RESOURCE PARTITIONING IN A GUILD OF MARSH-DWELLING AGONUM (COLEOPTERA: CARABIDAE) IN CENTRAL ALBERTA

1994 ◽  
Vol 126 (3) ◽  
pp. 709-728 ◽  
Author(s):  
Jean-François Landry
Keyword(s):  
Habitat Use ◽  
Activity Pattern ◽  
Resource Partitioning ◽  
Daily Activity ◽  
Laboratory Experiments ◽  
Temporal Distribution ◽  
The Other ◽  
Spatial And Temporal Distribution ◽  
Habitat Association ◽  
Dead Vegetation

AbstractThe spatial and temporal distribution of microsympatric species of marsh-inhabiting Agonum were investigated in central Alberta. Agonum nigriceps LeC., A. ferruginosum Dej., A. thoreyi Dej., and A. lutulentum (LeC.) were the most abundant carabid species in the emergent vegetation of the flooded zone. Agonum nigriceps was segregated from the other species through habitat use, being most abundant in emergent sedge tussocks. Agonum ferruginosum was most abundant in floating cattail mats, whereas A. thoreyi was rather evenly distributed across macrohabitats. Within flooded macrohabitats both A. ferruginosum and A. thoreyi predominantly occupied microsites with emergent substrate or clumps of dead vegetation. In one marsh where A. ferruginosum co-occurred with A. lutulentum, their macrohabitat distributions were mutually exclusive. Reproduction began earlier and teneral adults emerged earlier for both A. nigriceps and A. ferruginosum than for A. thoreyi. Agonum nigriceps, A. ferruginosum, and A. thoreyi were all nocturnal and showed no differences in daily activity pattern. In laboratory experiments, adults of A. nigriceps displayed the highest propensity to climb on narrow vertical structures, a behavior correlated with their main habitat association with structurally simple emergent sedge habitat. Adults of A. nigriceps are cryptically colored to blend into their habitat background.

scholarly journals Spatial and temporal distribution of gerrid (Heteroptera) and predation on microcrustaceans from a tropical shallow lake

2016 ◽  
Vol 77 (2) ◽  
pp. 289-298 ◽  
Author(s):  
A. R. Domingos ◽  
M. S. Arcifa
Keyword(s):  
Spatial Distribution ◽  
Laboratory Experiments ◽  
Ingestion Rate ◽  
Aquatic Insect ◽  
Temporal Distribution ◽  
Spatial And Temporal Distribution ◽  
Population Fluctuations ◽  
Size Selectivity ◽  
Predator Prey ◽  
Adult Insect

Abstract Predator-prey interactions involving an aquatic insect and zooplanktonic prey of different sizes were investigated to quantify prey mortality exposed to predators. Laboratory experiments were undertaken with the young and adult gerrid Rheumatobates crassifemur to test predation and size selectivity on the cladocerans Daphnia gessneri, Ceriodaphnia richardi, and Bosmina tubicen. Population fluctuations and spatial distribution of the gerrid were also evaluated in a small and shallow Brazilian lake throughout 12 months in fortnightly samples. The insects were more abundant in the littoral (mean density 7.0 ± 1.2 ind.m–2) compared to the limnetic zone. The period with the highest densities was late January to June, in both zones. Predation by young instars on Daphnia and Ceriodaphnia was significant (mean ingestion rate of 1.3 ± 0.1 D. gessneri and 0.7 ± 0.1 C. richardi per predator per hour). Adult insect fed only the large-sized prey (mean ingestion rate of 1.0 ± 0.1 D. gessneri per predator per hour). Young gerrids have greater potential to prey on cladocerans than adults, and size selectivity occurred for both predators. Preference of adults by the larger prey is probably related to difficulties in manipulating smaller planktonic prey, such as Ceriodaphnia. Due to higher densities of insects in the littoral, higher predation on zooplankton in this zone is expected. This study does contribute to a better understanding of trophic interactions in tropical shallow lakes and is the first to investigate predation of a gerrid on cladocerans in laboratory experiments.

scholarly journals Pattern of distribution and environmental influences on the Scienidae community of the Southeastern Brazilian coast

2012 ◽  
Vol 60 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Thassya Christina dos Santos Schmidt ◽  
June Ferraz Dias
Keyword(s):  
Species Richness ◽  
Temporal Distribution ◽  
The Other ◽  
Brazilian Coast ◽  
Spatial And Temporal Distribution ◽  
East Side ◽  
Influence Of Temperature ◽  
Factors Influencing ◽  
Numerical Abundance ◽  
Total Composition

The Sciaenids have among the highest species richness, numerical abundance and biomass of any family of fishes along the Brazilian coast. The aim of this study was to analyze the composition and spatial and temporal distribution of as well as the influence of temperature, salinity and depth on the sciaenid assemblage of Santos Bay. A total of 29,306 individuals belonging to 13 genera and 21 species were captured, between November 2004 and December 2005, with Stellifer rastrifer representing 70.4% of the total composition. Highest abundance and biomass occurred on the east side of the bay, and the highest species richness occurred near the mouth of the Santos Channel, which was also the site with least similarity to the other sites. Highest abundances occurred in April 2005 and lowest in September 2005. Key environmental factors influencing distribution of sciaenids were depth and temperature.

scholarly journals Neotropical tadpoles: spatial and temporal distribution and habitat use in a seasonal lake in Veracruz, México

2002 ◽  
Vol 1 (2) ◽  
pp. 81 ◽  
Author(s):  
Roberto E. Torres-Orozco ◽  
Cecilia L. Jimenez-Sierra ◽  
Richard C. Vogt ◽  
Jose-Luis Villarreal Benitez
Keyword(s):  
Habitat Use ◽  
Temporal Distribution ◽  
Spatial And Temporal Distribution

scholarly journals New mathematical modelling tools for co-culture experiments: when do we need to explicitly account for signalling molecules?

2020 ◽  
Author(s):  
Wang Jin ◽  
Haolu Wang ◽  
Xiaowen Liang ◽  
Michael S Roberts ◽  
Matthew J Simpson
Keyword(s):  
Cell Migration ◽  
Diffusion Equation ◽  
Discrete Model ◽  
Temporal Distribution ◽  
Reaction Diffusion ◽  
The Other ◽  
Reaction Diffusion Equation ◽  
Spatial And Temporal Distribution ◽  
Full Model ◽  
Signalling Molecules

AbstractMathematical models are often applied to describe cell migration regulated by diffusible signalling molecules. A typical feature of these models is that the spatial and temporal distribution of the signalling molecule density is reported by solving a reaction–diffusion equation. However, the spatial and temporal distributions of such signalling molecules are not often reported or observed experimentally. This leads to a mismatch between the amount of experimental data available and the complexity of the mathematical model used to simulate the experiment. To address this mismatch, we develop a discrete model of cell migration that can be used to describe a new suite of co–culture cell migration assays involving two interacting subpopulations of cells. In this model, the migration of cells from one subpopulation is regulated by the presence of signalling molecules that are secreted by the other subpopulation of cells. The spatial and temporal distribution of the signalling molecules is governed by a discrete conservation statement that is related to a reaction–diffusion equation. We simplify the model by invoking a steady state assumption for the diffusible molecules, leading to a reduced discrete model allowing us to describe how one subpopulation of cells stimulates the migration of the other subpopulation of cells without explicitly dealing with the diffusible molecules. We provide additional mathematical insight into these two stochastic models by deriving continuum limit partial differential equation descriptions of both models. To understand the conditions under which the reduced model is a good approximation of the full model, we apply both models to mimic a set of novel co–culture assays and we systematically explore how well the reduced model approximates the full model as a function of the model parameters.

scholarly journals Individual variability of wild juvenile Atlantic salmon activity patterns: effect of flow stage, temperature, and habitat use

2013 ◽  
Vol 70 (7) ◽  
pp. 1082-1091 ◽  
Author(s):  
Mathieu L. Roy ◽  
André G. Roy ◽  
James W.A. Grant ◽  
Normand E. Bergeron
Keyword(s):  
Atlantic Salmon ◽  
Habitat Use ◽  
Activity Pattern ◽  
Daily Activity ◽  
Activity Patterns ◽  
Diel Activity ◽  
Large Network ◽  
Lower Velocity ◽  
Trade Offs ◽  
Flow Stage

The magnitude of variation of diel activity patterns and habitat use of wild Atlantic salmon (Salmo salar) parr was examined during the summer and autumn through a gradient of declining temperature. Fish were marked with passive integrated transponders and tracked using a large network of flatbed antennas. High interindividual variability was observed, as some individuals were predominantly nocturnal whereas others frequently changed their daily activity pattern. Overall fish activity decreased with decreasing temperature and increasing flow stage, but most of these changes in daily activity were observed in crepuscular periods. Parr used habitats with lower velocity at night than in the day during the summer, but not in the autumn. Furthermore, there was no difference between day and night habitats for fish that were cathemeral (active both day and night during a given day), so differences between day and night habitats were the result of individuals adopting different activity patterns. These results suggest that habitat interacts with activity pattern, as individuals using suboptimal habitats seem to increase daytime foraging to secure sufficient energy. Temporal and among-fish variability of activity patterns illustrate the dynamic nature of foraging decisions that may partly result from trade-offs experienced at the microhabitat scale.

Diet selection in Arctic lemmings (Lemmus sibiricus and Dicrostonyx groenlandicus): demography, home range, and habitat use

1986 ◽  
Vol 64 (12) ◽  
pp. 2717-2727 ◽  
Author(s):  
Arthur R. Rodgers ◽  
Martin C. Lewis
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Resource Use ◽  
Temporal Distribution ◽  
Diet Selection ◽  
Spatial And Temporal Distribution ◽  
Intraspecific Interactions ◽  
Wet Meadow ◽  
Dicrostonyx Groenlandicus ◽  
Preferred Foods

In this study we explore the relationships between demography, patterns of habitat use, and the diets selected by Lemmus and Dicrostonyx at Igloolik Island, N.W.T. The demography of both species at Igloolik is similar to that recorded at other localities, but maximal densities vary between sites and may be related to the abundance of suitable forage. Home range characteristics and patterns of habitat use in each lemming species are related to the spatial and temporal distribution of preferred foods: in summer, Lemmus uses low-lying wet meadow habitats dominated by graminoids and mosses, whereas Dicrostonyx uses mainly upland dry heaths dominated by shrubs; in winter, both species make greater use of moist transitional habitats. Although the two species differ in their patterns of resource use, these differences may be altered through interspecific and intraspecific interactions.

Leading with Pedagogical Tact- a Challenge in Children's Sports in Sweden

2010 ◽  
Vol 19 (1-2) ◽  
pp. 127-147 ◽  
Author(s):  
Krister Hertting
Keyword(s):  
Daily Activity ◽  
The Other ◽  
Competitive Sport ◽  
Sports Clubs ◽  
Youth Politics ◽  
Pedagogical Tact ◽  
Children And Parents ◽  
Swedish Society ◽  
Long Time ◽  
Voluntary Commitment

Leading with Pedagogical Tact- a Challenge in Children's Sports in Sweden The purpose of this article is to elucidate and problemize meetings between children and leaders in children's sport. The competitive sport is high valuated in the Swedish society and sport for children is central in the Swedish youth politics. The foundation in Swedish sport, as well as in the other Nordic countries, has for a long time relied on voluntary commitment. Approximately 650 000 people are voluntary engaged as leaders in sport in Sweden and 70% of children between 7 and 14 years compete in sports clubs. There is, however, a tension in the Swedish sport system. The sports for children has double missions - ‘association nurturing’ and ‘competition nurturing’, missions which are not always in harmony. In the daily activity it is the voluntary leaders who have to deal with these missions, which creates a field of tension. In this article I argue for a bridge between these missions by a leadership based on pedagogical tact. The empirical outlook is a narrative based on statements from leaders, children and parents in a study dealing with voluntary leadership within children's football. In the end I argue that focusing on this bridge is a win-win situation, both for children and sports.

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