Sanctuaries, & biodiversity responses to pest control

John Innes, Rachelle Binny

Andrea Byrom, Neil Fitzgerald, Alex James, Roger Pech

Manaaki Whenua - Landcare Research

LINK seminar, Wellington, 19 October 2017 Fitzgerald Colbourne

Outline

• What and where are NZ’s sanctuaries?

• Major pest management regimes

• Importance of monitoring with standard methods

• Some Maungatautari results

• What can we learn from monitoring in fenced sanctuaries and mainland islands?

• Biodiversity monitoring database

• A meta-analysis of outcomes for sanctuaries

John

Innes

Rachelle

Binny

House mouse

Brushtail possum

Cat

Hedgehog

Ship rat

Stoat

Norway rat

Feral goat

Red deer

Ferret

Weasel

Fallow

deer

Rabbit

Dog

Nga

Ma

nu

Im

ag

es

Nga

Ma

nu

Im

ag

es

What are ‘biodiversity sanctuaries’?

Sites that:

• experimentally restore NZ ecosystems to indigenous dominance

and full species complement

• control or eradicate a broad suite of pests with best practice techniques

• reintroduce missing species

• manage a permanent and substantial risk of pest reinvasion

• inspire and galvanise communities to local conservation

We identified 82 such projects on or near the

NZ mainland

Map: Neil Fitzgerald, 8 Aug. 2017

SANCTUARIES

Mean area:

Stoats 2780 ha

Possums 1860 ha

Rats 940 ha

Total area:

50,500 ha

0.18% NZ

Goals

Unacceptable damage? at this site

Pest control Best practice?

Pest control 101

Residual pest abundance? Number killed

Use SOP indices

Biodiversity

outcomes?

Major regimes

1. Repeated aerial 1080

a) Ospri for Tb/DOC for forest health

b) Battle for our Birds (timed for mast)

c) 2-3 yearly – sustained ship rat control

2. Mainland island

- kaka, kiwi, kokako, robin, whio, tree weta

3. Fenced sanctuary/island

- hihi, tieke, takahe, kakapo, tuatara, giant weta

Regime 2 Mainland island

ship rats

stoat

possum

ferret

kokako Nga

Ma

nu

Im

ag

es

robin tree weta

S. W

ills

NI brown kiwi whio kaka

M.

Roth

we

ll

Ka

ka

riki G

am

es

Ark in the Park, Waitakeres, 2002-17*

*Gillian Wadams, Forest and Bird

Rat

trackin

g r

ate

R

at

trackin

g r

ate

Ship rat

Norway rat

Mean ship rat tracking %,Oct.-Feb.

0 10 20 30 40 50 60 70

% n

esti

ng

att

emp

ts f

led

gin

g y

ou

ng

0

20

40

60

80

100

Possum trap-catch at 1 Nov.

0 10 20 30 40 50 60 70

% n

esti

ng

att

emp

ts f

led

gin

g y

ou

ng

0

20

40

60

80

100

Kokako nesting success* vs

a) Possum trap-catch b) Ship rat tracking rate

* Innes et al. 1999. Biol Cons 87:201-214

CR

Ve

itch

Norbury et al. 2015. Biol. Cons. 191 409-420. Density-impact functions for terrestrial vertebrate pests and

indigenous biota: Guidelines for conservation managers.

Rat tracking rate

0 10 20 30 40

MG

W t

rackin

g r

ate

0

1

0

2

0

3

0

4

0

Mahoenui giant weta

Thornburrow

North Island robin

Corinne Watts et al. 2017.

Weta as bioindicators.

Jnl Insect Conservation

Mahoenui

Mangaokewa

Mahurangi Is.

Warrenheip

M. Rothwell

Kakariki Games

Doug Armstrong et al. 2006.

Robin viability vs predators.

Jnl Wildlife Management

Regime 3 Fenced sanctuary/island

Takahe

Tuatara

Hihi

Tieke

Little spotted kiwi

Giant

weta

Kakapo

Duvaucel’s

gecko

Invader pests at Orokonui, Dunedin (Elton Smith)

Mice alone at Maungatautari

3400 ha

Mouse density

Deb Wilson, Neil Fitzgerald, Scott Bartlam

YearJan-2011

Jul-2011 Jan-2012

Jul-2012 Jan-2013

Jul-2013 Jan-2014

Jul-2014 Jan-2015

Jul-2015 Jan-2016

Jul-2016

Ave

rage

nu

mb

er

of

inve

rte

bra

tes

cau

ght

pe

r tr

ap n

igh

t

0

1

2

3

4 M blockQ block

Similar patterns for:

• Beetles, spiders, weta, caterpillars

• Leaf litter samples

Invertebrate abundance Treatment

switch

Corinne Watts, Danny Thornburrow

Tui movement/spillover from M’tari

Neil Fitzgerald

= Mammal

eradication

Maungatautari 5mbc, 2002-14:

mobile frugivores

Neil Fitzgerald, Scott Bartlam

= Mammal

eradication

Maungatautari 5mbc, 2002-14:

insectivores

Neil Fitzgerald, Scott Bartlam

= Translocation

Conclusions

Pest levels (eg zero) known for some birds, lizards, inverts

Few density-impact functions known

Pest eradication impossible without fences

Competition and habitat also matter

There are winners and losers

PLEASE MONITOR:

- Residual pest abundance with SOP indices

- Diverse biodiversity outcomes

- For 10 + years……. Rachelle

Outline

• What and where are NZ’s sanctuaries?

• Major pest management regimes

• Importance of monitoring with standard methods

• Some Maungatautari results

• What can we learn from monitoring in fenced sanctuaries and mainland islands?

• Biodiversity monitoring database

• A meta-analysis of outcomes for sanctuaries

John

Innes

Rachelle

Binny

Predator Free New Zealand

What can sanctuaries teach us?

How do NZ’s flora and fauna respond to pest control?

• Compare different control regimes; initially fenced sanctuaries and mainland islands

• Understanding biodiversity benefits is a crucial step towards achieving goals of PF2050

Biodiversity monitoring database

• Database of biodiversity monitoring data from managed sites

• 782,322 records

• 21 sites (3 DOC Mainland Islands, 18 other sanctuaries)

• 17 unfenced, 4 fenced

• 1995-2016

• 438 species (birds, invertebrates, lizards, vegetation and pests)

Biodiversity monitoring database

Habitat

Beech

Podocarp-broadleaved

Site Type

Fenced

MainlandIslandUnfenced

Treatment type

Treatment

Non-treatment

34%

66% 83%

11% 6%

61% 39%

Taxa

Birds

Invertebrates

Lizards

Vegetation

65% 33%

< 1%

Combining biodiversity data: meta-analysis

“Effect size”: outcome with pest control, c.f. without

0 > 0 < 0

E.g. ↑ abundance,

↑ nesting success,

↑ counts per unit search effort,

↓ foliar browse damage, etc.

Positive response

to control

Negative response

to control No

response

Fenced vs. mainland islands

fenced

sanctuaries

all sanctuaries

mainland islands (MI)

Taxonomic groups Fenced & MIs

combined

Fenced

MIs

Taxonomic groups by regime

Native vs. introduced birds Fenced & MIs

combined

native

introduced

all birds

native

introduced

all birds

Native vs. introduced birds by regime

Fenced

MIs

Endemicity levels for NZ birds

Bird endemicity Fenced & MIs

combined

all native

all introduced

order (e.g. kiwi)

family (e.g. kōkako, hīhī)

genus (e.g. bellbird, tūi)

species (e.g. kākāriki, NI robin)

Bird endemicity by regime

order (e.g. kiwi)

family (e.g. kōkako, hīhī)

genus (e.g. bellbird, tūi)

species (e.g. kākāriki, NI robin)

all native

Fenced

MIs

all introduced

Primary guild for native birds

frugivore (e.g. bellbird, kererū)

insectivore (e.g. rifleman, tomtit)

omnivore (e.g. hīhī, silvereye)

carnivore

(top predators: kāhu, NZ falcon)

all native

Fenced & MIs

combined

Primary guild for native birds

frugivore (e.g. bellbird, kererū)

insectivore (e.g. rifleman, tomtit)

omnivore (e.g. hīhī, silvereye)

carnivore (top predators: kāhu, NZ falcon)

Fenced

MIs

all native

Habitat for native birds

podocarp-broadleaved

beech

mixed

all native

Fenced & MIs

combined

Habitat for native birds by regime

Fenced

MIs

podocarp-broadleaved

beech

mixed

all native

Species (5 mbc) Treatment

Non-treatment

Boundary Stream MI Wainuiomata MI

Rat Tracking Index (%) Rat Tracking Index (%)

Density-impact functions (Rotoiti)

Room for improvement?

Need consistent and long-term monitoring of biodiversity outcomes and residual pest abundance

• Standardised monitoring methods and measures

• Data sharing & reuse

• Data management

Conclusions

• Both increases and declines for species in sanctuaries

• How to measure success?

• Knowledge gaps: outcomes for communities and ecosystems

• Need consistent and long-term monitoring: diverse biodiversity measures and residual pest abundance using SOP indices

What next?

• Offshore, pest-free islands

Bellingham et al 2010

Acknowledgements

• DOC MI data access: Craig Gillies and Oliver Gansell (Department of Conservation, Hamilton)

• DOC MI staff for field data collection and reporting

• Sanctuaries data: Ark in the Park, Bluff Hill/Environment Southland,

Bream Head Scenic Reserve, Bushy Point, Corinne Watts (Landcare Research), East Taranaki Environment Trust, Forest Lifeforce Environment Trust, Glenfern Sanctuary, Halfmoon Bay Habitat Restoration Project, Kaipupu Point Wildlife Sanctuary, Mainland Island Restoration Operation, Maungatautari, Orokonui, Pirongia, Pomona and Rona Islands, Puketi, Totara Reserve/Horizons Regional Council, Wainuiomata Mainland Island, Windy Hill, Zealandia

• Robbie Price (Landcare Research)