Post on 21-Apr-2020
transcript
Pest mammals in
Hamilton city
Dai Morgan
Email: dai1@waikato.ac.nz
Phone: 8384466 extn 8123
Introduction
• Introduced mammalian pests are bad news
• Comparatively little research on urban predators
• Limited knowledge on which pests are in Hamilton
– Practically nothing known on their distributions
Videoed predators in podocarp-broadleaved
forest
REF harrier ship
rat
possum stoat more-
pork
Flux Mapara kokako 2 8 3 2 0
Innes Rotoehu kokako 5 1 4 0 0
Innes Motatau kereru 0 1 3 0 0
James W’holm kereru 0 0 1 0 0
Flux T/riro fantail 0 2 0 0 0
P’land W’naki kaka 0 0 1 0 0
Brown Kaharoa tomtit 0 7 0 0 0
Brown Kaharoa robin 0 3 0 0 2
TOTAL 7 22 12 2 2
Videoed predators in rural areas (Waikato)
magpie
Predator
ship rat harrier cat
pukeko
blackbird
thrush
goldfinch
greenfinch
mallard
TOTAL
1
1
1
5
1
7
3
3
1
1
8
3
2
5
1
1
total nests monitored= 38
no. fledged= 9 (24%)
Videoed predators in Hamilton City
• 21 nests monitored (mostly in residential gardens)
• Blackbird, song thrush, fantail, silvereye nests
• 10 nests successful (48%)
• 5 predation events filmed
species stage when
event occurred
predator
blackbird
blackbird
song thrush
fantail
fantail
chicks
chicks
eggs
chicks
eggs
cat
cat
ship rat
ship rat
ship rat
Pest mammal
inventory
Hamilton city
• Six gullies
• Six parks
• Six residential
areas
• Two of each
habitat types
surveyed per
week
• Survey
conducted in
March-April 2007
Survey methods
Device / method Target species
Tracking tunnel
WaxTag
Live catch traps
Scat/ animal sign survey
Public survey
rodents, hedgehog, mustelids
possum, rat
ship rat, Norway rat
rabbit, possum, cat, hedgehog
mainly cat
Tracking tunnel results
• NO MUSTELIDS DETECTED
Mean % of tunnels tracked by pests in each habitat
* = the number of areas per habitat that each species was detected
Species
Gullies
Parks
Residential
rat
hedgehog
mouse
15% (5/6)*
22% (5/6)*
30% (4/6)*
5% (2/6)*
25% (6/6)*
14% (3/6)*
0%
12% (3/6)*
0%
WaxTag results
Species
Gullies
Parks
Residential
possum
rat
19% (5/6)*
5% (3/6)*
0%
2% (1/6)*
0%
0%
* = the number of areas per habitat
that each species was detected
Footprint images courtesy of kiwifoundation.org.nz
rat possum
Ship rat vs. Norway rat
• Different behaviours
– Ship rats more
important predators
Hamilton survey
• 404 trap nights
• 2 Norway rats
• 19 ship rats Norway
Ship
Ship Norway
Ship
Norway
Monitoring pest mammals
• DOC established rodent and mustelid
protocols
• For gullies, presence/absence probably
most appropriate
• NPCA established possum protocols
• For gullies, presence/absence probably
most appropriate
Kill traps
WHY DO YOU WANT TO REDUCE MAMMALIAN
PESTS?
- need to determine what you want to achieve
Many types of traps; e.g.,
- Multi traps- mustelids and also rodents
- Snap traps for rodents
- Timms and Sentinel traps for possums (WRC
have Timms traps for borrowing)
• Comply with Wildlife Act
• Minimise non-target catch
Live capture traps
Good because of low non-
target species issues
Bad because you have to deal
with a live animal
Conclusions
• Most pests in Hamilton live in Gully habitat, and are
dominated by ship rat and possums (and cats)
• Identify predators in you gully before and after control
– Some easy and relatively cheap methods
• Establish why you want to control pest species in your
gully
• Determine an appropriate course of action and ask for
help if you need it!
Some useful contacts
Connovation (www.connovation.co.nz) – Tracking tunnels, possum
traps
Pest Control Research (www.pestcontrolresearch.co.nz) – Baits,
WaxTags, multi-traps and other traps (just about everything). Also,
bite-mark identification sheets etc
Pest Management Services (www.nopests.co.nz) – Live traps
Phil Proof (www.philproof.co.nz) – Baits, traps, stations, tracking
tunnels
NZ Kiwi Foundation (www.kiwifoundation.org.nz) – monitoring protocols
and footprint identification
Waikato Regional Council- advice and Timms traps