scholarly journals Applying abundance/biomass comparison curves to small mammals: a weak tool for detect urbanization-related stress in the assemblages?

2020 ◽  
Vol 47 (1) ◽  
pp. 10-15
Author(s):  
Ermellina di Bagno ◽  
Corrado Battisti ◽  
Francesco Zullo ◽  
Giovanni Amori
Keyword(s):  
Trophic Level ◽  
Small Mammal ◽  
Total Biomass ◽  
Tyto Alba ◽  
Synanthropic Species ◽  
Mosaic Landscapes ◽  
Related Stress ◽  
Mammal Assemblages ◽  
Almost All

AbstractUrbanization is a form of pervasive human-induced disturbance. We tested the effectiveness of Abundance/Biomass Comparisons (ABC) as an approach in detecting stress due to landscape urbanization in large small mammal assemblages obtained from pellets of Barn Owl (Tyto alba; Strigiformes). We compared three assemblages sampled in not urbanized contexts (agro-mosaic landscapes) with three assemblages preyed in highly urbanized contexts. In all assemblages, the role of strictly synanthropic species (in our case: rodents) emerged since almost all of total biomass was assigned to these species: indeed, everywhere (both in agro-mosaic and urbanized sites) species of low trophic level (i.e. omnivorous/herbivorous rodents) significantly prevail in biomass when compared to insectivorous species (i.e. shrews, Soricomorpha) linked to less anthropized habitats. This biomass dominance in rodent species is highlighted by the data on evenness, showing lower values in biomass when compared to abundance. This pattern did not match with the classic assumption expressed by the ABC model (i.e., species with higher biomass are typical of undisturbed assemblage) and could be wrongly interpreted. Our study evidenced as ABC approach is a not reliable tool to detect the effect of urbanization as landscape disturbance acting on small mammal assemblages. Therefore we suggest that the ABC assumptions are not universal but limited only to assemblages where high body mass species coincide to species of a higher trophic level.

The role of cephalopods in the world’s oceans: general conclusions and the future

1996 ◽  
Vol 351 (1343) ◽  
pp. 1105-1112 ◽  
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Sampling Methods ◽  
Total Biomass ◽  
Continental Shelves ◽  
Direct Sampling ◽  
Almost All ◽  
Neutrally Buoyant ◽  
Negatively Buoyant

In this volume we have considered the problems of investigation special to cephalopods. Almost all our knowledge of their general biology is restricted to the shelf-living, muscular, negatively buoyant (the Loliginidae and Octopodidae) or gas-supported species (the Sepiidae and Nautilidae) and members of the Ommastrephidae which move on to the continental shelves at certain seasons. These species of the continental shelves comprise only about 15% of all cephalopod genera and live in water of less than 300 m depth, which covers only 6% of the Earth’s surface. They do not represent the majority of cephalopod species or much of their total biomass; 85 % of genera are spread in the upper 2000 m and across the bottom of the deep oceans, which occupy 66 % of the Earth’s surface. Over 40% of these genera are neutrally buoyant by oil or chemical means and may have very different lifestyles from the forms we know from shallow water. Improvement of our knowledge of the ecology of deep water forms is hindered by our poor direct sampling methods and rests largely upon sampling from stomachs or regurgitations of the predators that eat cephalopods.

Growth and survival of Cherax destructor and Bidyanus bidyanus stocked in a communal aquarium system

2015 ◽  
Vol 21 (1) ◽  
pp. 199-204
Author(s):  
Rodnet E. Duffy ◽  
Ian Godwin ◽  
Ian Purvis ◽  
John Nolan
Keyword(s):  
Trophic Level ◽  
Large Scale ◽  
Single Species ◽  
The Other ◽  
Total Biomass ◽  
Growth And Survival ◽  
Cherax Destructor ◽  
Fish Survival ◽  
Positive Results

Abstract Polycultural aquaculture typically utilises a mix of low trophic level species to increase yield above that which can be obtained from a single species. Low trophic level species are not widely accepted for consumption within Australia, so this study focussed on two species that have market acceptance, the yabby (Cherax destructor) and the silver perch (Bidyanus bidyanus). Laboratory scale trials examined the effect of each species on the growth and survival of the other species as well as the role of shelter for crayfish in this system over a 13.5 week period. Neither species negatively impacted the growth of the other, however, survival was negatively impacted. Shelter enhanced crayfish survival, although fish survival was impacted in those treatments. A higher total biomass was harvested from polyculture treatments than monoculture treatments. The positive results warrant further investigation at the scale of mesocosm, prior to large-scale pond trials.

scholarly journals Small mammal diversity in Semi-deciduous Seasonal Forest of the southernmost Brazilian Pampa: the importance of owl pellets for rapid inventories in human-changing ecosystems

2020 ◽  
Vol 60 ◽  
pp. e20206025
Author(s):  
Narla Shannay Stutz ◽  
Patrícia Hadler ◽  
Jorge José Cherem ◽  
Ulyses Francisco José Pardiñas
Keyword(s):  
Small Mammal ◽  
Point Of View ◽  
Forest Fragments ◽  
Non Invasive ◽  
Forest Sites ◽  
Mammal Assemblages ◽  
Mammal Communities ◽  
Mammal Diversity ◽  
Owl Pellets

The Pampa biogeographic province covers a mere 2% of the Brazilian territory (176,496 km²). However, it stands out as a complex and diverse ecosystem, although its mammal communities are still scarcely understood. Human activities are transforming the territory into a mosaic of agroecosystems, native and exotic forest fragments, and grasslands. Here we conducted the first investigation to determine the richness of small mammal assemblages in the region based on extensive analyses of owl pellets (Tyto furcata). Craniodental remains were studied from samples collected from 12 Semi-deciduous Seasonal Forest sites in the municipality of São Lourenço do Sul, State of Rio Grande do Sul, Southern Brazil. A total of 2,617 individuals belonging to 19 taxa were recorded, including 2 marsupials (Didelphidae; 0.42%), 2 chiropterans (Molossidae, Phyllostomidae; 0.12%), and 15 rodents (Cricetidae, Muridae, Caviidae; 99.46%). The rodent genera Oligoryzomys, Mus, Calomys, and Akodon were the most common taxa. Large samples also included poorly known taxa, such as the cricetids Bibimys, Juliomys (recording here its southernmost occurrence), Lundomys, and Wilfredomys. From a biogeographical point of view, the recorded assemblage embraces a mixture of Platan, Pampean, and Atlantic Forest elements, highlighting the role of the southernmost Brazilian hills as a wedge favoring the penetration of forest micromammals to higher latitudes. Our findings testify to the great diversity of the Pampa, but also point to a growing homogeneity and dominance of rodent species that are widespread in agroecosystems. Rapid inventories based on owl pellets emerge as a suitable, economic, non-invasive tool to document these community changes.

Michael Kelly, Hilary Footitt, Myriam Salama-Carr (eds.): The Palgrave Handbook of Languages and Conflict

2020 ◽  
Vol 55 (2) ◽  
Author(s):  
Ľubomír Zvada
Keyword(s):  
International Relations ◽  
Foreign Languages ◽  
Military Operations ◽  
Sources Of Information ◽  
War And Peace ◽  
Interdisciplinary Field ◽  
Speakers Of Other Languages ◽  
War And Conflict ◽  
Almost All

This Handbook maps the contours of an exciting and burgeoning interdisciplinary field concerned with the role of language and languages in situations of conflict. It explores conceptual approaches, sources of information that are available, and the institutions and actors that mediate language encounters. It examines case studies of the role that languages have played in specific conflicts, from colonial times through to the Middle East and Africa today. The contributors provide vibrant evidence to challenge the monolingual assumptions that have affected traditional views of war and conflict. They show that languages are woven into every aspect of the making of war and peace, and demonstrate how language shapes public policy and military strategy, setting frameworks and expectations. The Handbook's 22 chapters powerfully illustrate how the encounter between languages is integral to almost all conflicts, to every phase of military operations and to the lived experiences of those on the ground, who meet, work and fight with speakers of other languages. This comprehensive work will appeal to scholars from across the disciplines of linguistics, translation studies, history, and international relations; and provide fresh insights for a broad range of practitioners interested in understanding the role and implications of foreign languages in war.

ON EVALUATION OF THE ROLE OF THERMAL AND WIND FACTORS FOR A PHYSICAL MODEL OF THE WORLD OCEAN GENERAL CIRCULATION SYSTEM

2019 ◽  
Vol 47 (3) ◽  
pp. 80-91
Author(s):  
V. G. Neiman
Keyword(s):  
Physical Model ◽  
Ocean Circulation ◽  
General Circulation ◽  
World Ocean ◽  
Circulation System ◽  
The Public ◽  
The World ◽  
Almost All ◽  
Conceptual Foundations

The main content of the work consists of certain systematization and addition of longexisting, but eventually deformed and partly lost qualitative ideas about the role of thermal and wind factors that determine the physical mechanism of the World Ocean’s General Circulation System (OGCS). It is noted that the conceptual foundations of the theory of the OGCS in one form or another are contained in the works of many well-known hydrophysicists of the last century, but the aggregate, logically coherent description of the key factors determining the physical model of the OGCS in the public literature is not so easy to find. An attempt is made to clarify and concretize some general ideas about the two key blocks that form the basis of an adequate physical model of the system of oceanic water masses motion in a climatic scale. Attention is drawn to the fact that when analyzing the OGCS it is necessary to take into account not only immediate but also indirect effects of thermal and wind factors on the ocean surface. In conclusion, it is noted that, in the end, by the uneven flow of heat to the surface of the ocean can be explained the nature of both external and almost all internal factors, in one way or another contributing to the excitation of the general, or climatic, ocean circulation.

Methyl mercury in the dutch rhine delta

1994 ◽  
Vol 30 (10) ◽  
pp. 213-219 ◽  
Author(s):  
Hendrik Pieters ◽  
Victor Geuke
Keyword(s):  
Suspended Matter ◽  
Methyl Mercury ◽  
Mercury Contamination ◽  
Benthic Organisms ◽  
Considerable Decrease ◽  
Continuous Sedimentation ◽  
Highly Correlated ◽  
High Level ◽  
Almost All

Samples of yellow eel from various locations in the Dutch Rhine area have been analyzed for trend monitoring of mercury since 1977. In the western Rhine delta mercury levels in eels have hardly changed since the seventies, whereas in the eastern part of the Dutch Rhine area a considerable decrease of mercury concentrations in eel has occurred. Because of continuous sedimentation of contaminated suspended matter transported from upstream regions, accumulation rates and concentrations of mercury in eel in the western Rhine delta remained at a relatively high level. Analyses of methyl mercury in biota have been performed to elucidate the role of methyl mercury in the mercury contamination of the Dutch Rhine ecosystem. Low percentages of methyl mercury were observed in zooplankton (3 to 35%). In benthic organisms (mussels) percentages of methyl mercury ranged from 30 to 57%, while in fish species and liver of aquatic top predator birds almost all the mercury was present in the form of methyl mercury (> 80%). During the period 1970-1990 mercury concentrations of suspended matter in the eastern Rhine delta have drastically decreased. These concentrations seemed to be highly correlated with mercury concentrations of eel (R = 0.84). The consequences of this relation are discussed.

The contribution of raptorial birds to patterning in small mammal assemblages

Paleobiology ◽  
1988 ◽  
Vol 14 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Rob Hoffman
Keyword(s):  
Small Mammal ◽  
Mus Musculus ◽  
House Mice ◽  
Potential Contribution ◽  
Quantitative Analyses ◽  
Interspecies Variability ◽  
Fossil Assemblages ◽  
Mammal Assemblages

Seven taxa of raptorial birds were experimentally fed a controlled sample of 50 house mice (Mus musculus). Bones recovered from the pellets were examined for interspecies variability in preservation to assess the potential contribution of specific raptors to patterning in fossil assemblages. Quantitative analyses demonstrate that patterns in bone fragmentation may assist in the identification of particular raptor species as depositional agents in small mammal assemblages.

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