Detecting the threatened Julia Creek dunnart (Sminthopsis douglasi) using alternative techniques such as remote camera trapping and Eastern Barn Owl (Tyto delicatula) dietary pellets.

Overview

https://research.qut.edu.au/environment/https://research.qut.edu.au/environment/

The Julia Creek Dunnart, Sminthopsis douglasi, is a species of small, carnivorous marsupial believed to be restricted to north-west Queensland, where it inhabits tussock grasslands on cracking clay soils. The species is threatened and listed as Vulnerable under the federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and Endangered under the Queensland state Nature Conservation Act 1992 (NC Act).

In the past, S. douglasi has been successfully detected using live capture (Elliott) traps. While this traditional detection technique is successful, it is labour intensive and prohibitive when considering a large number of deployments across numerous sites. Thus, we are interested in exploring the utility of other methods to detect the species.

PROJECT

The aim of this project is to assess alternative techniques to detect the Julia Creek Dunnart (Sminthopsis douglasi). Depending on availability of material, the project will assess the utility of either camera trap images and/or owl pellets for detecting the species.

Cameras

Julia Creek Dunnarts have been detected under white-flash cameras in low abundance at Bladensburg NP (S of Winton) during our monitoring research in 2022. Cameras are likely to be used in future projects as a detection tool for the species, but we want to assess whether Infra-Red (IR) or White-flash (WF) cameras are best for detection. To do this, we will be deploying an array of IR and WF cameras at Bladensburg NP (April-June 2024), with each type of camera separated by ~200m. The camera rigs are all short focal length (70cm) and oriented vertically (facing towards the ground), so close-up photos will be obtained of various mammal species (with a 6cm diameter bait container in every photo for size comparison). Images from both camera types will then be compared.  Plausibly, the white flash might be deterring some individuals from spending time at (or approaching) the bait container; infra-red would potentially avoid this. However, it is uncertain how confident we can be of species level identification using the IR cameras, because colour (as well as size) is useful for discrimination between dasyurids, especially considering that three dunnart species may co-occur in north-west Qld.

Owl pellets

Eastern Barn Owls usually swallow their prey whole, and the undigested remains, including bones and craniodental material, regurgitated in pellets, are generally readily identifiable (in the case of mammals, to species level). Individual Eastern Barn Owls also frequently roost in the same location, meaning that pellets accumulate at the roost site, sometimes for decades. Even more tantalising is the fact that, once all the pellets from a site have been collected, the pellets regurgitated by the owl from that point onward (until the date of next collection) can be accurately dated. Essentially, each owl represents a mobile open pitfall trap that collects prey most nights of the year and conveniently deposits the remains in a growing spoil pile that can be collected and assessed at an ecologist’s convenience! In 2023, collections of Eastern Barn Owl pellets were made at several sites where S. douglasi is known or considered likely to occur. Further collections will be made at these and other locations during 2024 and 2025 to obtain owl pellet samples of known age. In 2024, two parallel Honours projects will analyse the owl pellet samples. The first project will assess mammal presence, frequency of occurrence and richness between collection periods at one site (Toorak), while the second project will analyse the owl pellets collected across all locations and compare the results between sites, with reference to the surrounding habitat. However, there will be a surplus of owl pellet material that will not be analysed in the Honours projects.

The project is biological/zoological/ecological in nature and is attached to an existing funded project on the detection, ecology and conservation of Julia Creek Dunnarts funded as part of a Federal Threatened Species Research Offset run by CI A/Prof AM Baker.

Research engagement

The successful VRES student will assess camera trap footage retrieved from Bladensburg NP in April-June 2024 and/or assist with analysing a subset of owl pellet material collected during 2024 that was not assessed by Honours students who complete their analysis in October 2024.

Research activities

For cameras, this will involve identifying and enumerating all vertebrate species identified under both IR and WF cameras and assessing their relative utility at detecting various mammal species. For owl pellets, this will involve teasing apart individual owl pellets with forceps (separating the craniodental material) and taking the collected material to the Queensland Museum. The student will then use the Museum’s reference skull collection to identify the diversity and abundance of mammals present in each pellet. In both cases, the student may be able to undertake analyses of the results.

Outcomes

The aim of this project is to assess alternative techniques to detect the Julia Creek Dunnart (Sminthopsis douglasi). Depending on availability of material, the project will assess the utility of either camera trap images and/or owl pellets for detecting the species. Results from the project will contribute to our database of information about distribution and abundance of this threatened species in various locations in north-west Qld.

Skills and experience

Ideally, the student will have completed BVB214 (Vertebrate Life) with a high grade (5-7) and have a keen interest in small mammal ecology, threatened mammal species and/or microscope / identification (ID) work. However, if the student has a keen interest in this area, a strong academic record, an eye for detail, but has not completed BVB214, they would also be considered for the position.

Start date

18 November, 2024

End date

28 February, 2025

Location

QUT and Qld Museum

Additional information

Supervisors will assist the student in learning the techniques involved (dissection, identification, etc). If the work involves owl pellets, the student will have access to the Qld Museum collection.

Keywords

• mammal
• dasyurid
• identification

Contact

A/prof Andrew Baker, 0424 272 051, am.baker@qut.edu.au