Volume 16, Number 3 July 2006 ISSN 0268-0130 THE HERPETOLOGICAL JOURNAL Published by the BRITlSH HERPETOLOGlCAL SOCIETY The Herpetological Journal is published quarterly by the British Herpetological Society and is issued fr ee to members. Articles are listed in Current Awareness in Biological Sciences, Current Contents, Science Citation Index and Zoological Record. Applications to purchase copies and/or for details of membership should be made to the Hon. Secretary, British Herpetological Society, The Zoological Society of London, Regent's Park, London NWI 4R Y, UK. Instructions to authors are printed inside the back cover. All contributions should be addressed to the Scientific Editor (address below). Scientific Editor: Wolfgang WUster, School of Biological Sciences, University of Wales, Bangor, Gwynedd, LL57 2UW, UK. E-mail: [email protected] Associate Scientific Editors: J. W. Arntzen (Leiden), R. Brown (Liverpool) Managing Editor: Richard A. Griffiths, The Durrell Institute of Conservation and Ecology, Marlowe Building, University of Kent, Canterbury, Kent, CT2 7N R, UK. E-mail: R [email protected] Associate Managing Editors: M. Dos Santos, J. McKay, M. Lock Editorial Board: Donald Broadley (Zimbabwe) John Cooper (Trinidad and Tobago) John Davenport (Cork) Andrew Gardner (Abu Dhabi) Tim Halliday (Milton Keynes) Michael Klemens (New York) Colin McCarthy (London) Andrew Milner (London) Richard Tinsley (Bristol) Copyright It is a fu ndamental condition that submitted manuscripts have not been published and will not be simultaneously submitted or published elsewhere. By submitting a manu­ script, the authors agree that the copyright for their article is transferred to the publisher ifand when the article is accepted for publication. The copyright covers the exclusive rights to reproduce and distribute the article, including reprints and photo­ graphic reproductions. Permission for any such activities must be sought in advance from the Editor. ADVERTISEMENTS The Herpetological Journal accepts advertisements subject to approval of contents by the Managing Editor, to whom enquiries should be addressed. Herpetological Journal website: http://biology.bangor.ac.uk/-bss 166/H.I FRONT COVE R: Male Mannophrvne trinila/us carrying larvae (S. Watt) HERPETOLOGICAL JOURNAL, Vol. 16, pp. 233-237 (2006) INTER-POPULATION VARIATION IN LIFE-HISTORY TRAITS OF A CHINESE LIZARD (TA KYDROMUS SEPTENTRIONA LIS, LACERTIDAE) WEI-GUO DU1, XIANG JI1 AND YONG-PU ZHANG2 'Hangzhou Key Laboratory.forAni mal Sciences, School of Life Sciences, Hangzhou Normal College, Zhej iang, Pe ople 's Republic of China 2School of Life and Environmental Sciences, Wenzhou Normal College, Wenzhou, Zhejiang, People 's Republic of China Detecting inter-population differences in life-history traits is the fi rst step in exploring the proximate and ultimate causes of such variation. We measured maternal body size and reproductive output of the lacertid lizard Takydromus septentrionalis from two island populations in eastern China to quantify inter-population variation. We captured female T. septentrionalis from the field and conducted a "common garden" experiment in the laboratory to measure their reproductive output. The study revealed major divergences in female body sizes, clutch mass and egg mass, but no significant difference in these traits was found between the fi rst clutch and the later clutches. This suggests that the inter-population divergences persisted when the same groups of females were maintained in identical conditions in captivity. In contrast, there were no inter­ population differences in size-adjusted fecundities, clutch size and relative clutch masses. Therefore, maternal body size plays an important role in determining female reproductive output in this species, but it does not account for all variation in reproductive traits. The egg size is less variable than the clutch size in each population, which gives support to the optimal egg size theory. Key words: body size, fecundity, inter-population variation, offspringsize, reproductive output INTRODUCTION 1994). Therefore, life-history data on Asian species, even descriptive data, should be very useful in com­ Life-history traits are directly related to organismal pletely understanding life-history evolution 111 fitness and hence are major targets of natural selection. squamates. Species differ substantially in life-history traits, reflect­ For inter-population studies of life histories, while ing both genetic and environmental effects. Even the geographic pattern of I ife-history variation such as geographically separate populations of a single species latitudinal and altitudinal variations has attracted a can evolve diffe rent life histories depending on local great number of studies (Ballinger, 1983; Dunham et ecological conditions (Roff, 2002). As ectotherms, al., 1988; James & Shine, 1988; Grant & Dunham, squamates are highly dependent upon climatic condi­ 1990), islands have been of special interest to ecolo­ tions and have thus attracted considerable research on gists because of the rapid adaptive shifts possible in the contribution of the environment to life-history varia­ island taxa with small and discrete populations, living tion (Dunham et al., 1988; Adolph & Porter, 1993; under different conditions and selective pressures Niewiarowski, 1994; Angilletta et al. , 2004). Whereas (Case, 1982). Compared with parallel studies on geo­ earlier studies on this topic focused on interspecificvari­ graphically separated populations in the continent - for ation in life histories (e.g. Tinkle et al. , 1970; Dunham et example, elevational comparisons (e.g. Ballinger, al., 1988), inter-population variation in lifehi stories has 1977; Grant & Dunham, 1990) - inter-island compari­ been emphasized more recently (e.g. Forsman & Shine, sons can reveal rn icrogeographic variation in I ife 1995; Niewiarowski et al., 2004). The inter-population histories forpopulations with relatively low gene flow comparison may lend considerable insight toward our or migration among them. Several authors have quanti­ understanding of genetic and environmental causes of fi ed inter-island variation in morphology and some life-history variation and the evolution of life histories ecological traits of snakes and lizards (e.g. Shine, (Niewiarowski, 1994; Angilletta et al., 2004; 1987; Case & Schwaner, 1993; Hasegawa, 1994; King, Niewiarowski et al. , 2004). To achieve this end, we need 1997; Thorpe & Malhotra, 1998); these studies sug­ a broad collection of data sets describing inter-popula­ gested that the inter-island variation might stern from tion variation in life histories of squamates. However, both genetic and environmental factors. such studies mainly focus on North American and Euro­ The northern grass lizard Takydromus pean species (e.g. Dunham et al., 1988; Castilla & septentrionalis is a small (up to 80 mm snout-vent Bauwens, 1989; N iewiarowski, 1994), whereas the infor­ length [SYL]) slender-bodied, long-tailed (up to 270 mation on Asian taxa is quite limited (but see Hasegawa, mm) lacertid. Among the 16 or 17 species of grass liz­ Correspondence: Wei-Guo Du, Hangzhou Key Laboratory for ards from the genus Takydromus in the oriental and Animal Sciences, School of Life Sciences, Hangzhou Normal palearctic regions (Arnold, 1997), T. septentrionalis is College, 310036, Hangzhou, Zhejiang, People's Republic of a later evolved species (Lin et al. , 2002), and is mainly China. E-mail: [email protected] distributed over a large area of eastern and northern 234 WEI-GUO DU ET Al. TABLE I. Inter-population variation in seasonal reproductive output of the northern grass lizard, Takydromus septentrionalis. One-way ANOVA as well as ANCOVA with maternal SVL as a covariate were used to detect between-island differences in reproductive traits. Symbols immediately after F values represent significant level: NS=non-significant, ** = P<O.O I. Beij i island Dongtou island (n=40) (n=27) ANOYA ANCOYA F F Mean ± SE Adjusted Mean±SE Adjusted 1.14 1.13 mean±SE mean±SE Number of clutches 2.0±0.2 1.9±0.2 1.9±0.2 1.9±0.2 0.46NS o.004r-:s Seasonal fe cundity 5.2±0.4 4.9±0.4 4.7±0.5 5.1±0.5 0.71 NS 0.05NS Seasonal total egg mass (g) 1.60±0. 11 1.49±0. 11 1.14±0. 13 1.24±0. 13 6.42" O. l 9NS China (Zhao & Adler, 1993). These insectivorous liz­ sand. Each small terrarium was checked at least three ards are primari ly diurnal and terrestrial; fe males times a day forfreshly laid eggs. All eggs were weighed produce clutches of 1-5 elongate eggs from April to (± 0.00 I g) promptly so as to minimize potential July (Ji et al., 1998; Du, 2003 ). T. septenfrionalis has changes in mass due to water exchange. Postpartum fe ­ relatively small energy reserves and therefore the en­ males were returned to their original terraria. The ergy to produce a clutch of eggs mainly come from the experiment was carried out between I 0 April and I 0 current food intake (Du et al., 2003 ). The lizards are lo­ July. cally abundant on two offs hore islands, Dongtou and We calculated relative clutch mass (RCM) as the ra­ Beiji, 13 km apart off the eastern coast of China. These tio of clutch mass to maternal postoviposition mass two islands have similar annual average air temperature (Shine, 1980). The difference in RCM between and annual total precipitation (Zhejiang Bureau of Me­ populations was tested using an analysis of covariance teorology). Microhabitats for lizards are grassy areas. with clutch mass as the variable and body mass as the However, the