Tasmanian Boobook migration pathways across Bass Strait revealed using satellite-tracking

Recently-published research led by lab member Jessica Zhou used lightweight

across Bass Strait. This represents the first tracking study of any land bird migration

across Bass Strait, and unlocks the mystery surrounding Tasmanian Boobook

sightings on mainland Australia.

Tasmanian Boobooks were long thought to be endemic to Tasmania, with Southern

Boobook Ninox boobook being the common hawk-owl species found on mainland

Australia. However, since the 1800s, there have been occasional reports of

boobooks with trademark bright yellow eyes (and therefore resembling Tasmanian

Boobook) scattered across mainland Australia. In recent years, this speculation that

Tasmanian Boobooks were migrating and overwintering in Victoria grew due to

repeated sightings of these owls gathering on southern Victorian headlands in

spring.

Lab members travelled to Cape Liptrap and Wilsons Promontory in October-

November 2022 to capture and tag Tasmanian Boobooks. The tracks showed that

the tagged birds completed their migration in non-stop, overnight, ~250km flights

from Victoria to Tasmania. Instead of prioritizing strong tailwinds and using the

eastern islands to facilitate their journeys across, these birds flew directly across the

open water and in variable weather conditions. Most birds appeared to settle in Tasmania’s

central highlands after arriving on land. These tracks confirmed that Tasmanian

Boobooks are in fact a partially migratory species, meaning that some individuals

migrate annually while others remain.

This study provided a first insight into landbird migration across Bass Strait,

highlighting the importance of understanding this flyway in the age of offshore

industrial change. More than 24 land bird species, including parrots, raptors, and

songbirds, migrate between Tasmania and mainland Australia. However, the details

of these journeys, such as the pathways used, flight heights, stop-over behaviours,

timing, and weather preferences, are still largely unknown.

Moreover, several offshore wind farm projects in Bass Strait have commenced into

planning and environmental assessment phases. Research such as this study, that

incorporates fine-scale movement data, will be vital for informing these assessments,

so that the necessary transition to green energy is done in a way which also

safeguards biodiversity.

Read more about this research on The Conversation.

Zhou, J. W., Sperring, V. F., Allen, P., & Clarke, R. H. (2025). Satellite-tracking

provides first description of migration in Tasmanian Boobooks Ninox leucopsis. Emu - Austral Ornithology, 125(1), 47–59. https://doi.org/10.1080/01584197.2024.2432867

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