Sienna Grady
- PhD Student, Lab of Animal Ecology, Hawkesbury Institute for the Environment, Western Sydney University.
- Topic: Understanding the spatiotemporal consumer-resource dynamics between the nomadic grey-headed flying-fox and flowering eucalypts
- Research Umbrella: Flying-fox movement ecology; Flying-fox conservation management
- Supervisors: Prof Justin Welbergen, Dr Jessica Meade, Prof Matthias Boer
- Contact: Sienna Grady
Bio
I completed a Bachelor of Science (Zoology) at Western Sydney University in 2019. Afterwards, I participated in several volunteer programs of bush regeneration until I volunteered for the Lab of Animal Ecology in studying the vocal mimicry of the female Superb Lyrebird in the Blue Mountains. This reinforced my interest in wildlife research, leading me to go back and do a Master of Research at Western Sydney University with the Lab of Animal Ecology in mid-2020.
I completed my Master of Research on the impacts of the 2019/20 megafires on the grey-headed flying-fox (Pteropus poliocephalus) in 2022, and I began my PhD project on understanding the spatiotemporal consumer-resource dynamics between the nomadic grey-headed flying-fox and flowering eucalypts in September 2023. I am interested in the field of spatial ecology, remote sensing, and all things wildlife conservation.
I completed a Bachelor of Science (Zoology) at Western Sydney University in 2019. Afterwards, I participated in several volunteer programs of bush regeneration until I volunteered for the Lab of Animal Ecology in studying the vocal mimicry of the female Superb Lyrebird in the Blue Mountains. This reinforced my interest in wildlife research, leading me to go back and do a Master of Research at Western Sydney University with the Lab of Animal Ecology in mid-2020.
I completed my Master of Research on the impacts of the 2019/20 megafires on the grey-headed flying-fox (Pteropus poliocephalus) in 2022, and I began my PhD project on understanding the spatiotemporal consumer-resource dynamics between the nomadic grey-headed flying-fox and flowering eucalypts in September 2023. I am interested in the field of spatial ecology, remote sensing, and all things wildlife conservation.

Research
The understanding of the movement of nomadic animal species is incomplete as such species are inherently difficult to track and the ephemeral resources they rely on are difficult to map. Nomadic species are characterised by their highly dynamic spatial and temporal distributions; nomadism is most often considered a response to erratic resource environments resulting in irregular, wide-ranging movement dynamics that can be studied at the level of individuals, populations, and species. Australia’s flying-foxes are large, nomadic bats that by night preferentially forage on eucalypts – the dominant forest tree species in Australia. Flying-foxes rest by day in arboreal roosts that may contain colonies of many thousands of individuals. Such roosts form nodes in a vast continental network of highly dynamic “staging posts” through which nomadic individuals travel far and wide to track nectar pulses produced by flowering eucalypts that are widely scattered in space and time. Their extreme mobility is thought to make them pivotal to forest ecosystems as long-distance pollinators and seed dispersers, providing key linkages between habitat fragments across anthropogenic and natural barriers. However, at present, there is a lack of reliable information on both the spatiotemporal patterns of flying-fox populations and the resources that drive these patterns, which poses important impediments for conservation management of flying-foxes. With the recent advances in both remote sensing and tracking technologies, there are now opportunities to better understand and thus conserve this widespread but threatened movement strategy in the face of human-induced environmental change.
The overarching aim of the research is to generate an integrated mechanistic understanding of the spatiotemporal population dynamics of Australia’s best-studied species of flying-fox – the grey-headed flying-fox (Pteropus poliocephalus) – with respect to the flowering phenology of its primary forage plants, "eucalypts" (Myrtaceae, genera Eucalyptus, Corymbia, and Angophora). To achieve this, I will formally link observed data of P. poliocephalus across spatial and temporal scales and across different levels of ecological organisation to large-scale mapping and forecasting of eucalypt flowering that covers the entire species range of P. poliocephalus. The specific objectives are to:
- Generate high-resolution maps of eucalypt flowering across the entire species range of P. poliocephalus, using a combination of drone and satellite remote sensing data.
- Infer the historical movement dynamics of P. poliocephalus from individuals to colonies and entire populations across spatial and temporal scales as a function of the spatiotemporal distribution of eucalypt flowering at comparative scales.
- Forecast the spatiotemporal dynamics of eucalypt flowering and, by extension, the spatiotemporal population dynamics of P. poliocephalus.
How can you help?
For Objective 1, I aim to collect very high-resolution imagery of flowering canopies of forests that are dominated by "eucalypts" - a collective term for species in the three genera, Eucalyptus, Corymbia and Angophora - using a drone in order to upscale known levels of flower abundance to publicly available Sentinel-2 satellite imagery. This allows the creation of maps that show the distribution of eucalypt flowering in space and time to be at a much larger scale where and when there is no drone imagery available.
To achieve this, I need known locations of flowering events in eucalypt-dominated forests. Since specific locations of eucalypt flowering vary unpredictably across eastern Australia, it is not possible for me to be everywhere at once. But you, among the network of enthusiastic citizen scientists, have the potential to directly observe any potential flowering while being out and about in the bush.
You can assist me with my research by providing the following information, including:
- Geographic locations of eucalypt forests that are currently or will likely be in flower for the data collection of drone images, and/or...
- Geographic locations of past flowering events of eucalypt forests for the model validation of generated flowering maps.
If you have the above information, please feel free to contact me via email: [email protected]
Looking forward to hearing from you in the interest of research!
For commercial beekeepers only, I understand that you may not want to share your information regarding flowering locations due to concerns of potential overstocking in these areas. I assure you that I will not publicly disclose any of the information you will provide. I will only use the flowering events for the model training and validation of flowering maps. Also, I’m more than happy to sign a non-disclosure agreement, provided by either you or Western Sydney University.