Reintroductions

Australian and New Zealand perspectivesCanadian reintroductionsCase studies

The good, the bad and the ugly??Other issues to consider

Australia

100+ species of plants and animals have gone extinct in the last 200 yrsMammals25 species extinct10 species only on islands17 species in remnant habitat

10% of their pre-European range

Australia

Fig 1 Cardillo and Bromham 2001

Medium and large species are more vulnerable to extinction

Reintroductions in Australia

Many macropod reintroductions have been attempted

Success rateIslands no predators 82%Mainland/island with predators 8%

Failure attributed to predation - foxes and cats

Short 1992

Reintroductions in Australia

PREDATOR FREE ISLANDS Eg Faure Island Sanctuary, WA

2002 Burrowing bettong 20 released now 100

2002 Shark Bay Mouse 100 released now all over island

2005 Banded hare wallaby 16 released “thriving”

Faure Island 6000 ha

What about the mainland?

Australian Wildlife Conservancy

Triple barrier sanctuaries

release

Predator removal

Predator control

fence

12 km buffer zone

Woylie

Karakamia Sanctuary

Reintroductions in AustraliaBasic premiseLimit the impact of predation

IMPACT = NUMBER X EFFICIENCY

Options Lethal Control Fertility Reduce Primary Prey

Eg Flinders RangeRabbit haemmorhagic diseaseRabbit population down 85%Fox and cat population down 40%

Limit the impact of predation

IMPACT = NUMBER X EFFICIENCY

Options Pre-release training Aversion therapy Enhance refuges

Stokes et al.2004Wire net

Limit the impact of predation

Stokes et al.2004

Wire netRefuges from predation

Giving up densities Foraging pathWire net

New Zealand

Area of NZ - 27 million hectaresArea not invaded by exotics 2000 ha

No terrestrial mammals prior to humansBut 245 spp birds 71 % endemic

Early Extinctions 33Post-European extinctions 19

Cause - exploitation - invasive spp - 33 mammals

Conservation in New Zealand

Step 1

% conservation budget - 40%Area where exotics eradicated 30,000 haIslands > 55 ha: 53 one spp removed

36 free of all introduced spp

Reintroductions in New Zealand

Black robin

1977: 1 female

1994: 200

Examples

Giant weta

2001: 81 released

2003 - producing young

Tuatara1996-2004Releases on 4 islands Number translocations >400

Number animal taxa - 68 +

Reintroductions in New Zealand

Restoration aimsrecreate structure, function and dynamics of original ecosystemWhat do you do if keystone spp is extinct?

Norfolk island - 2 extinct pigeons Chatham Island - extinct parrot

What do you do if keystone spp is extinct?

Consider use of a “functional surrogate”

Reintroductions In Australia and New Zealand

Common tool to -reduce extinction risk of vulnerable species-- restore degraded ecosystems

Key factor: removal/control of predators

Why?

Introduced predators are the major cause of population declines

Exploring reintroductions In Canada

Why?

1) 577 Species at Risk

70% of Recovery Plans consider translocations

2) Climate Change and possible need to re-assemble communities

Reintroductions: the good?

Reintroductions: Burrowing Owl

Reintroductions: Burrowing Owl

Population < 1000 pairs in Canadadeclines 22%/yr

Issues - habitat loss - lack of burrows - shortage of food - vulnerability to predators - migration - fewer refuges - wintering grounds ??????

Reintroductions: Burrowing Owl

In BC

Attempt 1 1983-1989 Vaseaux/Osoyoos Lake Wild ct breeding pairs released

in artificial burrow Produced young But no birds returned to site FAILED

Reintroductions: Burrowing Owl

In BC

Attempt 2 1990 - now Thompson/Nicola Captive breeding

in Vancouver/Kamloops

1 yr old birds released at historical sitesartificial colonies created by volunteers

Reintroductions: Burrowing Owl

Reintroductions: Burrowing Owl

Attempt 2 - owls breed, migrate and return - population small but increasing

Additional benefitsongoing research on captive breedingpublic outreach and educationlandowner support for initiative

modified grazing regimesimprovements to grassland habitat

Reintroductions: Vancouver Island marmot

Numbers in wild1984 2351997 1021998 712000 36

Distribution

25 sites on 13 mountains;

67% of animals on 4 mountains

Vancouver Island marmot

Occupy small patches of sub-alpine meadow

Patches available but no longer colonized

Issues: logging and clearcuts predation disease climate change (snowfall/snowpack)

Reintroductions: Vancouver Island marmot

1997-1999 17 removed for captive breeding1999-2004 38 more removed2008 4 facilities - 160 animals

Releases2003 4 (all 1-2 yrs - all dispersed -- >killed)2004 9 (6 m 3 f; all 2 yrs)2005 15 (10 m 5 f; all 2 yrs)

A marmot update

2008 total releases = 155 11 litters born 7 litters with 1+

captive parent

A marmot update

2003 2008

Captivity 77 162Wild 21 102

Mountains withMarmots 4 17Possible pairs 3 17+

Summary

Reintroductions

Are an increasingly common tool

Are successful if the cause of declines are known and eliminated/reduced

Are less successful if the reasons for declines are uncertain

Genetic issues in reintroductions

1. Where do we get individuals from?

Natural selection ---> local adaptation

To far away ---> hybridisation/outbreeding depression

2. How many founders are needed?

Too few --> low genetic diversity and inbreeding depression?

Practical issues in reintroductions

How and whom to release?

Soft or hard introductions

Age/number/relationships of individuals