest exhibited more attacking patterns and that the receiver displayed more escape acts. Relative body size significantly affected the frequency of aggressive acts. The proportion of aggressive acts performed by the larger larva was positively related to relative larval body size. Density significantly affected the number of aggressive interactions observed. Significantly more aggressive acts were received or displayed by the focal larva at high density. Body size seems to be an important cue which is correlated with the outcome of aggressive interactions in Salamandra salamandra larvae. By visually assessing size asymmetry, individuals are able to use this difference to assess fighting ability, and can adjust their behaviour accordingly to avoid escalation of the aggressive encounter

pp.20-25

Authors: Pedro Galán

Abstract: This paper presents data on reproductive and fat body cycles of the oviparous lacertid lizard Podarcis bocagei in northwest Spain. Testes exhibited their maximal volume during December-March and decreased in size throughout the summer. This pattern agrees with the "mixed type" of spermatogenetic cycle proposed by Saint Girons ( 1963, 1982). Vitello genesis started at the end of March or April. Females with oviductal eggs were found from mid-April to mid-July. Oviposition occurs between mid-May and the end of July. Fat bodies of males were smallest during the spring mating period. Female fat body volumes declined during vitellogenesis. No significant decline of lipid stores was detected during the winter period (October-March).

pp.26-29

Authors: John Davenport And Shona H. Magill

pp.30-31

Authors: Mark Wilkinson

pp.32-34

Authors: J. R. Downie

pp.35-36

Authors: J. Alan Holman