Environmental factors affecting the web and activity of a psammophilous spider in the Namib Desert
TL;DR: In this paper, the authors describe the structure of the web and examine the influence of certain environmental factors on web design and spider activity, including wind-blown sand covering the web's capture elements and disrupting foraging activity.
About: This article is published in Journal of Arid Environments.The article was published on 1992-03-01. It has received 54 citations till now. The article focuses on the topics: Sand dune stabilization & Seothyra.
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TL;DR: This chapter discusses the occurrence of group living in spiders and illustrates that, as this terminology is also somewhat unwieldy, for convenience it revert to the commonly used shorthand designations of social and subsocial, for nonterritorial permanent‐social and territorial periodic‐social, respectively.
Abstract: Publisher Summary This chapter discusses the occurrence of group living in spiders. Group living has arisen in spiders in basically two different forms. Cooperative or nonterritorial permanent‐social species are the main focus of the chapter. The form of group living in spiders has been termed “colonial” or “communalterritorial.” Colonial species have been likened to foraging flocks of birds and are described as foraging societies. Social spiders can be viewed as an ideal evolutionary experiment with independent replicates, both within and across several families. The designation of species as nonterritorial permanent‐social and nonterritorial periodic‐social applies to groups of traits that generally occur together. The chapter illustrates that, as this terminology is also somewhat unwieldy, for convenience it revert to the commonly used shorthand designations of social and subsocial, for nonterritorial permanent‐social and territorial periodic‐social, respectively.
259 citations
Cites background from "Environmental factors affecting the..."
...…Theridion, Achaearanea; Agnarsson, 2004), in all Eresidae that have been studied to date (Dorceus, Eresus, Seothyra, Stegodyphus; D’Andrea, 1987; Henschel and Lubin, 1992; Kraus and Kraus, 1988; Kullmann, 1972; Y. L., personal observations), in the Amaurobioidea families Agelenidae…...
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01 Jan 1998
TL;DR: An Informal Discussion of Hearing in Insects and the Sensory Coevolution of Moths and Bats.
Abstract: 1 Acute as a Bug's Ear: An Informal Discussion of Hearing in Insects.- 2 Biophysics of Sound Localization in Insects.- 3 The Sensory Ecology of Acoustic Communication in Insects.- 4 Development of the Insect Auditory System.- 5 Neural Processing of Acoustic Signals.- 6 The Evolutionary Innovation of Tympanal Hearing in Diptera.- 7 The Vibrational Sense of Spiders.- 8 The Sensory Coevolution of Moths and Bats.
162 citations
TL;DR: The results indicate that invasive plants that change the architecture of native vegetation can substantially impact native food webs via nontraditional plant → predator →-consumer linkages.
Abstract: As primary producers, plants are known to influence higher trophic interactions by initiating food chains. However, as architects, plants may bypass consum- ers to directly affect predators with important but underappreciated trophic ramifications. Invasion of western North American grasslands by the perennial forb, spot- ted knapweed (Centaurea maculosa), has fundamentally altered the architecture of native grassland vegetation. Here, I use long-term monitoring, observational studies, and field experiments to document how changes in vegetation archi- tecture have affected native web spider populations and predation rates. Native spiders that use vegetation as web substrates were collectively 38 times more abundant in C. maculosa-invaded grasslands than in uninvaded grass- lands. This increase in spider abundance was accompanied by a large shift in web spider community structure, driven primarily by the strong response of Dictyna spiders to C. maculosa invasion. Dictyna densities were 46-74 times higher in C. maculosa-invaded than native grasslands, a pattern that persisted over 6 years of monitoring. C. mac- ulosa also altered Dictyna web building behavior and foraging success. Dictyna webs on C. maculosa were 2.9- 4.0 times larger and generated 2.0-2.3 times higher total prey captures than webs on Achillea millefolium, their primary native substrate. Dictyna webs on C. maculosa also captured 4.2 times more large prey items, which are crucial for reproduction. As a result, Dictyna were nearly twice as likely to reproduce on C. maculosa substrates compared to native substrates. The overall outcome of C. maculosa invasion and its transformative effects on vegetation archi- tecture on Dictyna density and web building behavior were to increase Dictyna predation on invertebrate prey C89 fold. These results indicate that invasive plants that change the architecture of native vegetation can substantially impact native food webs via nontraditional plant ? preda- tor ? consumer linkages.
145 citations
Cites background from "Environmental factors affecting the..."
...Individual spiders can modify web attributes as a behavioral response to variation in predation threats, prey availability, microclimatic conditions, and changing resource demands (Higgins 1990, 1992; Henschel and Lubin 1992; Heiling 1999; Venner et al. 2003)....
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...modify web attributes as a behavioral response to variation in predation threats, prey availability, microclimatic conditions, and changing resource demands (Higgins 1990, 1992; Henschel and Lubin 1992; Heiling 1999; Venner et al. 2003)....
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TL;DR: The spider Parawixia bistriata spun two types of webs in response to temporally fluctuating prey availability: small webs of fine mesh were spun daily at sunset and ceptured mainly small dipterans of the genus Dorhniphora.
Abstract: 1. Plasticity in foraging strategies may be an evolutionary response of predators to temporally or spatially variable resources. Although orb-weaver spiders use the web to capture a variety of prey types and sizes, plasticity in web design in response to such variation has rarely been documented. 2. The spider Parawixia bistriata spun two types of webs in response to temporally fluctuating prey availability. Small webs of fine mesh were spun daily at sunset and ceptured mainly small dipterans of the genus Dorhniphora. Large webs of wide mesh were spun only during diurnal termite swarms
139 citations
TL;DR: This work critically evaluates contemporary evolutionary hypotheses that might be used to explain the evolution of specialised foraging in predators, and proposes a unifying concept within which four types of trophic categories are defined using ecological (diet breadth) and evolutionary contexts.
Abstract: Predators appear to be less frequently specialised (i.e. adapted to restricted diet) on their prey than herbivores, parasites or parasitoids. Here, we critically evaluate contemporary evolutionary hypotheses that might be used to explain the evolution of specialised foraging in predators. We propose a unifying concept within which we define four types of trophic categories using ecological (diet breadth) and evolutionary (degree of adaptations) contexts. We use data on spiders (Araneae), the most diversified order of terrestrial predators, to assess applicability of frameworks and evolutionary concepts related to trophic specialisation. The majority of spider species are euryphagous but a few have a restricted prey range, i.e. they are stenophagous. We provide a detailed overview of specialisation on different prey types, namely spiders, crustaceans, moths, dipterans, ants, and termites. We also review the available evidence for trophic adaptations, classified into four categories: behavioural, morphological, venomic and metabolic. Finally, we discuss the ecological and evolutionary implications of trophic specialisation and propose avenues for future research.
122 citations
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TL;DR: This work presents several examples of exaptation, indicating where a failure to concep- tualize such an idea limited the range of hypotheses previously available, and proposes a terminological solution to the problem of preadaptation.
Abstract: Adaptation has been defined and recognized by two different criteria: historical genesis (fea- tures built by natural selection for their present role) and current utility (features now enhancing fitness no matter how they arose). Biologists have often failed to recognize the potential confusion between these different definitions because we have tended to view natural selection as so dominant among evolutionary mechanisms that historical process and current product become one. Yet if many features of organisms are non-adapted, but available for useful cooptation in descendants, then an important concept has no name in our lexicon (and unnamed ideas generally remain unconsidered): features that now enhance fitness but were not built by natural selection for their current role. We propose that such features be called exaptations and that adaptation be restricted, as Darwin suggested, to features built by selection for their current role. We present several examples of exaptation, indicating where a failure to concep- tualize such an idea limited the range of hypotheses previously available. We explore several consequences of exaptation and propose a terminological solution to the problem of preadaptation.
3,996 citations
Book•
01 Jan 1941
TL;DR: The physics of blown sand and desert dunes, The physics of windblown sand and sand dunes, this paper, and the physics of dunes in the Middle East and Africa.
Abstract: The physics of blown sand and desert dunes , The physics of blown sand and desert dunes , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
3,315 citations
Book•
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TL;DR: An updated translation of the definitive text on spider biology by the author of the second German-language edition from Thieme Verlag, with greater emphasis on ecology and systematics.
Abstract: 1. An Introduction to Spiders 2. Functional Anatomy 3. Metabolism 4. Neurobiology 5. Spider Webs 6. Locomotion and Prey Capture 7. Reproduction 8. Development 9. Ecology 10. Phylogeny and Systematics
2,115 citations
Book•
01 Jan 1965
TL;DR: In this article, the effect of low plant cover on the surface air layer of a level ground without vegetation was analyzed. And the influence of topography on the microclimate was investigated.
Abstract: Introduction 1 Introduction Part 1 2 Earth's Surface Energy Budget Part 2 3 The Air Layer over Level Ground without Vegetation Part 3 4 Influence of the Underlying Surface on the Adjacent Air Layer Part 4 5 Futher Analysis of the Energy Balance Part 5 6 The Effect of Low Plant Cover on the Surface Air Layer Part 6 7 Forest Climatology Part 7 8 The Influence of Topography on the Microclimate Part 8 9 Interrelation of Animals and Humans to the Microclimate
1,954 citations
1,137 citations