Aspects of the ecology and management of small mammalian predators in northern New Zealand

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*tLoa

Arpects of tho Ecology an'd Management of Small Mammalian Predators in Northern New Zealznil

Crafig Glllicn

A

thesis m-bmitted,

fortfte

dqgee

ofDoetor ofPhillosopfinin

Enyirorrrneutat Science, The UniVersitlt

of Aue*fantl'

1998.

Table of Contents.

ABSTRACTS.

CrLq,prsRI...

^{... 1}

The prey species of domestic cats @elis catus) in two suburbs of Auckland city, New

Zea\and...

...

/ CHeprsRII...

^{... 1}

Diets of coexisting alien mammalian carnivores in Northern New Zealand...

I Crnprrn trI. ... ...2

Home range of introduced mammalian carnivores,

feral

^{cats (Felis} catus), stoats (Mustela erminea) and

aferret

^(M.

furo)

^{at Trounson}

Kauri

Park, Northland, New

Zeahand...

... 2

CHepren

IV...

^{... 3}

Secondary poisoning of introduced mammalian carnivores during possum and rodent

control

operations at Trounson

Kauri

Park, Northland New Zealand... 3

Cnnprsn V. ... ... 3

Managing alien mammals in mainland New

Zealand:

The implications

for predator/prey

interactions in complex

communities

... 3

ACKNOWLEDGEMENTS.

...,. 5

GEI{ERAL INTRODUCTION. BncrcRouvo ...7

NoRrrneuD

AND TnouNsoN Keuru

Pem.

^{... 8}

THn NRruRs oF THIs

sruDy...

^{... 9}

Arus.

...

l0 CIIAPTER I. TIIE PREY

SPECIES

OF DOMESTIC CATS (FELIS CATAS) IN TWO

SUBURBS

OF AUCKLAI\ID CITY,IYEW ZEALAI\D ...1I INrnonucnoN... ... 11

Sruov AnBns. ,...l2 MerHoos. ...l4 Rrsur.rs... ... 15

Response to the

initial survey.

^{... 15}

ONBvsensuRVEY.

^{... 16}

Total

prey

catch

in

Oratia and Browns

Bay.

-...-.-... 16

Seasonal

distribution

of prey take and comparisons between areas. ... 20

Cat age, sex and individual predation

efficiency.

...,... 24

Rodent surveys and

bird counts.

... 26

D1scussroN...

^...28

Prey species and seasonal trends in prey

take...

^{... 28}

Assumptions, sources of

error

and analysls.

...

^{... 34}

Predicting

total predation and

implicationsfor

conservation... 36

CHAPTER II. DIETS OF COE)ilSTING ALIEN MAMMALIAII

CARNTVORES IN NORTHERN

IYEW

ZEALA}ID.

CHAPTER III. HOME RANGE OF INTRODUCED MAMMALIAI\

CARNryORES, FERAL CATS (FELIS

CATUS),

STOATS (MUSTELA ERMINEA) AND A FERRET (M.

FURO)

AT TROUNSON KAT]RI PARIE NORTI{LAND.

IYEW

ZEALAI\TD

INrRonucuoN...

... 68

SrunvAnre.

...69

MerHons.

^...71

Rrsurrs...

^...75

Cat home

ranges. ...75

Sub-adult male

cats..

...76

Adult

male

cats.. ...8I

Female

cats... ...86

Home range overlap between sexes and age classes of

cats.

...92

Kittens. ...93

Mustelid home

ranges.

... 95

Stoats...

... 95

The

Ferret.

...-....96

Home range overlaps between mustelids and

cats.

... 102

Drscussrou

^{.. 103}

Feral cats... ... 103

Mustelids.

...

/08

Interactions between

predators....

... ^I I

I

Recommendationsfor conserl)ation

management...

... 112 39

68

II

CHAPTER IV. SECONDARY POISOIIING

OF

INTRODUCEI) MAMMALIAN CARNWORTS DURING

POSSTJM

AND RODENT

CONTROL OPERATIONS AT TROUNSON KAURI PARIE NORTHLAI\ID

NEW ZEALAND

...114

INrRooucrroN...

... 114

SrupvAnee.

... 115

Mnrnoos.

^{... 116}

Department of Conservation Pest Control

Operations

^...

I16

Predator monitoring and secondary

poisoning.

... 117

Department of Conservation rodent

surveys.

... I 18 Rabbit

survsys.

..,... 119

Resulrs... ...l2l

Secondary

poisoningfrom 1080.

... 121

Secondary

Poisoningfrom Brodifucoum...

... 122

Brodifacoum

residues

...-...-... 124

Rodent

Indices...

^{... 126}

Rabbit

surveys.

...-.. 128

DrscussroN... ....128

Secondary

poisoningfollowing

the IA80

operation.

^{... 128}

Secondary poisoning during the brodifucoum operation.

...

^{... 129}

Comparison between secondary poisoning

fficts

^after

the

^{l,080 and} brodifacoum

operations

... 131

Differences in

proportions

of brodifucoum detected between carnivore species.l33 Implications

for

consertation.

...

...

I34 CHAPTER V. MANAGING ALIEN MAMMALS IN MAINLA}ID FIEW ZEALAI\D: THE IMPLICATIONS FOR PREDATOR / PREY INTERACTIONS IN COMPLEX COMMI'MTIES.

137

lurRonucroN...

... 137

Dep,q,RrNmhrr oF CoNSERVATToN ^pEST coNTRoL opERATToNS AT TRouNsoN

Keunt PemJuNe

1996

roJ.lNunRv

1998.

...

^{... 138}

INonBcT EFFECTS UPoN VEGETATIoN AND NATIVE FAUNA oF ALIEN MAMMAL PEST MANAGEMENT.

...

... 140

INapTTc.ATIoNS oF INTENSIVE MAMMAL CONTRoL FoR CARNIVORES AND PREDATOR- PREY

INTERACTIONS. ...I44 Implicationsfor

predator prey

communities

... 144

Rabbit

calicivirus

disease

RCD...

... 145

Rabbits and

predators...

... 147

Rodents...

... 149

Mustelids.

... 150

Changes in the predator

guild.

^...

I52 CoNcr-usroN

... 153

ls7

REFERENCES.

n

ry

List of tables.

TABLE

r ...

THn

nBIeuVE

IMPoRTANCE oF DIFFERENT PREY ryPES AS REPORTED BY CAT OWNERS nq

OneneexoBRowNsBev.

TABLE II t7

Cotr4perusoN emo BRowus

oF pREy rAKE

(ev rnxa)

^pER cAT ovER oNE vEAR BETwEEN

Onern Bnv.

TABLE III

Snesot*Ier coMpARISoNS oF BIRD pREy rAKEN BETwEEN LocATIoNS.

Seesonnl

coMpARIsoNS oF IN"'r'ERTEBRATE pREy rAKEN BETwEEN LocATIoNs.

SsesoNnl

coMpARISoNs oF RoDENT pREy rAKEN BETwEEN LocATIoNS.

TABLE VI

^...24

SeA,soNAL coMpARrsoNs oF LTzARD pREy rAKEN BETwEEN LocATIoNS.

RopBNrrRep TABLE VIIIA

CAPTURES n,I ORATIA nNTo

BRowNsBey.

Hvn mrure

^BrRD couNTS FRoM

Onnrrn.

TABLE VIIIB

FrvB

rrfillt-rs

BIRD couNTs ^FRoM BnowNrs

Bev.

Acs class

^{AND sEX} oF cATS FRoM TUE THREE HABITATS.

TABLE X... ...49

Snx

or

sroATS FRoM TI{E THREE HABITATS.

TABLE Xr...

Houn

RANcES

or 1l

renaI- cATS MoMToRED BETwEEN

Jexuanv

1996

ro

FrsRuA,Rv 1997.

TABLE XII.

Holm

RANGES oF FrvE MUSTELTDS MoMToFGD BETwEEN

FrsnueRv

1996

ro Mev

1997.

TABLE )ilII.

1080

nrspuEs

rN SKELETAL MUSCLE.

r22 2l

22

27

27 23

26

75

95 46

V

123 PnsneroRs MoNIToRED THRoucH

BRoomecouu

^porsoN opERATroN TARGETTNG POSSUMS AND RODENTS AND TO)ON RESIDUES FOUND IN LIVERS.

..tzs

PnopomoNs

oF MALE AND FEMALE cARMVoRE LIVERS CoNTAINING BRODIFACOUM RESIDUES.

List of Figures.

FIG.

1..

l6

Relative Proportions of Prey Take

Oy

type) over one year, for both study ^areas.

FIG.2A.

Relative Proportions of

Bird

Prey Take (by taxa) over one year

in

Oratia.

FIG.28.

l8

t8

Relative Proportions of

Bird

Prey

F'IG.3A.

Take (by taxa) over one year in Browns Bay.

Relative Proportions of Invertebrate Prey Take (by taxa) over one year

in

Oratia.

FIG.3B.

Relative Proportions of Invertebrate Prey Take (by taxa) over one year in Browns Bay.

FrG.4..

...21

Comparison of bird prey taken per cat, per month between Oratia and Browns Bay.

FIG.5. ,...22

Comparison

of

invertebrate prey taken per cat, per month between Oratia and Browns Bay.

FIG.6..

...23

Comparison of rodent prey taken per cat, per month between Oratia and Browns Bay.

FIG.

7..

Comparison

of

lizard prey taken per cat, per month between Oratia and Browns Bay.

FIG.

8..

Average number of prey items brought in by cats from different age classes

from

Oratia and Browns Bay.

19

19

24

25

VI

FIG.9

Location map showing areas in Northland New Zealand from which carnivore carcasses were obtained.

FIG.

IO. ,...45

Percentage

of

feral cat guts containing each prey group from the three habitat types.

FIG.

11.

.46

Percentage contribution by weight

of

each prey type

in

feral cat guts

in

each habitat.

FIG.

12.

.46

Percentage

of

feral cat guts containing each prey group by three month season.

FIG.

13.

Percentage

of

stoat guts containing each prey group from the three habitat types.

FrG. 14.

...49

Percentage contribution by weight of each prey type

in

stoat guts

in

each habitat.

FrG. 15.

...49

Percentage

of

stoat guts containing each prey group by three month ^season.

FIG.

16.

Percentage frequency of occurrence of main prey types in the guts of cats.

FIG.

17.

Percentage frequency of occurence

ofmain

prey types in the guts

of

stoats.

FIG.

18.

Percentage frequency of occurrence of main prey types in the guts of weasels.

FrG. 19.. ...52

Percentage frequency of occurrence of main prey _types in the guts

of

fenets.

FIG.20.

Percentage contribution by weight

of

each prey type in cat guts.

FIG.21.

Percentage contribution by weight

of

each prey type

in

stoat guts.

FIG.22.

Percentage contribution by weight

of

each prey type in weasel guts.

FIG.23.

Percentage contribution by weight of each prey type in ferret guts.

FIG.24.

Map of core study area and surrounds, adapted from Department of Lands and Survey topographical maps of the Trounson area.

43

48

51

52

53

53

54

54

70

VII

FIG.25. ...74

Predators caught at Trounson

Kauri

Park between January 1996 to January 1997 anid duration monitored.

FrG.26..

...77

Home ranges (MCP) of four sub-adult male cats monitored from January 1996 to October 1996.

FIG.27A.

... 78

Three dimensional non parametric range utilisation distribution

plot

of the home range

of

sub-adult male cat 801, monitored from January October 1996.

FIG.27B.

Three dimensional non paramehic range utilisation distribution

plot

of the home range

of

sub-adult male cat 810, monitored from February to June 1996.

FIG.27C.

Three dimensional non parametric range utilisation distribution

plot

of the home range

of

sub-adult male cat 814, monitored from February to June 1996.

FIG. 27D.

,...81

Three dimensional non parametric range utilisation dishibution

plot

of the home range

of

sub-adult male cat 816, monitored from March to June 1996.

FIG.28.

Home ranges OdCP)

of

three adult male cats monitored from January 1996 to February 1997.

FIG.

29A.

Three dimensional non parametric range utilisation distribution

plot

of the home range

of

adult male cat 802, monitored from January to

March

1996.

FIG.29B.

Three dimensional non parametric range utilisation distribution

plot

of the home range

of

adult male cat 823, monitored from May to October 1996.

FIG. 29C. ...86

Three dimensional non parametric range

utitsation

distribution

plot

of the home range

ofadu

FrG.

30...

It male cat825, monitored from

April

1996 to February 1997.

Home ranges (MCP)

of

four female cats monitored from January to June 1996.

FIG. 31A...

Three dimensional non parametric range utilisation distribution plot of the home range of sub-adult female cat 803, monitored from January to June 1996.

FrG.31B.

...90

Three dimensional non parametric range utilisation distribution

plot

of the home range

of

sub-adult female cat 809, monitored from February to June 1996.

79

80

83

84

85

88

89

\rIU

FIG. 31C.

...91 Three dimensional non parametric range utilisation distribution

plot

of the home range

of

adult female cat 807, monitored from February to June 1996.

FIG.31D.

Three dimensional non parametric range utilisation dishibution

plot

of the home range

of

adult female cat 815, monitored from March to June 1996.

FIG.32.

Home ranges O4CP)

of

four stoats and one ferret monitored from February 1996 to

May

1997.

FIG.33A.

...98

Three dimensional non parametric range utilisation distribution

plot

of the home range

of

FIG.33B.

male stoat 813, monitored from February to Jtme 1996.

Three dimensional non parirmetric range utilisation

dishibutionplot

of the home range

of

male stoat 820, monitored from

April

to June 1996.

FIG.33C. r00

Three dimensional non parametric range utilisation distribution

plot

of the home range of male stoat 842, monitored from January to

May

1997.

FIG.33D.

^...101

Three dimensional non parametric range utilisation distribution

plot

of the home range

of

fernale stoat 838, monitored from January to

May

1997.

FIG.34.... ....102

Three dimensional non parirmetric range utilisation

distributionplot

of the home range of male ferret 817, monitored from March to June.

FrG.3s.

... 120

Location map showing Trounson

Kawi

Park and trapping and bait station layout

in

the studv area.

FIG.36.

124

Brodifacoum residues in carnivores

killed

during Department

of

Conservation pest

conkol

operations at Trounson kauri Park.

FIG.37.

... 125

Mean levels of brodifacoum detected

in

male and female carnivores from Trounson Kauri Park.

FIG.38. ...126

Rodent snap trap capture rates at Trounson Kauri Park.

F',IG.39.

...127

Rodent snap trap capture rates at Maungatapere Reserve and

Katui

Scenic Reserve.

92

99

x

FrG.40.

...127 Rodent tracking tunnel indices at Trounson Kauri Park and

Katui

Scenic Reserve, 18th September 1997.

FIG.41.

143

Schematic representation of the relationship between marrrmalian pest management practices and predator-prey interactions in New Zealand.

List of Plates.

PLATE I.

Feral cat photographed

whilst

restrained

in

a soft catch leghold

tap

at Trounson

Kauri

Park, Northland,

New

Zealand.

PLATE

2...

View

looking north towards the Oratia study site.

View

looking north accross the Browns Bay study site.

PLATE

4.

A

male stoat in the restraining net immediately

following

administration of the anaesthetic.

PLATE 5...

...94

13

13

73

Kitten

806

PLATE

6.

under the kitchen table

waiting

for me to do the trap rounds.

119

'?hilproof

Feeder" baitstation at Trounson Kauri Park.

PLATE 7...

...156

Cat 833 recaptured in February 1998.

X

Abstracts.

Each chapter

in this

thesis has been

written

as a separate paper intended

for

later

publication.

Rather than

write

one summary, an abstract

for

each chapter has been given

in

the order they are presented in the thesis.

Chapter I.

The prey species of domestic cats (Felis catus) in two suburbs of Auckland city, New Zealand.

The prey brought in

by

80 cats (Felis catus), over ^a year was monitored

in two

suburbs

of

Auckland

New Zealand.

The survey technique

followed

that

of

Churcher

& Lawton

(1987) where cat owners were asked

to

record (and

if

possible keep) the prey

their

cats brought

in.

^{The results}

for

the year indicated that there were distinct differences

in the type of prey

taken

by

cats

in

each

area.

Rodents

were

the most

important prey brought in by

domestic cats

in

an urban

/ forest fringe habitat

and invertebrates were the main prey brought

in by

domestic cats

in

a

fully

urban habitat.

Birds

and lizards were the second and

third

most important prey groups

in

both study areas. Rat and mouse snap trap indexes which were run at each study location, did not

detect

rodents in the urban

habitat.

The results from the urban/forest fringe concurred more

with

studies

of feral

cat

diet in New

Zealand

whilst

those

from

the urban area compared

more to

studies

of

domestic

and

stray

cat diet in urban

areas overseas.

There were seinonal trends

in

the

prey

captured

in

each area and

in both

areas cats hunted less over the winter months.

Chapter II.

Diets of coexisting alien mammalian carnivores in Northern New Zealand.

120

feral

cats,

85

stoats (Mustela

erminea),28

weasels

(M. nivalis) and

¹⁶ ferrets (M.

furo)

^{were caught over} three years,

in

Northland,

New Zealand.

The gut contents

of

these animals were examined and

their

food habits

described.

The main

prey

groups

of

^cats

were (in

^order

of

importance

by weight),

lagomorphs, rodents (Rattus spp

& Mus

musculus), other mammals,

birds

and

invertebrates. The

main

prey of stoats were rodents, birds, lagomorphs, skinks (Cyclodina spp)

and

invertebrates. Skinks, followed by mice,

were

the main prey of weasels.

Rabbits

(Oryctolagus

cuniculus) were

the

most

commonly

occurring

prey item in the

ferret

guts. The food

habits

for

cats and stoats were compared between

different

habitats

within the Northland

region where these animals were collected

from.

There was

little difference

between habitats,

but

invertebrates

occuned more frequently

and lagomorphs less

frequently in the diet of

animals

from

forest habitats compared to those

from

forest

/

pasture and coastal habitats.

No

differences were found

in

the prey of male and female cats, but invertebrates occurred more frequently in the guts

of

sub-

adult

cats compared

to adult cats.

Skinks occurred

more frequently in the guts of

female stoats,

which

tended to take smaller prey items than males.

Chapter III.

Home range of innoduced mammalian carnivores,

feral

^{cats (Felis} catus), stoats (Mustela erminea) and

aferret

^(M.

furo)

^{at Trounson}

Kauri

Park, Northland, New

Zealand.

The

minimum

home ranges of eleven feral cats, four stoats and one male ferret were examined by radio telemetry at Trounson

Kawi

Park

in

Northland New Zealand.

The average

minimum

home range

of

male feral cats was 305

+ 74ha. This

was

not significantly

larger than the L22

*

35 ha minimum average home range

of

female cats.

The minimum

average

home

range

of

^three

male

stoats

was

108

+19 ha

and the

minimum

home range

of

one female stoat was 50

ha.

The male ferret had a

minimum

home range

of

179

ha.

There was

no

overlap spatially,

in

the home range

of

three adult male

cats.

There was also

very little

spatial overlap

in

the home range

of four

female

cats.

There was substantial home range overlap

with four

sub-adult male cats.

The home ranges

of

these sub-adult male cats also overlapped spatially

with

those

of

the adjacent females and adult males. The home ranges

of

two male stoats overlapped spatially

to

some degree and the home range

of

another male stoat overlapped that

of

the female stoat substantially. The home range of the male ferret overlapped the home ranges

of all of

the cats occupying

similar

areas

of

the

park.

The home ranges

of two

male stoats overlapped the home ranges

of

the adjacent cats

but not into

the

"core"

areas

ofthose

cats ranges.

Chapter IV.

Secondary poisoning of introduced mammalian carnivores during possum and rodent control operations at Trounson

Kauri

Park, Northland New Zealand.

Predatory mammals were monitored by radio telemetry through a 1080 then brodifacoum poison baiting operation at Trounson Kauri Park in Northland, New Zealand to taf,get possums (Trichosurus vulpecula) and rodents (Rattus

rattus,

Rattus norvegicus

&

Mus musculus).

All

six feral cats

(Felis

catus), and the single stoat (Mustela erminea) and ferret

(Mustelafuro)

being monitored at the beginning of the operation died

of

secondary poisoning

following

the 1080 operation.

A

further

two

cats and four stoats were radio tagged and monitored through the ongoing poisoning campaign using brodifacoum

in

^a continuous baiting

regime.

None of these radio tagged carnivores died

of

secondary

poisoning.

However, tissue analysis of additional camivores trapped at Trounson found that cats, weasels (Mustela

nivalis)

and to a lesser extent stoats did contain brodifacoum residues. The duration that the radio tagged predators were alive

in

and around Trounson Kauri Park suggested that the secondary poisoning effect was much reduced under the continuous baiting strategy, compared to the

initial

1080 poison operation.

Chapter V.

Managing alien mammals in mainland New

Zealand:

The

implicationsfor

predator/prey interactions in complex communities.

Recent advancements

in

alien pest mammal control technologies have enabled conservation managers to attempt long term, large scale, predator and browser control prograrnmes

at mainland sites in New Zealand. At Trounson Kauri Park (in

Northland, New Zealand) feral cats, ferrets,

stoats

and

weasels

plus rodents

and possums

were controlled for two and a half years. Early

results

from

Trounson suggested

that

some native

birds

and plants responded

positively

and

quickly to

the

control of

these

alien

pest

mammals.

Howevero

the

management also affected the predator-prey and predator-predator interactions,

within

the mammalian community,

with

changes

in

the predator

guild

and some

prey

species increasing

in

abundance.

The long term effects

of

these responses

within

the mammalian community to control efforts are

unclear. A

review

of

the international literature served

only to confirm

the

view

that managing alien mammals where re-invasion

is

constant

will

be a complex

task.

Conservation management at mainland sites

like

Trounson

Kauri

Park,

may in effect be acting as

crude

mammalian

predator

removal experiments. Monitoring

changes

in

predator-prey interactions and predator-predator interactions

at this

and other intensive management sites over sufficient

time

frames could provide scientists

with

the

critical

ecological data required

to

construct useful predictive

models.

The

ability of

^managers

to target specific pests at critical times would

represent a

significant

advancement

in controlling predatory

mammals

on the New

Zealand mainland.

Plate l. Feral cat

photographed

whilst

restrained

in a soft catch leghold trap

at Trounson

Kauri

Park, Northland, New Zealand.

Acknowledgments.

The list of

^people

who

have assisted

me at

various

times over the last

few years

is

huge,

I have tried to mention

everyone

who

has helped here

but if I've forgotten to mention

anyone

it is entirely unintentional and I'm deeply sorry

but

thanks anyway. Firstly I'm really grateful to my PhD

supervisors, Associate Professor

Mick Clout

and

Dr.

Ray Pierce

for their

guidance and assistance

with

the project

right

the

way

tbrough and

to

Professor John Craig

for

backing me

to

convert

this from

a

MSc to

a PhD

project. A

special thank

you to Dr.

Elaine

Murphy,

even

though she was not one of my official supervisors her advice, support

and encouragement over the last year have been

really

excellent,

I

could never have got to

this

stage

without it. I would also really like to thank Chris Edkins from

the

Department of Conservation, Science and

Research

unit for taking rny

crude diagrams,

territory

outlines and traced maps and

drafting them into really

excellent

illustrations. I'm

^also

really

grateful

to

the householders

in

Oratia and

Browns

Bay

for

agreeing to participate

in

the domestic cat survey and

allowing

me access to carry

out rodent trapping on their property. I'm also grateful to the Department of

Conservation

for ftlnding

the predator research at Trounson and

for allowing

me the time to

write

up this thesis

whilst

employed by them.

I would

also

like to

thank the

DoC

staff

involved with

the Trounson project,

particularly

Pete Graham, Scott Theobold,

Mark

Leach and

Tom Herbert.

Thanks

also to Nigel Miller (DoC Northland) for letting me use the results from

his Maungatapere

rodent

snap

trapping indices

as

a

non-treatment comparison

for

the Trounson

results. I

am also grateful

to the other

students and volunteers involved

with the efforts

at Trounson who

took

the

time to

give me a hand

with

trapping and autopsies over the years,

particularly

Natasha Coad, Bettina

Meier,

Richard Hendra, Rachael Ashton and a special thanks

to

Joss Deeming

for

stepping

in to monitor

the

kiwi

chicks when the rest

of

us were way too busy to keep on top

of it. Also I would

like

to thank the DoC

library

services particularly Shona Mackay, .Ianet Rumming and

Fiona

Paine,

without whom I'd

have never tracked

down half of the

references

I

needed. Thanks to the others from

DoC

Science and Research

unit,

who have helped

out, Dr. Clare VeLfuan for her

he,lpfirl oomrnents

on

eh4ptem

one

and

four, itlan

Sauuders for the many enthusiastio discussions

regarding'Mainland Islands'aud Keri Neilson

and

Dr.

Dave Toqvns

for

describing the

lizard

speGics:

fiat

^occur

in

Browns Bay and Northland.

Thsnks'to Dr. Mike

Fitzgerald

for

showirry ure some

quick

and easy w,ays

of

identifying

^pney items rn cat guts and providing _me

with

oopjes

of,m

many hard to get referencos.

llanks to Dr. Briar Gill

frorn the Auckland War lv.[e,

orial

Museum

for

assistarrce

in identitying

sorno

of

the

bjrd

re,mains.

I

^would also

like

to thaqk, Simone Bocker from Eff,em Foods

(NZ) Ltd.

fo-r discussmg the results of

their

1993 marketing

$xrv€y amd

Brian

B,ell

for

diseussing

the

results

of his

uqpublished survey

of

^urban

bird life

in W,eniagtoo.

Thank

also to Dr. John Dowding for dissussing the results

of

his

seconda,r'y

poisoning

researeh

on Motuihe Island with me. Finally I'm totally

indebted to Traey;

fot

keeping me sane and

putting

up

with

me

fortho

last couple

of

months.