The Ecological Significance of Sexual Dimorphism in Size in the Lizard Anolis conspersus.
27 Jan 1967-Science (American Association for the Advancement of Science)-Vol. 155, Iss: 3761, pp 474-477
TL;DR: Anolis conspersus selects prey from a wide range of taxa and shows no obvious intraspecific specialization not connected to differences in microhabitat and prey size.
Abstract: Adult males of Anolis conspersus capture prey of significantly larger size and occupy perches of significantly greater diameter and height than do adult females; similarly, these three dimensions of the niche are significantly larger for adult females than for juveniles. Adult males on the average eat a smaller number of prey, and the range in size of prey is larger. The relationship between the average length of the prey and that of the predator is linear when the predator size is above 36 millimeters, but becomes asymptotic when it is below that value. Subadult males as long as adult females eat significantly larger food than do the latter, but only in the larger lizards is this correlated with a relatively larger head. Anolis conspersus selects prey from a wide range of taxa and shows no obvious intraspecific specialization not connected to differences in microhabitat and prey size. The efficiency of this system for solitary species is pointed out.
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01 Nov 2018
TL;DR: The obtained results satisfactorily confirm the high ability of the ANNs in predicting the gender of Darevskia bithynica.
Abstract: The main aim of the manuscript is to predict the gender of Darevskia bithynica by using a feed-forward back-propagation multilayer artificial neural network (ANN). Nine morphological characters were used as an input parameters of the model. The gender type male or female is the output parameter. The total number of data is 115. In order to train, validate and test the ANN model 70%, 15% and 15% of the total data are randomly selected. The regression coefficient (R) values are evaluated as prediction performance. The network with 20 neurons in the hidden is the optimal structure of the ANN that predict the lizard gender with a high R values as 0.98, 0.97 and 0.96 for training, testing and all data, respectively. The lower mean square error (MSE) values for training and testing data are calculated as 0.0145 and 0.0161, respectively. The obtained results satisfactorily confirm the high ability of the ANNs in predicting the gender of Darevskia bithynica.
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Cites background from "The Ecological Significance of Sexu..."
...Sexual dimorphism is a common phenomenon among lizard species [14-20]....
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05 Feb 2010
TL;DR: This thesis is based on the following articles: Comparative studies of quantitative trait and neutral marker divergence: a metaanalysis, and Predation-imposed selection on threespine stickleback morphology: a test of the refuge usage hypothesis.
Abstract: 6 Introduction 7 Variation between populations drift or selection? 7 Variation within populations genetic variance and covariance structure 8 Variation between individuals within populations 12 Threespine stickleback as a model organism 14 Aims of this thesis 15 Main results and discussion 16 Relative roles of drift and selection in population divergence 16 Within population variance and population divergence 18 The role of selection in adaptive divergence 20 Conclusions and future directions 21 Acknowledgements 22 Literature cited 24 This thesis is based on the following articles, which are referred to in text by their Roman numerals: I Leinonen, T., Cano, J.M., Makinen, H. & Merila, J. 2006. Contrasting patterns of body shape and neutral genetic divergence in marine and lake populations of threespine sticklebacks. Journal of Evolutionary Biology 19: 1803-1812. II Leinonen, T., O’Hara, R.B., Cano, J.M. & Merila, J. 2008. Comparative studies of quantitative trait and neutral marker divergence: a metaanalysis. Journal of Evolutionary Biology 21: 1-17. III Leinonen, T., Cano, J.M. & Merila, J. Genetics of body shape and armour variation in threespine sticklebacks. Manuscript. IV Leinonen, T., Cano, J.M. & Merila, J. Genetic basis of sexual dimorphism in the threespine stickleback. Manuscript. V Loehr, J., Leinonen, T., Herczeg, G., O’Hara, R.B. & Merila, J. Heritability of fluctuating asymmetry in the threespine stickleback. Manuscript. VI Leinonen, T., Cano, J.M., Herczeg, G. & Merila, J. Predation-imposed selection on threespine stickleback (Gasterosteus aculeatus) morphology: a test of the refuge usage hypothesis. Manuscript.
1 citations
Cites background from "The Ecological Significance of Sexu..."
...Indeed, the ecological differences between the sexes can be larger than those between species (Schoener 1967, 1969, Dayan et al. 1994)....
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01 Dec 2013
TL;DR: Variation in prey availability, sample sizes and dates of collecting events could explain minor geographic variation in some aspects of the foraging ecology in this species.
Abstract: Anolis lizards exhibit high morphological diversity, partially related to variation in structural resource use, that probably influences foraging behavior and prey selection of individuals and species. Anoles are largely insectivorous: most species are generalists/opportunists and few are specialists. Dietary differences between sexes and among individuals from different populations have been observed in several species. Sexual size dimorphism, spatial niche divergence between sexes and species, competition and food availability are some of the factors responsible for these differences. We characterized the diet of Anolis ventrimaculatus (Squamata: Dactyloidae), a species with sexual size and shape dimorphism, widely distributed in highland Colombian environments. Stomach and proximal intestinal content of preserved adults were analyzed. Prey items were classified to order and, when possible, to family. A. ventrimaculatus eats variable preys (mostly Hymenoptera, Coleoptera, and insect larvae) and is classified as a generalist/opportunist. Vegetal debris, shed skin, and stones presumably were ingested incidentally. Diets of males and females are similar. Sexual dimorphism and geographic variation in the diet were minimal. Males and females exhibited differences in total number and percentage of use of frequently consumed prey (Orthoptera and Hymenoptera), and these differences varied among localities. Total prey numbers consumed by females also varied among localities, whereas consumption of Coleoptera and Orthoptera varied in both sexes. Differences in prey size could explain the variation in prey number between sexes, with males probably ingesting larger items. Variation in prey availability (most likely attributable to differences in structural microhabitat use), sample sizes and dates of collecting events could explain minor geographic variation in some aspects of the foraging ecology in this species.
01 Jan 2012
TL;DR: Anolis porcatus lives in gardens, at the edge of roads, and in human constructions in Cuba, and for every individual was annotated their substrate, height above ground and illumination.
Abstract: Anolis porcatus lives in gardens, at the edge of roads, and in human constructions. Data on this species is scattered and generalized and there are not papers on Guanajay, Artemisa province. In February 2001, dry season for Cuba, it was searched in the surroundings of the houses; for every individual was annotated their substrate, height above ground and illumination. Sixteen males and five females were collected, and was measured their snout-vent length, head length,
References
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TL;DR: The eight species of the genus Anolis in Puerto Rico can be divided into four morphological similarities as discussed by the authors : perch height, perch diameter, high-shade preference and low-shading preference.
Abstract: The eight species of lizards of the genus Anolis in Puerto Rico can be divided into four morphological similarities. One, Anolis curvieri, is very different from the rest and has not been discussed here. The other seven species fall into three groups. Each of these groups occupies a different structural habitat which can be defined in terms of perch height and perch diameter. Within each of these three groups the species have very similar but not indential structural habitats but differ very widely in climatic habitat defined in terms of shade. Shade preferences seem to result from the temperature preferences of the species involved. In each group there is one species with high shade preference which is essentially restricted to the mountains. Each group also has a species with a lower shade preference which occurs in the lowlands and extends up into the mountains in exposed or sunny situations. One of the three groups has an additional species which is restricted to the hot and southwest corner of Puerto Rico. When one compares the temperature preferences or eccritic temperatures of the various species, one finds in each group that the highland species has a lower eccritic temperature than does the lowland species. There is little temperature difference between the lowland species and arid southwest species in the group where this additional third species is present. The species within each structural habitat show many morphological similarities which may be the result of their being closely related or may be the result of adaptation to similar environments. The differences in microhabitat between the Puerto Rican anoles separate them spatially though not completely. In species occupying different structural habitats in the same area the overlap may involve part of the home range of most of the individuals in the area. In species occupying the same structural but different climatic habitats the overlap may involve all of the home range of some individuals but of only a small fraction of the individuals in the total population. The spatial separation among Puerto Rican Anolis can be suggested to be of ecological significance because it reduces interspecific competition and because it allows the various species to adapt more precisely to different parts of the available habitat. Thus members of a genus may exploit the habitat more efficiently.
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01 Jan 1964
TL;DR: The life of the rainbow lizard , The life of a rainbow lizard, مرکز فناوری اطلاعات £1,000,000 ($2,000; £1,500,000)
Abstract: The life of the rainbow lizard , The life of the rainbow lizard , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
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"The Ecological Significance of Sexu..." refers background in this paper
...On the basis of essentially the same pattern of staining, other investigators have reached the same conclusion (3, 4), or have attributed staining additionally or alternatively to the processes of the bipolar cells (5, 6), the ganglion cells (4, 5), or centrifugal fibers from the optic nerve (7)....
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...A greater proportion of large insects were found in larger adult males than in adult females of Anolis lineatopus and Agama agama (4, 5); similarly, juveniles take smaller food than adults (5-7)....
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