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•Tasmania provides a unique opportunity to study suites of
organisms that have declined or disappeared in the mainland since
European settlement (c. 1788).
•Since the outbreak of DFTD (Devil Facial Tumour Disease),
Tasmanian devil (Sarcophilus harrisii) populations have collapsed in
many areas (Jones et al., 2007; Brüniche-Olsen et al., 2013; Hollings
et al., 2013). This, and the recent introduction of the red fox (Vulpes
vulpes) in Tasmania (Saunders, 2006; Berry et al., 2007), makes likely
substantial food web changes.
•Traditional methods of studying food webs (direct observations and
morphological identification of stomach content or morphological
scat analysis) can provide useful information but are often time
consuming, costly and unlikely to detect all interactions among
species.
•We have collected 2885 scats from 241 sites in eastern
Tasmania during 16 weeks in autumn 2014 (see Catriona
Campbell’s poster, “The great poo hunt”, for more
information on the field work) to match identical sites
sampled in 2008/09.
•We are also developing a reference database of
mitochondrial DNA sequences from voucher specimens (road
kills, museum specimens, publicly available sequences), to
improve taxonomic assignment of unknown sequences using
meta-barcoding.
Thanks to the Institute for Applied Ecology and
the Department of Primary Industries, Parks,
Water and Environment. Special thanks to
Catriona Campbell and Elise Dewar.
Funding by the Invasive Animal Cooperative
Research Centre
About the author
•We will produce a distribution map of
native vs. introduced prey and predators
occurring in Tasmania and identify shifts in
diet among predators.
•We aim to measure changes in species
distributions and interactions across the
two sample periods with the information
taken out from the scats.
•We will identify species that may be subject
to extreme distributional changes and
hence, should be the focus of
managements. For example, if an
introduced predator, the feral cat, is
feeding intensively on a native prey, the
long-tailed mouse.
Background information
Results & Discussion
Conclusions and Outcomes
Research question
What are the impacts on prey populations of recent
changes in predator abundance and distribution?
•Our aim is to use NGS to identify predator-prey interactions through
analysis of scats collected from 241 sites (3km by 3km squares) in
eastern Tasmania
•Preliminary analysis of scats collected in 2008/09 suggests
that we will be able to obtain information about many
vertebrate prey. We expect to be able to test for systematic
differences in diet between native and introduced predators
in Tasmania and to use our next-generation sequencing data
to model the distributions of both predators and their prey.
•Studying food webs will assist in understanding the
interactions between predators and prey providing ecologists
and wildlife managers with the tools to construct better
predictive models of carnivore communities and to develop
management solutions.
•Moreover, knowing the change in distribution of a class of
prey (e.g. rodents) endemic to a place (Tasmania) can help to
better target the predators to control.
Example of a simple food web perturbation with only one introduction
event. Arrows represent the direction of the food cascade.
Scat DNA will be extracted
and PCRs set up within a
trace DNA laboratory and
amplified using mammalian
and generic primers targeting
informative mitochondrial
DNA genes. Amplicons will
then be sequenced with a
high-throughput next-
generation sequencer
(Illumina MiSeq). Meta-
barcoding will help us to
assign the sequences found.
•In contrast, genetic methods have obvious
benefits in studying the diet of predators
which eat soft-bodied prey, prey with fragile
bones or completely digested prey.
•Scats analysis using DNA is increasingly
being used for this purpose as it is non-
invasive and generates new data on the
feeding ecology of cryptic species such as
cats, foxes and native carnivores.
•Next-generation sequencing (NGS) of amplicons is a new and cost
effective approach for detecting multiple prey species from non-
invasive and degraded DNA samples such as scats (Pompanon et al.,
2012). NGS allows us to sequence simultaneously hundreds of
thousands of mixed taxonomic sequences amplified with generic
primers. Coupled with meta-barcoding, this approach can reveal
much about what predators consume.
Materials & Methods
Elodie Modave – PhD candidate
Institute for Applied Ecology
University of Canberra,
ACT 2601, Australia
PH: 0405 162 978
Email: elodie.modave@canberra.edu.au
Sources
Berry, O., Sarre, S. D., Farrington, L. and Aitken, N. (2007). Faecal DNA detection of invasive species: The case of feral
foxes in Tasmania. Wildl. Res. 34, 1–7.
Brüniche-Olsen, A., Burridge, C. P., Austin, J. J. and Jones, M. E. (2013). Disease induced changes in gene flow
patterns among Tasmanian devil populations. Biol. Conserv. 165, 69–78.
Hollings, T., Jones, M., Mooney, N. and McCallum, H. (2013). Trophic Cascades Following the Disease-Induced Decline
of an Apex Predator, the Tasmanian Devil. Conserv. Biol.
Jones, M. E., Jarman, P. J., Lees, C. M., Hesterman, H., Hamede, R. K., Mooney, N. J., Mann, D., Pukk, C. E., Bergfeld,
J. and McCallum, H. (2007). Conservation management of Tasmanian devils in the context of an emerging,
extinction-threatening disease: devil facial tumor disease. Ecohealth 4, 326–337.
Pompanon, F., Deagle, B. E., Symondson, W. O. C., Brown, D. S., Jarman, S. N. and Taberlet, P. (2012). Who is eating
what: diet assessment using next generation sequencing. Mol. Ecol. 21, 1931–1950.
Saunders, G. L. (2006). Foxes in Tasmania: a report of an incursion by an invasive species. Invasive Animals Co-
operative Research Centre.
Acknowledgments
Who is eating who from poo?
Predator-prey interactions in Tasmania inferred using next-generation sequencing of predator scats
Elodie Modave1, Catriona D. Campbell1, Anna J. MacDonald1, Bernd Gruber1, Stephen Harris2, Elise F. Dewar2, Stephen D. Sarre1
1Institute for Applied Ecology, University of Canberra, ACT 2601, Australia
2Department of Primary Industries, Parks, Water and Environment, TAS 7000, Australia