Gut content biomass of stream fishes: associations with streamflow velocity, population density, and prey abundance at two spatial scales

Hydrobiologia ◽  
2018 ◽  
Vol 826 (1) ◽  
pp. 85-97
Author(s):  
Sophia Qian Niu ◽  
Danelle M. Haake ◽  
Jason H. Knouft
Keyword(s):  
Population Density ◽  
Spatial Scales ◽  
Prey Abundance ◽  
Stream Fishes ◽  
Gut Content

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Great Plains ◽  
Life Histories ◽  
Environmental Heterogeneity ◽  
Environmental Variability ◽  
Spatial Scales ◽  
Stream Fish ◽  
Metapopulation Dynamics ◽  
Stream Fishes ◽  
Spatial And Temporal Scales ◽  
Trade Offs

<em>Abstract</em>.—Stream fishes carry out their life histories across broad spatial and temporal scales, leading to spatially structured populations. Therefore, incorporating metapopulation dynamics into models of stream fish populations may improve our ability to understand mechanisms regulating them. First, we reviewed empirical research on metapopulation dynamics in the stream fish ecology literature and found 31 papers that used the metapopulation framework. The majority of papers applied no specific metapopulation model, or included space only implicitly. Although parameterization of spatially realistic models is challenging, we suggest that stream fish ecologists should incorporate space into models and recognize that metapopulation types may change across scales. Second, we considered metacommunity theory, which addresses how trade-offs among dispersal, environmental heterogeneity, and biotic interactions structure communities across spatial scales. There are no explicit tests of metacommunity theory using stream fishes to date, so we used data from our research in a Great Plains stream to test the utility of these paradigms. We found that this plains fish metacommunity was structured mainly by spatial factors related to dispersal opportunity and, to a lesser extent, by environmental heterogeneity. Currently, metacommunity models are more heuristic than predictive. Therefore, we propose that future stream fish metacommunity research should focus on developing testable hypotheses that incorporate stream fish life history attributes, and seasonal environmental variability, across spatial scales. This emerging body of research is likely to be valuable not only for basic stream fish ecological research, but also multispecies conservation and management.

scholarly journals Simultaneous estimation of seasonal population density, habitat preference and catchability of wild boars based on camera data and harvest records

2020 ◽  
Vol 7 (8) ◽  
pp. 200579
Author(s):  
Yuichi Yokoyama ◽  
Yoshihiro Nakashima ◽  
Gota Yajima ◽  
Tadashi Miyashita
Keyword(s):  
Population Density ◽  
Habitat Preference ◽  
Population Control ◽  
Individual Recognition ◽  
Spatial Scales ◽  
Simultaneous Estimation ◽  
Effective Population ◽  
Time Model ◽  
Wild Mammals ◽  
Wild Boars

Analyses of life history and population dynamics are essential for effective population control of wild mammals. We developed a model for the simultaneous estimation of seasonal changes in three parameters—population density, habitat preference and trap catchability of target animals—based on camera-trapping data and harvest records. The random encounter and staying time model, with no need for individual recognition, is the core component of the model—by combining this model with the catch-effort model, we estimated density at broad spatial scales and catchability by traps. Here, the wild boar population in central Japan was evaluated as a target population. We found that the estimated population density increased after the birth period and then decreased until the next birth period, mainly due to harvesting. Habitat preference changed seasonally, but forests having abandoned fields nearby were generally preferred throughout the season. These patterns can be explained by patterns of food availability and resting or nesting sites. Catchability by traps also changed seasonally, with relatively high values in the winter, which probably reflected changes in the attractiveness of the trap bait due to activity changes in response to food scarcity. Based on these results, we proposed an effective trapping strategy for wild boars, and discussed the applicability of our model to more general conservation and management issues.

scholarly journals Variation in space and time: a long-term examination of density-dependent dispersal in a woodland rodent

2019 ◽  
Author(s):  
Simon T. Denomme-Brown ◽  
Karl Cottenie ◽  
J. Bruce Falls ◽  
E. Ann Falls ◽  
Ronald J. Brooks ◽  
...  
Keyword(s):  
Time Series ◽  
Population Density ◽  
Local Density ◽  
Spatial Scales ◽  
Deer Mice ◽  
Population Densities ◽  
Density Dependent ◽  
Regional Population ◽  
The Relationship ◽  
Density Dependent Dispersal

AbstractDispersal is a fundamental ecological process that can be affected by population density, yet studies report contrasting effects of density on propensity to disperse. Additionally, the relationship between dispersal and density is seldom examined using densities measured at different spatial scales or over extensive time-series. We used 51-years of trapping data to examine how dispersal by wild deer mice (Peromyscus maniculatus) was affected by changes in both local and regional population densities. We examined these patterns over both the entire time-series and also in ten-year shifting windows to determine whether the nature and strength of the relationship changed through time. Probability of dispersal decreased with increased local and regional population density, and the negative effect of local density on dispersal was more pronounced in years with low regional densities. Additionally, the strength of negative density-dependent dispersal changed through time, ranging from very strong in some decades to absent in other periods of the study. Finally, while females were less likely to disperse, female dispersal was more density-dependent than male dispersal. Our study shows that the relationship between density and dispersal is not temporally static and that investigations of density-dependent dispersal should consider both local and regional population densities.

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Spatial Scales ◽  
Distribution Patterns ◽  
Home Ranges ◽  
Stream Fishes ◽  
Ecological Processes ◽  
Individual Level ◽  
Population Spread ◽  
Heavy Tailed ◽  
Resource Patches ◽  
The Individual

<em>Abstract</em>.—Long-distance dispersal (LDD; relatively infrequent displacements occupying the tails of the dispersal kernel) and habitat connectivity (the degree to which the landscape facilitates or impedes movement among resource patches) influence many important ecological processes. These processes include population spread and redistribution, regulation of local and regional population dynamics, colonization of newly available habitats, maintenance of diversity in variable environments, and transfer of energy and nutrients. Field studies have shown that both LDD and instream barriers can have marked effects on the distribution patterns and demographic isolation of stream fishes at various spatial scales. Traditional summary measures of spatial use at the individual level, such as home ranges, have limited utility for examining the effects of connectivity in the presence of LDD or instream barriers; however, simple models can be tailored to extract and synthesize this information efficiently. This study presents a modeling framework for quantifying LDD of marked fish as well as their movements in the presence of barriers of differing porosity or permeability. Simulations are used to illustrate the feasibility of the modeling approach and explore sample size and spatial scale requirements. Comparison of model parameters across systems, species, and time periods should provide insights into the contribution of movement to structuring fish communities in riverine landscapes. The proposed framework can help improve on methods currently used (e.g., to quantify characteristic scales of habitat use by using median displacements or other appropriate percentile measures instead of home ranges and to relate fish movements to environmental or individual predictors by robust analyses based on heavy-tailed rather than simple normal distributions).

scholarly journals Incidence, Population Density, and Spatial Heterogeneity of Plant-Parasitic Nematodes in Corn Fields in Ohio

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2453-2464 ◽  
Author(s):  
Abasola C. M. Simon ◽  
Horacio D. Lopez-Nicora ◽  
Laura E. Lindsey ◽  
Terry L. Niblack ◽  
Pierce A. Paul
Keyword(s):  
Population Density ◽  
Spatial Scales ◽  
Management Strategies ◽  
Parasitic Nematodes ◽  
Growth Stages ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Sampling Protocols ◽  
Corn Fields ◽  
Plant Parasitic

Soil samples were collected from 425 corn fields in 28 Ohio counties between growth stages V3 and V6 during the 2013 and 2014 growing seasons. Ten morphological groups of plant-parasitic nematodes, namely spiral, lesion, lance, dagger, stunt, pin, ring, stubby-root, cyst, and “tylenchids” (several genera morphologically similar to members of the subfamily Tylenchinae [NCBI Taxonomy] including Cephelenchus, Filenchus, Malenchus, and Tylenchus) were identified. Eight species belonging to six of these groups were characterized. Spiral, tylenchids, lesion, pin, lance, stunt, and dagger nematodes were detected in 94, 96, 80, 57, 48, 48, and 37% of the fields, respectively, whereas the stubby-root, cyst, and ring nematodes were present in fewer than 14% of the samples. Averaged across fields, the spiral, tylenchids, and pin nematodes had the highest mean population densities. For all groups, incidence and population density varied among counties, and in some cases, among soil regions and cropping practices. Both population parameters were heterogeneous at multiple spatial scales, with the lowest heterogeneity among soil regions and the highest among fields within county and soil region. Estimated variances at the soil region level were not significantly different from zero for most of the nematodes evaluated. Stunt and lance were two of the most variable groups at all tested spatial scales. In general, the population densities were significantly more heterogeneous at the field level than at the county level. Findings from this study will be useful for developing sampling protocols and establishing on-farm trials to estimate losses and evaluate nematode management strategies.

Testing for human impacts in the mismatch of living and dead ostracode assemblages at nested spatial scales in subtropical lakes from the Bahamian archipelago

Paleobiology ◽  
2018 ◽  
Vol 44 (4) ◽  
pp. 758-782
Author(s):  
Andrew V. Michelson ◽  
Susan M. Kidwell ◽  
Lisa E. Park Boush ◽  
Jeanine L. Ash
Keyword(s):  
Population Density ◽  
Human Population ◽  
Human Impacts ◽  
Spatial Scales ◽  
Ecological Change ◽  
Human Population Density ◽  
Subtropical Lakes ◽  
Death Assemblages ◽  
Human Stress ◽  
Coarse Information

AbstractNaturally time-averaged accumulations of skeletal remains—death assemblages—provide reliable, albeit temporally coarse, information on the species composition and structure of communities in diverse settings, and their mismatch with local living communities usually signals recent human-driven ecological change. Here, we present the first test of live–dead mismatch as an indicator of human stress using ostracodes. On three islands along a gradient of human population density in the Bahamas, we compared the similarity of living and death assemblages in 10 lakes with relatively low levels of human stress to live–dead similarity in 11 physically comparable lakes subject to industrial, agricultural, or other human activities currently or in the past. We find that live–dead agreement in pristine lakes is consistently excellent, boding well for using death assemblages in modern-day and paleolimnological biodiversity assessments. In most comparison of physically similar paired lakes, sample-level live–dead mismatch in both taxonomic composition and species’ rank abundance is on average significantly greater in the stressed lakes; live–dead agreement is not lower in all samples from stressed lakes, but is more variable. When samples are pooled for lake-level and island-level comparisons, stressed lakes still yield lower live–dead agreement, but the significance of the difference with pristine lakes decreases—species that occur dead-only (or alive-only) in one sample are likely to occur alive (or dead) in other samples. Interisland differences in live–dead agreement are congruent with, but not significantly correlated with, differences in human population density. This situation arises from heterogeneity in the timing and magnitudes of stresses and in the extent of poststress recovery. Live–dead mismatch in ostracode assemblages thus may be a reliable indicator of human impact at the sample level with the potential to be a widely applicable tool for identifying impacted habitats and, perhaps, monitoring the progress of their recovery.

scholarly journals Effective spatial scales for evaluating environmental determinants of population density in Yakushima macaques

2014 ◽  
Vol 77 (2) ◽  
pp. 152-161 ◽  
Author(s):  
Naoki Agetsuma ◽  
Ryosuke Koda ◽  
Riyou Tsujino ◽  
Yoshimi Agetsuma-Yanagihara
Keyword(s):  
Population Density ◽  
Spatial Scales ◽  
Environmental Determinants

scholarly journals Energetic and ecological constraints on population density of reef fishes

2016 ◽  
Vol 283 (1823) ◽  
pp. 20152186 ◽  
Author(s):  
D. R. Barneche ◽  
M. Kulbicki ◽  
S. R. Floeter ◽  
A. M. Friedlander ◽  
A. P. Allen
Keyword(s):  
Species Richness ◽  
Body Size ◽  
Population Density ◽  
Species Interactions ◽  
Spatial Scales ◽  
Small Body ◽  
Reef Fishes ◽  
Abundant Species ◽  
Global Scale ◽  
Ecological Constraints

Population ecology has classically focused on pairwise species interactions, hindering the description of general patterns and processes of population abundance at large spatial scales. Here we use the metabolic theory of ecology as a framework to formulate and test a model that yields predictions linking population density to the physiological constraints of body size and temperature on individual metabolism, and the ecological constraints of trophic structure and species richness on energy partitioning among species. Our model was tested by applying Bayesian quantile regression to a comprehensive reef-fish community database, from which we extracted density data for 5609 populations spread across 49 sites around the world. Our results indicate that population density declines markedly with increases in community species richness and that, after accounting for richness, energetic constraints are manifested most strongly for the most abundant species, which generally are of small body size and occupy lower trophic groups. Overall, our findings suggest that, at the global scale, factors associated with community species richness are the major drivers of variation in population density. Given that populations of species-rich tropical systems exhibit markedly lower maximum densities, they may be particularly susceptible to stochastic extinction.

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