Spacing patterns

@article{brown1970spacing,
    author = "Brown, Jerram L. and Orians, Gordon H.",
    title = "Spacing Patterns in Mobile Animals",
    year = "1970",
    journal = "Annual Review of Ecology and Systematics",
    url = "https://doi.org/10.1146/annurev.es.01.110170.001323",
    doi = "10.1146/annurev.es.01.110170.001323",
    number = "1",
    pages = "239-262",
    volume = "1"
}

@article{brown1970spacing1,
    author = "Brown, J. L. and Orians, G. H",
    title = "Spacing patterns in mobile animals",
    year = "1970",
    journal = "Annual Review of Ecology and Systematics, v. 1, p. 239-262",
    note = "talkorigins\_source = {true}; raw\_reference = {Brown, J. L., and Orians, G. H., 1970, Spacing patterns in mobile animals: Annual Review of Ecology and Systematics, v. 1, p. 239-262.}"
}

Many exploited reef fish are vulnerable to overfishing because they concentrate over hard-bottom patchy habitats. How mobile reef fish use patchy habitat, and the potential consequences on demographic parameters, must be known for spatially explicit population dynamics modeling, for discriminating essential fish habitat (EFH), and for effectively planning conservation measures (e.g., marine protected areas, stock enhancement, and artificial reefs). Gag, Mycteroperca microlepis, is an ecologically and economically important warm-temperate grouper in the southeastern United States, with behavioral and life history traits conducive to large-scale field experiments. The Suwannee Regional Reef System (SRRS) was built of standard habitat units (SHUs) in 1991-1993 to manipulate and control habitat patchiness and intrinsic habitat quality, and thereby test predictions from habitat selection theory. Colonization of the SRRS by gag over the first six years showed significant interactions of SHU size, spacing, and reef age; with trajectories modeled using a quadratic function for closely spaced SHUs (25 m) and a linear model for widely spaced SHUs (225 m), with larger SHUs (16 standardized cubes) accumulating significantly more gag faster than smaller 4-cube SHUs (mean = 72.5 gag/16-cube SHU at 225-m spacing by year 6, compared to 24.2 gag/4-cube SHU for same spacing and reef age). Residency times (mean = 9.8 mo), indicative of choice and measured by ultrasonic telemetry (1995-1998), showed significant interaction of SHU size and spacing consistent with colonization trajectories. Average relative weight (W(r)) and incremental growth were greater on smaller than larger SHUs (mean W(r) = 104.2 vs. 97.7; incremental growth differed by 15%), contrary to patterns of abundance and residency. Experimental manipulation of shelter on a subset of SRRS sites (2000-2001) confirmed our hypothesis that shelter limits local densities of gag, which, in turn, regulates their growth and condition. Density-dependent habitat selection for shelter and individual growth dynamics were therefore interdependent ecological processes that help to explain how patchy reef habitat sustains gag production. Moreover, gag selected shelter at the expense of maximizing their growth. Thus, mobile reef fishes could experience density-dependent effects on growth, survival, and/or reproduction (i.e., demographic parameters) despite reduced stock sizes as a consequence of fishing.

@article{doi1018901051076120060160731dhsapb20co2,
    author = "Lindberg, William J and Frazer, Thomas K and Portier, Kenneth M and Vose, Frederic and Loftin, James and Murie, Debra J and Mason, Doran M and Nagy, Brian and Hart, Mary K",
    title = "Density-dependent habitat selection and performance by a large mobile reef fish.",
    year = "2006",
    journal = "Ecological applications: a publication of the Ecological Society of America",
    abstract = "Many exploited reef fish are vulnerable to overfishing because they concentrate over hard-bottom patchy habitats. How mobile reef fish use patchy habitat, and the potential consequences on demographic parameters, must be known for spatially explicit population dynamics modeling, for discriminating essential fish habitat (EFH), and for effectively planning conservation measures (e.g., marine protected areas, stock enhancement, and artificial reefs). Gag, Mycteroperca microlepis, is an ecologically and economically important warm-temperate grouper in the southeastern United States, with behavioral and life history traits conducive to large-scale field experiments. The Suwannee Regional Reef System (SRRS) was built of standard habitat units (SHUs) in 1991-1993 to manipulate and control habitat patchiness and intrinsic habitat quality, and thereby test predictions from habitat selection theory. Colonization of the SRRS by gag over the first six years showed significant interactions of SHU size, spacing, and reef age; with trajectories modeled using a quadratic function for closely spaced SHUs (25 m) and a linear model for widely spaced SHUs (225 m), with larger SHUs (16 standardized cubes) accumulating significantly more gag faster than smaller 4-cube SHUs (mean = 72.5 gag/16-cube SHU at 225-m spacing by year 6, compared to 24.2 gag/4-cube SHU for same spacing and reef age). Residency times (mean = 9.8 mo), indicative of choice and measured by ultrasonic telemetry (1995-1998), showed significant interaction of SHU size and spacing consistent with colonization trajectories. Average relative weight (W(r)) and incremental growth were greater on smaller than larger SHUs (mean W(r) = 104.2 vs. 97.7; incremental growth differed by 15\%), contrary to patterns of abundance and residency. Experimental manipulation of shelter on a subset of SRRS sites (2000-2001) confirmed our hypothesis that shelter limits local densities of gag, which, in turn, regulates their growth and condition. Density-dependent habitat selection for shelter and individual growth dynamics were therefore interdependent ecological processes that help to explain how patchy reef habitat sustains gag production. Moreover, gag selected shelter at the expense of maximizing their growth. Thus, mobile reef fishes could experience density-dependent effects on growth, survival, and/or reproduction (i.e., demographic parameters) despite reduced stock sizes as a consequence of fishing.",
    url = "https://pubmed.ncbi.nlm.nih.gov/16711059/",
    doi = "10.1890/1051-0761(2006)016[0731:dhsapb]2.0.co;2",
    pmid = "16711059"
}

@article{takada2007colonization,
    author = "Takada, Y and Abe, O and Shibuno, T",
    title = "Colonization patterns of mobile cryptic animals into interstices of coral rubble",
    year = "2007",
    journal = "Marine Ecology Progress Series",
    url = "https://doi.org/10.3354/meps06935",
    doi = "10.3354/meps06935",
    pages = "35-44",
    volume = "343"
}

Collective animal behavior studies have led the way in developing models that account for a large number of individuals, but mostly have considered situations in which alignment and attraction play a key role, such as in schooling and flocking. By quantifying how animals react to one another's presence, when interaction is via conspecific avoidance rather than alignment or attraction, we present a mechanistic insight that enables us to link individual behavior and space use patterns. As animals respond to both current and past positions of their neighbors, the assumption that the relative location of individuals is statistically and history independent is not tenable, underscoring the limitations of traditional space use studies. We move beyond that assumption by constructing a framework to analyze spatial segregation of mobile animals when neighbor proximity may elicit a retreat, and by linking conspecific encounter rate to history-dependent avoidance behavior. Our approach rests on the knowledge that animals communicate by modifying the environment in which they live, providing a method to analyze social cohesion as stigmergy, a form of mediated animal-animal interaction. By considering a population of animals that mark the terrain as they move, we predict how the spatiotemporal patterns that emerge depend on the degree of stigmergy of the interaction processes. We find in particular that nonlocal decision rules may generate a nonmonotonic dependence of the animal encounter rate as a function of the tendency to retreat from locations recently visited by other conspecifics, which has fundamental implications for epidemic disease spread and animal sociality.

@article{doi101073pnas1307071110,
    author = "Giuggioli, Luca and Potts, Jonathan R and Rubenstein, Daniel I and Levin, Simon A",
    title = "Stigmergy, collective actions, and animal social spacing.",
    year = "2013",
    journal = "Proceedings of the National Academy of Sciences of the United States of America",
    abstract = "Collective animal behavior studies have led the way in developing models that account for a large number of individuals, but mostly have considered situations in which alignment and attraction play a key role, such as in schooling and flocking. By quantifying how animals react to one another's presence, when interaction is via conspecific avoidance rather than alignment or attraction, we present a mechanistic insight that enables us to link individual behavior and space use patterns. As animals respond to both current and past positions of their neighbors, the assumption that the relative location of individuals is statistically and history independent is not tenable, underscoring the limitations of traditional space use studies. We move beyond that assumption by constructing a framework to analyze spatial segregation of mobile animals when neighbor proximity may elicit a retreat, and by linking conspecific encounter rate to history-dependent avoidance behavior. Our approach rests on the knowledge that animals communicate by modifying the environment in which they live, providing a method to analyze social cohesion as stigmergy, a form of mediated animal-animal interaction. By considering a population of animals that mark the terrain as they move, we predict how the spatiotemporal patterns that emerge depend on the degree of stigmergy of the interaction processes. We find in particular that nonlocal decision rules may generate a nonmonotonic dependence of the animal encounter rate as a function of the tendency to retreat from locations recently visited by other conspecifics, which has fundamental implications for epidemic disease spread and animal sociality.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC3801015/",
    doi = "10.1073/pnas.1307071110",
    pmcid = "PMC3801015",
    pmid = "24082100"
}

Drift fences with traps are commonly used for ecological research and survey. Field studies have examined the effectiveness of selected fence layouts, but comprehensive field testing is impractical. We applied a simulation approach to investigate how the interaction of fence layout and animal movement type influence fence encounter rates. A range of fence layouts, varying in spacing and configuration, were chosen based on common field practices and recommendations in the literature. Animal movement patterns ranged from meandering (Brownian) to highly directional over distances of 10 to 500 m. We found that fences in short, straight, widely spaced arrangements would be encountered more frequently by highly mobile animals than the same amount of fence in complex or continuous configurations. The dispersed arrangement was encountered just as often by animals with more limited movement patterns as were closer spaced fences. Consequently, for broad‐scale surveys, as opposed to studies on individuals' movements and microhabitat use, we recommend spacing trap/fence units in relation to the movement abilities of the most mobile species being sought. For studies that require intense point sampling, additional fencing should increase the total rate that animals encounter fences at a point but the increase will not be proportional to the additional fencing used. The software is provided to allow for other configurations of fences and movement patterns to be investigated.

@article{ellis2014a,
    author = "Ellis, Murray V. and Bedward, Michael",
    title = "A simulation study to quantify drift fence configuration and spacing effects when sampling mobile animals",
    year = "2014",
    journal = "Ecosphere",
    abstract = "Drift fences with traps are commonly used for ecological research and survey. Field studies have examined the effectiveness of selected fence layouts, but comprehensive field testing is impractical. We applied a simulation approach to investigate how the interaction of fence layout and animal movement type influence fence encounter rates. A range of fence layouts, varying in spacing and configuration, were chosen based on common field practices and recommendations in the literature. Animal movement patterns ranged from meandering (Brownian) to highly directional over distances of 10 to 500 m. We found that fences in short, straight, widely spaced arrangements would be encountered more frequently by highly mobile animals than the same amount of fence in complex or continuous configurations. The dispersed arrangement was encountered just as often by animals with more limited movement patterns as were closer spaced fences. Consequently, for broad‐scale surveys, as opposed to studies on individuals' movements and microhabitat use, we recommend spacing trap/fence units in relation to the movement abilities of the most mobile species being sought. For studies that require intense point sampling, additional fencing should increase the total rate that animals encounter fences at a point but the increase will not be proportional to the additional fencing used. The software is provided to allow for other configurations of fences and movement patterns to be investigated.",
    url = "https://doi.org/10.1890/es14-00078.1",
    doi = "10.1890/es14-00078.1",
    number = "5",
    pages = "1-20",
    volume = "5"
}

Drift fences with traps are commonly used for ecological research and survey. Field studies have examined the effectiveness of selected fence layouts, but comprehensive field testing is impractical. We applied a simulation approach to investigate how the interaction of fence layout and animal movement type influence fence encounter rates. A range of fence layouts, varying in spacing and configuration, were chosen based on common field practices and recommendations in the literature. Animal movement patterns ranged from meandering (Brownian) to highly directional over distances of 10 to 500 m. We found that fences in short, straight, widely spaced arrangements would be encountered more frequently by highly mobile animals than the same amount of fence in complex or continuous configurations. The dispersed arrangement was encountered just as often by animals with more limited movement patterns as were closer spaced fences. Consequently, for broad-scale surveys, as opposed to studies on individuals' movements and microhabitat use, we recommend spacing trap/fence units in relation to the movement abilities of the most mobile species being sought. For studies that require intense point sampling, additional fencing should increase the total rate that animals encounter fences at a point but the increase will not be proportional to the additional fencing used. The software is provided to allow for other configurations of fences and movement patterns to be investigated.

@misc{ellis2016a,
    author = "Ellis, Murray V. and Bedward, Michael",
    title = "A simulation study to quantify drift fence configuration and spacing effects when sampling mobile animals",
    year = "2016",
    publisher = "Figshare",
    abstract = "Drift fences with traps are commonly used for ecological research and survey. Field studies have examined the effectiveness of selected fence layouts, but comprehensive field testing is impractical. We applied a simulation approach to investigate how the interaction of fence layout and animal movement type influence fence encounter rates. A range of fence layouts, varying in spacing and configuration, were chosen based on common field practices and recommendations in the literature. Animal movement patterns ranged from meandering (Brownian) to highly directional over distances of 10 to 500 m. We found that fences in short, straight, widely spaced arrangements would be encountered more frequently by highly mobile animals than the same amount of fence in complex or continuous configurations. The dispersed arrangement was encountered just as often by animals with more limited movement patterns as were closer spaced fences. Consequently, for broad-scale surveys, as opposed to studies on individuals' movements and microhabitat use, we recommend spacing trap/fence units in relation to the movement abilities of the most mobile species being sought. For studies that require intense point sampling, additional fencing should increase the total rate that animals encounter fences at a point but the increase will not be proportional to the additional fencing used. The software is provided to allow for other configurations of fences and movement patterns to be investigated.",
    url = "https://figshare.com/collections/A\_simulation\_study\_to\_quantify\_drift\_fence\_configuration\_and\_spacing\_effects\_when\_sampling\_mobile\_animals/3308349",
    doi = "10.6084/m9.figshare.c.3308349"
}

Migrating animals occur along a continuum from species that spend the nonbreeding season at a fixed location to species that are nomadic during the nonbreeding season, essentially continuously moving. Such variation is likely driven by the economics of territoriality or heterogeneity in the environment. The Snowy Owl (Bubo scandiacus) is known for its complex seasonal movements, and thus an excellent model to test these ideas, as many individuals travel unpredictably along irregular routes during both the breeding and nonbreeding seasons. Two possible explanations for this large variation in the propensity to move are: (1) dominance hierarchies in which dominant individuals (adult females in this case) monopolize some key, consistent resources, and move less than subdominants and (2) habitat heterogeneity in which individuals foraging in rich and less heterogenic environments are less mobile. We analyzed fine-scale telemetry data (GPS/GSM) from 50 Snowy Owls tagged in eastern and central North America from 2013–2019, comparing space use during the winter period according to sex and age, and to land cover attributes. We used variograms to classify individuals as nomadic (58%) or range-resident (42%), and found that nomadic owls had ten times larger wintering areas than range-resident owls. The frequency of nomadism was similar in socially-dominant adult females, immatures and males. However, nomadism increased from west to east, and north to south, and was positively associated with use of water and negatively associated with croplands. We conclude that many individual Snowy Owls in Eastern North America are nomadic during the nonbreeding season and that movement patterns during this time are driven primarily by extrinsic factors, specifically heterogeneity in habitat and prey availability, as opposed to intrinsic factors associated with spacing behavior, such as age and sex.

@misc{mccabe2021landscape,
    author = "McCabe, Rebecca",
    title = "Landscape cover type, not social dominance, is associated with the winter movement patterns of snowy owls in temperate areas",
    year = "2021",
    publisher = "Dryad",
    abstract = "Migrating animals occur along a continuum from species that spend the nonbreeding season at a fixed location to species that are nomadic during the nonbreeding season, essentially continuously moving. Such variation is likely driven by the economics of territoriality or heterogeneity in the environment. The Snowy Owl (Bubo scandiacus) is known for its complex seasonal movements, and thus an excellent model to test these ideas, as many individuals travel unpredictably along irregular routes during both the breeding and nonbreeding seasons. Two possible explanations for this large variation in the propensity to move are: (1) dominance hierarchies in which dominant individuals (adult females in this case) monopolize some key, consistent resources, and move less than subdominants and (2) habitat heterogeneity in which individuals foraging in rich and less heterogenic environments are less mobile. We analyzed fine-scale telemetry data (GPS/GSM) from 50 Snowy Owls tagged in eastern and central North America from 2013–2019, comparing space use during the winter period according to sex and age, and to land cover attributes. We used variograms to classify individuals as nomadic (58\%) or range-resident (42\%), and found that nomadic owls had ten times larger wintering areas than range-resident owls. The frequency of nomadism was similar in socially-dominant adult females, immatures and males. However, nomadism increased from west to east, and north to south, and was positively associated with use of water and negatively associated with croplands. We conclude that many individual Snowy Owls in Eastern North America are nomadic during the nonbreeding season and that movement patterns during this time are driven primarily by extrinsic factors, specifically heterogeneity in habitat and prey availability, as opposed to intrinsic factors associated with spacing behavior, such as age and sex.",
    url = "https://datadryad.org/dataset/doi:10.5061/dryad.5dv41ns51",
    doi = "10.5061/dryad.5dv41ns51"
}