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Herringe CA, Middleton EJ, Boyd KC, Latty T, White TE. Benefits and costs of social foraging in velvet worms. Ethology 2021. [DOI: 10.1111/eth.13256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Caragh A. Herringe
- School of Life and Environmental Sciences The University of Sydney Sydney Australia
| | - Eliza J. Middleton
- School of Life and Environmental Sciences The University of Sydney Sydney Australia
| | - Kelsey C. Boyd
- School of Life and Environmental Sciences The University of Sydney Sydney Australia
- School of Earth, Atmospheric and Life Sciences University of Wollongong Wollongong Australia
| | - Tanya Latty
- School of Life and Environmental Sciences The University of Sydney Sydney Australia
| | - Thomas E. White
- School of Life and Environmental Sciences The University of Sydney Sydney Australia
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2
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Straus S, González AL, Matthews P, Avilés L. Economies of scale shape energetics of solitary and group-living spiders and their webs. J Anim Ecol 2021; 91:255-265. [PMID: 34758114 DOI: 10.1111/1365-2656.13628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 10/22/2021] [Indexed: 11/28/2022]
Abstract
Metabolic scaling, whereby larger individuals use less energy per unit mass than smaller ones, may apply to the combined metabolic rate of group-living organisms as group size increases. Spiders that form groups in high disturbance environments can serve to test the hypothesis that economies of scale benefit social groups. Using solitary and group-living spiders, we tested the hypothesis that spiders exhibit negative allometry between body or colony mass and the standing mass of their webs and whether, and how, such a relationship may contribute to group-living benefits in a cooperative spider. Given the diverse architecture of spider webs-orb, tangle and sheet-and-tangle, and associated differences in silk content, we first assessed how standing web mass scales with spider mass as a function of web architecture and whether investment in silk differs among web types. As group-living spiders are predominantly found in clades that build the presumably costlier sheet-and-tangle webs, we then asked whether cost-sharing through cooperative web maintenance contributes to a positive energy budget in a social species. We found that larger spiders had a relatively smaller investment in silk per unit mass than smaller ones, but more complex sheet-and-tangle webs contained orders of magnitude more silk than simpler orb or tangle ones. In the group-living species, standing web mass per unit spider mass continued to decline as colony size increased with a similar slope as for unitary spiders. When web maintenance activities were considered, colonies also experienced reduced mass-specific energy expenditure with increasing colony size. Activity savings contributed to a net positive energy balance for medium and large colonies after inputs from the cooperative capture of large prey were accounted for. Economies of scale have been previously demonstrated in animal societies characterized by reproductive and worker castes, but not in relatively egalitarian societies as those of social spiders. Our findings illustrate the universality of scaling laws and how economies of scale may transcend hunting strategies and levels of organization.
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Affiliation(s)
- Samantha Straus
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Angélica L González
- Biology Department & Center for Computational and Integrative Biology, Rutgers University, Camden, NJ, USA
| | - Philip Matthews
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Leticia Avilés
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
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3
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Predictors of colony extinction vary by habitat type in social spiders. Behav Ecol Sociobiol 2020; 74. [PMID: 32431472 DOI: 10.1007/s00265-019-2781-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Many animal societies are susceptible to mass mortality events and collapse. Elucidating how environmental pressures determine patterns of collapse is important for understanding how such societies function and evolve. Using the social spider Stegodyphus dumicola, we investigated the environmental drivers of colony extinction along two precipitation gradients across southern Africa, using the Namib and Kalahari deserts versus wetter savanna habitats to the north and east. We deployed experimental colonies (n = 242) along two ~ 800-km transects and returned to assess colony success in the field after 2 months. Specifically, we noted colony extinction events after the 2-month duration and collected environmental data on the correlates of those extinction events (e.g., evidence of ant attacks, no. of prey captured). We found that colony extinction events at desert sites were more frequently associated with attacks by predatory ants as compared with savanna sites, while colony extinctions in wetter savannas sites were more tightly associated with fungal outbreaks. Our findings support the hypothesis that environments vary in the selection pressures that they impose on social organisms, which may explain why different social phenotypes are often favored in each habitat.
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Majer M, Holm C, Lubin Y, Bilde T. Cooperative foraging expands dietary niche but does not offset intra-group competition for resources in social spiders. Sci Rep 2018; 8:11828. [PMID: 30087391 PMCID: PMC6081395 DOI: 10.1038/s41598-018-30199-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 07/06/2018] [Indexed: 11/23/2022] Open
Abstract
Group living animals invariably risk resource competition. Cooperation in foraging, however, may benefit individuals in groups by facilitating an increase in dietary niche. To test this, we performed a comparative study of social and solitary spider species. Three independently derived social species of Stegodyphus (Eresidae) occupy semi-arid savannas and overlap with three solitary congeners. We estimated potential prey availability in the environment and prey acquisition by spiders in their capture webs. We calculated dietary niche width (prey size) and breadth (taxonomic range) to compare resource use for these six species, and investigated the relationships between group size and average individual capture web production, prey biomass intake rate and variance in biomass intake. Cooperative foraging increased dietary niche width and breadth by foraging opportunistically, including both larger prey and a wider taxonomic range of prey in the diet. Individual capture web production decreased with increasing group size, indicating energetic benefits of cooperation, and variance in individual intake rate was reduced. However, individual biomass intake also decreased with increasing group size. While cooperative foraging did not completely offset resource competition among group members, it may contribute to sustaining larger groups by reducing costs of web production, increasing the dietary niche and reducing the variance in prey capture.
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Affiliation(s)
- Marija Majer
- Blaustein Institutes for Desert Research, Mitrani Department of Desert Ecology, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, 8499000, Israel
- Institute of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus, Denmark
| | - Christina Holm
- Institute of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus, Denmark
| | - Yael Lubin
- Blaustein Institutes for Desert Research, Mitrani Department of Desert Ecology, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, 8499000, Israel.
| | - Trine Bilde
- Institute of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus, Denmark
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5
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Dumke M, Herberstein ME, Schneider JM. Advantages of social foraging in crab spiders: Groups capture more and larger prey despite the absence of a web. Ethology 2018. [DOI: 10.1111/eth.12774] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Marlis Dumke
- Department of Biology, Zoological Institute and Museum; University Hamburg; Hamburg Germany
- Department of Biological Sciences; Macquarie University; North Ryde New South Wales Australia
| | - Marie E. Herberstein
- Department of Biological Sciences; Macquarie University; North Ryde New South Wales Australia
| | - Jutta M. Schneider
- Department of Biological Sciences; Macquarie University; North Ryde New South Wales Australia
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6
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Nahas L, Gonzaga MO, Del-Claro K. Wandering and web spiders feeding on the nectar from extrafloral nectaries in neotropical savanna. J Zool (1987) 2016. [DOI: 10.1111/jzo.12400] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- L. Nahas
- Universidade Federal de Uberlândia; Uberlândia MG Brazil
| | - M. O. Gonzaga
- Instituto de Biologia; Universidade Federal de Uberlândia; Uberlândia MG Brazil
| | - K. Del-Claro
- Instituto de Biologia; Universidade Federal de Uberlândia; Uberlândia MG Brazil
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7
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Sharpe RV, Avilés L. Prey size and scramble vs. contest competition in a social spider: implications for population dynamics. J Anim Ecol 2016; 85:1401-10. [PMID: 27300160 DOI: 10.1111/1365-2656.12559] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 06/07/2016] [Indexed: 11/27/2022]
Abstract
There are many benefits of group living, but also substantial costs, one of which is competition for resources. How scarce food resources are distributed among different members of a population or social group - whether via scramble or contest competition - can influence not only the variance in individual fitness, but also the stability and therefore survival of the group or population. Attributes of the food resources themselves, such as their size, may influence the type of intraspecific competition that occurs and therefore the intrinsic stability of a group or population. By experimentally manipulating the size of prey fed to artificial colonies of the social spider Anelosimus eximius, we investigated whether prey size could alter the degree of scramble vs. contest competition that takes place and, thus, potentially influence colony population dynamics. We found that large prey were shared more evenly than small prey and that individuals in poor condition were more likely to feed when prey were large than when prey were small. Additionally, we show that individuals participating in prey capture are also more likely to feed on the captured prey. We developed a simple mathematical model to explore the prey sizes that would be energetically worth defending, i.e. prey that are 'economically defendable'. The model shows that neither very small prey, nor prey above a certain size is worth monopolizing, with only intermediate size prey being 'economically defendable'. We therefore suggest the small and large prey in our experiment corresponds to our model's intermediate and large prey categories, respectively. As the size of prey captured by social spider colonies increases with colony size, our findings suggest that scramble competition may predominate in large colonies. Scramble competition, combined with the fact that prey biomass per capita declines as colonies grow beyond a certain size, would then explain why extremely large colonies of this social spider may suddenly go extinct. Our project thus illustrates the potential triple link between characteristics of the resources, individual behaviour and population dynamics, a link rarely considered in an empirical setting.
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Affiliation(s)
- Ruth V Sharpe
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Leticia Avilés
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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8
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Keiser CN, Wright CM, Pruitt JN. Increased bacterial load can reduce or negate the effects of keystone individuals on group collective behaviour. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.02.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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9
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Vanthournout B, Greve M, Bruun A, Bechsgaard J, Overgaard J, Bilde T. Benefits of Group Living Include Increased Feeding Efficiency and Lower Mass Loss during Desiccation in the Social and Inbreeding Spider Stegodyphus dumicola. Front Physiol 2016; 7:18. [PMID: 26869936 PMCID: PMC4735397 DOI: 10.3389/fphys.2016.00018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 01/12/2016] [Indexed: 01/13/2023] Open
Abstract
Group living carries a price: it inherently entails increased competition for resources and reproduction, and may also be associated with mating among relatives, which carries costs of inbreeding. Nonetheless, group living and sociality is found in many animals, and understanding the direct and indirect benefits of cooperation that override the inherent costs remains a challenge in evolutionary ecology. Individuals in groups may benefit from more efficient management of energy or water reserves, for example in the form of reduced water or heat loss from groups of animals huddling, or through reduced energy demands afforded by shared participation in tasks. We investigated the putative benefits of group living in the permanently social spider Stegodyphus dumicola by comparing the effect of group size on standard metabolic rate, lipid/protein content as a body condition measure, feeding efficiency, per capita web investment, and weight/water loss and survival during desiccation. Because energetic expenditure is temperature sensitive, some assays were performed under varying temperature conditions. We found that feeding efficiency increased with group size, and the rate of weight loss was higher in solitary individuals than in animals in groups of various sizes during desiccation. Interestingly, this was not translated into differences in survival or in standard metabolic rate. We did not detect any group size effects for other parameters, and group size effects did not co-vary with experimental temperature in a predictive manner. Both feeding efficiency and mass loss during desiccation are relevant ecological factors as the former results in lowered predator exposure time, and the latter benefits social spiders which occupy arid, hot environments.
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Affiliation(s)
| | - Michelle Greve
- Department of Bioscience, Aarhus UniversityAarhus, Denmark; Department of Plant Science, University of PretoriaHatfield, South Africa
| | - Anne Bruun
- Department of Bioscience, Aarhus University Aarhus, Denmark
| | | | | | - Trine Bilde
- Department of Bioscience, Aarhus University Aarhus, Denmark
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10
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Sutton GJ, Hoskins AJ, Arnould JPY. Benefits of Group Foraging Depend on Prey Type in a Small Marine Predator, the Little Penguin. PLoS One 2015; 10:e0144297. [PMID: 26674073 PMCID: PMC4682954 DOI: 10.1371/journal.pone.0144297] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/16/2015] [Indexed: 11/18/2022] Open
Abstract
Group foraging provides predators with advantages in over-powering prey larger than themselves or in aggregating small prey for efficient exploitation. For group-living predatory species, cooperative hunting strategies provide inclusive fitness benefits. However, for colonial-breeding predators, the benefit pay-offs of group foraging are less clear due to the potential for intra-specific competition. We used animal-borne cameras to determine the prey types, hunting strategies, and success of little penguins (Eudyptula minor), a small, colonial breeding air-breathing marine predator that has recently been shown to display extensive at-sea foraging associations with conspecifics. Regardless of prey type, little penguins had a higher probability of associating with conspecifics when hunting prey that were aggregated than when prey were solitary. In addition, success was greater when individuals hunted schooling rather than solitary prey. Surprisingly, however, success on schooling prey was similar or greater when individuals hunted on their own than when with conspecifics. These findings suggest individuals may be trading-off the energetic gains of solitary hunting for an increased probability of detecting prey within a spatially and temporally variable prey field by associating with conspecifics.
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Affiliation(s)
- Grace J. Sutton
- Deakin University, School of Life and Environmental Sciences (Burwood Campus), Geelong, Australia
- * E-mail:
| | - Andrew J. Hoskins
- CSIRO Land and Water, Canberra, Australian Capital Territory, Australia
| | - John P. Y. Arnould
- Deakin University, School of Life and Environmental Sciences (Burwood Campus), Geelong, Australia
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11
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12
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Keiser CN, Wright CM, Pruitt JN. Warring arthropod societies: Social spider colonies can delay annihilation by predatory ants via reduced apparency and increased group size. Behav Processes 2015. [PMID: 26205161 DOI: 10.1016/j.beproc.2015.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sociality provides individuals with benefits via collective foraging and anti-predator defense. One of the costs of living in large groups, however, is increased apparency to natural enemies. Here, we test how the individual-level and collective traits of spider societies can increase the risk of discovery and death by predatory ants. We transplanted colonies of the social spider Stegodyphus dumicola into a habitat dense with one of their top predators, the pugnacious ant Anoplolepis custodiens. With three different experiments, we test how colony-wide survivorship in a predator-dense habitat can be altered by colony apparency (i.e., the presence of a capture web), group size, and group composition (i.e., the proportion of bold and shy personality types present). We also test how spiders' social context (i.e., living solitarily vs. among conspecifics) modifies their behaviour toward ants in their capture web. Colonies with capture webs intact were discovered by predatory ants on average 25% faster than colonies with the capture web removed, and all discovered colonies eventually collapsed and succumbed to predation. However, the lag time from discovery by ants to colony collapse was greater for colonies containing more individuals. The composition of individual personality types in the group had no influence on survivorship. Spiders in a social group were more likely to approach ants caught in their web than were isolated spiders. Isolated spiders were more likely to attack a safe prey item (a moth) than they were to attack ants and were more likely to retreat from ants after contact than they were after contact with moths. Together, our data suggest that the physical structures produced by large animal societies can increase their apparency to natural enemies, though larger groups can facilitate a longer lag time between discovery and demise. Lastly, the interaction between spiders and predatory ants seems to depend on the social context in which spiders reside.
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Affiliation(s)
- Carl N Keiser
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - Colin M Wright
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jonathan N Pruitt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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13
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Pruitt JN, Riechert SE. How within-group behavioural variation and task efficiency enhance fitness in a social group. Proc Biol Sci 2010; 278:1209-15. [PMID: 20943687 DOI: 10.1098/rspb.2010.1700] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
How task specialization, individual task performance and within-group behavioural variation affects fitness is a longstanding and unresolved problem in our understanding of animal societies. In the temperate social spider, Anelosimus studiosus, colony members exhibit a behavioural polymorphism; females either exhibit an aggressive 'asocial' or docile 'social' phenotype. We assessed individual prey-capture success for both phenotypes, and the role of phenotypic composition on group-level prey-capture success for three prey size classes. We then estimated the effect of group phenotypic composition on fitness in a common garden, as inferred from individual egg-case masses. On average, asocial females were more successful than social females at capturing large prey, and colony-level prey-capture success was positively associated with the frequency of the asocial phenotype. Asocial colony members were also more likely to engage in prey-capture behaviour in group-foraging situations. Interestingly, our fitness estimates indicate females of both phenotypes experience increased fitness when occupying colonies containing unlike individuals. These results imply a reciprocal fitness benefit of within-colony behavioural variation, and perhaps division of labour in a spider society.
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Affiliation(s)
- Jonathan N Pruitt
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996-1610, USA.
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14
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Purcell J. Geographic patterns in the distribution of social systems in terrestrial arthropods. Biol Rev Camb Philos Soc 2010; 86:475-91. [PMID: 20840372 DOI: 10.1111/j.1469-185x.2010.00156.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The role of ecology in the evolution and maintenance of arthropod sociality has received increasing research attention in recent years. In some organisms, such as halictine bees, polistine wasps, and social spiders, researchers are investigating the environmental factors that may contribute to high levels of variation in the degree of sociality exhibited both among and within species. Within lineages that include only eusocial members, such as ants and termites, studies focus more on identifying extrinsic factors that may contribute to the dramatic variation in colony size, number of queens, and division of labour that is evident across these species. In this review, I propose a comparative approach that seeks to identify environmental factors that may have a common influence across such divergent social arthropod groups. I suggest that seeking common biogeographic patterns in the distribution of social systems or key social traits may help us to identify ecological factors that play a common role in shaping the evolution of sociality across different organisms. I first review previous studies of social gradients that form along latitudinal and altitudinal axes. Within families and within species, many organisms show an increasing degree of sociality at lower latitudes and altitudes. In a smaller number of cases, organisms form larger groups or found nests cooperatively at higher latitudes and altitudes. I then describe several environmental factors that vary consistently along such gradients, including climate variables and abundance of predators, and outline their proposed role in the social systems of terrestrial arthropods. Finally, I map distributions of a social trait against several climatic factors in five case studies to demonstrate how future comparative studies could inform empirical research.
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Affiliation(s)
- Jessica Purcell
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada.
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15
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Wickler W, Seibt U. Pedogenetic Sociogenesis via the “Sibling-route” and some Consequences for Stegodyphus Spiders. Ethology 2010. [DOI: 10.1111/j.1439-0310.1993.tb00452.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Schneider JM. Food Intake, Growth and Relatedness in the Subsocial Spider, Stegodyphus lineatus (Eresidae). Ethology 2010. [DOI: 10.1111/j.1439-0310.1996.tb01134.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Pasquet A, Leborgne R, Cantarella T. Opportunistic Egg Feeding in the Kleptoparasitic Spider Argyrodes gibbosus. Ethology 2010. [DOI: 10.1111/j.1439-0310.1997.tb00015.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Purcell J, Avilés L. Gradients of precipitation and ant abundance may contribute to the altitudinal range limit of subsocial spiders: insights from a transplant experiment. Proc Biol Sci 2008; 275:2617-25. [PMID: 18682370 PMCID: PMC2605798 DOI: 10.1098/rspb.2008.0582] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Accepted: 07/14/2008] [Indexed: 11/12/2022] Open
Abstract
Species range boundaries often form along environmental gradients that dictate the success of the phenotypes present in each habitat. Sociality may allow colonization of environments where related species with a solitary lifestyle cannot persist. Social spiders in the genus Anelosimus appear restricted to low- and mid-elevation moist environments in the tropics, while subsocial spiders, common at higher elevations and latitudes, appear to be absent from the lowland tropical rainforest. Here, we seek factors that may simultaneously prevent subsocial Anelosimus species from colonizing the lowland rainforest while favouring species with large social groups in this habitat. To this end, we transplanted small groups of a subsocial species, which contain the offspring of a single female, from cloud forest habitat in the centre of its natural range to lower montane rainforest on the range margin and to lowland rainforest outside of the species range. Groups transplanted at the range margin and below their range limit were less likely to disperse and experienced increased mortality. This was correlated with greater rainfall intensity and ant abundance. We show that protection from rainfall enhances the performance of small groups of spiders in the lowland rainforest, and suggest that predation or disturbance by ants may influence the geographical range limits of this species.
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Affiliation(s)
- Jessica Purcell
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4.
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19
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Pruitt JN, Riechert SE, Jones TC. Behavioural syndromes and their fitness consequences in a socially polymorphic spider, Anelosimus studiosus. Anim Behav 2008. [DOI: 10.1016/j.anbehav.2008.05.009] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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NELSON XIMENAJ, JACKSON ROBERTR. Anti-predator crèches and aggregations of ant-mimicking jumping spiders (Araneae: Salticidae). Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.2008.01006.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Powers KS, Avilés L. The role of prey size and abundance in the geographical distribution of spider sociality. J Anim Ecol 2007; 76:995-1003. [PMID: 17714278 DOI: 10.1111/j.1365-2656.2007.01267.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. Social species in the spider genus Anelosimus predominate in lowland tropical rainforests, while congeneric subsocial species occur at higher elevations or higher latitudes. 2. We conducted a comparative study to determine whether differences in total biomass, insect size or both have been responsible for this pattern. 3. We found that larger average insect size, rather than greater overall biomass per se, is a key characteristic of lowland tropical habitats correlating with greater sociality. 4. Social species occupied environments with insects several times larger than the spiders, while subsocial species nearing dispersal occupied environments with smaller insects in either high or low overall biomass. 5. Similarly, in subsocial spider colonies, individuals lived communally at a time when they were younger and therefore smaller than the average insect landing on their webs. 6. We thus suggest that the availability of large insects may be a critical factor restricting social species to their lowland tropical habitats.
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Affiliation(s)
- Kimberly S Powers
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
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22
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Fernández Campón F. Group foraging in the colonial spider Parawixia bistriata (Araneidae): effect of resource levels and prey size. Anim Behav 2007. [DOI: 10.1016/j.anbehav.2007.02.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Souza AL, Gonzaga MO, Vasconcellos-Neto J. Prey Capture Behaviour in the Social Spider Anelosimus eximius (Araneae: Theridiidae): Responses to Prey Size and Type. Ethology 2007. [DOI: 10.1111/j.1439-0310.2007.01384.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Purcell J, Avilés L. Smaller colonies and more solitary living mark higher elevation populations of a social spider. J Anim Ecol 2007; 76:590-7. [PMID: 17439475 DOI: 10.1111/j.1365-2656.2007.01228.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. There appears to be a pattern of decreasing sociality with increasing elevation across social spider species in the genus Anelosimus at tropical latitudes. Our data suggest that this pattern holds within a single species, Anelosimus eximius, on a smaller altitudinal gradient. 2. In comparing colony size at six different altitudes in north-eastern Ecuador, we find that the lowland A. eximius populations tend to have larger colonies and few solitary females. At higher elevations, many of the colonies are small and the proportion of solitary females is greater. 3. Contrary to expectation, we also found no difference in spider density between the upper elevation and lowland populations. This result may be partly due to the fact that upper elevation populations occur only at the forest edge (as opposed to both edge and interior) where populations at all elevations appear more robust.
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Affiliation(s)
- Jessica Purcell
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada.
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Avilés L, Gelsey G. Natal dispersal and demography of a subsocial Anelosimus species and its implications for the evolution of sociality in spiders. CAN J ZOOL 1998. [DOI: 10.1139/z98-177] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The transition to permanent-sociality in spiders is thought to have involved the suppression of the dispersal phase characteristic of hypothetical subsocial or periodic-social ancestral species. Extant periodic-social species may provide insights into this transition. The periodic-social Anelosimus jucundus in southern Arizona was found to form mother-offspring and sibling associations that disintegrate prior to the mating season. Following the breakdown of the social phase, more than twice as many females as males became established within a few metres of the natal nest. Given that the predispersal sex ratio was 1:1, a fraction of the males may have dispersed beyond the local area. The short dispersal distances of at least a fraction of individuals of both sexes, the clustering of nests in local areas, and at least two possible cases of sibling mating suggest, however, that dispersal may not eliminate the possibility of close inbreeding in this species. Estimated transition probabilities between life-history stages show that the heaviest loss of individuals occurs during dispersal. Once established, 41% of the females that reached maturity succeeded in producing grown progeny. We discuss the implications of these findings in terms of the transition from periodic to permanent sociality in spiders and of current models that consider the interplay between competition and inbreeding avoidance in the evolution of dispersal.
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