Territoriality

Territory is actively defended, home range is area utilized by individual.

=Literature Information=

Spencer et al (1990)

 * home range: "that area traversed by the individual in its normal activities of food gathering, mating, and caring for young" (Burt 1943)
 * site fidelity exists when the area utilized by an individual is significantly smaller than the area occupied by random movement (Munger 1984, Danielson and Swihart 1987)

Nonaka and Home (2007)

 * optimal foraging theory tries to quantitatively predict the optimal foraging strategies on patchy landscapes (Stephens and Krebs 1987)
 * natural selection favors individuals that can use patchy landscape more effectively for survival and reproduction (MacArthur and Pianka 1966, Pyke et al. 1977)

Reynolds (2007)

 * perfectly executed self-avoiding random walks (SAW) are super diffusive (mean squared displacement grows faster than linearly over time) and scale free
 * perfectly executed SAW statistically similar to Levy walk, which represents a sub-optimal search strategy (citing Viswanathan et al 1999)
 * imperfectly executed SAW better than perfectly executed SAW in random search scenarios
 * inverse-square power law distribution of move lengths is an emergent property of SAW

Borger et al (2008)

 * essential characteristics of a territory (a la Bown and Orians 1970):
 * a fixed area
 * presence of territorial defense or keep-out signals which elicit avoidance by competitors
 * exclusive use of territory by holder
 * sometimes analogous with home range - 'defended home ranges'
 * random walk approach to define home ranges - type of random walk influences territoriality
 * random walk (RW)
 * random direction
 * can be combined with distribution of step lengths
 * creates diffusion process
 * correlated random walk (CRW)
 * directional bias
 * persistent
 * positive autocorrelation
 * results in directional persistence
 * anti-persistent
 * negative autocorrelation
 * results in backtracking to previously visited sites
 * correlated random walk with simple long-term memory (MCRW)
 * same as a CRW, but at each step there is a chance with a certain probability that the individual will return to a previously visited location (randomly selected)
 * not sure the utility of this one
 * biased random walk (BRW)
 * direction consistently biased
 * by an attraction to a fixed point
 * turning rate modified by exposure to environmental properites(?)
 * two terms:
 * diffusion term - governs distance moved
 * advection term - influences the biased directionality of moves
 * all movements biased towards home range center
 * degree of bias determined by an attraction parameter (localizing tendency parameter)
 * produces circular home range
 * Incorporating memory
 * self-attractive random walk models
 * 'return to a previously visited location' rule
 * based on biased correlated random walk
 * movements biased towards previously visited sites (Siniff & Jessen 1969)
 * correlated random walk component keeps individual moving
 * Tan et al 2001, 2002 (2nd modifies by introducing memory decay, leads to gradual drift in home range)
 * Gautestad & Nysterud 2005 - multiscaled random walk model, contains site fidelity algorithm (ad-hoc rule?)
 * Gautestad & Nysterud 2005 - multiscaled random walk model, contains site fidelity algorithm (ad-hoc rule?)

Simpson, Raubenheimer, Charleston, and Clissold (2009)

 * Develop model structure that incorporates functional requirements of individual organisms with community ecology to recognize interactions between the two (emphasize agent-based approach)
 * useful to incorporate a geometric framework which describes a response as a function of multiple nutritional requirements
 * incorporates the multidimensional nature of organismal nutritional requirements
 * ie., egg production as a function of the interaction of carbohydrate and protein uptake
 * three different knowledge states influence the behavior and decision making of foragers:
 * short term learning and memory
 * intermediate memory via parental effects
 * ancestral memory genetically embodied in the default phenotype
 * three types of nutritional state dependent learning identified for insects and vertebrates
 * learned positive associations
 * learned aversions
 * non-associative responses (learning not directly through association with stimulus; ie if you're hungry, move to find food)
 * there are performance consequences of ingesting deficits and excesses of nutrient and non-nutrient food components (unbalancing diet) - Maklakov et al (2008), Simpson et al (2004)
 * change in temperature may trigger nutrient-specific response; ie. decrease in temp results in increased carb intake by rats, but protein uptake remains the same (Aubert et al 1995)
 * nutritional requirements dynamic
 * outline basic elements required of agents to meet this goal:
 * behaviors: feed, move, defend, metabolize, grow, excrete, develop, and reproduce
 * state and condition of the agent
 * position in space and time
 * Contains detailed questions to be addressed using heterarchical models of nutritional ecology

Giuggioli, Potts and Harris (2011)

 * use agent-based approach to simulate interactions that lead to emergence of territoriality
 * randomly move to one of von Neumann neighborhood
 * if scent exists, returns to either own territory or unmarked territory
 * not aware of scent before entering territory
 * marks over existing scent
 * key parameters "controlling territoriality" (not sure what that means) are the average territory size (inverse of population density) and the longevity of scent markings

=Notes=

Measures of home range / territory
 * area occupied
 * mean squared displacement analysis (Moorcroft and Lewis 2006; chapter 10)

=Hypothetical Thoughts=


 * influence of conspecifics important in shaping definition of territoriality
 * Negative correlation between foraging strategies which optimize uptake (+ correlated rw, Levy walk) and those that recreate territoriality (- correlated rw)
 * both assumed to be a function of resource limitation?
 * site fidelity decreases optimality of foraging strategy by restricting movement
 * Specifics of rw implementation (direction and distance selection) may be unimportant if movement limited by barriers (ie. other territories)

=References=


 * Aubert, A., Goodall, G., and Dantzer, R. (1995). Compared effects of cold ambient temperature and cytokines on macronutrient intake in rats. Physiology & Behavior 57, 869-873.
 * Börger, L., Dalziel, B. D., and Fryxell, J. M. (2008). Are there general mechanisms of animal home range behaviour? A review and prospects for future research. Ecology Letters 11, 637-50.
 * Maklakov, A. A., Simpson, S. J., Zajitschek, F., Hall, M. D., Dessmann, J., Clissold, F., Raubenheimer, D., Bonduriansky, R., and Brooks, R. C. (2008). Sex-specific fitness effects of nutrient intake on reproduction and lifespan. Current Biology 18, 1062-1066.
 * Simpson, S. J., Sibly, R. M., Lee, K. P., Behmer, S. T., and Raubenheimer, D. (2004). Optimal foraging when regulating intake of multiple nutrients. Animal Behaviour 68, 1299-1311.

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