Reintroduction of the eastern quoll to Mulligans Flat Woodland Sanctuary, Australia, using trials, tactics, and adaptive management

Abstract

This case study details the reintroduction of the eastern quoll to Mulligans Flat Woodland Sanctuary, Australia, using trials, tactics, and adaptive management. Ideal for use by reintroduction practitioners, the sections include background, goals, success indicators, project feasibility, implementation, post-release monitoring, major difficulties faced, major lessons learned, and outcomes of the project.

Full text

IUCN SSC Conservation Translocation Specialist Group
Global conservation
translocation perspectives: 2021
Global conservation translocation perspectives: 2021

ii
The designation of geographical entities in this book, and the presentation of the material,
do not imply the expression of any opinion whatsoever on the part of IUCN or any of the
funding organizations concerning the legal status of any country, territory, or area, or of its
authorities, or concerning the delimitation of its frontiers or boundaries.
The views expressed in this publication do not necessarily reflect those of IUCN.
IUCN is pleased to acknowledge the support of its Framework Partners who provide core
funding: Ministry of Foreign Affairs of Denmark; Ministry for Foreign Affairs of Finland;
Government of France and the French Development Agency (AFD); the Ministry of
Environment, Republic of Korea; the Norwegian Agency for Development Cooperation
(Norad); the Swedish International Development Cooperation Agency (Sida); the Swiss
Agency for Development and Cooperation (SDC) and the United States Department of
State.
Published by: IUCN SSC Conservation Translocation Specialist Group,
Environment Agency - Abu Dhabi & Calgary Zoo, Canada.
Copyright: © 2021 IUCN, International Union for Conservation of Nature and
Natural Resources
Reproduction of this publication for educational or other non-
commercial purposes is authorized without prior written permission
from the copyright holder provided the source is fully acknowledged.
Reproduction of this publication for resale or other commercial
purposes is prohibited without prior written permission of the copyright
holder.
Citation: Soorae, P. S. (ed.) (2021). Global conservation translocation
perspectives: 2021. Case studies from around the globe. Gland,
Switzerland: IUCN SSC Conservation Translocation Specialist Group,
Environment Agency - Abu Dhabi and Calgary Zoo, Canada. xiv +
353pp.
Edition: 7
th Edition
Cover photo: Clockwise starting from top-left:
I. Darwin’s rhea (Rhea pennata pennata) © Cristián Saucedo
II. Orinoco turtle (Podocnemis expansa)
III. Leopard cat (Prionailurus bengalensis) © Mei-Ting Chen
IV. White saxaul (Haloxylon persicum) © EAD
V. Southern pygmy perch (Nannoperca australis) © Michael Hammer
Cover design
& layout by: Pritpal S. Soorae, IUCN SSC Conservation Translocation Specialist
Group
Printed by: Arafah Printing Press LLC, Abu Dhabi, UAE
Download at: www.iucn-ctsg.org
www.iucn.org/resources/publications

194
Reintroduction of the eastern quoll to
Mulligans Flat Woodland Sanctuary, Australia
using trials, tactics and adaptive management
Belinda A. Wilson1*, Maldwyn J. Evans1, William G. Batson2, Sam C. Banks3, Iain J. Gordon1,4,
Donald B. Fletcher1, Claire Wimpenny2, Jenny Newport1, Emily Belton5, Annette Rypalski6,
Tim Portas7 & Adrian D. Manning1
1 - Fenner School of Environment and Society, The Australian National University,
Canberra ACT 0200 Australia * - belinda.wilson@anu.edu.au
2 - National Parks and Wildlife Service, Blue Mountains Branch, Blackheath, NSW 2785
Australia
3 - Charles Darwin University, Darwin, NT 0810 Australia
4 - Central Queensland University, Townsville, QLD 4810 Australia
5 - The Woodlands and Wetlands Trust, Forde Community Centre, Forde, ACT 2914 Australia
6 - Mt Rothwell Biodiversity Interpretation Centre, Little River, VIC 3211 Australia
7 - Zoo and Wildlife Veterinary Consultancy, Maleny, QLD 4552 Australia
Introduction
The Eastern quoll (Dasyurus viverrinus) is a small-to-medium marsupial that
previously inhabited south-eastern Australia. Last seen on the mainland in 1967,
its extinction has been attributed to predation by introduced predators, habitat
loss and disease. It is now restricted to Tasmania and listed as Endangered by
the IUCN Red List and the EPBC Act 1999. It is a nocturnal predator and
scavenger with a diet of invertebrates, birds, small mammals, reptiles, fruit, and
carrion. The species is sexually dimorphic with a mean adult body mass of 1,250
g for males and 850 g for females. Males have larger home ranges (mean 44 ha)
than females (mean 35
ha). Females can carry a
single litter of up to six
young per year. Annual
mortality in the wild is
high, with 20 - 58% of
juveniles surviving to their
first breeding season with
a life expectancy of three
to four years (Godsell,
1983). The reintroduction
site is Mulligans Flat
Woodland Sanctuary
(MFWS), a 485 ha area
containing critically
endangered Box-gum
grassy woodland situated
Eastern quoll © Adam McGrath & Woodlands and
Wetlands Trust

195
in north-east Canberra, Australian Capital Territory (ACT), Australia. MFWS is
enclosed by predator-proof fencing to exclude introduced Red foxes, cats,
European rabbits and hares, all of which were eradicated within the exclosure
prior to reintroductions.
Goals
 To establish a population of Eastern quolls at MFWS.
 To demonstrate how the use of trials, tactics and adaptive management
can improve reintroduction success.
Success indicators
 Survival: At least ≥67% of founders surviving after 42 days post-release for
each trial reintroduction. This will indicate that the environment is suitable,
and founders have settled into the landscape (achieved in Trials 2 and 3).
 Note that Eastern quolls that escaped the MFWS fence but were
retrieved alive, or were transferred to another facility, were considered
survivors, so we report here on ‘true’ survival (henceforth survival).
 Condition: At least ≥67% of founders maintaining body condition weight
within 10% of their release weight after 42 days post-release (achieved in
Trials 2 and 3).
 Reproduction: At least ≥67% of females successfully produce young by 42
days post-release for each trial reintroduction. This will indicate that the
environment offers sufficient denning sites and can support lactating
mothers (achieved in Trials 2 and 3).
 Additional success criteria include population growth, population
persistence, genetic diversity and behavior, which will be monitored over
the long-term.
Project Summary
Feasibility: The Eastern quoll reintroduction is a partnership project between The
Australian National University (ANU), ACT Government, Mt. Rothwell Biodiversity
Interpretation Centre, Woodlands and Wetlands Trust and James Cook
University, and is part of the long-term Mulligans Flat-Goorooyarroo Woodland
Experiment (www.mfgowoodlandexperiment.org.au). This major collaborative
partnership combined funding for conservation on public lands, drew on the
strengths of each organization, and built on the success of previous
reintroductions such as for the Eastern bettong (Bettongia gaimardi).
A translocation proposal was prepared including the success criteria outlined
above as well as a risk assessment (Manning, 2015). The predator-proof fence
surrounding MFWS removed the threat posed by introduced Red foxes and cats,
which are a major barrier to mainland reintroductions. Based on these, the
reintroduction was approved by the Tasmanian Department of Primary Industries,
Parks, Water and Environment (DPIPWE), Victorian Department of Environment,
Land, Water and Planning, ACT Territory and Municipal Services and the ANU

196
Animal Experimentation
Ethics Committee.
Implementation: The
reintroduction was
undertaken as a series of
three trials over three
consecutive years (Trial 1
in 2016, Trial 2 in 2017,
and Trial 3 in 2018). An
additional translocation
was conducted in 2019 to
maximize the genetic
diversity of the founding
population (not reported
here). We used the
Translocation Tactics Classification System (TTCS, Batson et al., 2015) as a
framework to adapt our tactics between trials to achieve our strategies of
maximizing survival and minimizing post-release dispersal. We also adopted an
adaptive management approach, using monitoring to facilitate rapid learning and
to implement interventions to improve reintroduction success (Wilson et al.,
2020).
In Trial 1, we translocated fourteen Eastern quolls (6 females & 8 males) to
MFWS in austral autumn. No females were carrying pouch young because the
mating period was yet to occur. Founders were selected from both captive (6) and
wild (8) populations. Captive founders were sourced from Mt. Rothwell, and wild
founders from free-ranging populations across 14 geographic regions in
Tasmania which were separated by at least 15 km or a significant geographical
barrier to eastern quoll dispersal (informed by a study of the genetics of these wild
populations in Tasmania (Cardoso, 2014)). We took no more than two animals
from each region to minimize impacts on the source population and maximize
genetic diversity. Releases were carried out as soon as possible (i.e. animals
were transported to the ACT, underwent health assessments, and released on
the same day) and at night to minimize stress and to provide maximum time to
explore MFWS and find a den before first light. No supplementary food was
provided.
Despite significant modifications to our predator-proof fence prior to the first
release, within days of the Trial 1 release, seven founders escaped over the
MFWS fence. Of these, two were found deceased (assumed to be preyed upon
by the red fox), three died from injuries whilst under observation in a care facility,
and two were retrieved alive and released back into MFWS. Of the remaining
seven founders, two were found deceased within MFWS, one was transferred to
Mt. Rothwell due to its poor condition, and four (3 females & 1 male) survived
without issue. In Trial 1, 43.8% of founders survived the establishment period,
37.5% maintained body condition, and 62.5% of females produced young.

Mulligans Flat release site © Mark Jekabsons

197
In Trial 2, we translocated thirteen female-only founders, preferring those that
were carrying pouch young that were fused to the teat (>60 days of age, ~25mm
crown rump length, Bryant, 1988). Releases in Trials 2 (and also in Trial 3) were
conducted from one of four central locations (separated by 50 m). This tactic
aimed to maximize the distance over which a founder would travel before
encountering the fence, while also allowing them to encounter food resources,
den sites, conspecifics, or other features of interest before the fence. In Trial 2,
92.3% of founders survived the establishment period, 92.3% maintained body
condition, and 84.6% produced young.
In Trial 3, we translocated 8 female-only founders, also preferring those carrying
fused pouch young. No significant differences in survival or dispersal were found
between captive and wild founders in Trials 1 and 2, so only the more genetically-
diverse wild founders were selected in Trial 3. No significant weight loss was
observed, so no supplementary feeding was provided. In Trial 3, 87.5% of
founders survived the establishment period, 100% maintained body condition,
and 87.5% produced young.
Post-release monitoring: Daily survival and den location were monitored using
VHF or GPS collars for 42 days post-release because survival plateaued after this
period in Trial 1. We conducted post-release health checks measuring weight,
condition, and pouch occupancy every two weeks, though timing and frequency
varied due to reproductive stage, weight fluctuations (influencing collar fit),
logistical constraints, and ability to re-trap the targeted animal.
Major difficulties faced
 Escapes: Within days of the Trial 1 release, several founders escaped over
the MFWS fence into the surrounding landscape and were preyed upon by
Red foxes. This translocation was also complicated by issues with collar fit
due to expanding neck sizes induced by breeding hormones (especially in
males).
 Weight loss: By 14 days post-release in Trial 2, four captive-bred founders
had lost >10% of their initial release weight. As an adaptive management
intervention, supplementary food was deposited into their dens, in declining
amounts as weights stabilized.
Major lessons learned
 Males were poor founders: In Trial 1 many founders, especially males,
escaped over the MFWS fence within the first few nights of release.
 Releases should occur in winter: We hypothesized that the greater number
of male escapes was exacerbated by the timing of release. Eastern quolls
experience elevated breeding hormones in autumn, and this stimulates
mobility and aggression in males, aiding them to acquire den sites and food
(Godsell, 1983). We suspect that females may have also struggled to settle
because they were being pursued by males and were likely to have
elevated hormones. We adapted our tactics in Trials 2 and 3 by conducting

198
releases in winter, after
the mating period. This
had the added benefit of
reducing stress and collar
fit issues associated with
breeding hormones.
 Females should be
translocated with pouch
young: Conducting
releases in winter allowed
us to translocate females
with fused pouch young.
This tactic meant we
could translocate new
male and female
juveniles sired by either
captive or wild males,
and avoided the elevated
male mortality and dispersal observed in Trial 1. We hypothesized that
females with pouch young would invest in finding and maintaining a natal
den, thereby reducing dispersal and potential escape from MFWS.
 Dispersal affects the survival: Founders that moved between dens on
consecutive nights were more likely to escape and less likely to survive,
and this den movement was lower for females and when den sharing with
another founder.
 Stress needs to be managed: Founders in Trial 1 were released from bags
by researchers, which may have increased stress. We adapted our tactics
in Trials 2 and 3 and placed founders in situ in a den box (wooden box with
a sliding door) with the door closed for one to two hours (delayed release).
After last light, the door was opened from behind the den box and the
founder could leave of its own accord. We hypothesized this would
minimize stress and provide maximum time for founders to explore MFWS
and find a den before first light.
Success of project
Reason(s) for success:
 We released healthy eastern quolls into a fenced predator-free
environment.
 We closely monitored the population post-release and adjusted our
reintroduction tactics to reduce factors driving dispersal over the fence and
mortality. Once we identified a way to establish founders inside MFWS we
were able to reduce our effort and focus on translocating more genetically-
diverse founders.
 We used the TTCS as a framework to improve our ability to identify, select

Highly Successful Successful Partially Successful Failure

Research team © Swimming Wombat
Photographics & Woodlands and Wetlands Trust

199
and design tactics to achieve our strategies of maximizing survival and
minimizing post-release dispersal.
 We used trials in an adaptive management framework to make informed
choices that improved reintroduction success. This approach is particularly
important for threatened species reintroductions, where rapid decisions are
often required despite the absence of complete knowledge.
 The passion, dedication, innovative thinking and collaborative effort of the
partners and volunteers which made the planning, operations and research
conducted in this project possible.
References
Batson, W.G., Gordon, I.J., Fletcher, D.B. & Manning, A.D. (2015) Translocation
tactics: a framework to support the IUCN Guidelines for wildlife translocations and
improve the quality of applied methods. In: Journal of Applied Ecology 52(6):
1598-1607.
Bryant, S.L. (1988) Seasonal breeding in the eastern quoll Dasyurus viverrinus
(Marsupialia: Dasyuredae). In: Thesis presented for the Degree of Doctor of
Philosophy, Department of Zoology, University of Tasmania, Australia.
Cardoso, M.J., Mooney, N., Eldridge, M.D.B., Firestone, K.B. & Sherwin, W.B.
(2014) Genetic monitoring reveals significant population structure in eastern
quolls: implications for the conservation of a threatened carnivorous marsupial. In:
Australian Mammology 36(2): 169-177.
Godsell, J. (1983) Ecology of the eastern quoll Dasyurus viverrinus (Dasyuridae:
Marsupialia). Thesis written for The Australian National University.
Manning, A.D. (2015) A proposal for a research translocation of wild eastern
quolls (Dasyurus viverrinus) to the Mulligans Flat Woodland Sanctuary, Australian
Capital Territory, to establish a genetically and behaviourally diverse founder
population, and to undertake experiments to maximise future reintroduction
success.
Wilson, B.A., Evans, M.J., Batson, W.G., Banks, S.C., Gordon, I.J., Fletcher,
D.B., Wimpenny, C., Newport, J., Belton, E., Rypalski, A., Portas, T. & Manning,
A.D. (2020) Adapting reintroduction tactics in successive trials increases the
likelihood of establishment for an endangered carnivore in a fenced sanctuary. In:
PLOS ONE 15(6): e0234455.

IUCN SSC Conservation Translocation Specialist Group
Global conservation
translocation perspectives: 2021
Global conservation translocation perspectives: 2021