Autecological Observations of Acanthodactylus erythrurus (Sauria: Lacertidae) in Southern Spain

1982 ◽  
Vol 3 (2) ◽  
pp. 237-255 ◽  
Author(s):  
Stephen D. Busack ◽  
Fabian M. Jaksic
Keyword(s):  
Plant Material ◽  
Sexual Maturity ◽  
Activity Period ◽  
Adult Size ◽  
Adult Males ◽  
Lizard Species ◽  
Male Population ◽  
Adult Females ◽  
Psammodromus Algirus ◽  
Human Predation

AbstractAutecological aspects of Acanthodactylus erythrurus were examined at La Algaida, Cádiz Province, Spain. The male population is composed of 60 % adult and 40 % subadult individuals; male hatchlings increase in size at a rate of 0.06 mm/day from hatching ( 31 mm snout-vent length) to sexual maturity (∼61 mm); 50 % do not survive beyond 1.5 years, but those which reach adult size may live 1.9 years. Females grow from hatching (∼ 28 mm) to sexual maturity( 57 mm) at a rate of 0.05 mm/day; less than half survive 1.4 years and the life span of some individuals is 2.1 years. Adult males outnumber adult females 1.4:1, but subadult ratios are 1:1. Adults and subadults associate with different plant species during their activity period, but each age class tends to avoid open sand patches. These 8.4-13 g lizards feed on a wide variety of insects and appreciable quantities of plant material. 49% ofall males and 82% ofall females actively consume Halimium halimifolium. We suspect this lizard species is wide ranging and non-territorial ; only one agonistic encounter was recorded and it was interspecific (with Psammodromus algirus). The frequency of escape from predation is estimated at 26.8 %, based on tail-loss figures, and the incidence of cestode parasitism (Oochoristica cf. tuberculata) is 2.1 %. The population studied was highly resilient to 16 months of intense human predation.

Sexual dimorphism in the Neotropical lizard, Tropidurus torquatus (Squamata, Tropiduridae)

2005 ◽  
Vol 26 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Helga Wiederhecker ◽  
Adriana Pinto ◽  
Guarino Colli
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Body Shape ◽  
Patch Size ◽  
Adult Males ◽  
Lizard Species ◽  
Central Brazil ◽  
Adult Females ◽  
Males And Females

AbstractWe describe the sexual dimorphism in coloration, body shape, and body size in Tropidurus torquatus, a widely distributed lizard species in central Brazil. Adult males have colored patches varying from yellow to yellow-and-black, and black on the abdomen, ventral aspect of the thighs, and pre-cloacal flap. Adult females lack ventral colored patches. During ontogeny, there is a gradual darkening of the patches, but no modification either in patch size or color is associated with the reproductive cycle. Adult males have wider heads and thinner bodies than females of the same body size. Males and females grow at the same rate prior to sexual maturity, but males take longer to reach sexual maturity, maturing at a larger body size than females.

scholarly journals Does ecophysiology mediate reptile responses to fire regimes? Evidence from Iberian lizards

2016 ◽  
Author(s):  
Catarina C Ferreira ◽  
Xavier Santos ◽  
Miguel A. Carretero
Keyword(s):  
Repeated Measures ◽  
Fire History ◽  
Fire Regimes ◽  
Biological Traits ◽  
Adult Males ◽  
Lizard Species ◽  
Water Losses ◽  
Evaporative Water ◽  
Interspecific Differences ◽  
Psammodromus Algirus

Background. Reptiles are sensitive to habitat disturbance induced by wildfires but species frequently show opposing responses. Functional causes of such variability have been scarcely explored. In the northernmost limit of the Mediterranean bioregion, lizard species of Mediterranean affinity (Psammodromus algirus and Podarcis guadarramae) increase in abundance in burnt areas whereas Atlantic species (Lacerta schreiberi and Podarcis bocagei) decrease. Timon lepidus, the largest Mediterranean lizard in the region, show mixed responses depending on the locality and fire history. We tested if such interspecific differences are of functional nature, namely, if lizard ecophysiological traits may determine their response to fire. Based on the variation in habitat structure between burnt and unburnt sites, we hypothesise that Mediterranean species increasing density in open habitats promoted by frequent fire regimes should be more thermophile and suffer lower water losses than Atlantic species. Methods. We submitted 6-10 adult males of the five species to standard experiments for assessing preferred body temperatures (Tp) and evaporative water loss rates (EWL), and examined the variation among species and along time by means of repeated-measures AN(C)OVAs. Results. Results only partially supported our initial expectations, since the medium-sized P. algirus clearly attained higher Tp and lower EWL. The two small wall lizards (P. bocagei and P. guadarramae) displayed low Tp and high EWL while the two large green lizards (T. lepidus and L. schreiberi) displayed intermediate values for both parameters. Discussion. The predicted differences according to the biogeographic affinities within each pair were not fully confirmed. We conclude that ecophysiology may help to understand functional reptile responses to fire but other biological traits are also to be considered.

Estimate of the population structure of the estern water dragon, Physignathus lesueurii (Reptilia : Agamidae), along riverside habitat

1993 ◽  
Vol 20 (5) ◽  
pp. 613 ◽  
Author(s):  
MB Thompson
Keyword(s):  
New South ◽  
Average Distance ◽  
First Year ◽  
Adult Size ◽  
Adult Males ◽  
Male Adult ◽  
Adult Females ◽  
South Wales ◽  
Size Growth ◽  
Theoretical Considerations

A population of eastern water dragons, Physignathus lesueurii, was investigated along 1.5km of the Gloucester River in central eastern New South Wales from November 1989 to December 1992. Dragons were caught in all months from September to April, but not in June. In all, 373 dragons were marked and 69 of these were recaptured on one or more occasions. Females are ovigarous in late October, November and December. Only about one third of females have palpable eggs during these months. Hatchlings enter the population in February and March at 4.5g, with a snout-vent length (SVL) of 53mm. In the next season they are 19.5g (SVL 80mm). The dragons grow rapidly for four years to reach adult size. Growth rates are fastest during the first year at 2.25mm SVL per month or 1.25 g per month. The Jolley-Seber population estimate for adult females was 103 +/-49 in the study site or 69 per km of river. Estimates for males and for the total population could not be calculated because individuals were not equally catchable (Leslie's test for equal catchability). However, theoretical considerations place the density of adult dragons at 138-215 per km of river. The largest male was 304mm SVL, 54mm longer than the next-largest water dragon reported. One male was heavier than 1000g. The largest female was 230mm SVL and the heaviest was 490g, or approximately half the mass of the heaviest male. Adult males and adult females have the same proportion of broken tails. Water dragons are fairly sedentary, with an average distance of 76m (range 0-785m) between captures.

scholarly journals Does ecophysiology mediate reptile responses to fire regimes? Evidence from Iberian lizards

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2107 ◽  
Author(s):  
Catarina C. Ferreira ◽  
Xavier Santos ◽  
Miguel A. Carretero
Keyword(s):  
Repeated Measures ◽  
Fire History ◽  
Fire Regimes ◽  
Biological Traits ◽  
Adult Males ◽  
Lizard Species ◽  
Water Losses ◽  
Interspecific Differences ◽  
Psammodromus Algirus ◽  
The Mediterranean

Background.Reptiles are sensitive to habitat disturbance induced by wildfires, but some species frequently show opposing responses. The functional causes of such variability have been scarcely explored. In the northernmost limit of the Mediterranean bioregion, a lizard species of Mediterranean affinity (Psammodromus algirusandPodarcis guadarramae) increase in abundance in burnt areas whereas Atlantic species (Lacerta schreiberiandPodarcis bocagei) decrease.Timon lepidus, the largest Mediterranean lizard in the region, shows mixed responses depending on the locality and fire history. We tested whether such interspecific differences are of a functional nature; namely, if ecophysiological traits may determine lizard response to fire. Based on the variation in habitat structure between burnt and unburnt sites, we hypothesise that the Mediterranean species, which increase density in open habitats promoted by frequent fire regimes, should be more thermophile and suffer lower water losses than Atlantic species.Methods.We submitted 6–10 adult males of the five species to standard experiments for assessing preferred body temperatures (Tp) and evaporativewater loss rates (EWL), and examined the variation among species and along time by means of repeated-measures AN(C)OVAs.Results.Results only partially supported our initial expectations, since the medium-sizedP. algirusclearly attained higherTpand lower EWL. The two small wall lizards (P. bocageiandP. guadarramae) displayed lowTpand high EWL while the two large green lizards (T. lepidusandL. schreiberi) displayed intermediate values for both parameters.Discussion.The predicted differences according to the biogeographic affinities within each pair were not fully confirmed. We conclude that ecophysiology may help to understand functional reptile responses to fire but other biological traits are also to be considered.

scholarly journals Does ecophysiology mediate reptile responses to fire regimes? Evidence from Iberian lizards

2016 ◽  
Author(s):  
Catarina C Ferreira ◽  
Xavier Santos ◽  
Miguel A. Carretero
Keyword(s):  
Repeated Measures ◽  
Fire History ◽  
Fire Regimes ◽  
Biological Traits ◽  
Adult Males ◽  
Lizard Species ◽  
Water Losses ◽  
Evaporative Water ◽  
Interspecific Differences ◽  
Psammodromus Algirus

Background. Reptiles are sensitive to habitat disturbance induced by wildfires but species frequently show opposing responses. Functional causes of such variability have been scarcely explored. In the northernmost limit of the Mediterranean bioregion, lizard species of Mediterranean affinity (Psammodromus algirus and Podarcis guadarramae) increase in abundance in burnt areas whereas Atlantic species (Lacerta schreiberi and Podarcis bocagei) decrease. Timon lepidus, the largest Mediterranean lizard in the region, show mixed responses depending on the locality and fire history. We tested if such interspecific differences are of functional nature, namely, if lizard ecophysiological traits may determine their response to fire. Based on the variation in habitat structure between burnt and unburnt sites, we hypothesise that Mediterranean species increasing density in open habitats promoted by frequent fire regimes should be more thermophile and suffer lower water losses than Atlantic species. Methods. We submitted 6-10 adult males of the five species to standard experiments for assessing preferred body temperatures (Tp) and evaporative water loss rates (EWL), and examined the variation among species and along time by means of repeated-measures AN(C)OVAs. Results. Results only partially supported our initial expectations, since the medium-sized P. algirus clearly attained higher Tp and lower EWL. The two small wall lizards (P. bocagei and P. guadarramae) displayed low Tp and high EWL while the two large green lizards (T. lepidus and L. schreiberi) displayed intermediate values for both parameters. Discussion. The predicted differences according to the biogeographic affinities within each pair were not fully confirmed. We conclude that ecophysiology may help to understand functional reptile responses to fire but other biological traits are also to be considered.

THE »EARLY-ANDROGEN« SYNDROME; ITS DEVELOPMENT AND THE RESPONSE TO HEMI-SPAYING

1964 ◽  
Vol 45 (1) ◽  
pp. 1-12 ◽  
Author(s):  
H. E. Swanson ◽  
J. J. van der Werff ten Bosch
Keyword(s):  
Sexual Maturity ◽  
Compensatory Growth ◽  
Testosterone Propionate ◽  
Single Injection ◽  
Weight Increase ◽  
Corpora Lutea ◽  
Transition Stage ◽  
Adult Females

ABSTRACT The »early-androgen« syndrome in the rat – i. e. anovulatory ovaries in adult females after a single injection of testosterone propionate (TP) within a week of birth – may not become apparent until some time after the attainment of sexual maturity. Large doses (50 or 100 μg) of TP were effective earlier than lower doses (5 or 10 μg). Rats which received 5 μg TP were ovulating at 10 weeks of age, mated but were infertile at 13 weeks of age, and were anovulatory at 21 weeks. In rats between 10 and 13 weeks old there was a marked fall in the number of corpora lutea in the ovaries of animals which had been given 5 μg TP. Hemi-spaying was followed by compensatory growth of the remaining ovary which consisted of corpora lutea in ovulating, and of follicles in anovulatory rats; little or no compensatory weight increase occurred in animals which seemed to be in the transition stage from the ovulatory to the anovulatory condition.

Two new species and taxonomic notes on the Neotropical spiny orb-weaving spi-ders Micrathena and Chaetacis (Araneae: Araneidae), with remarks on the development of Micrathena excavata IVAN L. F. MAGALHÃES & ADALBERTO J. SANTOS (Brazil)

Zootaxa ◽  
2011 ◽  
Vol 2983 (1) ◽  
pp. 39 ◽  
Author(s):  
IVAN L. F. MAGALHÃES ◽  
ADALBERTO J. SANTOS
Keyword(s):  
New Species ◽  
Junior Synonym ◽  
Adult Males ◽  
Development Stages ◽  
Brazilian Amazonia ◽  
Central Brazil ◽  
Adult Females ◽  
Two New Species ◽  
Senior Synonym ◽  
First Time

In this paper, M. yanomami n. sp., from Brazilian Amazonia, Chaetacis bandeirante n. sp., from Central Brazil, and the males of M. gaujoni Simon, 1897 and M. ruschii (Mello-Leitão, 1945) n. comb. , respectively from Ecuador and Brazil, are described and illustrated for the first time. An ontogenetic series of the last development stages of both sexes of Micrathena excavata (C. L. Koch, 1836) is illustrated and briefly described. Adult females are larger and have longer legs and larger abdomens than adult males. Probably females undergo at least one additional moult before adulthood, compared to males. Micrathena ornata Mello-Leitão, 1932 is considered a junior synonym of M. plana (C. L. Koch, 1836), and M. mastonota Mello-Leitão 1940 is synonymized with M. horrida (Taczanowski, 1873). Acrosoma ruschii Mello-Leitão, 1945 is revalidated, transferred to Micrathena and considered a senior synonym of M. cicuta Gonzaga & Santos, 2004. Chaetacis necopinata (Chickering, 1960) is recorded for Brazil for the first time. Chaetacis incisa (Walckenaer, 1841) is considered a nomen dubium.

Spacing, movements, and habitat selection of the river otter in boreal Alberta

1994 ◽  
Vol 72 (7) ◽  
pp. 1314-1324 ◽  
Author(s):  
D. G. Reid ◽  
T. E. Code ◽  
A. C. H. Reid ◽  
S. M. Herrero
Keyword(s):  
Lontra Canadensis ◽  
Home Ranges ◽  
Adult Males ◽  
Movement Rates ◽  
River Otters ◽  
Aquatic Mammal ◽  
Adult Females ◽  
Two Factors ◽  
Bog Lakes ◽  
Selection Of

Seasonal spacing patterns, home ranges, and movements of river otters (Lontra canadensis) were studied in boreal Alberta by means of radiotelemetry. Adult males occupied significantly larger annual home ranges than adult females. Males' ranges overlapped those of females and also each other's. In winter, home ranges of males shrank and showed less overlap. Otters often associated in groups, the core members typically being adult females with young, or adult males. Otters tended to be more solitary in winter. In winter, movement rates of all sex and age classes were similar, and much reduced for males compared with those in other seasons. These data indicated a strong limiting effect of winter ice on behaviour and dispersion. We tested the hypothesis that otters select water bodies in winter on the basis of the suitability of shoreline substrate and morphology for dens with access both to air and to water under ice. Intensity of selection was greatest in winter, with avoidance of gradually sloping shorelines of sand or gravel. Adults selected bog lakes with banked shores containing semi-aquatic mammal burrows, and lakes with beaver lodges. Subadults selected beaver-impounded streams. Apart from human harvest, winter habitats and food availability in such habitats are likely the two factors most strongly limiting otter density in boreal Alberta.

Variation within and between Rivers in Adult Size and Sea Age at Maturity of Anadromous Brown Trout, Salmo trutta

1991 ◽  
Vol 48 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
Jan Henning L'Abée-Lund
Keyword(s):  
Brown Trout ◽  
Sexual Maturity ◽  
Salmo Trutta ◽  
Adult Size ◽  
Age At Maturity ◽  
Migration Distance ◽  
Spawning Area ◽  
Brown Trout Salmo Trutta ◽  
Males And Females ◽  
The Mean

I compared adult size and sea age at sexual maturity among nine populations of anadromous brown trout, Salmo trutta, in two Norwegian rivers to determine the extent of inter- and intrariverine variations. Variation in the mean length of spawners and in the mean sea age at sexual maturity were mainly dependent on the variations found within rather than between rivers. Mean lengths and mean age at maturity of males increased significantly with increasing altitude of the spawning area and with migration distance in freshwater. In females, positive significant correlations were found with mean lengths and altitude of the spawning area and with mean sea age at maturity and both spawning site altitude and migration distance. Mean lengths and ages of males and females were not significantly correlated with the rate of water discharge in the streams during spawning. The size of gravel substrate for spawning was of minor importance in explaining interpopulation variation in mean female size. The increase noted in mean length and in mean sea age at maturity of both males and females is probably an adaptation to greater energy expenditure to reach the uppermost natal spawning areas.

scholarly journals Age of maturation and behavioral tactics in male yellow ground squirrel Spermophilus fulvus during mating season

2014 ◽  
Vol 60 (6) ◽  
pp. 700-711 ◽  
Author(s):  
Nina A. Vasilieva ◽  
Ekaterina V. Pavlova ◽  
Sergey V. Naidenko ◽  
Andrey V. Tchabovsky
Keyword(s):  
Body Size ◽  
Ground Squirrel ◽  
Life History Theory ◽  
Social Activity ◽  
Indirect Evidence ◽  
Adult Size ◽  
Adult Males ◽  
Mating Season ◽  
Active Season ◽  
Good Physical Condition

Abstract Life-history theory predicts that in hibernators age of maturation is related positively to body size and negatively to the duration of active season aboveground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observations of marked individuals to determine the age of maturation in males through analysis of age-dependent variation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behavior during the mating season. Yearling males were smaller, lighter, had lower level of fecal testosterone, emerged later and had smaller home ranges than older males. Social activity and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters varied with age. Cluster analysis revealed two behavioral tactics: “active” males (adults only) emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heavier than “passive” males (both yearling and adult). Thus, males of S. fulvus reached adult size and matured after two hibernations, which is relatively fast for such a big species with short active period. Indirect evidence for copulations and high variation among yearlings in all parameters suggest that some of them might successfully compete with adults. Active tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passive tactic of residing is energy saving and good for adults in poor condition and for yearlings that are continuing to grow.

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