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theses

In complex environments, the ability to encode information about the location of resources should confer selective advantages by improving foraging efficiency. What constitutes foraging goals, and to what degree species encode information about food resources remain largely unresolved. In this dissertation, I apply principles from nutritional geometry and movement ecology to 1) examine whether macronutrient balancing is a biologically relevant foraging goal for Bornean orangutans; and 2) investigate the relationship between preference indices and the nutritional geometry of orangutan foods, and 3) explore the ways in which movement and spatial cognition facilitate nutritional balancing. Orangutans were chosen as a model system because of their capacity for complex cognition, their solitary social system, and the high variability in food availability in orangutan habitats.
In Chapter 2, simulation and Behavioral Change Point Analysis are used to demonstrate that the balance of nutrient intake by orangutans cannot be attributed to chance, and that individuals modulate their movement behavior in response to nutrient intake in a goal directed manner. In Chapter 3, nutritional isocline plots and food electivity indices are used to demonstrate that the orangutans’ evaluation of food quality is significantly related to nutritional balancing. Items of high nutritional return are preferred and associated with fast trajectories through nutritional cartesian space. In Chapter 4, a continuous-space continuous-time movement framework (ctmm) is utilized to characterize patterns of space use by Bornean orangutans, and remote sensing and simulation modeling are used to evaluate different cognitive movement strategies in the context of nutritional balancing. Multispectral analysis and supervised machine learning techniques are used to map the nutritional landscape at Tuanan. Movement parameters from the ctmm analysis are used to parameterize models simulating memory and perception-based strategies of nutrient balancing. Simulation results suggest orangutans utilize spatial memory to facilitate nutritional balancing.

ETD_9301

doi:10.7282/T3J67MKV

Ph.D.

Includes bibliographical references

by Shauhin E. Alavi

ETD doctoral

The author owns the copyright to this work.