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You searched for subject:(Optimal Patch Use). Showing records 1 – 3 of 3 total matches.

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University of Alberta

1. Weclaw, Piotr. Optimal use of resources: classic foraging theory, satisficing and smart foraging – modelling foraging behaviors of elk.

Degree: PhD, Department of Renewable Resources, 2010, University of Alberta

It is generally accepted that the Marginal Value Theorem (MVT) describes optimal foraging strategies. Some research findings, however, indicate that in natural conditions foragers not always behave according to the MVT. To address this inconsistency, in a series of computer simulations, I examined the behaviour of four types of foragers having specific foraging efficiencies and using the MVT and alternative strategies in 16 simulated landscapes in an ideal environment (no intra- and inter-species interactions). I used data on elk (Cervus elaphus) to construct the virtual forager. Contrary to the widely accepted understanding of the MVT, I found that in environments with the same average patch quality and varying average travel times between patches, patch residence times of some foragers were not affected by travel times. I propose a mechanism responsible for this observation and formulate the perfect forager theorem (PFT). I also introduce the concepts of a foraging coefficient (F) and foragers’ hub (α), and formulate a model to describe the relationship between the perfect forager and other forager types. I identify situations where a forager aiming to choose an optimal foraging strategy and maximize its cumulative consumption should not follow the MVT. I describe these situations in a form of a mathematical model. I also demonstrate that the lack of biological realism and environmental noise are not required to explain the deviations from the MVT observed in field research, and explain the importance of scale in optimal foraging behaviour. I also demonstrate that smart foraging, which is a set of rules based on key ecological concepts: the functional response curve (FRC), satisficing, the MVT, and incorporates time limitations, should allow for fitness maximization. Thus, it should be an optimal behavior in the context of natural selection. I also demonstrate the importance of the FRC as a driver for foraging behaviors and argue that animals should focus more on increasing the slope of their FRC than on choosing a specific foraging strategy. Natural selection should, therefore, favor foragers with steep FRC. My findings introduce new concepts in behavioural ecology, have implications for animal ecology and inform wildlife management.

Subjects/Keywords: functional response curve; Cervus elaphus; smart foraging; foraging strategy; optimal use of resources; the perfect forager theorem; foragers’ hub; computer simulation model; satisficing; elk; optimal foraging; the marginal value theorem; patch residence time

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Weclaw, P. (2010). Optimal use of resources: classic foraging theory, satisficing and smart foraging – modelling foraging behaviors of elk. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/ft848r23q

Chicago Manual of Style (16th Edition):

Weclaw, Piotr. “Optimal use of resources: classic foraging theory, satisficing and smart foraging – modelling foraging behaviors of elk.” 2010. Doctoral Dissertation, University of Alberta. Accessed May 07, 2021. https://era.library.ualberta.ca/files/ft848r23q.

MLA Handbook (7th Edition):

Weclaw, Piotr. “Optimal use of resources: classic foraging theory, satisficing and smart foraging – modelling foraging behaviors of elk.” 2010. Web. 07 May 2021.

Vancouver:

Weclaw P. Optimal use of resources: classic foraging theory, satisficing and smart foraging – modelling foraging behaviors of elk. [Internet] [Doctoral dissertation]. University of Alberta; 2010. [cited 2021 May 07]. Available from: https://era.library.ualberta.ca/files/ft848r23q.

Council of Science Editors:

Weclaw P. Optimal use of resources: classic foraging theory, satisficing and smart foraging – modelling foraging behaviors of elk. [Doctoral Dissertation]. University of Alberta; 2010. Available from: https://era.library.ualberta.ca/files/ft848r23q


Swedish University of Agricultural Sciences

2. Riber Albrectsen, Benedicte. The dynamics of a tephritid seed predator on Tripolium vulgare in a stochastic and heterogeneous environment.

Degree: 2000, Swedish University of Agricultural Sciences

In this thesis the factors regulating the interaction between the seed predatory fly Paroxyna plantaginis (Diptera: Tephritidae) and its host plant Tripolium vulgare, (former Aster tripolium, Asteraceae) are determined and evaluated. The host is patchily distributed on islands in the study area (the archipelago of Skeppsvik 63°44-48' N, 20°34-40'E) in northern Sweden. Possible factors that may cause the persistence of this system include direct density-dependent feedback processes, temporal and spatial heterogeneity, and the effect of stochasticity (chance). The impact of these forces is analysed through both pattern and process approaches, concentrating on the spatial and temporal distribution of the resource and the timing and dispersal of the fly, as well as the influence of stochasticity. Relating attack frequencies to host density showed no strong indication of tight regulation between the specialist seed predator and its host plant (Paper I). Smaller plants and subpopulations were subject to the highest variation in attack frequency, suggesting that there is a strong element of chance influencing the risk of attack. There were, however, indications of a spatial effect at low fly densities, which seemed to break down at higher densities, implying that dispersal behaviour and strength may be related to adult fly density. The fragmented resource is more evenly used at higher attack frequencies (Paper II) : an effect which may be coupled directely to fly densities (Paper III). A mismatch between the phenology of the fly and the sea aster flowering phenology seems to benefit the first flowering flower heads, which are less often attacked in a normal year (Paper III) . However, it was experimentally shown that the flies compensate for the temporal and spatial unpredictability by a female-biased density-dependent dispersal (Paper IV). Density-independent water-borne dispersal during the puparia stage may also affect the dynamics of the tephritid (Paper V). This system is an example of a highly persistent interaction, for which stochastic and spatial effects are of major importance. The density-dependent dispersal of females may act within generations in the spatially heterogeneous environment and this may be transformed from a local response to a mode of regulation that works between generations.

Subjects/Keywords: plant-animal interactions; population dynamics; regulation; densitydependence; stochasticity; temporal and spatial refuges; plant defence; dispersal; optimal patch use

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Riber Albrectsen, B. (2000). The dynamics of a tephritid seed predator on Tripolium vulgare in a stochastic and heterogeneous environment. (Doctoral Dissertation). Swedish University of Agricultural Sciences. Retrieved from https://pub.epsilon.slu.se/17687/

Chicago Manual of Style (16th Edition):

Riber Albrectsen, Benedicte. “The dynamics of a tephritid seed predator on Tripolium vulgare in a stochastic and heterogeneous environment.” 2000. Doctoral Dissertation, Swedish University of Agricultural Sciences. Accessed May 07, 2021. https://pub.epsilon.slu.se/17687/.

MLA Handbook (7th Edition):

Riber Albrectsen, Benedicte. “The dynamics of a tephritid seed predator on Tripolium vulgare in a stochastic and heterogeneous environment.” 2000. Web. 07 May 2021.

Vancouver:

Riber Albrectsen B. The dynamics of a tephritid seed predator on Tripolium vulgare in a stochastic and heterogeneous environment. [Internet] [Doctoral dissertation]. Swedish University of Agricultural Sciences; 2000. [cited 2021 May 07]. Available from: https://pub.epsilon.slu.se/17687/.

Council of Science Editors:

Riber Albrectsen B. The dynamics of a tephritid seed predator on Tripolium vulgare in a stochastic and heterogeneous environment. [Doctoral Dissertation]. Swedish University of Agricultural Sciences; 2000. Available from: https://pub.epsilon.slu.se/17687/


University of Illinois – Chicago

3. Sonny S. Bleicher (6498434). Divergent Behaviour amid Convergent Evolution: Common Garden Experiments with Desert Rodents and Vipers.

Degree: 2015, University of Illinois – Chicago

Desert ecosystems worldwide provide examples of convergent evolution for species and entire communities. In a series of common-garden experiments, I compare the communities of granivorous rodents and their predators from North American and Middle Eastern Deserts. I used populations of two Heteromyid rodents from the Mojave Desert and two Gerbillines from the Negev. Each population’s perception of risk of viper species, one known and one from the convergent system, was measured in three steps: initial (at first encounter), over a two month experiment of co-habitation with predators in a semi-natural arena, and post exposure. The initial and post exposure “interviews” revealed that all four rodent species fear most their native viper species. However, after two months of exposure, all four species exhibit greater fear for the sidewinder rattlesnake (Crotalus cerastes) from the Mojave, a snake capable of infra-red vision, than for the Saharan horned viper (Cerastes cerastes) from the Negev, a snake “blind” on dark nights. In the semi-natural arena (vivarium), all four species exhibited fear (higher giving-up densities in depletable food patches) of snakes and owls. As evidence of predator facilitation, all four rodents respond to owls by favoring the shrub cover and respond to snakes by favoring the open areas. More subtle responses to moonphase, particular viper species, and interactions of owls and snakes were rodent species specific. The evolutionary history with predators proved to be more important in shaping the evolution of anti-predator strategies than environmental forces of climate, substrate and food availability. Heteromyids, who evolved with heat sensing vipers exhibited fixed strategies that fluctuate in intensity based on the overall risk in the environment. The Gerbillines on the other hand reassess the risk based on the greatest threat in the environment. All species however respond to all vipers with the strategies best suited to the vipers they evolved with.

Subjects/Keywords: Uncategorized; Allenby’s Gerbil (Gerbillus andersoni allebyi); Behavioural Ecology; Barn owl (Tyto alba); Convergent Evolution; Desert Pocket Mouse (Cheatodipus penicillatus); Desert dunes; Evolutionary Ecology; Gerbilline Rodents; Giving Up Densities (GUDs); Greater Egyptian Gerbil (Gerbillus pyramidum); Habitat Selection; Heteromyid Rodents; Landscapes of Fear; Merriam’s Kangaroo Rat (Dipodomys merriami); Optimal Patch Use; Predator-Prey Dynamics; Saharan Horned Viper (Cerastes cerastes); Sidewinder rattlesnake (Crotalus cerastes)

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

(6498434), S. S. B. (2015). Divergent Behaviour amid Convergent Evolution: Common Garden Experiments with Desert Rodents and Vipers. (Thesis). University of Illinois – Chicago. Retrieved from http://hdl.handle.net/10027/19398

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

(6498434), Sonny S. Bleicher. “Divergent Behaviour amid Convergent Evolution: Common Garden Experiments with Desert Rodents and Vipers.” 2015. Thesis, University of Illinois – Chicago. Accessed May 07, 2021. http://hdl.handle.net/10027/19398.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

(6498434), Sonny S. Bleicher. “Divergent Behaviour amid Convergent Evolution: Common Garden Experiments with Desert Rodents and Vipers.” 2015. Web. 07 May 2021.

Vancouver:

(6498434) SSB. Divergent Behaviour amid Convergent Evolution: Common Garden Experiments with Desert Rodents and Vipers. [Internet] [Thesis]. University of Illinois – Chicago; 2015. [cited 2021 May 07]. Available from: http://hdl.handle.net/10027/19398.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

(6498434) SSB. Divergent Behaviour amid Convergent Evolution: Common Garden Experiments with Desert Rodents and Vipers. [Thesis]. University of Illinois – Chicago; 2015. Available from: http://hdl.handle.net/10027/19398

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.