Persistence and size of seasonal populations on a consumer–resource relationship depends on the allocation strategy toward life-history functions

AbstractThe long-term ecological dynamics of a population inhabiting a seasonal environment is analyzed using a semi-discrete or impulsive system to represent the consumer–resource interaction. The resource corresponds to an incoming energy flow for consumers that is allocated to reproduction as well as to maintenance in each non-reproductive season. The energy invested in these life-history functions is used in reproductive events, determining the size of the offspring in each reproductive season. Two long-term dynamic patterns are found, resulting in either the persistence or the extinction of the population of consumers. In addition, our model indicates that only one energy allocation strategy provides an optimal combination between individual consumption and long-term population size. The current study contributes to the understanding of how the individual-level and the population-level are interrelated, exhibiting the importance of incorporating phenotypic traits in population dynamics.

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Suitability of a young deciduous-dominated forest for American marten and the effects of forest removal

Canadian Journal of Zoology ◽

10.1139/z04-006 ◽

2004 ◽

Vol 82 (3) ◽

pp. 423-435 ◽

Cited By ~ 25

Author(s):

Kim G Poole ◽

Aswea D Porter ◽

Andrew de Vries ◽

Chris Maundrell ◽

Scott D Grindal ◽

...

Keyword(s):

Populus Tremuloides ◽

Forest Cover ◽

Agricultural Land ◽

Prey Availability ◽

Population Level ◽

Home Ranges ◽

American Marten ◽

Individual Level ◽

The Individual

American marten (Martes americana (Turton, 1806)) are generally considered to be reliant upon and most successful in continuous late-successional coniferous forests. By contrast, young seral forests and deciduous-dominated forests are assumed to provide low-quality marten habitat, primarily as a result of insufficient structure, overhead cover, and prey. This study examined a moderate-density population of marten in northeastern British Columbia in what appeared to be comparatively low-quality, deciduous-dominated habitat, overgrown agricultural land primarily consisting of 30- to 40-year-old stands of regenerating trembling aspen (Populus tremuloides Michx.). Over 4 years, we monitored 52 radio-collared marten. The population appeared to be stable, as indicated by large numbers of adults, relatively constant densities, long-term residency of many individuals, low mortality rates, and older age structure. Relatively small home ranges (males, 3.3 km2; females, 2.0 km2) implied good habitat quality and prey availability. Shearing (removal of immature forest cover) of 17% of the study area resulted in home range shifts at the individual level but no detectable impact at the population level. Categorically, marten avoided nonforested cover types and preferred mature coniferous (>25% conifer) stands (7% of the study area) but otherwise appeared to use all forested stands relative to their availability, including extensive use of deciduous-dominated stands and deciduous stands <40 years of age. Thus, these young deciduous forests appeared to have sufficient structure, overhead cover, and prey to maintain moderate densities of resident marten on a long-term basis.

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Hurricane-induced demographic changes in a non-human primate population

Royal Society Open Science ◽

10.1098/rsos.200173 ◽

2020 ◽

Vol 7 (8) ◽

pp. 200173

Author(s):

Dana O. Morcillo ◽

Ulrich K. Steiner ◽

Kristine L. Grayson ◽

Angelina V. Ruiz-Lambides ◽

Raisa Hernández-Pacheco

Keyword(s):

Population Level ◽

Matrix Population Models ◽

Individual Level ◽

Animal Populations ◽

Level Data ◽

Climatic Event ◽

Free Ranging ◽

Human Primate ◽

Population Fitness

Major disturbance events can have large impacts on the demography and dynamics of animal populations. Hurricanes are one example of an extreme climatic event, predicted to increase in frequency due to climate change, and thus expected to be a considerable threat to population viability. However, little is understood about the underlying demographic mechanisms shaping population response following these extreme disturbances. Here, we analyse 45 years of the most comprehensive free-ranging non-human primate demographic dataset to determine the effects of major hurricanes on the variability and maintenance of long-term population fitness. For this, we use individual-level data to build matrix population models and perform perturbation analyses. Despite reductions in population growth rate mediated through reduced fertility, our study reveals a demographic buffering during hurricane years. As long as survival does not decrease, our study shows that hurricanes do not result in detrimental effects at the population level, demonstrating the unbalanced contribution of survival and fertility to population fitness in long-lived animal populations.

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Example Four: Facultative Anadromy in Salmonid Fishes

Modeling Populations of Adaptive Individuals ◽

10.23943/princeton/9780691195285.003.0007 ◽

2020 ◽

pp. 86-92

Keyword(s):

Life History ◽

Life Histories ◽

Population Level ◽

Dynamic State ◽

Salmonid Fishes ◽

Individual Level ◽

State Variable ◽

Level Model ◽

Fitness Benefits ◽

The Individual

This chapter offers a fourth example model, with the objective of (1) illustrating the application of state- and prediction-based theory (SPT) to a new kind of decision—a life history decision—in a case where dynamic state variable modeling (DSVM) has been applied successfully; and (2) describing the unique ability of models utilizing SPT to address population-level questions of particular interest to conservationists and managers. In this case, SPT produced individual-level decisions similar to those of DSVM, but including them in a population-level model led to quite different conclusions than those implied by the individual-level DSVM analysis. Salmonid fishes exhibit amazing life history diversity. One fundamental distinction among salmonid life histories is whether or not individuals migrate to the ocean. In general, facultative anadromy can be seen as an adaptive behavior that trades off the fitness benefits of going to the ocean versus those of remaining resident. The anadromy versus residency decision is important to fish conservation and resource management.

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Multi-Level Resources to Support Health Behavior Maintenance

Innovation in Aging ◽

10.1093/geroni/igaa057.3022 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 827-827

Author(s):

Susan Hughes ◽

Janet Bettger ◽

Mina Raj ◽

Jaime Hughes

Keyword(s):

Health Behaviors ◽

Local Community ◽

Population Level ◽

Individual Level ◽

Safe Environment ◽

Multi Level ◽

The Individual ◽

Behavior Maintenance ◽

Term Maintenance

Abstract Although behavior change is largely thought to occur on the individual level, maintenance of health behaviors also depends upon factors at the community and population levels. As discussed in earlier presentations, health behaviors can be influenced by social support, environmental context, and population-level policies. For example, maintaining a physical activity regimen is made easier when an older adult has access to a safe environment, support of family and friends, and/or ongoing access to a program that is continuously offered, or sustained, at a local community center. This presentation will focus on the importance of discussing sustainability when considering long-term maintenance of health behaviors. Specifically, this presentation will use examples from the evidence-based Fit & Strong! program, now being offered in 32 states, to explore sustainability of programs at the participant and community level and will provide an overview of barriers and facilitators faced by community organizations.

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Small-scale spatial variation in population- and individual-level reproductive parameters of the blue-legged hermit crabClibanarius tricolor

PeerJ ◽

10.7717/peerj.3004 ◽

2017 ◽

Vol 5 ◽

pp. e3004 ◽

Cited By ~ 1

Author(s):

J. Antonio Baeza ◽

Donald C. Behringer

Keyword(s):

Life History ◽

Body Size ◽

Florida Keys ◽

Population Level ◽

Small Scale ◽

Reproductive Parameters ◽

Future Studies ◽

Individual Level ◽

Female Body Size ◽

History Of

Management of the few regulated ornamental fisheries relies on inadequate information about the life history of the target species. Herein, we investigated the reproductive biology of the most heavily traded marine invertebrate in the western Atlantic; the blue-legged hermit crabClibanarius tricolor. We report on density, individual-level, and population-level reproductive parameters in 14 populations spanning the Florida Keys. In C. tricolor, abundance, population-level, and individual-level reproductive parameters exhibited substantial small-scale spatial variation in the Florida Keys. For instance, the proportion of brooding females varied between 10–94% across localities. In females, average (±SD) fecundity varied between 184 (±54) and 614 (±301) embryos crab-1 across populations. Fecundity usually increases with female body size in hermit crabs. However, we found no effect of female body size on fecundity in three of the populations. Altogether, our observations suggest that C. tricolor may fit a source-sink metapopulation dynamic in the Florida Keys with low reproductive intensity and absence of a parental body size—fecundity relationship resulting in net reproductive loses at some localities. We argue in favor of additional studies describing population dynamics and other aspects of the natural history of C. tricolor (e.g., development type, larval duration) to reveal ‘source’ populations, capable of exporting larvae to nearby populations. Our observations imply that future studies aimed at assessing standing stocks or describing other aspects of the life history of this hermit crab need to focus on multiple localities simultaneously. This and future studies on the reproductive biology of this species will form the baseline for models aimed at assessing the stock condition and sustainability of this heavily harvested crustacean.

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Cannibalism in Size-Structured Systems

Population and Community Ecology of Ontogenetic Development ◽

10.23943/princeton/9780691137575.003.0011 ◽

2013 ◽

Author(s):

André M. de Roos ◽

Lennart Persson

Keyword(s):

Population Dynamics ◽

Population Level ◽

Metabolic Rates ◽

Intraspecific Interaction ◽

Individual Level ◽

Structured Systems ◽

Level Model ◽

Continuous Population ◽

Resource System ◽

Consumer Resource

The previous two chapters discussed how the size scaling of foraging and metabolic rates affected the dynamics of consumer-resource systems. Using different modeling approaches, it was shown that stage-dependent competitive ability was the main predictor of population dynamics; that is, it largely set the conditions for different types of cycles to occur. This chapter adds another intraspecific interaction on top of the consumer-resource system, namely, cannibalism. It uses a discrete-continuous population-level model based on individual-level net-production energetics to investigate the effects of cannibalism. The focus will be on the effects of cannibalism on population dynamics related to four processes that have been discussed in the literature regarding cannibalism: effects on mortality, competition, energy gain, and the size dependence of interactions.

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A modular hierarchical array camera

Light Science & Applications ◽

10.1038/s41377-021-00485-x ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Xiaoyun Yuan ◽

Mengqi Ji ◽

Jiamin Wu ◽

David J. Brady ◽

Qionghai Dai ◽

...

Keyword(s):

High Performance ◽

Modular Design ◽

Population Level ◽

Real World Data ◽

Camera System ◽

Individual Level ◽

The Individual ◽

Term Monitoring ◽

Array Camera

AbstractArray cameras removed the optical limitations of a single camera and paved the way for high-performance imaging via the combination of micro-cameras and computation to fuse multiple aperture images. However, existing solutions use dense arrays of cameras that require laborious calibration and lack flexibility and practicality. Inspired by the cognition function principle of the human brain, we develop an unstructured array camera system that adopts a hierarchical modular design with multiscale hybrid cameras composing different modules. Intelligent computations are designed to collaboratively operate along both intra- and intermodule pathways. This system can adaptively allocate imagery resources to dramatically reduce the hardware cost and possesses unprecedented flexibility, robustness, and versatility. Large scenes of real-world data were acquired to perform human-centric studies for the assessment of human behaviours at the individual level and crowd behaviours at the population level requiring high-resolution long-term monitoring of dynamic wide-area scenes.

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A modelling exercise to show why population models should incorporate distinct life histories of dispersers

10.1101/402198 ◽

2018 ◽

Author(s):

Jacques A. Deere ◽

Ilona van den Berg ◽

Gregory Roth ◽

Isabel M. Smallegange

Keyword(s):

Life History ◽

Population Growth ◽

Life Histories ◽

Population Level ◽

Population Models ◽

Integral Projection Model ◽

Projection Model ◽

Individual Level ◽

Population Growth Rates ◽

Dispersal Probability

AbstractDispersal is an important form of movement influencing population dynamics, species distribution, and gene flow between populations. In population models, dispersal is often included in a simplified manner by removing a random proportion of the population. Many ecologists now argue that models should be formulated at the level of individuals instead of the population-level. To fully understand the effects of dispersal on natural systems, it is therefore necessary to incorporate individual-level differences in dispersal behaviour in population models. Here we parameterised an integral projection model (IPM), which allows for studying how individual life histories determine population-level processes, using bulb mites, Rhizoglyphus robini, to assess to what extent dispersal expression (frequency of individuals in the dispersal stage) and dispersal probability affect the proportion of dispersers and natal population growth rate. We find that allowing for life-history differences between resident phenotypes and disperser phenotypes shows that multiple combinations of dispersal probability and dispersal expression can produce the same proportion of leaving individuals. Additionally, a given proportion of dispersing individuals results in different natal population growth rates. The results highlight that dispersal life histories, and the frequency with which disperser phenotypes occur in the natal population, significantly affect population-level processes. Thus, biological realism of dispersal population models can be increased by incorporating the typically observed life history differences between resident phenotypes and disperser phenotypes, and we here present a methodology to do so.

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Epidemiology of COVID-19 and public health restrictions during the first wave of the pandemic in Ireland in 2020

Journal of Public Health ◽

10.1093/pubmed/fdab049 ◽

2021 ◽

Author(s):

Robert Conway ◽

David M Kelly ◽

Paul Mullane ◽

Cliodhna Ni Bhuachalla ◽

Lois O’Connor ◽

...

Keyword(s):

Public Health ◽

Population Level ◽

Individual Level ◽

The Public ◽

Effective Suppression ◽

Community Transmission ◽

Epidemiological Trends ◽

And Control ◽

Close Contacts

Abstract Background We describe the epidemiological trends and report and review the public health restrictions implemented during the first wave of the COVID-19 pandemic in Ireland. Methods The study reviewed confirmed cases of COVID-19 notified from 1 March to 18 July 2020. Data were obtained from the national COVID-19 Data Hub, the National Health Protection Surveillance Centre, the National Contact Management Programme and the European Centre for Disease Prevention and Control. Results A total of 25 617 cases were notified during the study period. Weekly cases and deaths peaked in mid-April 2020 at 5701 and 316, respectively. Mean number of close contacts per case was lowest at 0.7 in April, rising to 6.6 by July. Outbreak settings shifted from travel and workplace in March, to healthcare in April. Restrictions implemented on 12 March extended to full lockdown on 27 March. Phased relaxation of restrictions commenced 18 May. Effective suppression of community transmission of COVID-19 was achieved by June 2020. Conclusion Lockdown is a crude population-level restriction effective in controlling COVID-19. Phased relaxation of restrictions in Ireland, however, led to an immediate increase in mean number of contacts per case, which facilitates viral transmission unless individual-level restrictions are adhered to. This demonstrates a limitation of lockdown as a long-term mechanism of pandemic control.

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Hurricane-induced demographic changes in a nonhuman primate population

10.1101/2020.06.08.140566 ◽

2020 ◽

Author(s):

Dana O. Morcillo ◽

Ulrich K. Steiner ◽

Kristine L. Grayson ◽

Angelina V. Ruiz-Lambides ◽

Raisa Hernández-Pacheco

Keyword(s):

Nonhuman Primate ◽

Population Level ◽

Matrix Population Models ◽

Individual Level ◽

Animal Populations ◽

Level Data ◽

Climatic Event ◽

Free Ranging ◽

Population Fitness

AbstractMajor disturbance events can have large impacts on the demography and dynamics of animal populations. Hurricanes are one example of an extreme climatic event, predicted to increase in frequency due to climate change, and thus expected to be a considerable threat to population viability. However, little is understood about the underlying demographic mechanisms shaping population response following these extreme disturbances. Here, we analyze 45 years of the most comprehensive free-ranging nonhuman primate demographic dataset to determine the effects of major hurricanes on the variability and maintenance of long-term population fitness. For this, we use individual-level data to build matrix population models and perform perturbation analyses. Despite reductions in population growth rate mediated through reduced fertility, our study reveals a demographic buffering during hurricane years. As long as survival does not decrease, our study shows that hurricanes do not result in detrimental effects at the population level, demonstrating the unbalanced contribution of survival and fertility to population fitness in long-lived animal populations.

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