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The basic anatomy of the lacertid hemipenis (intromittent organ) and methods for its investigation are described. In many members of the Lacertidae, the hemipenis has a structure quite unlike that of other squamate reptiles: the distal lobes of the retracted organ are complexly folded and there is a well-defined supporting structure of dense connective tissue, the armature. This incorporates blood sinuses and has an intramuscular portion embedded in the m. retractor penis magnus and two club-shaped bodies, the clavulae, that support the lobes in the erect organ. Unarmatured hemipenes occur in some lacertids and, like those of other squamates, possess sac-like lobes in the retracted state, but they are singular in having the lobes invested by the m. retractor penis magnus. It is argued that many of these apparently primitive hemipenes are in fact secondary derivatives of the armatured type. There is considerable inter-specific variation in hemipenial structure which is described systematically. In some cases this involves differences in size, asymmetry and simplification, which may arise as physical isolating mechanisms and is useful in distinguishing otherwise very similar species, particularly in the genus Mesalina (p. 1253). Other shared derived hemipenial features provide useful information about relationships between species and higher taxa and a summary of the hypotheses that they support is given (p. 1254).

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Differences in surface structure (ober- hautchen) of body scales of lacertid lizards involve cell size, shape and surface profile, presence or absence of fine pitting, form of cell margins, and the occurrence of longitudinal ridges and pustular projections. Phylogenetic information indicates that the primitive pattern involved narrow strap-shaped cells, with low posteriorly overlapping edges and relatively smooth surfaces. Deviations from this condition produce a more sculptured surface and have developed many times, although subsequent overt reversals are uncommon. Like variations in scale shape, different patterns of dorsal body microornamentation appear to confer different and conflicting performance advantages. The primitive pattern may reduce friction during locomotion and also enhances dirt shedding, especially in ground-dwelling forms from moist habitats. However, this smooth microornamentation generates shine that may compromise cryptic coloration, especially when scales are large. Many derived features show correlation with such large scales and appear to suppress shine. They occur most frequently in forms from dry habitats or forms that climb in vegetation away from the ground, situations where dirt adhesion is less of a problem. Microornamentation differences involving other parts of the body and other squamate groups tend to corroborate this functional interpretation. Microornamentation features can develop on lineages in different orders and appear to act additively in reducing shine. In some cases different combinations may be optimal solutions in particular environments, but lineage effects, such as limited reversibility and different developmental proclivities, may also be important in their genesis. The fine pits often found on cell surfaces are unconnected with shine reduction, as they are smaller than the wavelengths of most visible light.

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New and additional distribution records are given for 12 amphibian, 25 lizard, one amphisbaenian, and five snake taxa from the Cape Province, South Africa. Some of the new records represent large range extensions, whereas others fill in gaps or confirm the occurrence of taxa in the region.

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The taxonomic status, distribution and ecology of the herpetofauna of the Orange Free State are discussed, based on the examination of 10 096 specimens housed in various southern African museums. The majority of specimens were collected during the years 1972 - 1978 and 1983 - 1992, and are housed at the National Museum, Bloemfontein. A total of 25 amphibian and 95 reptilian (one translocated species) forms have been determined as occurring in the Orange Free State, 12 (three amphibians, nine reptiles) of which are new (or recently published) records for the province. An additional 10 amphibian and 28 reptilian forms have been determined as occurring nearby but extralimitally to the O.F.S., and several of these forms are expected to occur in the province. New distributional records have resulted in the amendment of the ranges of several species. Detailed taxonomic data on new material, including rare species, have been given. Some problem areas in the taxonomy of O.F.S. taxa have been higlighted. An analysis of habit utilization indicated that 84,0% of amphibians and 61,1% of reptiles are terricolous, whereas up to 21,5% of reptiles are rupicolous. The majority of snakes (72,2%) are terrestrial in habits, but 13,9% are fossorial. More than half of all lizards (52,8%) are terrestrial, although 34,6% are rupicolous. A total of six amphibian and 27 reptile forms utilize inactive termitaria as a microhabitat, including several basically terrestrial forms. Snake forms were particularly well represented in termitaria, 60,6% of all forms known from the O.F.S. having been recorded from inactive termitaria. General features of the ecology of O.F.S. amphibians and reptiles have also been discussed. The biogeographical analysis indicated that O.F.S. amphibian forms can be classified into one of nine range clusters (common patterns of distribution), and reptiles into 13 such cluster groups. By testing these classifications by means of a transect through the northern O.F.S. (from eastern to western borders), it was determined that a fairly distinct east-west subtraction of amphibian and reptilian species and subspecies occurs in the O.F.S. Clustering of range boundaries and high species and subspecies diversity at the western and eastern ends of the transect zone suggest dynamic biogeographical situations occurring in those areas - the western group being associated with the transition from grassland to bushveld, and the eastern group associated with the transition from Highveld Grassland to Drakensberg Mountains. The general eastern and western groupings of taxa appear to be associated with the cooler, wetter and mountainous east vs the warmer, drier and lowerlying west, respectively. Despite a great deal of collecting having been conducted in the O.F.S. from 1972 to 1992, an analysis of the number of taxa collected in each quarter-degree unit in `the O.F.S. indicated that additional collecting would be required in order to conduct effectively a mathematically-based biogeographical analysis.

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1. Physiological factors relating to activity metabolism were measured in two species of African lacertid lizards that differ greatly in natural foraging patterns: Eremias lineoocellnta, a sitandwait predator, and E. lugubris, a widely foraging animal. 2. Maximal oxygen consumption at 37 `C is greater in E. lugubris [3.22 ml O,/(g x h)] than in E. lineoocellata [2.49 ml 02/(g x h)]. 3. Anaerobic scope and capacity at 37 `C are greater in E. lineoocellata [2.56 mg lactate/(g x min) and 1.81 mg lactate/g] than in E. lugubris [2.12 mg lactate/(g x min) and 1.40 mg lactatelg]. 4. Relative heart mass and hematocrit are greater in E. lugubris than in E. lineoocellata (0.28% and 0.24% body mass; 30.1 and 24.4, respectively). 5. No significant interspecific differences occur in hind limb muscle mass as a percentage of body mass or in myoglobin concentration, citrate synthase or myofibrillar ATPase activity of hind limb skeletal muscle. 6. No significant interspecific differences occur in isometric contractile properties (twitch and tetanic tension, twitch rise time and half-relaxation time, and fatigue response to tetanic stimulation) of the iliofibularis muscle. 7. Organismal metabolic patterns of aerobic and anaerobic capacity reflect differences in locomotor capacity and natural foraging patterns of these species.

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In this field experiment we investigate the impact of land use induced savanna degradation on movement behaviour of the spotted sand lizard (Pedioplanis l. lineoocellata) in the southern Kalahari. Foraging behaviour of lizards was tested in a factorial design (low vs. high prey availability) in degraded and non-degraded habitats. An interaction between habitat structure and prey availability affected movement behaviour. In degraded habitats with low prey availability and in non-degraded habitats with high prey availability the spotted sand lizard moved more like an active forager. In contrast, in degraded habitats with high prey availability and in non-degraded habitats with low prey availability lizards moved like sit-and-wait foragers. Interestingly, the behavioural flexibility of the spotted sand lizard seems to buffer extreme conditions and negative effects of land use impacts.

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A checklist of the lizards of the Cape Province, South Africa is presented. A total of 143 species and subspecies is recognized. The taxonomic status of no less than 84 (59,1%) of these has changed since the last review of the Cape lizards by FitzSimons (1943). Comments on the distribution and taxonomic status of problematic groups are included.

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The results of a survey of the reptiles and amphibians of the Addo Elephant National Park (AENP) are presented. A total of 49 species, comprising 16 amphibians, 14 lizards, 15 snakes and 4 chelonians, occur in the AENP. Observations on the biology and distribution of these species in the AENP are given, and the relative composition and diversity is compared with the herpetofauna of the surrounding eastern Cape and the more distant Kruger National Park. The zoogeographic affinities of the AENP herpetofauna are similar to those of the surrounding eastern Cape (i.e. Cape Temperate 46,9, Temperate- Transitional 16,3, Eastern Tropical Transitional 10,2, Western Tropical Transitional 8,2, Tropical East Coast Littoral 2,0 and Temperate Wideranging 16,3). Resource partitioning among the AENP herpetofauna is discussed and the conservation status of the species summarised. A list of species that may still be collected within the AENP is included.

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This review looks at available literature on the reptiles (including terrapins, tortoises, lizards, amphisbaenians, crocodiles) and amphibians of the Four Corners trans-frontier area, which covers both wetland and dryland habitats. The zoogeography of these groups is outlined. This is followed by an annotated list of the 178 species recorded to date. Particular species ands sites of conservation interest are briefly outlined. The herpetofauna of the Four Corners area is a comparatively well studied group, although the Hwange District in northwestern Zimbabwe has received the most attention.

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Relationships among representatives of five genera of lacertid lizards from Iberia, Morocco, and South Africa were studied using quantitative micro-complement fixation analysis of serum albumin evolution. Using the albumin molecular clock to establish divergence times we suggest (1) South African Ichnotropis and North African Psammodromus diverged from the lineage representing Lacerta lepida-L. monticola during the Oligocene, (2) South African Pedioplanis and Heliobolus diverged from this lineage during the late Miocene, and (3) ancestral representatives of L. andreanszkyi, L. perspicillata and Podarcis hispanica diverged from lineages leading to L. monticola and L. lepida during the mid-Miocene. Radiation within the Palearctic Lacertidae has clearly been extensive, yet fewer than twenty percent of the species in this radiation have been examined biochemically. Until additional data can be gathered, the current classification of the Palearctic Lacertidae cannot be much improved and we recommend adherence to the taxonomy proposed by Arnold (1973).

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We discuss three aspects of the thermal biology of lacertid lizards. First, we provide an overview of the available data on field body temperatures (Tb), the thermal sensitivity of various performance functions and selected body temperatures in different species of lacertid lizards. We also briefly summarise information on the mechanisms of thermoregulation. Second, we discuss recent developments to estimate the »precision« of thermoregulation, and the contribution of distinct behavioural mechanisms. Finally, we revise available evidence for the existence of evolutionary adjustments of thermal characteristics in lacertid lizards. Existing studies have mainly dealt with within- and among-species differences in thermoregulatory behaviour (selected temperatures) and thermal physiology of adults (optimal temperatures, heating rates). Available data provide only limited evidence for clear-cut evolutionary shifts in thermal physiology characteristics along climatic gradients.

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Phylogenetic relationships among the 13 currently recognized species of Pedioplanis were analyzed using nuclear and mitochondrial DNA. Previous measures of species diversity within the genus appear to be underestimated, as novel, undescribed lineages were found within P. lineoocellata, P. namaquensis and the P. undata species complex. Further fine-scaled population genetic analyses were conducted to assess levels of genetic admixture, identify potential hybrid zones and uncover historical demographic patterns. Within P. lineoocellata, my results show that the three currently recognized subspecies do not represent independently evolving lineages. Further analyses suggest a South African origin of the species, with a subsequent northern expansion during the late Miocene. P. namaquensis appears to be comprised of two distinct and highly divergent lineages, furthermore the Orange River appears to represent a geographic barrier between them. Finally, interspecific relationships within the P. undata complex appear to be more complicated than previously thought as instances of paraphyly, polyphyly and several novel lineages were all revealed by the phylogenetic analyses.

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The lacertid genus Pedioplanis is a moderately speciose group of small-bodied, cryptically-colored lizards found in arid habitats throughout southern Africa. Previous phylogenetic work on Pedioplanis has determined its placement within the broader context of the Lacertidae, but interspecific relations within the genus remain unsettled, particularly within the P. undata species complex, a group largely endemic to Namibia. We greatly expanded taxon sampling for members of the P. undata complex and other Pedioplanis, and generated molecular sequence data from 1,937 bp of mtDNA (ND2 and cyt b) and 2,015 bp of nDNA (KIF24, PRLR, RAG-1) which were combined with sequences from GenBank resulting in a final dataset of 455 individuals. Both maximum likelihood and Bayesian analyses recover similar phylogenetic results and reveal the polyphyly of P. undata and P. inornata as presently construed. We con- firm that P. husabensis is sister to the group comprising the P. undata complex plus the Angolan sister species P. huntleyi + P. haackei and demonstrate that P. benguelensis lies outside of this clade in its entirety. The complex itself comprises six species including P. undata, P. inornata, P. rubens, P. gaerdesi and two previously undescribed entities. Based on divergence date estimates, the P. undata species complex began diversifying in the late Miocene (5.3 ± 1.6 MYA) with the most recent cladogenetic events dating to the Plio- cene (2.6 ± 1.0 MYA), making this assemblage relatively young compared to the genus Pedioplanis as a whole, the origin of which dates back to the mid-Miocene (13.5 ± 1.8 MYA). Using an integrative approach, we here describe Pedioplanis branchi sp. nov. and Pedioplanis mayeri sp. nov. representing northern populations previously assigned to P. inornata and P. undata, respectively. These entities were first flagged as possible new species by Berger-Dell’mour and Mayer over thirty years ago but were never formally described. The new species are supported chiefly by differences in coloration and by unique amino acid substitutions. We provide comprehensive maps depicting historical records based on museum specimens plus new records from this study for all members of the P. undata complex and P. husabensis. We suggest that climatic oscillations of the Upper Miocene and Pliocene-Pleistocene era in concert with the formation of biogeographic barriers have led to population isolation, gene flow restrictions and ultimately cladogenesis in the P. undata complex.

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Although reptile diversity in Africa is high, it is poorly represented in Angola, with just 257 species known. Despite its greater surface area and habitat diversity Angola has significantly lower lacertid lizard diversity than adjacent Namibia. This is particularly notable in African sand lizards (Pedioplanis), where 10 species (two endemic) are known from Namibia but only two are recorded from adjacent Angola. Pedioplanis benguelensis was described from Angola, but its taxonomic status is problematic and it was previously synonymised with P. namaquensis. All other Angolan Pedioplanis were referred to Namibian P. undata, although this taxon is now known to comprise a complex of at least five different species and the relationship of Angolan material to this complex has not been assessed. In this study, we investigated the phylogenetic placement of Angolan Pedioplanis using two mitochondrial (ND2 and 16S) and one nuclear (RAG-1) markers. A Bayesian analysis was conducted on 21 samples from Angola, combined with existing data for 45 individuals from GenBank and three additional samples from central Namibia. The phylogeny demonstrates that P. benguelensis is a valid species and that it is not the sister taxon to P. namaquensis with which it has been morphologically confused. In addition, Angolan lacertids previously referred to P. undata are not conspecific with any of the Namibian or South African species in that complex. Rather, there is strong support for the presence in Angola of additional species of Pedioplanis, which form a wellsupported sister clade to the P. undata complex (sensu stricto) of Namibia and two ofwhich are described herein. These discoveries highlight the need for further biodiversity surveys in Angola, as similar increases in species diversity in other Angolan taxa might be found given sufficient investment in biodiversity surveys.

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Most lacertids are active foragers, but intrafamilial variation in foraging mode is greater than in most lizard families. We collected data on eight species of African lacertids to assess this variation. Both active and ambush foraging occurred within Pedioplanis and Meroles. Meroles ctenodactylus had a proportion of time moving and proportion of attacked prey detected while moving intermediate to those for actively foraging and ambushing Pedioplanis, but its number of movements per minute was exceptionally high. This species has a unique mixed foraging mode. Like active foragers, it seeks food by tongue-flicking while moving and spends a high percentage of the time moving. Like ambush foragers, it searches visually for prey during pauses between movements. Our findings confirm published data on four Kalahari lacertids. We discuss the history of foraging modes in advanced lacertids.

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The Spotted Sand Lizard, Pedioplanis lineoocellata, is widespread across much of southern African found primarily in open habitats. Recent work uncovered four mitochondrial DNA clades which were previously unknown. The formation of these clades is thought to be linked to the Plio-Pleistocene glacial cycles. Furthermore, two of the most geographically widespread clades occur sympatrically in the Loeriesfontein region which has raised questions of possible hybridisation. To investigate gene flow between the latter two clades, samples were profiled at nine microsatellite markers and genetic patterns assessed using estimates of divergence and migration, and a discriminant analysis of principle components. While measures of genetic differentiation and the proportion of recent migrates at each population supports greater gene flow over a few 10s of kilometres and far less over 100s of kilometres, there was no isolation-by-distance pattern. This suggests that gene flow is influenced by barriers or environmental resistance to gene flow. Microsatellite genetic clusters did not match mitochondrial clades which was interpreted as evidence of recent gene flow between the two clades. Hybridisation at Loeriesfontein could not be detected because mitochondrial clades were not genetically distinct in terms of microsatellite loci investigated. Mitochondrial lineages may occur sympatrically at places other than Loeriesfontein but were not sampled by chance because of small sample sizes in the previous study. The regions of overlap between mitochondrial clades may be more extensive than previously thought. Further clarity regarding the formation of clusters awaits more comprehensive sampling.

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Dispersal determines connectivity between populations within a species and is a regulator of genetic differentiation through gene flow. Although the necessity of dispersal for gene flow is clear, for many taxa the relationship between the two is not well understood. Gene flow, or a restriction thereof, may be inferred from population-level genetic divergence estimates. These measures are averages of contemporary and historic gene flow and as such they are not necessarily easily compared to measures of real-time dispersal. Changes in dispersal have been inferred from present day spatial genetic structure for many southern African taxa and further associated with environmental change events. Pedioplanis lineoocellata is a southern African endemic lacertid with a mitochondrial DNA structure that may have been the result of Plio-Pleistocene glacial climatic oscillations. As a wide-spread, open habitat species, P. lineoocellata is an excellent study species for examining the relationship between dispersal and gene flow. In the first data chapter, Chapter 2, nine new microsatellite markers are described for several populations for the purpose of examining gene flow and genetic structure in the species. The possibility of null alleles, population bottlenecks and high inbreeding are investigated as possible explanations for the detected deviation from Hardy-Weinberg equilibrium (HWE). The presence of null alleles and, at one population, relatively high inbreeding best explains the HWE deviations. While null allele frequencies were not excessively high, this caveat should be borne in mind when interpreting results. In Chapter 3 the microsatellite markers were used to assess the geographic genetic patterns for P. lineoocellata across the distribution of the two most wide-spread mitochondrial lineages and to test for evidence of hybridization at a point of clade contact in the Loeriesfontein area. Microsatellite genetic clusters did not match the mtDNA lineages, a possible result of gene flow between clades. However, measures of genetic differentiation and recent migration indicate only weak contemporary long distance gene flow. There was no evidence of genetic admixture at the Loeriesfontein area despite sympatric mtDNA lineages. The complexity of the geographic arrangement of the microsatellite clusters may be attributed to historic range contraction and expansion events for the species. In the last data chapter, evidence for an isolation-by-distance (IBD) pattern was examined within the most widespread mtDNA clade. Sampling over hundreds of kilometres produced an IBD pattern when using spatial autocorrelation while failure to detect IBD using the Mantel test was likely a result of the complex arrangement of microsatellite clusters. A combination of genetic data and demographic data was used to estimate the annual dispersal distances based on the neighbourhood size concept. Results indicated high levels of dispersal that covered distances of a few hundred metres, greater than is expected for a lacertid lizard. Strong dispersal propensity would have influenced gene flow and genetic structure found in this thesis and will further influence future responses to environmental changes for the species.

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Comparative analyses were carried out about the variability of the pileal shields of different species belonging to the family Lacertidae. The results of the comparisons have been evaluated in respect to the phylogenetical relationships existing between the different genera and species of the family.

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The phenotype of an individual has often been used as the descriminating factor in distinguishing species. However, with the advent of more precise molecular techniques, the genotype of species is increasingly being used as the preferred method in taxonomic classifications. Many taxa have recently been demonstrated to be incongruent in terms of their genetic and morphological groupings, and this may due to the influence that the environment may have on the morphological and functional aspects of a species. Selective pressures often act upon the performance of a species within a particular habitat first, and then selection for the morphological characters that allow for optimal performance occurs. Should genetically disparate species inhabit a particular environment, convergence in morphologies and performance may evolve. Historically, lizard species descriptions were based primarily on external morphologies, and thus misclassfication of species may have occurred due to mistakenly grouping species with convergent morphologies together. In the current dissertation, the links between morphology, performance capacities, diet and behaviour is explored in comparison to the environment and genetic relationships of southern African lacertid lizards. The performance capacities and associated morphological traits were expected to be more closely linked with the environment, and not closely linked with genetic relationships. To investigate these expectations, a multidisciplinary approach was taken, and genetic, morphological and performance analyses were done and compared with dietary behavioural and environmental analyses. In the first chapter, the link between habitat openness and the lizard bauplans is investigated and the presence of convergent morphologies within this group of lizards is uncovered. These convergences are shown to have resulted in misclassification of two lacertid species, and taxonomic revisions within the family are discussed. The second chapter explores the link between performance and associated morphological traits, and the dietary composition of the members of the Nucras genus. The third chapter identifies the link between the predator escape strategies employed by the members of the Meroles genus, and their morphologies and performance capacities. The fourth chapter explores the intraspecific, inter-population differences in morphologies and investigates the link between the morphological groupings and the population genetic groupings within Pedioplanis lineoocellata. The final chapter identifies whether adaptation to a novel habitat can occur over a relatively short period of time, and the morphological traits, functional aspects, and population genetic structure is investigated in conjunction with environmental analyses of vegetation and substrate between the populations of Meroles knoxii. It was concluded that the morphological and functional aspects of the southern African lacertid lizards are more closely related to the environment, particularly the microhabitat structure, than to their genetic relationships, and that future work using this group of lizards should involve a multidisplinary approach as different selective pressures are playing a role in shaping the morphologies and performance capacities of these lizards, compared to those that are acting upon the genotypes of the lizards.

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Eremiadinae, one of three subfamilies of Lacertidae, are distributed throughout Asia and Africa. Previous phylogenetic studies suggested that one of the main groups of Eremiadinae (the Ethiopian clade) consist of two clades with predominately East-African and South-African distribution. Yet, especially the latter one, which includes the genera Pedioplanis, Meroles, Ichnotropis, Tropidosaura and Australolacerta, was not well supported in the molecular phylogenetic analysis. In this study, we analysed the phylogenetic relationships among the genera of the ‘South African clade’ to assess whether this group actually forms a highly supported clade and to address questions concerning the monophyly of the genera. We sequenced sections of the widely used mitochondrial genes coding for 16S rRNA, 12S rRNA and cytochrome b (altogether 2045 bp) as well as the nuclear genes c-mos, RAG-1, PRLR, KIF24, EXPH5 and RAG-2 (altogether 4473 bp). The combined data set increased the support values for several nodes considerably. Yet, the relationships among five major lineages within the ‘South African clade’ are not clearly resolved even with this large data set. We interpret this as a ‘hard polytomy’ due to fast radiation within the South African lacertids. The combined tree based on nine marker genes provides strong support for the ‘South African Clade’ and its sister group relationship with the ‘East African Clade’. Our results confirm the genus Tropidosaura as a monophylum, while Ichnotropis is paraphyletic in our trees: Ichnotropis squamulosa appears more closely related to Meroles than to Ichnotropis capensis. Furthermore, the monophyly of Meroles is questionable as well. Based on our results, I. squamulosa should be transferred from Ichnotropis into the genus Meroles. Also, the two species of Australolacerta (A. australis and A. rupicola) are very distantly related and the genus is perhaps paraphyletic, too. Finally we propose a phylogeographical scenario in the context of palaeoclimatic data and compare it with a previously postulated hypothesis.

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The reproductive cycle of the spotted sand lizard, Pedioplanis lineoocellata, is described from histological examination of gonadal material. Reproduction is seasonal and mainly confined to summer. Males have a testicular cycle in which spermiogenesis occurred primarily in December-February. Females with enlarged ovarian follicles (> 4 mm length) occurred January-February and October. The presence of females with corpora lutea from a previous clutch and yolk deposition for a subsequent clutch suggests more than one clutch can be produced in the same reproductive season. Mean clutch size for 22 females with enlarged ovarian follicles was 6.8 [+ or -] 2.0 SD, range: 2-11. Two eggs is a new minimum clutch size and 11 is a new maximum clutch size for P. lineoocellata. The smallest reproductively active male measured 42 mm SVL and the smallest reproductively active female measured 50 mm SVL.

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An annotated checklist of indigenous and potentially indigenous Namibian terrestrial, aquatic and marine reptiles is presented. The purpose is to serve as an interim description of Namibian reptile diversity, to establish a taxonomic and biogeographical baseline, and as a preliminary review of the conservation status of Namibian reptiles. Two hundred and forty species of indigenous reptiles are presently known to occur in Namibia. These species comprise an array of approximately 265 described (but not always recognized) taxa, several of which are probably unwarranted. Species accounts are presented for all these species. Four accounts are for new species currently being described. Nineteen species have not yet been recorded from Namibia, but are expected to (accounts given) and another 6 species are less likely to occur (no accounts given). Full accounts are given for the 17 species which have been formally recorded in the past, but the lack of recent evidence suggests that the species is now locally extinct, the original report erroneous, or the species’ occurred as vagrants. Four additional species had been included on various published lists in the past, but have never been formally documented, no specimens are known to exist, and it is unlikely that the species would occur today even as vagrants (no accounts given). In total, 276 species-accounts are presented. Each account cites the original reference and type locality for each taxon, and a short description of the Namibian distribution. Emphasis is placed on Namibian and international legal and conservation status. Eighty-five species (33%) were found to be of local conservation concern. Gaps in knowledge (e.g. taxonomy, biogeography, and conservation status), where future research should be directed, are noted.

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The herpetofauna of the southern Kalahari has mixed affinities, as this area lies on a rainfall gradient in a critical area where a transition between the arid south-west and the moister north-east takes place. As the variation in substrate type is relatively limited, the effect of the rainfall gradient appears to influence and determine the range limits of many taxa in both directions, resulting in an area in which of 55 recorded reptiles, 11 western taxa overlap or form a parapatric zone with 25 eastern taxa, while the remaining taxa are endemic or wideranging.

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Namibia is mostly an arid and semi-arid country with a high number of reptile and fewer amphibian species. We review the herpetological literature dealing with Namibian species over the past fifty years, and provide up-to-date amphibian and reptile accounts using a widely accepted taxonomy and nomenclature. We critically discuss species accounts, draw attention to the historical development of species inventories for the country, and indicate species endemism for Namibia and the Namib Desert. In Namibia, the lizard families Gekkonidae, Lacertidae, and Scincidae have undergone adaptive radiations and are species-rich. This also applies to the snake family Psammophiidae. Areas of herpetological research that have received most attention are systematics (with its disciplines faunistics (area inventories), taxonomy, and phylogeny), ecology, and physiology. The former is indicative of early stages of herpetological research such as area inventories and the subsequent analyzes of the collections. The latter two were largely enabled by (1) species highly adapted to life in the hyper-arid Namib Desert, and (2) by the accessibility of these species in the Namib Desert through the infrastructure provided by the Gobabeb Research and Training Center. The majority of the eco-physiological research has focused on three highly psammophilus, diurnal lizard species; Meroles anchietae, M. cuneirostris, and Gerrhosaurus skoogi, whilst diverse geckos form the basis of eco-morphological studies. The concentration of research localities around cities and the Gobabeb Research and Training Center is characteristic for opportunistic research. Geographic centers of herpetological research have been the central Namib Desert (i.e. Gobabeb), and areas around Swakopmund and Windhoek. Extensive parts of Namibia remain barely touched. Herpetological publication frequency has been approximately the same since its beginning in the early 1800`s until the 1970`s. The period between 1986 and 2003 experienced a remarkable increase of publication activity that has slightly subsided around 2004 and picked up again in recent years. Recent conservation related studies investigate the impact of overgrazing with land degradation and water related issues such as canals and hydroelectric dam projects on herpetological communities. In the near future the impact of mining, especially Uranium mining in the Namib Desert, and the effects of climate change with the predicted drying and warming will demand increased attention. Advances in biotechnology with ever-increasing amounts of data and decreasing cost have and will progressively enable advances in traditional disciplines like taxonomy, phylogeny, and systematics. Additionally, these technologies will increasingly empower the newer disciplines of molecular ecology and conservation biology in Namibia. Annotated, updated species checklists highlight Namibian and Namib diversity and endemicity, and also direct researchers to the numerous taxonomic problems that still confound full understanding of the region`s herpetofauna.

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The evolutionary diversification of many terrestrial vertebrate groups is strongly linked to climatic events in the Cenozoic, the period from 65 Million years ago to today when modern animals first appeared. I investigated the effects of Cenozoic climate change on the taxonomic and morphological diversification of the Old World lizard family Lacertidae, with particular emphasis on the African radiation. African lacertids exhibit an unusual pattern of diversification, in which their highest species richness occurs in deserts north and south of the equator, despite being spread throughout the continent. This disparity is particularly surprising given that desert lacertids are thought to be evolutionarily younger than their mesic-dwelling relatives, suggesting increased diversification rates in arid habitats. To identify the evolutionary factors underlying this pattern, I use a combination of phylogenetic, morphological and ecological techniques. In Chapter 1, I apply Bayesian methods and fossil-based calibrations to molecular sequence data to construct a time-calibrated phylogeny for Lacertidae. I estimate that the family arose in the early Cenozoic, with the majority of their African radiation occurring in the Eocene and Oligocene. In Chapter 2, I describe changes in lacertid body shape across biomes and substrates, and find widespread morphological convergence in similar habitat types. I suggest that in addition to foraging demands, fluctuating and extreme climatic conditions, largely driven by precipitation and temperature, contribute to morphological convergence across independent arid-dwelling clades. Finally, I test if ancestral transitions in ecology, morphology, and rates of diversification temporally coincide with paleoclimatic events in the Cenozoic. I use High Resolution X-ray Computed Tomography to characterize changes in the skull related to life in arid habitats, and apply maximum likelihood methods to test if the origins of those traits temporally coincide with significant shifts in habitat, diversification rates and climatic changes. My results show that African lacertids experienced three major peaks in diversification, accompanied by the evolution of suites of arid-adapted morphological traits. These changes coincide with climatic shifts in Africa, including the transition from closed forests to open grasslands and savanna in the late Oligocene, prior to the peak temperatures of the mid-Miocene Climatic Optimum, and following the formation of the Benguela current leading to hyper-aridity in southern Africa. I conclude that deserts are important centers for reptile evolution, but that expected changes in climate due to global warming may outpace the ability of arid-dwelling species to adapt and persist in the future.

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Closely related lacertid lizards (Eremias, Nucras) in the Kalahari desert differ in patterns of foraging behaviour. Some species are relatively sedentary (‘sit-and-wait’) whereas others are more active (‘widely-foraging’) predators. We determined whether whole-animal locomotor capacities (cruising endurance on a treadmill, initial speed and maximum burst speed in a racetrack, and sprint endurance in a torus-shaped track) correlated with interspecific differences in foraging behaviour. Two of three widely-foraging species had greater cruising endurance, graater sprint endurance, but lower burst speed than did a sit-and-wait species. However, the two species that sprinted quickly also had limited endurance, and vice versa. Pre-feeding negatively influenced endurance but not sprint capacity. Theoretical models of foraging behaviour should recognize that ectotherms have limited endurance, that there can be a trade-off between speed and endurance, and that pre-feeding can reduce some aspects of locomotor capacity.

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We discuss seasonal variation in thermoregulatory behavior and its consequences on body temperature for 12 species of diurnal lizards in the southern Kalahari semidesert of Africa and also evaluate several methods of attempting to document thermoregulatory behavior using a descriptive data base. Lizards vary time of activity among seasons, which limits the variation in ambient conditions actually experienced. Ground-dwelling lizards and probably arboreal lizards move nonrandomly with respect to sun and shade; thus the percentage of lizards in sun in inversely proportional to air temperature. Arboreal lizards shift to higher perches at midday in summer and to logs or ground in winter thus decreasing and increasing incident heat loads, respectively. Both juveniles and adults of 3 species, only juveniles of 2 species, and only adults in 1 species are active in winter: both adults and juveniles of 6 species brumate [= hibernate]. Mean body temperature (T`b) varies within days and among months and is positively correlated with corresponding mean air temperature (T`a) in almost all species. Nonetheless, correlation and regression analysis suggests that thermoregulatory behaviors reduce the impact of variations in ambient conditions on Kalahari lizards. The mean T`b of different species reflect evolutionary relationships. In summer, mean T`b is proportional to the percentage of lizards in sun and with the tendency of lizards to be active only in summer. Thus, lizards with inferred low optimal temperatures are active during more months of the year.

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The performance of ectotherms integrated over time depends in part on the position and shape of the distribution of body temperatures (Tb) experienced during activity. For several complementary reasons, physiological ecologists have long expected that Tb distributions during activity should have a long left tail (left‐skewed), but only infrequently have they quantified the magnitude and direction of Tb skewness in nature. To evaluate whether left‐skewed Tb distributions are general for diurnal desert lizards, we compiled and analysed Tb (∑ = 9,023 temperatures) from our own prior studies of active desert lizards in three continents (25 species in Western Australia, 10 in the Kalahari Desert of Africa and 10 species in western North America). We gathered these data over several decades, using standardized techniques. Many species showed significantly left‐skewed Tb distributions, even when records were restricted to summer months. However, magnitudes of skewness were always small, such that mean Tb were never more than 1°C lower than median Tb. The significance of Tb skewness was sensitive to sample size, and power tests reinforced this sensitivity. The magnitude of skewness was not obviously related to phylogeny, desert, body size or median body temperature. Moreover, a formal phylogenetic analysis is inappropriate because geography and phylogeny are confounded (i.e. are highly collinear). Skewness might be limited if lizards pre‐warm inside retreats before emerging in the morning, emerge only when operative temperatures are high enough to speed warming to activity Tb, or if cold lizards are especially wary and difficult to spot or catch. Telemetry studies may help evaluate these possibilities.

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We discuss seasonal variation in thermoregulatory behavior and its consequences on body temperature for 12 species of diurnal lizards in the southern Kalahari semidesert of Africa and also evaluate several methods of attempting to document thermoregulatory behavior using a descriptive data base. Lizards vary time of activity among seasons, which limits the variation in ambient conditions actually experienced. Ground-dwelling lizards and probably arboreal lizards move nonrandomly with respect to sun and shade; thus the percentage of lizards in sun is inversely proportional to air temperature. Arboreal lizards shift to higher perches at midday in summer and to logs or ground in winter thus decreasing and increasing incident heat loads, respectively. Both juveniles and adults of 3 species, only juveniles of 2 species, and only adults in I species are active in winter: both adults and juveniles of 6 species brumate [= hibernate]. Mean body temperature (T,) varies within days and among months and is positively correlated with corresponding mean air temperature (T,) in almost all species. Nonetheless, correlation and regression analysis suggests that thermoregulatory behaviors reduce the impact of variations in ambient conditions on Kalahari lizards. The mean Tb of different species reflect evolutionary relationships. In summer, mean T i s proportional to the percentage of lizards in sun and with the tendency of lizards to be active only in summer. Thus, lizards with inferred low optimal temperatures are active during more months of the year.

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A survey of the distribution, status and general ecology of amphibians, reptiles and mammals was undertaken on the Nylsvley Nature Reserve, Transvaal from mid-1974 to mid-1977 as part of the South African Savanna Ecosystem Project. A total of 18 frog, 3 tortoise, 1 terrapin, 23 lizard, 1 amphisbaenid, 29 snake and 62 mammal species were recorded on the Reserve. As new additions continued to be made late in the survey, it is clear that the checklist is not yet complete.

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Several specimens of different genera of Lacertid lizards were collected during a 4-week-trip into the Limpopo Province of South Africa. Depending on their habitat members of the different species occurred within different reptile species assemblages. On the Soutpansberg specimens of Nucras intertexta were recorded in unusual habitat and a genetic study shall resolve their systematic position. No Lacertids were recorded in the high altitudes of the Blouberg and Wolkberg, which is most probably attributed to sampling artifacts.

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Reptiles are supposed to be relatively invulnerable to the ongoing rapid anthropogenic climate change as they are able to actively regulate their body temperature (Tb) through behaviour, tolerate high Tb and resist water loss. However, recent studies have shown that lizards and snakes seem to be more at risk than previously expected. In Mexico, increased local extinction probability in lizards correlated with the magnitude of warming during the reproductive period, questioning the assumption of climate invulnerability. We tested the hypothesis that different lizard species of the family Lacertidae are vulnerable to rises in maximum temperatures in Namibia, especially in the Namib and the Kalahari. We predicted that inhabiting different habitats with different microhabitat temperatures and different preferred Tb within different distribution ranges would result in differences in local extinction probability. As opposed to other studies our model integrates past and present distributions verified by museum collections and ground-truthed, a quantifiable physiological parameter (preferred body temperature Tpref) and available operative temperatures in correlation to air temperatures. Data was collected for 17 species (Meroles anchietae, M. cuneirostris, M. suborbitalis, M. ctenodactylus, M. reticulatus, M. micropholidotus, M. knoxii, Pedioplanis namaquensis, P. laticeps, P. lineoocellata, P. breviceps, P. rubens, P. undata, P. inornata, P. gaerdesi, P. husabensis and Heliobolus lugubris). Our first results seem to indicate that populations of at least one of the tested species were extirpated (both predicted by the model and verified) in the hottest area of its distribution range due to increased maximum temperatures during the reproductive season since the mid-1970s. Furthermore, different extents in future extinction risk are predicted under consideration of the currently accepted climate change scenarios. It seems that Namibian Lacertidae under current conditions already live at their thermal maximum.

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Aim To map and assess the richness patterns of reptiles (and included groups: amphisbaenians, crocodiles, lizards, snakes and turtles) in Africa, quantify the overlap in species richness of reptiles (and included groups) with the other terrestrial vertebrate classes, investigate the environmental correlates underlying these patterns, and evaluate the role of range size on richness patterns. Location Africa. Methods We assembled a data set of distributions of all African reptile species. We tested the spatial congruence of reptile richness with that of amphibians, birds and mammals. We further tested the relative importance of temperature, precipitation, elevation range and net primary productivity for species richness over two spatial scales (ecoregions and 1° grids). We arranged reptile and vertebrate groups into range-size quartiles in order to evaluate the role of range size in producing richness patterns. Results Reptile, amphibian, bird and mammal richness are largely congruent (r = 0.79–0.86) and respond similarly to environmental variables (mainly productivity and precipitation). Ecoregion size accounts for more variation in the richness of reptiles than in that of other groups. Lizard distributions are distinct with several areas of high species richness where other vertebrate groups (including snakes) are species-poor, especially in arid ecoregions. Habitat heterogeneity is the best predictor of narrow-ranging species, but remains relatively important in explaining lizard richness even for species with large range sizes. Main conclusions Reptile richness varies with similar environmental variables as the other vertebrates in Africa, reflecting the disproportionate influence of snakes on reptile richness, a result of their large ranges. Richness gradients of narrow-ranged vertebrates differ from those of widespread taxa, which may demonstrate different centres of endemism for reptile subclades in Africa. Lizard richness varies mostly with habitat heterogeneity independent of range size, which suggests that the difference in response of lizards is due to their ecological characteristics. These results, over two spatial scales and multiple range-size quartiles, allow us to reliably interpret the influence of environmental variables on patterns of reptile richness and congruency.

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In both December 1992 and September 1995 I travelled through South Africa and Namibia. In the Daan Viljoen park in Windhoek Agama planiceps, Mabuya spilogaster and Pachydac- tylus bibroni were found. Pedioplanis brevi- ceps was seen in trees and bushes of the Namib Desert while in the barer valleys Pedioplanis undata undata was observed. A Chamaeleo namaquensis was seen in a small bush. Other species which were recorded were M. spilogaster and Ptenopus garrulus macula- Ius. In the Kalahari Gemsbokpark only M. spi- logaster, Agama aculeata aculeata and Pelomedusa subrufa were seen, the latter after a shower. Pedioplanis undata inomata, Mabuya sulcata, Mabuya variegata, Platysaurus capensis, Agama anchietae, Pedioplanis namaquensis, Cordylus po/yzonus and Pachydactylus bibroni were found in Fish River Canyon by the camp site. The tempera- ture can rise to 45°C over the day. The lizards seemed to go into shock when captured. In 1995 I spent a long time in Namaqualand. Here a lot of reptiles were found in a relative- ly small area. These included: Cordylus cataphractus, Cordylus polyzonus, Pediopla- nis lineocellata pulchella, Meroles suborbi- talis, Agama hispida hispida, Bitis arietans, Homopus signatus signatus and Chersina angulata. In the Mediterranean climatic zone and in the Karoo the following unusual species were recorded: Psammo- bates tentorius trimeni, Geochelone parda- lis and Pseudocordy/us capensis.

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The diversity of lacertid lizards in Africa is highest in the southern African subcontinent, where over two-thirds of the species are endemic. With eleven currently recognized species, Pedioplanis is the most diverse among the southern African genera. In this study we use 2200 nucleotide positions derived from two mitochondrial markers (ND2 and 16S rRNA) and one nuclear gene (RAG-1) to (i) assess the phylogeny of Pedioplanis and (ii) estimate divergence time among lineages using the relaxed molecular clock method. Individual analyses of each gene separately supported different nodes in the phylogeny and the combined analysis yielded more well supported relationships. We present the first, well-resolved gene tree for the genus Pedioplanis and this is largely congruent with a phylogeny derived from morphology. Contrary to previous suggestions Heliobolus/Nucras are sister to Pedioplanis. The genus Pedioplanis is monophyletic, with P. burchelli/P. laticeps forming a clade that is sister to all the remaining congeners. Two distinct geographic lineages can be identified within the widespread P. namaquensis; one occurs in Namibia, while the other occurs in South Africa. The P. undata species complex is monophyletic, but one of its constituent species, P. inornata, is paraphyletic. Relationships among the subspecies of P. lineoocellata are much more complex than previously documented. An isolated population previously assigned to P. l. pulchella is paraphyletic and sister to the three named subspecies. The phylogeny identifies two biogeographical clades that probably diverged during the mid-Miocene, after the development of the Benguella Current. This probably led to habitat changes associated with climate and, in conjunction with physical barriers (Great Escarpment), contributed towards speciation within the genus Pedioplanis.

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Taxonomic changes and new findings concerning the subfamily Eremiainae in Africa are summarized to update SZCZERBAK`s (1975) catalogue of the African Sand Lizards. Furthermore, a key to the species and subspecies of the genus Pedioplanis is provided.

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13 species of the genera Aporosaura, Meroles, Pedioplanis, and Heliobolus horn Namibia and additionally Pedioplanis burcheUi from the Republic of South-Africa have been investigated proteinelectrophoretically concerning 14 genetic loci. Pedioplanis and Meroles turned out to be sister groups, Heliobolus and Aporosaura are standing further apart. The su bgenera of Meroles (Meroles s. str. and Saurites) could not be parted distinctly. The morphological correspondence between Aporosaura and Saurites has been interpreted as convergent adaptions to their habitat.

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Die Wüstenrenner-Eidechsen Namibias werden derzeit in folgende vier Gattungen eingeteilt: Pedioplanis, Meroles, Aporosaura und Heliobolus. Während zweier Reisen konnten sie im Freiland studiert werden. Im Terrarium wurden sieben Arten gehalten, von denen vier Arten nachgezüchtet werden konnten. Neben Pedioplanis rubens, P. lineoocellata pulchella und P. namaquensis erweist sich vor allem Meroles cuneirostris als ein sehr gut zu haltendes, interessantes Terrarientier.

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One hundred and seven reptiles (11 families, 32 species) from the Northern and Western Cape Provinces of South Africa were examined for helminths. Twenty-three (22%) individual reptiles were found to harbor at least 1 species of nematode; 3 (7%) reptiles harbored multiple infections of 2 nematode species. Eight species within 5 families of Nematoda were found in the reptiles surveyed including 1 atractid, 1 diaphanocephalid, 1 heterakid, 3 pharyngodonids, and 2 physalopterans. Ten new host records are reported. A summary of the nematode parasites identified from South African reptiles is provided.

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Lizards are a diverse clade in which one radiation consists entirely of sit-and-wait foragers and another consists of wide foragers. Lizards utilizing these two foraging modes are known to differ in diet, but little is known about how feeding morphology relates to diet and/or foraging mode. This study tested the hypothesis that skull morphology and biting performance are related to diet preference, and consequently, coevolve with foraging mode. Four species of lacertid lizard were studied because they vary in foraging mode, their phylogenetic relationships are known and they are well studied ecologically. Using an ‘ecomorphological’ approach, skull morphology and biting performance were quantified and mapped on to the phylogeny for the species. The results indicate that sit-and-wait species have shorter, wider skulls than the wide foraging species, and that all are significantly different in overall head shape. The sit-and-wait species had similar values for biting performance; however, clear phylogenetic patterns of covariation were not present between sit-and-wait and wide foraging species for either biting performance or skull morphology. Thus, skull morphology and performance have little influence on diet and foraging mode in these species. Instead it is likely that other factors such as seasonal prey availability and/or life history strategy shape foraging mode decisions.

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Foraging behaviors exist along a continuum from highly sedentary, ambush foraging, to more continuous searching, or active foraging. Foraging strategies, or modes, are defined based upon locomotor behaviors (e.g. percent time moving, moves per minute). In lizards, traits correlated with ambush and active foraging have been of interest for some time; however, general patterns of correlated evolution between locomotor morphology and locomotor behavior have only recently begun to be quantified. In this study, variation in hindlimb morphology is investigated in a model group of lizard species that vary between active foraging and more sedentary (or mixed) foraging mode. Canonical variates analysis reveals that the two active foraging species occupy similar regions of the morphospace, while the two more sedentary species occupy different regions. The active foraging species have a narrow pelvis with shorter tibia and femora. The more sedentary species have a wide pelvis, long tibia and femora, and slightly longer metatarsals. Phylogenetic patterns of trait variation were examined through ancestral character state reconstruction and show morphological shifts in concert with foraging mode in these species. The observed shifts in locomotor morphology are discussed in light of published data on sprint speed and endurance in these species. Together, the data show that linking morphological variation to variation in stride length and stride frequency is critical to understanding the evolution of locomotor performance. Much more stride length and frequency data are needed among ambush, mixed, and active foraging species because these parameters, and their morphological components, are likely correlated with variation in food acquisition mode.

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Aim Body size is instrumental in influencing animal physiology, morphology, ecology and evolution, as well as extinction risk. I examine several hypotheses regarding the influence of body size on lizard evolution and extinction risk, assessing whether body size influences, or is influenced by, species richness, herbivory, island dwelling and extinction risk. Location World-wide. Methods I used literature data and measurements of museum and live specimens to estimate lizard body size distributions. Results I obtained body size data for 99% of the world`s lizard species. The body size–frequency distribution is highly modal and right skewed and similar distributions characterize most lizard families and lizard assemblages across biogeographical realms. There is a strong negative correlation between mean body size within families and species richness. Herbivorous lizards are larger than omnivorous and carnivorous ones, and aquatic lizards are larger than non-aquatic species. Diurnal activity is associated with small body size. Insular lizards tend towards both extremes of the size spectrum. Extinction risk increases with body size of species for which risk has been assessed. Main conclusions Small size seems to promote fast diversification of disparate body plans. The absence of mammalian predators allows insular lizards to attain larger body sizes by means of release from predation and allows them to evolve into the top predator niche. Island living also promotes a high frequency of herbivory, which is also associated with large size. Aquatic and nocturnal lizards probably evolve large size because of thermal constraints. The association between large size and high extinction risk, however, probably reflects a bias in the species in which risk has been studied.

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Aim Temperature influences most components of animal ecology and life history – but what kind of temperature? Physiologists usually examine the influence of body temperatures, while biogeographers and macroecologists tend to focus on environmental temperatures. We aim to examine the relationship between these two measures, to determine the factors that affect lizard body temperatures and to test the effect of both temperature measures on lizard life history. Location World-wide. Methods We used a large (861 species) global dataset of lizard body temperatures, and the mean annual temperatures across their geographic ranges to examine the relationships between body and mean annual temperatures.We then examined factors influencing body temperatures, and tested for the influence of both on ecological and life-history traits while accounting for the influence of shared ancestry. Results Body temperatures and mean annual temperatures are uncorrelated. However, accounting for activity time (nocturnal species have low body temperatures), use of space (fossorial and semi-aquatic species are ‘colder’), insularity (mainland species are ‘hotter’) and phylogeny, the two temperatures are positively correlated. High body temperatures are only associated with larger hatchlings and increased rates of biomass production. Annual temperatures are positively correlated with clutch frequency and annual longevity, and negatively correlated with clutch size, age at first reproduction and longevity. Main conclusions Lizards with low body temperatures do not seem to have ‘slower’ life-history attributes than species with high body temperatures. The longer seasons prevalent in warm regions, and physiological processes that operate while lizards are inactive (but warm enough), make environmental temperatures better predictors of lizard life-history variation than body temperatures. This surprisingly greater effect of environmental temperatures on lizard life histories hints that global warming may have a profound influence on lizard ecology and evolution.

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Point distribution data were used to evaluate the biogeographical influence of the arid Tankwa Karoo Basin on the distribution of reptiles in the south-western districts of South Africa. Under-representation of the Tankwa Karoo in the dataset required an additional field survey of this region. Prior to the survey, available records from the Tankwa Karoo Basin represented only 13 reptile species. A total of 36 species (24 lizards, nine snakes, three chelonians) was recorded during our survey of this area. Turnover across the Basin is high, species richness is lower than in surrounding mountainous areas and there are no species endemic to the area. The Tankwa Karoo Basin acts as a dispersal barrier for many reptile species occurring in the surrounding more mesic areas. At the same time, the ranges of a number of typical northern, arid-adapted species extend southward along the Tankwa plains. A number of species range extensions in the region are reported.

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Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long wavelength-based) and lateral (short wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties.

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From 12 to 18 species of desert lizards occur in ecologic sympatry on 10 study areas in the Kalahari desert of southern Africa. The number of species of diurnal lizards is similar to the number in the North American deserts, while the nocturnal component of the saurofauna is more comparable to that occurring in the Australian deserts. The between-habitat component of species density is similar in the American and the Kalahari deserts, but is markedly greater in the Australian desert. A variety of climatic and vegetational statistics are examined for the 10 areas, and correlations with lizard species density are discussed.

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Four lacertid lizards, Pedioplanis laticeps, P. lineo-ocellata, Meroles knoxii and Nucras tessellata, occur sympatrically on the arid plains of the Tankwa Karoo Basin in South Africa. The aim of this study was to evaluate the significance of foraging strategy in resource partitioning among the four species, allowing them to co-occur in a structurally simple system with a limited number of potential niches. Previous workers already identified P. lineo-ocellata and M. knoxii as sit-and-wait foragers and N. tessellata as an active forager. We recorded data on three foraging variables: movements per minute, proportion of time spent moving, and proportion of attacks on prey whilst moving, for juveniles and adults of P. laticeps. By comparing the foraging data obtained for P. laticeps to those for other lacertid species, we were able to demonstrate that adult P. laticeps are ambush foragers. We also noted a significant ontogenetic shift in foraging behaviour in P. laticeps, and, due to a significantly higher frequency of short brief movements, we classified juveniles as mixed foragers. The sharing of an ambush foraging strategy by at least three of the four lacertid species co-occurring on the Tankwa plains, suggests considerable overlap along the trophic dimension of ecological space. This overlap presumably promotes occupation of separate microhabitats by the three ambush foragers in the Tankwa Karoo Basin.

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Four lacertid lizards, Pedioplanis laticeps, P. lineo-ocellata, Meroles knoxii and Nucras tessellata, occur sympatrically on the arid plains of the Tankwa Karoo Basin in South Africa. The aim of this study was to determine whether the four species are spatially separated in terms of the microhabitat each species occupies, allowing them to occur in sympatry in this structurally simple system with a limited number of potential niches. The habitat preferences of the four species were investigated on the farm Gansfontein in the southwestern parts of the Tankwa Karoo Basin. The area was surveyed by walking transects through different habitat types and recording all active lizards. For each lizard observed, the species was identified and a photograph was taken of its microhabitat. At the end of the sampling period the microhabitats in which lizards were found were sorted into distinct types on the basis of substrate composition. During the survey, only one individual of N. tessellata was recorded, but sample sizes for the other three species were sufficiently large to provide a clear perspective of habitat segregation among the three species. The results showed that the three species are spatially separated at the study site, with P. lineo-ocellata being restricted to rocky areas, P. laticeps preferring gravel substrates and M. knoxii frequenting sandy areas. Although only anecdotal information is available, all indications are that the observed spatial separation of the three species is mainly the result of historical adaptation to the different substrate types.

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An updated distribution map of Heliobolus lugubris is presented, based on an analysis of different museum collections and of recently published data. The distribution area includes southern Angola northwards to the 11th degree of latitude as weil as the whole coastal region of Namibia up to Swakopmund and the Namib desert. Changes in the known distribution area occur furthermore in southern Namibia and RSA. Within this area, Heliobolus lugubris inhabits different vegetations zones, from dry savannas to desert regions. A detailed description of the habitat structure is given for two localities in the northern Cape Province and in northern Transvaal. Field observations of territorial and social behaviour suggest a strong pair-bonding, being maintained also outside the mating season. This long period of pair-bonding seems to be also important for the sucessful maintenance of Heliobolus lugubris in captivity, as the lizards proved to be unsociable in the terrarium regardless of sex. Field data of diurnal and annual activity are given and discussed in relation to microclimatic preferences (temperature and moisture) evaluated in the laboratory. Adults and juveniles clearly differ in temperature preferences. Hatchlings are characterised by a jet black ground colour. Advantages and disadvantages of this body colouration are discussed in relation to their preferred temperature, habitat, and diurnal activity. Finally, the paper describes the foraging strategies and diet of H. lugubris in comparison with the related and sympatric lizard Pedioplanis lineoocellata.

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In this paper, the evolution and ecology of directional asymmetry (DA) during the developmental trajectory (DT) is compared with that of its product, morphological DA (MDA). DT and MDA are calculated for two bilateral morphological scale characters of lizards, the number of subdigital lamellae beneath the fourth toe in 10 agamid and 28 lacertid taxa, and the number of rows of ventral scales in 12 lacertid taxa. MDA, the subtraction between left and right sides (classical measure of DA), is functional in adult animals. Results confirm the hypodiesis that, in DT, the regression parameters a (constant) and b (regression slope) of counts on the right side with those on the left describe a developmental process. No phylogenetic or environmental effects were observed on a and b, but analyses considering both a and b together show non-random phyletic patterns. Independent analyses deduced the same ancestral DT in Agamidae and Lacertidae. In Lacertidae, distance between pairs of taxa in a + b (standardized values) correlates positively with die phylogenetic distance between taxa. Phyletic trends in MDA are indirect, and due to the link of MDA with a + b. The MDA of species is more dissimilar in sympatry than in allopatry. The phyletic trends suggest evolution of DT, while die association of MDA witii sympatry suggests that ecological pressures shape MDA in adult animals. Evolution of DT is independent from tiiat of its product, MDA–adaptive determinism defines the result of, but not the mechanistic process of, development. Deterministic environmental processes define MDA, and deterministic evolutionary processes define the interactive result of a and b, but not each separately. According to circumstances, different DTs produce similar or different MDA, and a particular DT can produce different MDAs.

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The present paper of N. N. SZCZERBAK was originally published in Russian as `Katalog afrikanskih Jascurok` by the Academy of Sciences, Institute of Zoology, Museum of Zoology, USSR, Kiev (83 pp., 30 maps) in 1975. Lists of synonyms, bibliography, maps and table of contents - all being parts of the original paper - have not been included in this translation which was carried out with the consent of the author by R. GÜNTHER (Berlin) and H. GRILLITSCH (Vienna). The English summary was taken over as provided in the original version. As a SHORT NOTE in this issue of HERPETOZOA subsequent to the translation comments and updated addenda by W. MAYER are provided indicated by [aa* bb* etc.] in the text.

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Population genetic methods can be useful for understanding spatial genetic patterns, gene flow and diversity. While genetic markers such as gene sequences are useful for understanding broad scale phylogeographic patterns, microsatellite markers allow for inferences within species and on smaller spatial scales. Such data can then be used to glean information on biological processes at the landscape level. Because portions of southern Africa are predicted to be heavily impacted by climatic changes forecast for the next century, a better understanding of the biota at the species level would be beneficial for advancing knowledge on the southern African system. Therefore, we characterised 11 microsatellite markers for an arid adapted lacertid lizard, Pedioplanis lineoocellata, in order to obtain a microsatellite library for future studies. Five of 11 loci were out of Hardy-Weinberg (H-W) equilibrium, showing a homozygote excess. Frequency-based analysis suggested this is due to the presence of null alleles. We further investigated this using a model-based Bayesian approach to simultaneously estimate inbreeding, null alleles and random amplification failures. In contrast to the frequency-based approach, this method indicated that both inbreeding and random amplification failures, not null alleles, are the most significant components of the model for nine of 11 loci. Overall, the inbreeding coefficient was low, but not zero, suggesting that low levels of inbreeding contribute to H-W deviations. Finally, we examined whether population bottlenecks could be a factor in deviations from H-W using multiple methods, but found no evidence to suggest that bottlenecks have played a role.

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Locomotion is important to animals because it has direct implications for fitness through its role in predator escape, prey capture, and territory defence. Despite significant advances in our understanding of animal locomotion, studies exploring how substrate properties affect locomotor performance remain scant. In the present study, we explore how variation in substrate (sand, slate, cork) affects locomotor performance in lacertid lizards that differ in morphology. Moreover, we explore whether substrate effects are the same for different types of locomotor performance (speed, acceleration, and stamina). Our results show that the substrate affected most types of locomotor performance studied but not always in the same way. Although substrate effects were species-dependent for the maximal speed over 50 cm and the distance run to exhaustion, this was not the case for acceleration capacity. These results suggest that substrate texture differentially affects burst performance vs. longer duration measures of locomotor performance. Finally, straightforward relationships between habitat use and the substrate on which performance was maximized were not observed. This suggests that the evolution of locomotor capacity is complex and that animals may show compromise phenotypes allowing them to deal with a variety of substrates in their natural environment.

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Evolutionary changes in foraging style are often believed to require concurrent changes in a complex suite of morphological, physiological, behavioural and life-history traits. In lizards, species from families with a predominantly sit-and-wait foraging style tend to be more stocky and robust, with larger heads and mouths than species belonging to actively foraging families. Here, we test whether morphology and foraging behaviour show similar patterns of association within the family Lacertidae. We also examine the association of bite force abilities with morphology and foraging behaviour. Lacertid lizards exhibit considerable interspecific variation in foraging indices, and we found some evidence for a covariation between foraging style and body shape. However, the observed relationships are not always in line with the predictions. Also, the significance of the relationships varies with the evolutionary model used. Our results challenge the idea that foraging style is evolutionarily conservative and invariably associated with particular morphologies. It appears that the flexibility of foraging mode and its morphological correlates varies among lizard taxa.

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We studied the effects of overgrazing on the foraging behaviour of the lizard Pedioplanis l. lineoocellata (Spotted Sand Lizard), a sit-and-wait forager, in habitats of differing vegetation states to determine the effects of habitat degradation on this species. At high grazing intensity where vegetation cover and diversity is low, the lizard P. lineoocellata moves more frequently, spends more time moving and covers larger distances than in habitats where vegetation cover and diversity is high. These behavioural changes in movement patterns can be explained by less abundant prey in habitats with low vegetation cover and diversity. Although morphology, phylogeny and physiology of P. lineoocellata should constrain the change in foraging behaviour, the species has modified its foraging strategy from sit-and-wait to actively foraging. We assume that this behavioural flexibility of P. lineoocellata is a buffer mechanism enabling the species to use and survive in degraded (unfavourable) habitats.

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Although the effects of grazing-induced savannah degradation on animal diversity are well documented, knowledge of how they affect space use or responding behaviour remains poor. In this study, we analysed space use of the spotted sand lizard (Pedioplanis l. lineoocellata) in degraded versus nondegraded habitats of southern Kalahari savannah habitats. Lizards were radio tracked, daily movement distances recorded and home range sizes calculated. In degraded Kalahari savannah habitats where plant diversity and perennial grass cover are low but shrub cover high, P. lineoocellata moves larger distances (40.88 ± 6.42 m versus 27.43 ± 5.08 m) and occupies larger home ranges (646.64 ± 244.84 m2 versus 209.15 ± 109.84 m2) than in nondegraded habitats (high plant diversity, high perennial grass cover and low shrub cover). We assume that this increase in daily movement distances and home range sizes is a behavioural plasticity to limited food resources in degraded savannah habitats. Although P. lineoocellata is able to adjust to resource-poor savannah habitats, the increase in the lizard’s movement activities is likely to result in a higher predation risk. This is supported by the lower availability of protective vegetation i.e. perennial grass cover. Hence, we conclude that despite behavioural plasticity of P. lineoocellata, overgrazing has a severe negative impact on the space use of P. lineoocellata.