bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations on activity, display behavior, coloration and androgen levels in the keeled earless lizard, Holbrookia propinqua
Authors: Cooper William E. , Guillette Louis J. 
Published: April 2008

AbstractWe observed the distance moved, number of movements, and frequency of displays in ten minute intervals for two male color morphs, coral and yellow, and for brightly colored females, of Holbrookia propinqua. We also measured body sizes and, for males, plasma androgen concentrations. Distance moved, number of movements, and number of social displays were positively correlated in males. Females exhibited similar correlations, but the relationship between distance moved and number of displays was not significant. Males moved more often and greater distances than females. Females performed displays as frequently as did males, perhaps because we selected large, dominant females for observation. Distance moved, number of movements, and number of displays increased with body size in males. That these relationships did not hold in females may indicate a sex difference or reflect the small sample size and body size range of females. Plasma androgen concentrations increased with male body size, suggesting a possible androgenic mechanism of sexual selection for large size. Androgen level did not affect display frequency or distance moved. Distance moved increased with plasma androgen concentration, but when effects of body size were held constant, this relationship vanished. Coral and yellow males did not differ in androgen concentration, size, or in the observed behaviors.
Hybridization and low numbers in isolated populations of the natterjack, Bufo calamita, and the green toad, B. viridis, in southern Sweden: possible conservation problems
Authors: Schlyter Fredrik , Höglund Jacob , Strömberg Gunnar 
Published: April 2008

Abstract
Two isolated rock pool localities in southern Sweden with breeding green toads (Bufo viridis) and natterjacks (B. calamita) were studied, one on the mainland coast (Vik) and one on an island in the Baltic (Utklippan). Both localities are isolated by at least 30 km from other known populations of either species. A new character, dark throat patches present in B. calamita, aided in species separation on Utklippan. Body length was larger (9-41 % ) than reported from continental Europe. Individuals intermediate between the two species in size, morphologv and mating calls were found on Utklippan, suggesting the occurrence of viable hybrids. In Vik, neither of these characters nor electrophoretic data indicated hybridization. We suggest that the number of suitable breeding ponds may explain why the two species hybridize on Utklippan since only one sympatric breeding pond could be found on this site and a number of suitable ponds were found on Vik. Thus the species may be spatially more scparated at the Vik site making hybridization less likely to occur. However, few green toad males could be found on Utklippan making the sex ratio highly skewed. Accordingly, the low number of male green toad may explain why the species hybridize. Hybridization may be a potential threat to the persistence of endangered populations already in low numbers, if a large proportion of female gametes are wasted in hybrid matings. Thus this possibility is important when considering the conservation of endangered species.
Glandular epidermal structures in cordylid lizards
Authors: van Wyk J.H. , Mouton P. le F. N. 
Published: April 2008

AbstractThe epidermal glandular structures in lizards belonging to the family Cordylidae are described. In addition to the large tubulo-follicular holocrine glands in the femoral region, "glandular scales" in the femoral, pre-cloacal, dorsal body and anterior antebrachial regions resembling epidermal "generation" glands are for the first time described histologically. In contrast to generation glands described in other lizards, a sequential buildup of glandular generations occur in these structures. Based on histological features, two types of cordylid generation glands are recognized, depending on whether the sequential buildup of the glandular generations is above ("protruding" type) or below ("pit" type) the stratum germinativum profile of the normal epidermis.
The reproductive cycle of the newt Triturus italicus
Authors: Guarino Fabio M. , Caputo Vincenzo , Angelini Francesco 
Published: April 2008

AbstractThis paper describes the reproductive cycle in male and female newts Triturus italicus (Peracca, 1898) from a mountain population living in southern Italy. The male shows a well-defined seasonal testicular cycle: spermatogenesis almost stops from November to March, resuming in April-May; the maturative stage of spermatogenesis occurs in summer and spermiohistogenesis is completed by late October. Spermiation starts in late autumn and culminates in the next spring. The female shows a seasonal ovarian cycle. Vitellogenesis starts in September; ovulation and egg deposition occur between late January and early June. Thus potentially long reproductive activity is demonstrated in both males and females of T italicus. Testicular and ovarian weights seem to be reliable indices of the reproductive status of an animal. Annual variation in gonadal weight appears unrelated to annual variation in fat body weight in both sexes.
Progeny of water frog populations in central Poland
Authors: Berger Leszek , Berger W. Andrew 
Published: April 2008

Abstract
The authors discuss progenies of 18 watcr frog populations. Individuals with esculenta phenotype which arc hybridogenetic hybrids between Rana ridibunda and Rana lessonae are the most numerous frogs among the adults and progeny. Esculenta tadpoles began and finished their metamorphosis mostly as first, and in progeny with esculenta phenotype there were more females than males. In pure esculenta population most of progeny belonged to ridibunda phenotype and female sex. The froglets caught in August were larger on an average than those in October or after hibernation.
Size variation, growth and survivorship in nesting green iguanas (Iguana iguana) in Panama
Authors: Rand A. Stanley , Bock Brian C. 
Published: April 2008

AbstractOver five years, 188 adult female green iguanas were captured one or more times, permanently marked, and measured at a nesting aggregation in Panama. Growth in these adult iguanas was very slow (averaging 6.8 mm/year) and appeared to be asymptotic, but there was substantial variability in the nesting female sizes observed (295 to 425 mm). This variation is biologically important because of the close relationship of female size to fecundity but little of this variation is explainable by differences in female ages (as estimated by skeletochronology) or in adult growth rates. Smaller females grew faster than larger ones but, controlling for size, younger iguanas did not grow faster than older ones. There is no evidence of alternative strategies with a trade-off between nesting sooner but smaller and nesting later but larger. Differences in adult sizes probably result from differences in juvenile growth rates, perhaps influenced by local differences in food quality and/or differences in the adult sizes at which growth trajectories asymptote. Energetic resources probably are not limiting for adult growth or reproduction. The high disappearance rate of iguanas from year to year (ca 60% per year) probably resulted mostly from mortality.
Adaptation of the reproductive cycle in Triturus alpestris apuanus to an unpredictable habitat
Authors: Andreone Franco , Dore Bruno 
Published: April 2008

Abstract
The annual reproductive cycle was studied in a Triturus alpestris apuanus population from northwestern Italy. Adult and larval newts were captured and measured monthly. By using histological techniques, the status and evolution of male gonads were examined. T. a. apuanus shows a post-nuptial gametogenesis, and testes reach their smallest size and weight in spring, when there are mainly mature sperm ampullae and yellow glandular tissue. Secondary sexual characters reach their maximum development during this period, decreasing during gametogenesis and increasing again in early autumn. Breeding activity begins at the same time, and is interrupted by the winter. Reproduction starts again in spring, lasting until summer. Eggs are laid at least twice a year, and the two larval cohorts live together. It is suggested that all these biological features are adaptations to unpredictable aquatic environments in a Mediterranean dry climate. These results suggest high levels of flexibility and variability in newt seasonal cycles.
In loco and systematic alteration in vitamin A content during tail regeneration in the gekkonid lizard, Hemidactylus,flaviviridis
Authors: Ramachandran A.V. , Valsamma E.P. , Shah R.V. 
Published: April 2008

Abstract
A quantitative evaluation was made of the levels of vitamin A in the liver, kidney and tail regenerate during tail regeneration in H. flaviviridis. Vitamin A in the liver increased on the first three days and decreased on the 5th day post-autotomy; a second increase was noted on the 7th day. Thereafter a subnormal level was noted on the 10th, 15th and 25th days. Vitamin A levels in the tail remained raised throughout regeneration except on the 7th and 60th days when the levels were in the normal (pre-autotomy) range. Kidney vitamin A content showed a steep increase on the 10th day while at other periods it remained in the normal range. The depletion in hepatic vitamin A content corresponded with high vitamin content in the regenerate, indicating the mobilization of this vitamin to the site of regeneration. The decreased level during dedifferentiation indicates greater utilisation of this vitamin. Supra normal levels of vitamin A in the regenerate during the blastemic and differentiation phases suggest an intimate association of this vitamin with the many events characteristic of these phases of regeneration.
Reproductive cycle of the parthenogenetic lizard Teius suquiensis
Authors: Martori R.A. , Aun L. 
Published: April 2008

AbstractThe reproductive cycle of the parthenogenetic lizard Teius suquiensis was studied. Females were reproductive after their second winter. The first eggs were laid in early November and oviductal eggs were present up to early January. Mean clutch size was 4.2 (range 2-8). Fat bodies were smallest during the reproductive season.
Variability and microevolutionary patterns in Triturus marmoratus from Portugal: age, size, longevity and individual growth
Authors: Caetano M.H. , Castanet J. 
Published: April 2008

Abstract
We conducted a comparative study of some biological parameters between different allopatric northern (high and low altitudes) and southern (low altitude) populations of Triturus marmoratus in Portugal. Individual age was determined by counting lines of arrested growth in histological sections of the humerus and phalanx. This study documents interpopulational differences in longevity, age of sexual maturity and growth of individuals. Individuals from high altitudes in the north reached older ages than those from low altitudes but both reached older ages than those from the south. Maturity was reached sooner among the southern newts for both sexes when compared to the northern populations. The southern newts also reached their sexual maturity at smaller mean sizes than the northern ones. We interpret these differences and suggest how genetical and epigenetical components can be both involved and account for the observed variability.
Sexual behaviour of Bosca's newt, Triturus boscai
Authors: Mouta Faria Manuel 
Published: April 2008

AbstractThe sexual behaviour of Bosca's newt, Triturus boscai is characterized by an extended phase of static display, during which tail fanning is the main display. This behaviour is similar to that of another species, T. italicus. During the static display phase males may also push the females' throat with the snout, and perform tail flicking movements. Unlike the other small-bodied Triturus species, T. boscai males receive very little or no indication on the part of the female signalling them to begin the spermatophore transfer phase, and do not perform retreat display. As in T. italicus, the tail-touch behaviour by the female of T. boscai appears to be less stereotyped than in the T vulgaris-helveticus-montandoni group. Spermatophore transfer success was highest at the beginning of the sexual encounters, the so-called early sequences. These sequences had little or no fanning behaviour before the spermatophore transfer. Luring behaviours are often performed, mainly during the spermatophore transfer phase.
Habitat choice of the salamander Chioglossa lusitanica: the effects of eucalypt plantations
Authors: Vences Miguel 
Published: April 2008

AbstractEvidence is presented that golden-striped salamander Chioglossa lusitanica populations in eucalypt plantations may be subject to two influences. There is a low density of leaf litter invertebrates which are the preferred prey. Substrate choice experiments show that that the salamanders avoid eucalypt leaves as substrates for shelter. A long-term study of Chioglossa populations at two brooks in northern Portugal, however, showed that the numbers at one site did not change notably after plantation with eucalypts in comparison with the other, less altered, locality. Chioglossa is the most abundant amphibian species along water courses in the Spanish province of La Coruña, although eucalypts are planted along most of them.
Tree selection by the broad-headed skink, Eumeces laticeps: size, holes, and cover
Authors: Cooper William E. 
Published: April 2008

AbstractBroad-headed skinks (Eumeces laticeps) are semiarboreallizards that are strongly associated with live oak trees (Quercus virginiana). Examination of the frequencies with which lizards occupied the largest of four nearest-neighbor trees and those having holes revealed a strong preference for large trees having holes. The presence of holes large enough for entry was a more important factor than tree size per se, as indicated by consistent occupation of smaller trees having holes when the largest of the four nearest neighbors lacked holes, although a significant preference for large size was demonstrated by the significantly greater than chance occupation of the largest of four nearest neighbor trees among those having holes. Large adults occupied significantly larger trees than did smaller adults, suggesting that larger individuals aggressively exclude smaller ones from preferred trees. Pairs consisting of an adult female and the male guarding her preferred trees surrounded by dense bushes, presumably because bushes limit detection and attack by predators and possibly because they harbor prey. Broad-headed skinks thus prefer large live oaks having holes and a fringe of dense cover.
Morphological variation and ecological distribution of co-occurring larval forms of Oreolalax (Anura: Pelobatidae)
Authors: Zhao Er-Mi , Inger Robert F. , Wu Guan-Fu , Shaffer H. Bradley 
Published: April 2008

Abstract
The amphibian fauna of Sichuan Province, China, is remarkable for the large number of species of pelobatid frogs, of which species of Oreolalax form a large portion. We have collected larvae of five species of Oreolalax on Mt. Emei, Sichuan, four of these five at a second locality 40 km from Mt. Emei, and larvae of two additional species at a locality 200 km S of Mt. Emei. These tadpoles are very similar to one another morphologically, a conclusion supported by multivariate analysis. We give diagnostic descriptions and a key for the identification of these seven larval forms. All tadpoles of Oreolalax have lotic habits, and the seven species in our study live in small to medium-sized streams (maximum width 8 m). These species show only moderate ecological segregation in terms of stream size and microhabitat type.
Survie et incubation des oeufs dans deux populations ovipares de Lacerta vivipara
Authors: Heulin Benoit , Osenegg Kirsten , Michel David 
Published: April 2008

Abstract
Lacerta vivipara est un lézard présentant à la fois des populations ovipares et vivipares. La survie et l'incubation des œufs ont été étudiées pendant quatre ans dans deux populations ovipares de cette espèce, à Louvie (370 m) et à Gabas (1100 m) dans les Pyrénées françaises. Dans la population de Louvie 25 à 56% des jeunes femelles de un an participent à la reproduction. Et la plupart des femelles adultes (âge>=2 ans) réalisent deux pontes par an. Dans la population de montagne de Gabas aucune femelle de un an ne participe à la reproduction, et moins de 20% des femelles adultes réalisent une deuxième ponte annuelle. Dans les conditions climatiques normales la période des premières pontes est comprise entre la deuxième et la dernière semaine de juin à Louvie, et entre la dernière semaine de juin et la mi-juillet à Gabas. La période de deuxième ponte a généralement lieu au cours de la deuxième quinzaine de juillet à Louvie, et au cours de la première quinzaine d'aout à Gabas. Le printemps frais de 1991 occasiona un retard de 2 semaines pour les périodes de pontes et d'éclosion de cette année. Un grand nombre de sites de pontes ont été découverts entre 1 et 3 cm de profondeur sous les mousses des tourbières étudiées. Dans les deux populations l'incubation des premières pontes dure environ 40 jours pour une température moyenne d'incubation de 18°C à 20°5. La durée moyenne d'incubation se réduit à moins de 30 jours les deuxièmes pontes de Louvie incubées à une température moyenne de 20°5 à 21°5. Les survies moyennes de œufs à Louvie et Gabas ont respectivement été de 0.49 et 0.84 pour les premières pontes et de 0.68 et 0.92 pour les seconde pontes. La prédation est la principale cause de mortalité des œufs et est particulièrement importante à Louvie. La courtillère Gryllotalpa gryllotalpa est très vraisemblablement responsable d'une grande partie (jusqu' à 44%) de la mortalité par prédation observée dans les pontes de Louvie. Les caractéristiques des populations ovipares ont été comparés à celles des populations vivipares précédemment étudiées. Ces données ne permettent pas de dégager des différences évidentes de dates de naissance et de taux de survie embryonnaire entre les deux modes de reproduction. En revanche elles confortent l'hypothèse théorique d'un accroissement de fécondité annuelle lié aux pontes multiples dans les populations ovipares de basse altitude.
Ecology of a Speleomantes ambrosii population inhabiting an artificial tunnel
Authors: Salvidio Sebastiano , Lattes Aldo , Tavano Maria , Melodia Federico , Pastorino Mauro Valerio 
Published: April 2008

Abstract
A Speleomantes ambrosii population living in an artificial tunnel in NW Italy was studied for two consecutive years. Activity on the walls varied cyclically in relation to seasonal temperatures and food abundance. The main food item was the trogloxenic dipteran Limonia nubeculosa, which accounted for more than 80% of the total ingested prey by volume. Juvenile cave salamanders had a broader trophic nich than adults. Oviposition and juvenile recruitment appeared to be seasonal. The spatial distribution inside the tunnel was related to microhabitat heterogeneity and particularly to the distance from the entrance. Juveniles were observed outside or close to the entrance more often than adults. Movement of adult salamanders were generally low and averaged 7 cm/day; some repeatedly recaptured individuals had a mean home range of 6 m2.
Changes in the components of phenotypic variance and covariance among traits during ontogeny in the sharp-snouted rock lizard (Lacerta oxycephala)
Authors: Aleksic I. , Tucic N. 
Published: April 2008

AbstractWe estimated changes in the components of phenotypic variance and covariance among seven metric traits over the first 90 days of growth in the sharp-snouted rock lizard (Lacerta oxycephala). The broad-sense heritability estimated from the data representing mostly size components of the seven morphometic traits over four age periods was about 90%. The average broad-sense heritability for the shape components of the same traits and age periods amounted to about 42%. By using bivariate and multivariate statistical methods, ontogenetic allometry coefficients have been estimated. The average heritability estimated for the bivariate allometric coefficients was about 69%. Genetic correlation structures were highly integrated within each age period and this integration increased from newborn lizards to lizards aged up to 90 days. For absolute measurements, phenotypic correlation structures were less integrated than genetic correlation structures, while for size-free measurements the opposite trend was observed.
Xenophidion, a new genus with two new species of snakes from Malaysia (Serpentes, Colubridae)
Authors: Günther Rainer , Manthey Ulrich 
Published: April 2008

Abstract
A new snake genus Xenophidion gen. nov., as well as two new species, X. acanthognathus spec. nov. and X. schaeferi spec. nov., are described on the basis of two specimens from Malaysia. Xenophidion is regarded as a distinct evolutionary lineage, presumably of the Colubridae, whose closest relatives remain to be identified.
Growth of the tropical sand lizard Liolaemus lutzae in southeastern Brazil
Authors: Rocha Carlos Frederico Duarte 
Published: April 2008

AbstractThe growth of males and females of the tropidurid lizard Liolaemus lutzae was studied in the seasonal tropical habitat of the restinga da Barra de Maricá, Rio de Janeiro State, southeastern Brazil. Growth rates of lizards decreased with size in both sexes; the size specific growth rates of females were significantly lower than those of males. Adult males were larger than adult females. The data indicate that despite maturing at a larger size, males grow faster than females and mature at similar ages. There was a significant relationship between amount of rainfall and lizard growth rate in both sexes.
Aspects of the reproductive biology of Physalaemus cuvieri (Anura: Leptodactylidae) in northeastern Brazil
Authors: Barreto Larissa , Andrade Gilda V. 
Published: April 2008

AbstractObservations were made on the reproductive biology of Physalaemus cuvieri from open area habitat in São Luis, MA, Brazil, from August 1988 to August 1989. The reproductive tactics are compared to those of the same species in southeastern Brazil. Vocalization and reproductive activity were restricted the rainy season (January to June), with peaks of activity during late March and early April. Nocturnal calling activity turn was prolonged, with little variation in the number of individual calling during the night. The presence of communal foam nests suggests non-territorial behaviour in this species. However, males called from the same sites all night long. They showed differentiated vocalizations or antiphony, and aggressive physical interactions, which suggests that there may be some territorial behaviours in males. The remainder of the territorial behaviour is related to persistence of the invading male. Satellite behaviour, females mate choice, and a stereotyped behaviour (e.g. quick circular movement of both male and female) prior to amplexus, were also associated with territoriality.
Population structure of Emys orbicularis in the Bardello (Po Delta, Northern Italy)
Authors: Mazzotti Stefano 
Published: April 2008

AbstractA population of Emys orbicularis in the Bardello (Po Delta, Northern Italy) was studied for 3 years using capture-mark-recapture methods, 23.6% of which were male, 57,5% female and 18.9% were juvenile specimens. The sex ratio of 127 specimens was 1:2. Certain morphometric variables such as the carapace length and shell height were examined in order to establish their sexual dimorphism. The population structure was defined by means of frequency distributions of carapace length. Using the Lincoln-Petersen and Jolly-Seber indices it was possible to estimate the population size as an average of 7.2 specimens per hectare.