Effects of age and sex on intra-group spacing behaviour in juvenile savannah baboons,Papio cynocephalus cynocephalus

Twenty juvenile members of known genealogies in two baboon groups were studied over a 16-month period to evaluate a number of predictions about juvenile spacing behaviour based on the natural history of savannah baboons. Young juveniles (1–2·5 years old) approached more frequently and spent more time in proximity to other group members than did old juveniles (3–5·5 years old). In particular, young juveniles associated more closely with their mothers, particular adult males (possible fathers) and age-peers than did old juveniles. Approaches of young juveniles towards unrelated, high-ranking adults were more likely to occur during feeding than were those of old juveniles. Also, following such an approach, young juveniles were more likely than old juveniles to begin feeding immediately. The overall rates of feeding of old juveniles were depressed when they were in proximity to unrelated, high-ranking adults, whereas the feeding rates of young juveniles were not. Juvenile males approached adult males more often than did juvenile females. Juvenile females approached unrelated adult females more often than did juvenile males. Sex differences also existed in juveniles' choices of unrelated adult female neighbours. Juvenile females associated most often with lactating females, whereas juvenile males associated primarily with cycling females. During group resting, juvenile females approached adult females from higher-ranking matrilines more often than they approached adult females from lower-ranking matrilines. Juvenile males did not exhibit this attraction. Also, among old juveniles, females associated closely with their mothers, whereas males did not. Taken together, the results support the hypotheses that juvenile baboons associate with group members in ways that (1) enhance the probability of surviving an early period of high mortality, (2) create opportunities for social learning of sex-typical behaviours/skills, and, for females, (3) facilitate acquisition of familial dominance status.     

Facultative development of courtship and communication in juvenile male cowbirds (Molothrus ater)

We investigated effects of naturally occurring variation inexperience with adult males on development of song and courtshipcompetence in captive juvenile cowbirds. We studied birds ingroups housed in large outdoor aviaries that allowed birdsto regulate access to social stimulation. In two aviaries, we housed juvenile males and females either with or withoutadult males. Birds remained in these conditions from September1999 through their breeding season. We documented social andvocal development of juvenile males in the two aviaries bymeasuring social assortment and patterns and frequencies of their song interactions. We then brought the juveniles fromthe two aviaries together to compete against each other foraccess to females. In addition, we recorded juveniles' songsfour times over the study and played back their breeding seasonsongs to females in sound-attenuating chambers to measure the effectiveness of songs in eliciting copulatory responses fromthe females. Compared to juvenile males housed with adult males,juvenile males housed without adult males developed atypicalbehavior patterns. They (1) displayed little intrasexual aggressionor near-neighbor associations and (2) exhibited different patternsof courtship and copulation, but (3) were as successful at competing for copulations. Furthermore, they developed stereotypedsongs sooner and developed more potent breeding season songs.These different outcomes could not be traced to one variablebut to a cascade of effects involving diverging patterns ofsong acquisition and social interaction. The patterns of socialskills that emerged indicate considerable plasticity in the mechanisms underlying acquisition of courtship competence.     

Agonistic Interactions of Juvenile Savanna Baboons

19 juvenile members of known genealogies in two wild baboon groups were studied over a 16-month period to compare the ontogeny of agonistic experience and dominance relations for males and females. Juveniles of all age-sex classes were disproportionately likely to receive aggression from and submit to adult males per unit of time spent in proximity. This pattern intensified with increasing juvenile age. With age, juvenile females more often submitted to unrelated adult females from higher-ranking families, whereas this was not true for juvenile males. All juveniles received aggression from older group members more often during feeding than was expected by chance. High rates of agonistic interaction with unrelated adult females accounted for old juvenile females (3–5.5 years-old) interacting agonistically more frequently than male age peers and young juveniles of either sex (1–2.5 years-old). Adult females were also more aggressive toward females among young juveniles, suggesting that adult females target females among juveniles for aggression and resistance to rank reversal. Within juvenile age groups, males dominated all females and all younger males, irrespective of maternal dominance status. Dominance relations among female age-peers were generally isomorphic with relations among their mothers. No juvenile targeted any older male for rank reversal. Males targeted all older females, whereas females typically targeted only older females from families lower-ranking than their own. The strong sexual dimorphism in adult body size in baboons may explain why juvenile males' dominance relations with peers and adult females are not structured along lines of family membership as is true for the less dimorphic macaques. Acquisition of higher agonistic status probably allows juveniles of both sexes to increase their success in within-group feeding competition during late stages of juvenility, which, in turn, could affect important life-history traits such as age at menarche and adult body size.     

Seasonal Differences in Social Behavior among Adult and Juvenile Meadow Voles,Microtus pennsylvanicus

Seasonal differences in behavioral interactions between wild-caught adult and juvenile meadow voles, Microtus pennsylvanicus, were measured in paired encounters in a neutral arena. Seasonal differences existed in the adult-juvenile paired encounters. Early in the breeding season (May—Aug.) paired encounters between adult males and juvenile males were more agonistic than other adultjuvenile pairings. Late in the breeding season (Sep.—Dec.) adult female-juvenile male encounters were more agonistic than other adult-juvenile pairings. Odor preferences of juveniles were determined in a Y-maze olfactometer. Juveniles did not demonstrate seasonal differences in odor preference. Males preferred the odor of adult females to the odor of adult males or their own odor. Females preferred the scent of an adult male to the odor of an adult female, but did not show a preference between their own odor and the odor of an adult male or an adult female. The results are consistent with hypotheses that state in a promiscuous species, females should be philopatric, and males should disperse as a consequence of adult competition. The data suggest that agonistic behavior by adults may regulate juvenile dispersal and recruitment, and define the composition of overwintering groups.     

Female brown-headed cowbirds', Molothrus ater, organization and behaviour reflects male social dynamics

In four large aviaries, we studied social assortment and reproductive behaviour of female brown-headed cowbirds housed with males differing in age class and in corresponding levels of intrasexual interaction. Juvenile and adult females resided with either (1) adult males, (2) juvenile males, (3) adult and juvenile males, or (4) no males. We observed social behaviour of males and females from September 1999 through to the 2000 breeding season. Throughout the year, males in the different conditions showed different levels of social interaction, with adult males being most engaged in male-male interactions and juvenile males being least engaged in male-male interactions. Females in the four conditions differed in their associations with males and with other females. In conditions with adult males, females spent more time near males, approached males more often, and associated with females less. During the breeding season, females in conditions with more adult males copulated more and produced more fertile and viable eggs. In the condition where females were housed with juvenile males, they copulated less, laid fewer eggs and destroyed more of their eggs. Results indicate that throughout the year, females are sensitive to male age and behaviour in their social group, and that this sensitivity can have reproductive consequences. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

Post-release survival of translocated fishers: implications for translocation success

As a vital tool for the conservation of species at risk, translocations are also opportunities to identify factors that influence translocation success. We evaluated factors associated with post-release survival of 90 radio-tracked fishers (Pekania pennanti) translocated from central British Columbia, Canada, to the Olympic Peninsula of Washington, USA, from 2008 to 2011. We hypothesized that the survival of translocated fishers would be affected by the same factors that influence the survival of resident, native fishers (i.e., sex, age, season, body condition), and additional factors that were associated with the translocation process (e.g., duration of captivity, release date, yr of release). Fisher survival was most strongly influenced by translocation year (i.e., release-yr cohort), season, sex, and age class of fisher; whereas duration of captivity, standardized body mass, release date, and number of intact canines did not influence survival. Survival was lowest for fishers released in cohort 2 in 2009 and during the breeding season (Mar–Jun), and was greatest for juveniles and males. When combined across release-year cohorts, year 1 survival rates were greatest for juvenile males followed by juvenile females, adult females, and adult males. Sex and age-related differences in survival of translocated fishers were counter to those commonly reported for established fisher populations, where adult females often have the highest survival rates and juveniles the lowest. Predation (40%) and vehicle strikes (20%) were the most common causes of known mortality among the 24 recovered fishers for which cause of death was determined. We speculate that females face higher risks of mortality in translocated populations because their small size makes them more vulnerable to predation and because adult females in resident populations are less likely than males and juveniles to disperse. Our findings support designing translocations that favor releasing a preponderance of female fishers in recognition of their lower survival rates and to ensure adequate breeders are established in the population, and juvenile and young adult fishers to enhance survival of both sexes. Releases conducted over multiple years will minimize the impact of stochastic annual events that may adversely affect survival in any given year. Persistence, widespread distribution, and documented reproduction of fishers within our study area for ≥6 years following the last releases indicate that survival parameters we measured contributed toward successful population establishment over the short term.     

Developmental effects of testosterone on behavior in male and female green anoles (Anolis carolinensis)

This study addressed the role of testosterone (T) in the development of sexually dimorphic behavior in the green anole lizard, Anolis carolinensis. We documented the pattern of endogenous T concentrations during ontogeny and we determined the behavioral effects of experimentally elevated T in juvenile males and females. T concentrations were measured in the plasma of hatchlings from eggs incubated in the laboratory, in juveniles of all sizes sampled in the field, and in the yolks of freshly laid eggs in the laboratory and were compared to plasma T in adult females (measured in this study) and adult males. There were no sex differences in plasma T in hatchling and small juvenile (<26-mm snout-vent length, SVL; <14 days old) males and females, concentrations of which in both sexes tended to decline over the 14-day posthatching period. Plasma T sharply increased in juvenile males, but not females, after approximately 14 days posthatching (>25-mm SVL), and it became significantly higher after approximately 38 days posthatching (>30-mm SVL). Plasma T for juvenile males was within the range detected in breeding adult females, but it was 20- to 45-fold lower than that of adult males, breeding or postbreeding. All eggs contained detectable yolk T, but eggs that gave rise to males contained nearly twice as much yolk T as those that gave rise to females. We do not know whether this yolk T comes from the mother, embryo, or both. In behavior trials conducted in the laboratory, juveniles (36- to 42-mm SVL) with T implants, regardless of whether they were male or female, had increased activity levels compared to juveniles with blank implants, due to increased rates of nearly every behavior monitored. These results are discussed in the context of the organization-activation theory of sexual differentiation and the particular life history of A. carolinensis.     

Prey use of the fishing spider Dolomedes triton (Pisauridae,Araneae): an important predator of the neuston community

Summary Prey of feeding juvenile and adult Dolomedes triton (Walckenaer 1837) were sampled over two seasons on three small ponds in central Alberta, Canada. Prey were mainly insects active at the water surface with truly aquatic species making up about 14% of the diet. Throughout the season aquatic and semi-aquatic Heteroptera represented about 30% of the prey. Diptera and adult Odonata were also important prey items but their abundance in the diet was more variable seasonally. Of the 625 prey items recorded nearly 50% were represented by taxa taken no more than once by spiders in one of the five size classes (adult females, adult males, large, intermediate and small juveniles). Large spiders did not take the smallest prey available, although small and intermediate-sized spiders fed on nearly the full size range taken by larger spiders. Cannibalism was common, accounting for 5% of the observations, with females and large juveniles as the most frequently observed cannibals. We hypothesize that intraguild predation (including cannibalism) could be an important coevolutionary force structuring phenology, population dynamics and microhabitat use of the predatory guild of the neuston community.     

Facultative dispersal by juvenile males in the cooperative stripe-backed wren

We present genetic and demographic data documenting juveniledispersal in the cooperatively breeding stripe-backed wren (Campylorhynchusnuchalis) of Venezuela. Parentage and DNA fragment-sharing analysesrevealed 12 cases in which juveniles were unrelated to othergroup members. Of these 12 foreign juveniles, (1) all were males,(2) eight of 12 had been found with breeding pairs lacking helpersrather than with groups containing helpers, and (3) four outof seven of those observed as adults courted or sired offspringwith the dominant females in their new groups despite the strongincest avoidance of this species. Furthermore, juvenile maleshad a significant tendency to disappear from natal groups intheir first year, and singleton juveniles observed with pairsafter the breeding season were mostly males. These data supportthe hypothesis that foreign juveniles were dispersers from intactgroups and not products of conspecific brood parasitism or adoptionfollowing group dissolution. We suggest that unassisted pairsmight accept juvenile males into their groups as helpers toincrease their future reproductive success and that dispersersthemselves might leave large natal groups in which their helpingis superfluous to join small groups of nonrelatives in whichthey might soon reproduce.     

The Development of Local Song Preferences in Female Cowbirds (Molothrus ater): Flock Living Stimulates Learning

We carried out two experiments across 2 yr on song perception in female cowbirds (Molothrus ater). In the first experiment, juvenile and adult female brown‐headed cowbirds, living in same‐sex flocks in outdoor aviaries, were periodically tutored with recordings of local male cowbirds’ songs. In the spring, four adult male cowbirds were placed with half of the females for a 12‐d period. We then tested song preferences of all females by measuring copulation solicitation displays during the breeding season. We found that the females exposed only to tape‐tutor songs preferred those songs to those of the unfamiliar males used as companions and that the females allowed to interact with males preferred their songs over the familiar tape‐tutor songs. These data establish the modifiability of female cowbirds’ song preferences at the level of local song. In a second experiment, we studied the playback responses of juvenile females, hand‐reared from the egg, who were tape‐tutored only in the spring in the presence or absence of adult females. There were no differences between the responses of juveniles housed with or without adult females and the hand‐reared juveniles were significantly less responsive to song than adult females. Adult females responded more to familiar songs than to the unfamiliar songs: juvenile females made no such distinction. Taken as a whole, these data are the first to document that female cowbirds’ song preferences for local song can be reshaped by post‐natal experience. These data complement recent study in cowbirds and other species showing that socially more complex contexts reveal plasticity in female song preferences that are not apparent when learning opportunities are constrained by impoverished laboratory settings.     

Movement patterns of yellow baboons (Papio cynocephalus): Sex differences in juvenile development toward adult patterns

Age-sex differences in the sociospatial positioning of progressing baboon troops have been postulated as an important, protective aspect of baboon adaptation to a terrestrial existence. The protection theory is an ultimate hypothesis which can be disproven by showing that the postulated age-sex positioning fails to occur. Alternatively, confidence in the protection theory can be increased if the postulated positioning persists across several troops despite significant opportunities for variation, and if progression order is shown to be linked to biological phenomena such as sex differences in physical maturation. Data from 73 individually identified, free-ranging juveniles of both sexes were compared with previous findings. Small juveniles of several troops were more centrally located than large juveniles. Large juveniles males were more toward the front than were large juvenile females. As male walking infants and juveniles aged, a change in positioning (i.e., location) occurred: males were located increasingly toward the front of progressions. Comparable data from females suggest that the adult female pattern had begun to form among large juveniles. Data are consistent with an ultimate protection theory.     

浙江丽水中国石龙子的食性、两性异形和雌性繁殖

丽水分布的中国石龙子（Ｅｕｍｅｃｅｓ ｃｈｉｎｅｎｓｉｓ）摄入的食物均为无脊椎动物,分别属于环节、软体和节肢动物,涉及３０余科,成体和幼体的食物生态位宽度分别为７．２６和６．６９,成体的幼体的食物生态们重叠度为０．５９。性成熟雄性个体大于雌体。成雄和幼体的头长和头宽随体长ＳＶＬ的增长速率大于成雌,成雄头长随ＳＶＬ的增长速度显著大于幼体,成雌和幼体的头长随ＳＶＬ的增长速率无显著差异。成雄头部大于成雌     

Testosterone and its effects on courtship in golden-collared manakins (Manacus vitellinus): seasonal, sex, and age differences

Male golden-collared manakins gather on leks and perform an acrobatic display to attract females. In temperate breeding species, testosterone (T) activation of courtship displays has been well studied. Few studies have examined T activation of displays in tropical species; even fewer have explored the activational role of T in elaborate courtship displays such as in the manakin. In some tropical species, including manakins, territorial aggression or song behavior are uncoupled from T. We have previously shown that T activates display behavior in manakin males when endogenous T levels are low in the non-courtship season. To understand how T functions in breeding birds, we examined T levels in a large group of manakins sampled during the courtship and non-courtship season. In addition, during the courtship season, we gave T implants to adult males, juvenile males, and females. We found that T levels were low during the non-courtship season and comparatively higher on average during the courtship season. However, T levels were low in many adult males during the courtship season, especially when compared to temperate breeding species. Regardless of initial endogenous T levels during the courtship season, T implants did not increase the display frequency of adult males. T-treated females and juvenile males did display under similar conditions. Our data suggest that the effects of T on manakin display vary with season, sex, and age and that high T is not necessary for display.     

Frequency and demographic parameters of white-tipped common dormiceMuscardinus avellanarius

Out of 1154 marked common dormiceMuscardinus avellanarius (Linnaeus, 1758), 219 animals (19.0%) had white tail tips at Vilkaraistis forest (Moletai district, east Lithuania) in 1984–1993. The extent of white tail-tip varied from a slight tuft to a notable 22 mm length of white hair in the tail tip. In this population white-tipped individuals represented, on average, 25.7% among juvenile females, 24.9% among adult females, 13.4% among juvenile males, and 15.7% among adult males. White-tipped females were significantly more frequent than males, both in juveniles and in adults. The share of white-tipped dormice fluctuated in different years from 12.5% to 25.6% among adult dormice, and from 9.2% to 28.3% among juveniles. The percentage of white-tipped dormice among juveniles in different years was directly proportional to population density in autumn. There was no clear difference or trend in the mortality rate in white-tipped versus normal dormice. The contribution of white-tipped females to population reproduction was relatively lower than that of normal females: only 18.4% out of all registered breeding cases (n=212) were due to white-tipped females.     

Weights and growth rates in the Mountain hare Lepus timidus scoticus

Mountain hares were weighed during live trapping on a study area near Dufftown, Banffshire, from June 1958 to August 1966. Hares shot or killed by other means on the study area and elsewhere were also weighed. Females were heavier than males throughout the year and this difference became apparent in juveniles by August of their year of birth. Male hares lost weight during the breeding season (January to June) but regained it in late summer. Young hares gained weight initially at about 14 g per day, then at about 6 g per day to adult weight. Small juveniles, or those born late in the season, tended to become small adults, large or early juveniles to become large adults. Small hares moulted less completely andjbegan to breed later in the season than large hares. The effects of disease, starvation, severe weather and injury on hare weights were considered. Female weights were greater when the population was small, due to more late pregnancies or more embryos per female. Weight could not be used to distinguish between adult and juvenile hares above 2.1 kg, nor between young and older adults.     

Sex and age differences in juvenile social priorities in female philopatric,nondespotic blue monkeys

Juveniles should choose social partners on the basis of both current and future utility. Where one sex is philopatric, one expects members of that sex to develop greater and sex‐typical social integration with group‐mates over the juvenile period. Where a partner's position in a dominance hierarchy is not associated with services it can provide, one would not expect juveniles to choose partners based on rank, nor sex differences in rank‐based preferences. We tested these ideas on 39 wild juvenile (3.2–7.4 years) blue monkeys (Cercopithecus mitis stuhlmanni), cercopithecines with strict female philopatry and muted hierarchies. We made focal animal observations over 6 months, and computed observed:expected amounts of proximity time, approaches and grooming given to various social partners. Overall, our results agree with the hypothesis that juvenile blue monkeys target social partners strategically. Spatial proximity, approaches and active grooming showed similar patterns regarding juvenile social preferences. Females were far more sociable than males, groomed more partners, reciprocated grooming more frequently, and preferred—while males avoided—infants as partners. Older juveniles (5–7 years) spent more time than younger juveniles (3–4 years) near others, and older females were especially attracted to infants. Close kin, especially mothers and less consistently adult sisters, were attractive to both male and female juveniles, regardless of age. Both sexes also preferred same‐sex juveniles as social partners while avoiding opposite‐sex peers. Juveniles of both sexes and ages generally neither preferred nor avoided nonmaternal adult females, but all juveniles avoided adult males. Partner's rank had no consistent effect on juveniles' preference, as expected for a species in which dominance plays a weak role. Juveniles' social preferences likely reflect both future and current benefits, including having tolerant adult kin to protect them against predators and conspecifics, same‐sex play partners, and, for females, infants on which to practice mothering skills. Am. J. Primatol. 72:193–205, 2010. © 2009 Wiley‐Liss, Inc.     

Quantitative observations of grooming behavior in free-rangingMacaca mulatta

Quantitative methods of observation and analysis were used in a 12-month study of grooming behavior of free-rangingMacaca mulatta on La Cueva Island at La Parguera, Puerto Rico. Observations lasting 30–120 minutes were made from eight positions on the island at a standard time of day when monkeys were either feeding or resting. Two dependent variables were obtained: (1) the number of monkeys present in the observation area were noted by age and sex class at five-minute intervals throughout each observation, and (2) the frequency of grooming encounters was tabulated by the age and sex class(es) of groomer and recipient. These data were computed as grooms/hour/possible interacting combination of monkeys. Grooming frequencies were higher in non-feeding situations than when monkeys were feeding. The largest social group had the lowest mean grooming rates, while the smallest group had the highest grooming frequencies. More grooming occurred during the November-to-February mating season than at other periods of the year. Adult females were involved in over 60% of all grooming behavior, juveniles participated in 25% of the grooming, while adult males groomed females, primarily during the mating season, and rarely groomed other males or juveniles. Genealogical relationships, levels of group aggression and the feeding or resting context all influenced the frequency of grooming. This study provides support for the hypothesis that the basic social unit for rhesus macaques consists of a core of adult females with their juvenile and infant progeny.     

Discrimination of conspecific faecal chemicals and spatial decisions in juvenile Iberian rock lizards (<Emphasis Type="Italic">Lacerta monticola</Emphasis>)

Faeces play a role in intraspecific chemical communication in many vertebrates, including lizards. Here, we hypothesised that juvenile Iberian rock lizards (Lacerta (=Iberolacerta) monticola) use substrate-borne conspecific faecal chemicals to assess the social environment and base their spatial decisions. To test this hypothesis, we prepared chemical stimuli by dissolving faeces in an organic solvent (dichloromethane, DCM) and conducted chemosensory trials where we quantified latency to the first tongue flick (TF) and TF rates when young captive-borne juveniles were placed in an arena compartment whose substrate was labelled by (1) a control (DCM), (2) their own faecal chemicals, (3) faecal chemicals of another juvenile, (4) faecal chemicals of an adult female or (5) faecal chemicals of an adult male. Following TF observations, we removed a partition that separated the labelled compartment from a chemically unlabelled one, and recorded for 5 min when juveniles first crossed to the unlabelled compartment and total time spent in the labelled compartment. Each juvenile was tested with all stimuli in a randomised order. In addition, juveniles belonged to different families and were unrelated to and unfamiliar with faeces donors. Taken together, TF and spatial responses toward stimuli indicate that juveniles discriminated between faecal chemicals of conspecific juveniles, adult females and males, and that they avoided remaining in substrates labelled by adult male faecal chemicals. We suggest that juveniles assess the social environment based on conspecific faecal chemicals thus avoiding aggression and cannibalistic risks undertaken from encounters with adult males.     

A test of the randomness of paternity of members of maternal sibships in six captive groups of rhesus monkeys (Macaca mulatta)

Results of previous studies have shown that in captive groups of rhesus monkeys (Macaca mulatto)fathers associate more frequently with their own offspring than with those of other males and that mothers are most permissive of physical contact between their own infant and a juvenile when that juvenile shares the same father with her infant. These two observations suggest that the identity of offspring born in captive groups of rhesus monkeys is recognized by at least some adult members of the group. Consistent patterns of mating among mating seasons might explain this apparent recognition of offsprings’ paternity. Fathers, for example, might regularly associate with young who maintain a close relationship with females with whom they have previously mated, and mothers might selectively permit juveniles who maintain a close relationship with males with whom they have previously mated to associate with their infants. This hypothesis is tested in this paper by comparing the observed distribution of 70 maternal sibships, members of which were fathered by the same or by different adult males over a 4-year period in six captive groups of rhesus monkeys, with that distribution expected based on random mating from season to season. Seasonal mating patterns were found to be random. Preparations are now underway to test this hypothesis in several free-ranging groups.     

Sex Ratio and Sexual Size Dimorphism in a Toad-headed Lizard,Phrynocephalus guinanensis

Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism(SSD) is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P. guinanensis. Our results indicated that the sex ratio of males to females was 1:2.8. Males had a lower survival rate(6%) than females(14%) across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates.