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This is our fifth report in a series on our whereabouts while collecting data for a future revision of the present subspecific order of the endemic Balearic sisterspecies Podarcis lilfordi (GÜNTHER, 1874) and Podarcis pityusensis (BOSCÁ, 1883), which data are stored in our free accessible database at www.pityusensis.nl (VAN DEN BERG & ZAWADZKI 2011 ; VAN DEN BERG et al. 2013 ; VAN DEN BERG et al. 2014a ; VAN DEN BERG et al. 2014b). During this trip from the 9th of May until the 23rd of May 2015, we were able to collect data on a few mainland Ibiza locations, as well as the following adjacent islands: Punta Galera, Es Canaret, Illa de la Xanga (Sal Rossa), Pouet de Ses Illetes, Formentera, Purroig, Es Vedrà, Rates, Malví Pla (North), Malví Rodó (South), S’Espardell, Calders, Penjats and Ses Margalides. We continue with the ventral coloration as a possible determining key as introduced in our 2014 trip report (VAN DEN BERG et al. 2014b). Images of the anal shields are presented of each lizard for purposes of illustration.

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EL ESTUDIO ABORDADO EN LA TESIS VERSA SOBRE LA CARACTERIZACION TAXONOMICA DE LA LAGARTIJA DE LAS PITIUSAS PODARCIS PITVUSENSIS. SE ANALIZAN LAS DISTINTAS POBLACIONES DESDE TRES ASPECTOS DISTINTOS: EL ANALISISBIOMETRICO EL ANALISIS ELECTROFORETICO DE DISTINTAS PROTEINAS Y EL ANALISIS COLORIMETRICO. LOS ANALISIS ESTADISTICOS APLICADOS SOBRE LAS VARIANTES BIOMETRICAS DEMUESTRAN LA EXISTENCIA DE DIVERSOS GRUPOS DE POBLACIONES MUY SEMEJANTES ENTRE SI. LA VARIABILIDAD DE LA ESPECIE NO SOLO ES FENOTIPICA SINO QUE TAMBIEN ES GENETICA DETECTANDOSE UNA DIVERSIDAD EN ESTOS CARACTERES SUPERIOR A LA ESPERADA EN REPTILES. SE OBSERVA UNA ALTA HETEROSIS QUE ES CARACTERISTICA DE LA ESPECIE LO QUE PARECE DEMOSTRAR QUE ESTA SE ENCUENTRA EN LAS PRIMERAS FASES DE COLONIZACIONY ADAPTACION A LOS DIFERENTES HABITATS OFRECEN LAS ISLAS QUE OCUPA. SE CONSTATA LA ACCION DEL EFECTO FUNDADOR Y LA DERIVA GENETICA EN LOS TRES ASPECTOS CONSIDERADOS EN LA TESIS ASI COMO UNA TENDENCIA EVOLUTIVA HACIA EL AUMENTO DE TAMAÑO SIEMPRE QUE NO EXISTA UNA PRESION SELECTIVA CONTRARIA. SUCEDE LO MISMO CON EL MELANISMO. CONSIDERANDO EL ESTADO EVOLUTIVO ACTUAL DE LA ESPECIE REFLEJADO EN LA PLASTICIDAD DE LAS DISTINTAS POBLACIONES DE ESTALAARTIJA Y EN LA ADAPTACION QUE MANIFIESTAN EN CADA NICHO CONCRETO ASI COMO EL CONCEPTO RESTRICTIVO ACTUAL DE SUBESPECIE LA AUTORA CONSIDERA QUE SOLO PUEDEN CONSIDERARSE SEIS TAXONES SUBESPECIFICOS O SUBESPECIES DE LA LAGARTIJA DE LAS PITIUSAS.

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In this paper are presented the results obtained with 45 populations of Podarcis pityusensis. Several multivariant technics are performed: discriminant analysis, cluster analysis and canonic analysis of populations. These populations present gradual change in all their biometric characteristics, and also a great interpopulation variability, that invalidate th statistical methods to discriminate between all of them. In different analysis very related population groups are found, that suggests they are constitute the same subspecies, in the actual taxonomic sense. These groups always inhabits islands with the same geological age, it is therefore necessary to complete the study with othr biological reflections, all of which are getting ready.

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The dorsal, side and belly colours of 118 specimens of Podarcis pityusensis have been analysed with physical methods. Twenty samples from 16 islands have been chosen, 3 of then from Eivissa Island (Ibiza), 2 from Formentera Island and 2 from Espardell Island. The results reveal great colouration differences between the same island samples and sometimes similar colouration between different islands (different subspecies). specimens. This feature seems to show the colour criteria is not useful in taxonomic subjects for this species.

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The variation in morphological and colouring features shown by the insular lacertid populations of Podarcis pityusensis is discussed from the point of view of their adaptive advantages to specific insular ecosystems. Insularity factors, i.e. area and island-age, have been found to be related to average body size, and the average luminosity of each population. Populations tend to show a size increase, a greater morphological homogeneity and darker dorsal colouring on smaller and older islands. Genetic drift seems to play a secondary role, whereas a positive selection in favour of melanism and giantism is observed. Both features are not linked as cause and effect, but seem to share a common cause: isolation and time enough to allow selection to take place. Predation, though slight in degree, does exist, and seems to be one of the selective pressure favouring melanism, together with the parallel trend towards an increase in body size and the need to an effective thermoregulation during the early hours of the day.

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We provide a fi rst complete list of the present and lost reptile type material of the Zoologische Staatssammlung München (ZSM) and discuss various problems involved. The collection currently houses primary types of 184 taxa (128 holotypes, 44 lectotypes, and 12 taxa based on syntype series), 112 of them currently considered valid. Furthermore, 63 taxa are exclusively represented by secondary types (paratypes, paralectotypes). The ZSM collection strongly suffered from losses during World War II. Approximately 90 primary reptile type specimens or primary type series are considered to be destroyed during that time. The historical focus of the collection is the South American region. This is primarily based on material collected by Spix and Martius during their expedition to Brazil from 1817 to 1820. Primary types of 83 reptile taxa were collected during this expedition – approximately half of them described by J. G. Wagler – but currently specimens of only 53 taxa are still present in Munich. Subsequently, herpetological research in South America was continued during the fi rst half of the 20th Century by L. Müller und W. Hellmich, who deposited primary type material of 95 reptile taxa (49 from South America, among them 26 of the iguanid genus Liolaemus) in the ZSM, 47 of them still represented by primary types. Another geographical focus of the reptile type collection is the Mediterranean area, the Macaronesian region and the Middle East with a total of 46 extant primary types. Herpetological research in this area dates back to descriptions by G. Jan in 1863 and was continued by L. Müller, H. H. Schleich, A. Beutler, and especially J. F. Schmidtler and their respective collaborators.

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An electrophoretic comparison of ten colonies of Podarcis pityusensis Bosca, 1882 (Lacertidae) from Ibiza, Formentera and neighbouring islets (Balearic Is., Spain). 71 animals from ten colonies (vide list in text) of the Ibiza wall lizard Podarcis pi- tyusensis Bosca, 1882 were analysed by electrophoresis, on 12 % starch gel, and 16 gene- tic loci were studied, by checking against samples of Podarcis muralis muralis. The genetic frequency resulting in NEI`s identity index (I), reveals no clear differen- ces between the various colonies. However, itcan be seen on the resultant dendogram that P. p. carlkochi (affinis group) is distinct from the pityusensis sensu stricto group colonies. By other means we found characteristic allels for Podarcis pityusensis in four loci: GOT-1, IDM-1, G-6-PD-2 and 6-PGD, which differed from Podarcis muralis allels.

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The population of Illiot de Sa Mesquida: Podarcis pityusensis characae (Buchholz 1954) is regarded as a synonym of Podarcis pityusensis pityusensis (Boscá 1883).

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The status of the populations of Podarcis pityusensis on about 70 islets and small islands around Ibiza and Formentera (Balearic Islands) is examined, using data from our own observations, and, to a lesser amount, other publications. Lizard populations were found on 43 islets, but data are lacking for another 13. Only 10 sites (18 %) have abundant and well-maintained populations. In 13 localities (23%), there is no geographic isolation between the populations, or this isolation is very poor and incomplete. The high probability of populations mixing, or actual observation of this mixing, in 19 islands (34%) is indicated. Human pressure on lizard populations is strong in 14 cases (25 %). And finally, 18 populations (about one third) may be considered highly endangered or already extinct by elimination or genetic mixing with other populations. Among the subspecies which became extinct through mixing are P.p. miguelensis, P.p. subformenterae, P.p. algae, P.p. sabinae and P.p. grueni. The need for adequate protective measures aimed at the conservation of the remaining populations is emphasized.

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We examined the diets of several species of Podarcis from different western Mediterranean islands. We tested the prediction of more generalized diets in lizards from poor environments. We also examined the extert and mode of herbivory in relation to arthropod diversity in the diet. Lizards from the Tuscan Archipelago, P. sicula from Menorca, and P. tiliguerta from Corsica all show a rather generalized diet. In contrast, P. lilfordi and P. pilyusensis from the Balearic Islands and, to a lesser extent, P. hispanica from Benidorm Island, appear much more stenophagous, including a high proportion of clumped prey in their diets. Plant matter is a common food item in most of the population studied, specially in Balearic lizards. A marked seasonal shift in the degree of herbivory was observed in these species where high-energy plant parts are frequently consumed during summer. In one of the Balearic Islands (Nitge), the bulk of the summer diet was formed by pollen and nectar of one particular plant species. Herbivory, consumption of clumped prey and other dietary peculiarities of insular populations of Mediterranean lizards indicate a very flexible feeding behaviour compared to mainland congenerics. This could result from a lack of predation pressure allowing high population densities to be reached in islets with poor trophic resources. Differences found in dietary characteristics among island populations can be interpreted as a consequence of different current ecological conditions, as well as historical and biogeographical differences among the islands.

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The effect of several abiotic and biotic factors (island area, distance from a potential colonizing source, sex, age and diet of the host) on helminth diversity of the endemic balearic lizards Podarcis pityusensis and Podarcis lilfordi caught on small islets of the Balearic islands, has been studied.

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The knowledge of the helminth communities of reptiles and their ecological relationships with their hosts are until the present not well known. Some general researches have been made only on American herps (AHO 1990). Recently, ROCA & HORNERO (1991a, 1991b) attempted similar kind of researches from Mediter- ranean insularlizards.

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A survey of the helminth communities of Podarcis pityusensis (Bosca, 1883) and Podarcis lilfordi (Gunther, 1874) (Sauria: Lacertidae) from the Pityusic and Gimnesic islands, respectively, in the Balearic Islands, Spain, was conducted. Both host species harbour similar though not identical helminth infracommunities. An analysis of the patterns of diversity for all helminths revealed that both lizards have depauperate isolationist infracommunities, possibly as a result of factors such as host ectothermy, the simplicity of their digestive canal, low vagility, and generalist feeding.

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There is a census of groups of lizards in some of the small islands of the Balearics, obtained by method of simplified successive suppression. The results are coherent with the observations in 50% of the cases. The minimum known group is of 6 ex. in the small islet of Fornol (Cabrera). The highest density corresponds to Escull Vermell in the group of Ses Bledes in Ibiza with 50 ex. in 350 m2 (1428 ex/Ha).

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Survey of the present known occurrences of population exposures within the Ibiza wall lizard (Podarcis pityusensis Boscà,1883). Probably more often than it has been documented in the past, lizards are transported with the help of men to other islands or islets where either no lizards live or which are inhabited by different subspecies. Therefore the mixing of populations is possible and the genetic barrier is broken which leads to complications in the taxonomy of these species. In some cases unfortunately such transported lizards have probably been described as different subspecies. In the future taxonomic studies of this specie the possible precence of such transported lizards within various populations should be given more attention.

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Some subspecies of the endemie Ibiza wall lizard Podarcis pityusensis (BoscA, 1883) were observed in their natural environment and are briefly described with some complementary notes on their population density.