Habitat use, reproductive traits and social interactions in a stream-dweller treefrog endemic to the Brazilian Cerrado

2012 ◽  
Vol 33 (3-4) ◽  
pp. 337-347 ◽  
Author(s):  
Renato C. Nali ◽  
Cynthia P.A. Prado
Keyword(s):  
Reproductive Investment ◽  
Reproductive Traits ◽  
Reproductive Activity ◽  
Spatial Distance ◽  
Brazilian Cerrado ◽  
Habitat Alterations ◽  
Gonad Mass ◽  
Gallery Forests ◽  
History Of ◽  
Data Deficient

The richest anuran fauna is found in the Neotropics, but the natural history of most species is unknown. Bokermannohyla ibitiguara is a stream-dweller treefrog endemic to the Brazilian Cerrado and classified as “Data Deficient” by the IUCN. Herein we describe the species’ reproductive biology. Fieldwork was conducted from August 2010 to July 2011. Reproductive activity occurred from October to June and was positively correlated with air temperature, humidity, and monthly rainfall. Individuals were observed only in gallery forests at the margins of streams and males used various kinds of substrates as calling sites. Males did not aggregate in specific parts of the streams and spatial distance between males was higher in the dry season. Males and females did not differ in length, but females without mature oocytes were lighter than males. The reproductive investment (gonad mass/body mass) of males was 0.29% and that of females was 20.26%. Female ovaries contained a mean of 202 ± 75 mature oocytes with a mean diameter of 1.96 ± 0.16 mm. We describe, for the first time for the genus, a complex courtship behaviour and also male-male fight and satellite behaviour. The Cerrado is probably the most threatened savanna in the world, having been intensively modified over the last decades. Endemic species associated to gallery forests, such as B. ibitiguara, are highly vulnerable to habitat alterations. Thus, our study provides important data on the species’ biology, which might be useful for conservation practices, but also to investigate taxonomic and phylogenetic relationships in this genus.

scholarly journals Challenging the Environmental History of the Cerrado: Science, Biodiversity and Politics on the Brazilian Agricultural Frontier

2020 ◽  
Vol 10 (1) ◽  
pp. 82-116 ◽  
Author(s):  
Sandro Dutra e Silva
Keyword(s):  
Environmental History ◽  
Political Process ◽  
Historical Change ◽  
Complex Relationship ◽  
Brazilian Cerrado ◽  
Agricultural Frontier ◽  
Environmental Consequences ◽  
Environmental Interactions ◽  
History Of

This article presents an overview of the environmental history of the Brazilian Cerrado, its environmental characteristics and the processes related to the historical change in the landscapes of this endangered ecosystem. It highlights competing classifications of the Cerrado, the role of politics in establishing them, and the environmental consequences of such classifications. More than just describing an environment, classifying an ecosystem is a political process that involves complex socio-environmental interactions. The sources used points out the different attempts to get to know and "conquered" the Cerrado, bringing together interdisciplinary perspectives from a variety of actors and institutions. Historiographic challenges go beyond environmental descriptions in that the socio-environmental interactions that made up this unique ecosystem are equally complex. This paper’s conclusions reinforce the interdisciplinary role of environmental history in the study of ecosystems and the complex relationship between culture and nature.

Altitudinal variation in reproductive strategy of the toad-headed lizard, Phrynocephalus vlangalii in North Tibet Plateau (Qinghai)

2007 ◽  
Vol 28 (4) ◽  
pp. 509-515 ◽  
Author(s):  
Yuan-Ting Jin ◽  
Nai-Fa Liu
Keyword(s):  
Litter Size ◽  
Altitudinal Gradient ◽  
Reproductive Effort ◽  
Reproductive Investment ◽  
Reproductive Traits ◽  
Tibet Plateau ◽  
Sand Lizard ◽  
Survival And Growth ◽  
The Common ◽  
Anatomical Constraints

Abstract Phrynocephalus vlangalii, a toad-headed viviparous sand lizard, is endemic in the Northern Tibet (Qinghai) Plateau in China. Lizards were collected from 14 localities along the large altitudinal gradient (2289-4565 m a.s.l) to analyze the variation of reproductive traits among localities. Both litter size and mean offspring (scaled embryo) mass were positively correlated with female snout-vent length (SVL). Females produced fewer and larger offspring with increasing elevation when the effect of body size (SVL) was removed. This strategy may possibly be correlated with early survival and growth of offspring. The decreased litter size cline along altitudinal gradient might be correlated with more anatomical constraints at higher altitudes. The lizard has lower coefficient of variation (CV) of litter size at higher environments. Moreover, females from higher elevations had less reproductive investment (relative litter mass, RLM). Study concluded that P. vlangalii fit into the common pattern of higher elevation animals that have smaller clutches of larger offspring and lower reproductive effort.

Linking plant spatial aggregation with reproductive traits and near-source seed dispersal: ecological adaptation to heavy grazing

2020 ◽  
Vol 13 (4) ◽  
pp. 489-498
Author(s):  
Wenting Liu ◽  
Shixian Sun ◽  
Chunping Zhang ◽  
Shijie Lv ◽  
Quanmin Dong
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Morphological Characteristics ◽  
Reproductive Traits ◽  
Reproductive Activity ◽  
Individual Characteristics ◽  
Small Scale ◽  
Heavy Grazing ◽  
Bare Land ◽  
Reproductive Individual

Abstract Aims Ecological strategies related to the adaptation of plants to environmental stress have long been studied by ecologists, but few studies have systematically revealed the ecological process of plant adaptation to herbivores as a whole. Methods In this study, Stipa breviflora, the dominant species in the desert steppe of Inner Mongolia, was used to analyse its reproductive individual characteristics and seed traits as well as the soil seed bank and spatial patterns under heavy-grazing and no-grazing treatments. Important Findings The results showed that the number of reproductive branches positively affected the number of vegetative branches. The analysis of the soil seed bank showed that the density of S. breviflora seeds beneath reproductive S. breviflora individuals was significantly higher than that in bare land. The seed density was also significantly negatively correlated with the seed characteristics and the soil seed bank in bare land. The spatial distribution of S. breviflora was aggregated under heavy grazing. Our results suggest that under heavy grazing, reproductive activity plays a key role in resource allocation. Stipa breviflora evolved the ecological strategy of nearby diffusion by regulating the morphological characteristics of the seeds, which promotes a positive spatial correlation between the juvenile and adult populations at a small scale, thus leading to the formation of ‘safe islands’.

Differences in egg quantity and quality among hatchery- and wild-origin Chinook salmon (Oncorhynchus tshawytscha)

2016 ◽  
Vol 73 (5) ◽  
pp. 737-746 ◽  
Author(s):  
Michaela W. Haring ◽  
Tom A. Johnston ◽  
Murray D. Wiegand ◽  
Aaron T. Fisk ◽  
Trevor E. Pitcher
Keyword(s):  
Stable Isotopes ◽  
Adult Development ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Neutral Lipids ◽  
Fatty Acid Content ◽  
Reproductive Investment ◽  
Gonadal Development ◽  
Gonad Mass ◽  
In The Wild

Each year, millions of hatchery-raised juvenile salmon are released into the wild to help bolster salmon populations all over North America. These fish often differ from their wild-origin conspecifics in terms of survival and reproductive success after release, but our understanding of their reproductive investment is limited. We examined differences in egg number (gonad mass and fecundity) and quality (mass, lipids, fatty acids) between spawning hatchery- and wild-origin Chinook salmon (Oncorhynchus tshawytscha) from Lake Ontario. Hatchery-origin females were found to not differ significantly in body size, age, egg total lipids, and fatty acid content of eggs relative to wild-origin females, but hatchery-origin females allocated significantly less body mass and neutral lipids into egg and gonadal development compared with wild-origin females. We also examined diets of both groups of females using stable isotopes and found that carbon and nitrogen stable isotopes suggested limited differences in the diet between hatchery- and wild-origin adult females. The results from the present study provide evidence that the differing environmental conditions and associated selection pressures of captive environments during early life in hatchery settings can alter certain life-history traits later in adult development, namely gonad mass and egg size, and could contribute to differences in their performance in the wild.

scholarly journals First record of Scinax centralis (Anura, Hylidae) in the Triângulo Mineiro region, state of Minas Gerais, southeastern Brazil, with further data on its vocalization

2021 ◽  
Vol 61 ◽  
pp. e20216177
Author(s):  
Davi Lee Bang ◽  
Marcio Pie ◽  
Ariovaldo Antonio Giaretta
Keyword(s):  
First Record ◽  
Dominant Frequency ◽  
Minas Gerais ◽  
The State ◽  
Southeastern Brazil ◽  
Clinal Variation ◽  
Brazilian Cerrado ◽  
Gallery Forests

Scinax comprises more than 120 species which are split in two clades, the S. ruber and the S. catharinae clades. A few species within the S. catharinae clade occur in gallery forests of the Brazilian Cerrado. We here extend the distribution of S. centralis southwards based on new populations sampled in the banks of the Rio Paranaíba, in the borders of Minas Gerais (MG) and Goiás (GO) states, southeastern Brazil. We also provide further data on the species vocalization. Variation was seen among our population and topotypes regarding SVL and call dominant frequency, both likely representing a clinal variation. Our new population of S. centralis represents the first record of the species for the state of Minas Gerais.

scholarly journals Departementalitet eller guvernementalitet – organisationers og organisationsteoriers historiske sociologi

2010 ◽  
Vol 21 (4) ◽  
pp. 27-49
Author(s):  
Gorm Harste
Keyword(s):  
System Theory ◽  
Conceptual Framework ◽  
Key Words ◽  
Max Weber ◽  
Historical Sociology ◽  
Spatial Distance ◽  
Organisation Theory ◽  
History Of ◽  
Organisational Sociology ◽  
Sociology Of Organisations

Artiklen undersøger de selvbeskrivelser, der er blevet fremsat i forsøgene på at organisere organisation lige siden 1000-tallet. Moderne organisationsforståelse er opstået gennem hundreder af år. Koder for organisatorisk kommunikation er blevet sammensat, udviklet og raffineret eksempelvis i konflikter om centralisering eller decentralisering i korpsånd og i bureaukrati. I tolkningen heraf anvendes Niklas Luhmanns begrebsdannelse, der udviser en anden tilgang til organisationshistorie og organisationssociologi, end den, der kendes fra Weber og Foucault. Søgeord: Organisationssociologi, Foucault, Luhmann, historisk sociologi. ENGELSK ABSTRACT: Gorm Harste: Departmentality or Governmentality – the Historical Sociology of Organisations and Organisation Theory History of organisations probably goes back to the 11th century. The long story of their development has been told by Max Weber and Michel Foucault. However Foucault did not elaborate a general organisational sociology and Weber’s story created a somewhat incomprehensible disordered complexity. Hence traditional organisational analyses trace organisation theory back a hundred years – to Weber and a few others. The present story about departmentality derives its conceptual framework not within governing or steering as Foucault does, but in the problem of delegation. The concept and theories of power were established in order to handle coordination at spatial distance. The aim of powerful concepts and theories of organisation was to establish communication in forms of simultaneous cooperation between distant operations. The article establishes this temporal conception in a historical sociology of organisation using Niklas Luhmann’s system theory. Power only empowers if centralised power is able to decentralise and abstain from forced control in favour of the activity of parts departed and detached from the whole. The parts and the members of the organ got their identity fi rst described in a conception of ”corpus spiritus”, later called ”esprit de corps” and then ”corporate spirit”. The article analyses these semantics and their developments. Key words: Luhmann, Foucault, history of organizations, historical sociology, governmentality, department.

Reproductive life history of snakes in temperate regions: what are the differences between oviparous and viviparous species?

2019 ◽  
Vol 40 (3) ◽  
pp. 291-303
Author(s):  
Gisela Paola Bellini ◽  
Vanesa Arzamendia ◽  
Alejandro Raúl Giraudo
Keyword(s):  
Life History ◽  
Hydrological Cycle ◽  
Reproductive Potential ◽  
Reproductive Traits ◽  
Reproductive Mode ◽  
Raw Material ◽  
Genetic Characteristics ◽  
Reproductive Life ◽  
History Of ◽  
Reproductive Cycles

Abstract Studying life history (LH) allows a broader understanding of organisms and populations’ responses to their environments. Snakes display an immense diversity in terms of reproductive traits, which is reflected in LH traits. The aim of this study is to compare reproductive biology and morphological variables in viviparous and oviparous snakes of a temperate South American community. We studied nearly 1000 specimens of eight oviparous and seven viviparous species pertaining to the four taxonomic families that inhabit the Paraná basin floodplain. Dimorphic variables did not show a different tendency between oviparous and viviparous species. Our results showed that the reproductive mode determined some reproductive traits of a snake’s LH, such as reproductive frequency and reproductive potential. Oviparous snakes reproduce annually, while viviparous snakes reproduce biannually or multi-annually. All species showed seasonal reproductive cycles and no correlation between clutch size (fecundity) and maternal body size. The reproductive strategy of both oviparous and viviparous species of the Paraná River floodplain was to adjust their reproductive cycles to both hydrological cycle of the river and temperature regime. The reproductive traits under study are suggested to have been influenced by environmental factors as well as by genetic characteristics. The studied assemblage is the result of an admixture of evolutionarily distinct clades, each contributing a set of species with different reproductive traits. Although we do not ignore this fact, we emphasize the importance of studying reproductive LH as raw material for an integrative analysis.

scholarly journals Differences in morphological and physiological leaf characteristics between Tabebuia aurea and T. impetiginosa is related to their typical habitats of occurrence

2012 ◽  
Vol 26 (3) ◽  
pp. 519-526 ◽  
Author(s):  
Juliana Pfrimer Capuzzo ◽  
Davi Rodrigo Rossatto ◽  
Augusto César Franco
Keyword(s):  
Leaf Area ◽  
Environmental Conditions ◽  
Evolutionary History ◽  
Leaf Traits ◽  
Co2 Assimilation ◽  
Savanna Vegetation ◽  
Gallery Forests ◽  
History Of ◽  
Morphological And Physiological Traits ◽  
Mass Basis

The genus Tabebuia is representative of the Cerrado biome, occurring in savanna and forest formations. These vegetation types are associated with distinct environmental conditions in terms of water availability, microclimate and soil properties. We compared morphological and physiological traits between Tabebuia aurea (Silva Manso) Benth. & Hook. f. ex S. Moore, which is typical of the savanna vegetation, and T. impetiginosa (Mart. ex DC.) Standl, which is commonly found in the gallery forests that occur along streams and rivers. Both were sampled in savanna conditions under full sun. The savanna species had higher values of leaf and petiole thickness, specific leaf mass, maximum CO2 assimilation on a leaf area basis, stomatal conductance, transpiration and in leaf concentration of carotenoids. The forest species stood out by higher values of specific leaf area, petiole length and of CO2 assimilation on a mass basis, parameters related to shade tolerance and higher growth rates. This functional distinction in a range of leaf traits that was maintained when both were naturally growing under similar environmental conditions, suggests that these are probably the result of differences in the evolutionary history of the two species in response to the contrasting environmental conditions in the typical habitats where they occur.

scholarly journals Effects of Fish Predators on the Mass-Related Energetics of a Keystone Freshwater Crustacean

Biology ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 40 ◽  
Author(s):  
Douglas S. Glazier ◽  
Jonathan J. Borrelli ◽  
Casandra L. Hoffman
Keyword(s):  
Reproductive Investment ◽  
Reproductive Traits ◽  
Adult Survival ◽  
Selective Predation ◽  
Scaling Exponents ◽  
Mass Scaling ◽  
Fish Predators ◽  
The Face ◽  
Food Assimilation ◽  
Reported Data

Little is known about how predators or their cues affect the acquisition and allocation of energy throughout the ontogeny of prey organisms. To address this question, we have been comparing the ontogenetic body-mass scaling of various traits related to energy intake and use between populations of a keystone amphipod crustacean inhabiting freshwater springs, with versus without fish predators. In this progress report, we analyze new and previously reported data to develop a synthetic picture of how the presence/absence of fish predators affects the scaling of food assimilation, fat content, metabolism, growth and reproduction in populations of Gammarus minus located in central Pennsylvania (USA). Our analysis reveals two major clusters of ‘symmorphic allometry’ (parallel scaling relationships) for traits related to somatic versus reproductive investment. In the presence of fish predators, the scaling exponents for somatic traits tend to decrease, whereas those for reproductive traits tend to increase. This divergence of scaling exponents reflects an intensified trade-off between somatic and reproductive investments resulting from low adult survival in the face of size-selective predation. Our results indicate the value of an integrated view of the ontogenetic size-specific energetics of organisms and its response to both top-down (predation) and bottom-up (resource supply) effects.

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