Please use this identifier to cite or link to this item: https://hdl.handle.net/1959.11/60851
Title: Exploring the Brain and Behaviour of a Reverse Keystone Species, The Noisy Miner (Manorina Melanocephala)
Contributor(s): Farrow, Lucy Florence  (author); Hamlin, Adam Scott  (supervisor)orcid ; McDonald, Paul  (supervisor)orcid 
Conferred Date: 2024-06-17
Copyright Date: 2023
Thesis Restriction Date until: 2027-06-17
Handle Link: https://hdl.handle.net/1959.11/60851
Related Research Outputs: https://hdl.handle.net/1959.11/60852
Abstract: 

The aim of this thesis was to study the cognitive complexity of the noisy miner (Manorina melanocephala) in an attempt to better understand its success in urban environments. Furthermore, the thesis aimed to use this species, not widely known for its cognitive prowess despite possessing complex behaviours and the proposed tool-kit for intelligence, to better understand potential indicators of cognition, namely, whether brain size is an accurate gauge of intelligence.

We first sought to conduct species-specific behavioural studies to test aspects of noisy miner behaviour that may assist their navigation of novel environments. Adapting the mirrormark test, we identified that noisy miners quickly habituate to reflective surfaces, following a behavioural sequence that initially begins with conspecific/social behaviours, and ends with the bird disengaging, and thus saving energetic costs, from the surface. We then investigated whether noisy miners were capable of “true” individual recognition, a complex behaviour that involves the ability of receivers to not only recognise a signaller, yet place a reliability status to this signaller regardless of context. Noisy miners not only reduced responses to unreliable signallers, they maintained this response across vocal contexts, indicating that they are capable of distinguishing individuals based on vocalisations alone, a characteristic likely maintained through their use of vocalisations to facilitate cooperative events such as group mobbing of predators.

Finally, we challenged the cognitive capacity of noisy miners through studying whether they could identify individuals of another species, humans, and allocate these novel people as “good” (providing food) or “bad” (captured individuals in nets) based on interactions. We identified that noisy miners rapidly learned to summon colony members upon seeing the “good” mask, yet would respond harshly with terrestrial alarm calls (more syllables at higher frequencies and rates) upon seeing the “bad” mask after the aversive events.

We next developed a high-throughput, non-biased quantification method to measure neuronal density and identify nuclear sizes using flow cytometry. The results obtained were comparable to those identified using stereological counting methods and consequently we employed this method to determine neuronal density of the noisy miner. Despite being an avian species, the procedure proved efficient across taxa and provided clear and repeatable evidence that noisy miners possess greater neuronal densities than Wistar rats (Rattus norvegicus), a species known for their success in cognitive challenges such as the radial eight-arm maze, where the species flexibly adapts to changes in food location. However, the noisy miner, a species to which this challenge is not standard, proved to make fewer errors during trials, thus demonstrating greater behavioural flexibility. We interpret the greater behavioural flexibility of the noisy miner compared to the Wistar rat as a result of the species possessing greater neuronal densities, with size of cells across the two species not being significantly different, therefore resulting in noisy miners having a shorter distance between cells for signal transmission.

The density of neurons, composed of cells packed closely together, likely facilitates the cognitive complexity and behavioural flexibility that this thesis confirmed through the behavioural studies on the noisy miner. Subsequently, this ability to rapidly adapt allows for the success of the noisy miner even in the most rapidly growing urban areas. We propose that in having a comparable measure of cognitive complexity (i.e. method to measure neuronal density across taxa), that this approach could be applied to other species so that we can gain an understanding of those species most likely to be affected by further urbanisation and anthropogenic changes.

Publication Type: Thesis Doctoral
Fields of Research (FoR) 2020: 310901 Animal behaviour
310906 Animal neurobiology
310911 Animal structure and function
Socio-Economic Objective (SEO) 2020: 180601 Assessment and management of terrestrial ecosystems
180699 Terrestrial systems and management not elsewhere classified
280102 Expanding knowledge in the biological sciences
HERDC Category Description: T2 Thesis - Doctorate by Research
Description: Please contact rune@une.edu.au if you require access to this thesis for the purpose of research or study
Appears in Collections:School of Environmental and Rural Science
School of Science and Technology
Thesis Doctoral

Files in This Item:
2 files
File Description SizeFormat 
Show full item record
Google Media

Google ScholarTM

Check


Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.