The cognitive ecology of intraspecific differences in nest-building behaviour
Creators: Lambert, Connor Tarek
Publisher: name: University of Alberta Library
Year: 2024

<p>Physical cognition encompasses how animals acquire and use information about the structural properties of materials and the physical forces governing the environment. Most research on physical cognition has focused on a limited number of tool-using species such as apes, corvids, and parrots, while the evolutionary pressures shaping inter-species differences in physical cognition remain largely unknown. Nest building is one possible selection pressure associated with physical cognition in bird species. Nest building requires obtaining and manipulating materials from the environment to create a functional structure, is taxonomically widespread, is crucial to reproduction for avian species, and involves cognitive processes such as learning and memory- making it a biologically relevant context for the study of physical cognition. However, how nest building relates to physical cognition is unknown.For my dissertation research I conducted the first investigation of the question: is there an evolutionary relationship between nest-building behavioral ecology and physical cognition? I studied this question using zebra finches (Taeniopygia guttata) in the laboratory. Zebra finches build domed nests using grasses and twigs in the wild and readily build nests in captivity. Males are the primary builders and demonstrate learning about the physical properties influencing nest construction, such as length and flexibility of nest materials. I hypothesized that sex-differentiated roles in construction behaviour would be associated with sex-differences in physical (but not other) cognitive abilities. Because of the sex differences in nest-building behaviour of zebra finches, I predicted that male zebra finches would have enhanced physical cognition compared to females. I tested this prediction in a series of five experiments examining learning of, and memory for, structural compared to non-structural information.In Experiment 1 I tested birds’ ability to learn to discriminate based on material length and flexibility (both structural properties relevant to nest building) and also colour (non-structural). I found that males and females did not differ in learning to discriminate any of these properties (Chapter 3, data also used in Chapters 4 and 6). I then examined birds’ interactions with the stimuli used in Experiment 1, and found that males spent more time than females interacting with the stimuli. I then conducted Experiment 2 and tested additional birds’ abilities to discriminate based on material flexibility and colour- but accounting for male interaction with the stimuli- and once again found no sex differences in learning (Chapter 4). In Experiment 3, I re-tested all of the birds from Experiments 1 and 2 on the same discrimination tasks in a memory test and found no sex differences in memory (also in Chapter 4). In Experiment 4, I tested birds’ ability to learn about object relationships using a shape-frame matching task and found no sex differences. Birds could learn to solve this shape-frame matching task but did not generalize what they learned to similar problems (Chapter 5). For Experiment 5, I tested birds previously tested in Experiment 1 in acoustic discrimination tasks and found evidence for domain-general learning, meaning birds that learned well in physical cognition tasks tended to learn well in acoustic learning tasks, suggesting that the performance in physical property discrimination tasks may be underpinned by the same learning processes used in acoustic discrimination tasks (Chapter 6).In addition to the five fore-mentioned experiments, I also conducted a meta-analysis examining if environmental manipulations affect learning abilities, and found across over a hundred studies that environmental enrichment has significant effects on improving learning abilities (Chapter 7).Overall, my research found that, contrary to my hypothesis, sex-differentiated roles in nest-building ecology do not predict sex differences in physical cognition. Males did not perform better than females when learning to discriminate physical properties of materials or in shape-frame matching. My Chapter 6 experiment suggests that the physical cognition used in these tasks, and potentially in nest building, are driven by domain-general learning abilities that do not differ between the sexes and can be applied across diverse cognitive challenges. These findings suggest that sex differences in behaviour do not always translate into sex differences in cognition and provide a foundation for future studies of the relationship between nest building ecology and physical cognition. My final chapter further suggests that the environment individuals develop in can have impacts on an individuals’ learning abilities.</p>