The State of New Zealand's Birds 2006 - Special Report New Zealand's Seabirds
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The State of
New Zealand’s Birds
2006
Special Report
New Zealand’s Seabirds
The State of
New Zealand’s Birds 2006
Special Report Seabirds
Compiled and edited by Kerry-Jayne Wilson
The State of New Zealand’s Seabirds 2006 report presents an overview of
the current status of this country’s seabirds. It seeks to identify those species
that are in decline and not subject to active management and those for which
we have insufficient knowledge to know their true status. This statement
has been written on behalf of the Ornithological Society of New Zealand
(OSNZ) by ornithologists who share a concern for the well being of our
birds and their habitats. We hope this publication will highlight the plight of
our seabirds and encourage the Department of Conservation, OSNZ, other
NGOs, universities and authorities to focus on research and management that
address the problems we identify.
Introduction migration or on foraging forays. A major species which are, or may be, in decline, but
threat to New Zealand’s seabirds is fisheries are not yet sufficiently rare to have become
New Zealand is a major centre for seabird bycatch, much of which occurs in waters a DoC priority.
diversity. Globally, only about 350 species outside our jurisdiction, in some cases as far Some of the seabird survey priorities
of birds obtain all or most of their food away as Alaska or Argentina. While mention identified in this report could be carried
at sea and at least 84 of these breed in the is made of threats beyond our EEZ, the out by the Ornithological Society of
New Zealand Region. About 38 species emphasis here is on local issues that we in New Zealand (OSNZ) or other non-
of seabird are endemic to New Zealand, New Zealand can directly address. government organisations. The best
meaning they breed here and nowhere When it comes to bird conservation the available information on black-billed gulls
else. New Zealand now has about as focus of the Department of Conservation (Larus bulleri), white-fronted terns (Sterna
many species of threatened or endangered (DoC), the government department striata), black-fronted terns (S. albostriata)
seabirds as we have threatened non-marine charged with the conservation of New and Caspian terns (S. caspica) was obtained
birds, yet seabirds receive far less attention Zealand’s biota, is, and is likely to remain, during OSNZ surveys in the 1980s or 1990s.
than their terrestrial counterparts. on critically endangered species. In recent The Society should once again take a more
This report presents an overview of years DoC and other organisations have active role in the survey of these and other
the current status of each group of New focused on non-marine species at the accessible species. OSNZ in particular,
Zealand seabirds. It seeks to identify expense of seabirds. For most endangered but other organisations also, have among
species that are in decline and the main species that are under direct management, their membership a host of volunteers who
threats faced by those species. In this declines have been halted or in some would enjoy the opportunity to assist with
report we deal only with species that breed cases reversed. However, there are a large research and management of seabirds. The
in New Zealand or on the Kermadec, number of seabird species that are still Mana Island translocations and Chatham
Chatham, Snares, Auckland, Campbell, relatively common but whose populations Island taiko (Pterodroma magentae) recovery
Antipodes and Bounty Islands. Many New are in decline, and other species whose show what can be achieved at modest
Zealand breeding seabirds, including most status is unknown. We hope this report will cost when this pool of willing and able
of the endemic species disperse beyond identify those seabirds for which further volunteers is tapped.
our Exclusive Economic Zone (EEZ) during conservation action is required and those
2
We trust that the State of New Zealand’s Front, reduced food stocks and an
Seabirds report will provide OSNZ, NGOs, increase in the frequency of storm
regional councils and universities with events.
direction so that they can supplement the • The ozone hole may adversely affect
good work undertaken by DOC. oceanic foraging species as increased
UV levels may result in a reduction in
by Kerry-Jayne Wilson primary productivity thus reducing
Bio-Protection & Ecology Division,Lincoln the food available to seabirds.
University, Canterbury. • As a result of predation by introduced
wilsok@lincoln.ac.nz mammals many New Zealand
seabirds survive only on predator
free islands. These populations are
The Key Findings at risk from invasion of their island Above: Yellow-eyed penguin (Megadyptes antipodes)
sanctuaries by introduced predators. Photo by Dave Houston
• The number of seabirds that are under • The eradication of introduced
threat is increasing. mammals, in particular rats, from of threatened species.
• Reliable estimates of population size islands is a vital conservation strategy. • Much of the research and management
have been made for very few of New • It is now possible to translocate petrel on seabirds is reactive; there is no
Zealand’s seabird species. chicks from their natal island to another strategic plan for addressing the needs
• Research is required on the breeding site. This presents exciting new options of seabirds. A seabird strategy currently
biology, population dynamics, foods and for re-establishing petrels on islands being prepared will hopefully rectify
foraging ecology for most New Zealand recently cleared of predators or to this situation.
seabird species. predator-fenced areas on the mainland. • New Zealand currently has a shortage of
• Fisheries bycatch is a serious threat to • With the loss of virtually all of the once researchers and conservation managers
most New Zealand breeding albatrosses huge mainland petrel colonies, over with seabird expertise. The Department
and some petrels. Mitigation measures crowding on small islands and stacks of Conservation no longer has a scientist
are being developed for some species. is apparent and burrow competition or technical officer employed solely
• Migratory albatrosses, shearwaters may be contributing to declines in to work on seabirds and field staff
and other petrels are killed in fisheries some species. There has been almost seldom have adequate technical or
bycatch and perhaps through other no research to document the extent to financial support for the work they are
marine-based threats in waters far from which this impacts on burrow-breeding undertaking. The universities and other
New Zealand. Even very common species. research organisations are similarly
migratory species such as the sooty • Greater public awareness is required of under resourced when it comes to
shearwater are in decline. the threat that dogs, off-road vehicles work on seabirds. A heavy reliance on
• Recreational set-net fishing poses an and certain recreational activities pose to contract workers and students means
unquantified threat to some penguins, ground nesting seabirds. there is little continuity and loss of
shearwaters and shags. • The shags are the most neglected skilled workers as people move on at the
• Changes in oceanic conditions, perhaps group of seabirds, little is known of the end of their term. Funding and student
linked to global warming have the population dynamics, breeding biology, interest has directed seabird specialists
potential, and may already have foods, foraging ecology or population to work on other taxa.
contributed to declines in albatross and status for any of the endemic forms. • There is opportunity to make more use
petrel numbers by shifts in the Antarctic • The taxonomy of the Leucocarbo shags, of OSNZ volunteers. Here is a resource
albatrosses and mollymawks needs to of keen people looking for opportunities
Top Left: Pancake Rocks, Dolomite Point, Punakaiki be clarified. Likewise the taxonomic to contribute to the knowledge and
Photo by Richard Holdaway status of the Codfish population of the conservation of birds.
South Georgian diving petrel and the • Seabirds need greater advocacy. Most
Left: Black-winged petrel (Pterodroma New Zealand storm petrel need to be people have little knowledge of them.
nigripennis) determined. Even penguins and albatrosses, the most
Photo by Richard Holdaway • Much of the research conducted by iconic groups, need greater support.
DoC on seabirds is driven by pressure Petrels and terns are ‘out of sight, out
Below: Taiko (Pterodroma magentae) from external agencies or issues such as of mind’ and shags and gulls lack the
Photo by Graeme Taylor fisheries bycatch, rather than the needs charisma that attracts public support
for their conservation. There is a need
to increase the opportunities the public
have for seeing, experiencing and
learning about seabirds.
Birds to Watch
The species in greatest need of further
management include, in approximate
order of priority, the South Georgian
diving petrel, New Zealand fairy tern,
Chatham Island taiko, Chatham shag,
Chatham petrel, Kermadec storm petrel,
black-billed gull, Pitt Island shag, Chatham
mollymawk, Westland petrel, Fiordland
crested penguin, Kermadec petrel, lesser
fulmar prion, yellow-eyed penguin, black-
fronted tern, grey-headed mollymawk,
Bounty Island shag, , erect-crested penguin,
black petrel and rockhopper penguin.
The New Zealand storm petrel is a special
case, when and if its status as a distinct
endemic species is confirmed it must then
become a species of particular concern for
conservation management.
3
Albatrosses capped mollymawks. The Department
of Conservation is currently planning
New Zealand can be justifiably called the to eradicate these pigs but face
home of the albatross, with 13 out of 24 considerable logistic issues. Mouse (Mus
taxa of the great albatrosses (Diomedea), musculus) predation has been implicated
mollymawks (Thalassarche) and sooty in the decline of Tristan albatross on
albatrosses (Phoebetria) breeding here. Nine Gough Island, but there is no evidence
of these taxa are endemic. The taxonomy of a similar threat to the Antipodean
of the albatrosses is currently not settled. albatross.
For most of the 20th century it was accepted A small number of southern royal
that there were 13 species and a number albatross on Campbell Island banded
of sub-species. More recently it has been in the 1970s suffered injuries from
suggested each of the 24 taxa probably poorly fitting or poorly closed bands.
constitutes a distinct species. Department of Conservation staff have Above: Buller’s mollymawk (Thalassarche bulleri)
Almost all New Zealand’s albatrosses spent considerable resources in the last Photo by Kerry-Jayne Wilson
breed on sub-Antarctic islands or the few years removing these bands. Band
Chatham group, but there is a small colony redesign and tighter banding regulation Below: New Zealand white-capped mollymawk
of just 20 pairs of Pacific mollymawk on and supervision will prevent this (Thalassarche cauta) and
the Three Kings Islands, north of the North situation occurring in the future. Salvin’s (Th. salvini) mollymawks
Island. Most sub-Antarctic islands support Currently, all species are recorded as Photo by Kerry-Jayne Wilson
several species of albatross, with Campbell incidental by-catch in various fisheries.
Island having six. The only mainland Direct evidence of bycatch causing
breeding colony is at Taiaroa Head on reductions in populations is lacking.
Otago Peninsula where the first northern However, there is strong circumstantial
royal albatross was seen in 1914, the first evidence that bycatch resulted in
egg was laid in 1920, but disturbance from declines in the population of Campbell
predators and people meant that not until mollymawks during the 1980s and recent
1938 did a chick fledge. This success was suggestions that it may be affecting the
thanks to ornithologist Lance Richdale’s population of white-capped mollymawk
dedicated protection. In 2005-06 there were on the Auckland Islands. The effect of
17 nests and more than 65 birds. Predator fisheries is exacerbated by albatross’s
control and visitor facilities now give the propensity to cover vast distances over
birds and the public a good experience. large areas of ocean in search of food.
This is one of most accessible albatross When breeding, they are more restricted
colonies in the world for people to visit. in their choice of feeding area as they
Albatrosses were hunted by Māori have to return to their nest. Even so,
and later by sealers and shipwrecked breeding albatrosses forage considerable
sailors until given complete protection distances, which vary depending upon
the eggs had hatched, while the chick
while in the New Zealand realm in 1922. the stage of the breeding cycle. In recent
was guarded, the adults made daily trips
The illegal harvest of small numbers of years research, using satellite telemetry,
extending about 200 km east of The Snares.
albatross and mollymawk chicks continues has illustrated the foraging ranges of
When the chick was large enough to be left
on the Chatham Islands.The majority of some albatross species in New Zealand
alone at the nest, the parents alternated
New Zealand breeding sites are free, or and complex patterns of food choice have
between short trips (1–2 days, 200 km) east
have recently become free of introduced been revealed. For example, four distinct
of The Snares to long trips (5–6 days, 780
mammalian predators. Despite this two foraging patterns were identified for
km) along the east coast of the South Island.
issues remain: pigs (Sus scrofa) are of Buller’s mollymawk on The Snares. During
Finally, when the chick was within a few
concern on the main Auckland Island incubation, the off-duty parent made trips
weeks of fledging, female parents switched
where they take chicks and adult New averaging 12 days, ranging up to 1,500
to feeding off the West Coast of the South
Zealand wandering albatross and white- km over the Tasman Sea or 750 km along
Island (trips of 4–5 days and 650 km) and
the east coast of the South Island. After
male parents resorted to
Table 1: New Zealand’s breeding albatrosses trips of about 2 days and 300
km around Stewart Island.
Population
(breeding Status in In Fisheries
After breeding, adults
Taxon Name pairs) NZ Bycatch travel even longer distances.
For example, Buller’s,
Diomedea antipodensis Antipodean albatross 8600 Increasing Yes
antipodensis Salvin’s and Chatham
mollymawks cross the
Diomedea antipodensis gibsoni Gibson’s albatross 5,800 Stable Yes
Pacific Ocean to forage off
Diomedea epomophora Southern royal albatross 8,200-8,600 Stable Yes the coast of Chile and Peru.
Diomedea sanfordi Northern royal albatross 6,500-7,000 Declining/ Yes Southern and northern
Stable royal albatrosses travel
Thalassarche chlororhynchos Eastern yellow-nosed mollymawk 1 Stable Yes even further, to feed off
carteri the coast of Argentina in
Thalassarche chrysostoma Grey-headed mollymawk 6,000-9,000 Declining Rarely the South Atlantic Ocean.
(p.a) Northern royal albatrosses
Thalassarche melanophris Black-browed mollymawk 140 Increasing Yes have been tracked using
Thalassarche impavida Campbell mollymawk 19,000- Stable/ Yes satellite transmitters. After
26,000 increasing breeding, they disperse
Thalassarche bulleri bulleri Buller’s mollymawk 13625 Increasing Yes east from Taiaroa Head
Thalassarche bulleri n. ssp. Pacific mollymawk 16,000 Unknown Yes and the Chatham Islands to
locations off Chile, and then
Thalassarche cauta steadi New Zealand white-capped 70,000- Unknown Yes
mollymawk 80,000 around Cape Horn to feed
off Argentina and Uruguay,
Thalassarche eremita Chatham mollymawk 5500 Stable Yes
where they remain until
Thalassarche salvini Salvin’s mollymawk 32,000 Stable Yes near the start of the next
Phoebetria palpebrata Light-mantled sooty-albatross 7,000 (p.a) Declining Rarely breeding season. To return
Sources: Primarily Taylor 2000a, 2000b
4
Annual variation in counts of breeding pairs of Buller's mollymawks on The number of breeding Antipodean and Gibson’s wandering albatrosses
the North Promontory, The Snares, 1992-2005 alive each year on Antipodes and Adams Island, respectively (estimated by
mark-recapture analysis of birds banded in the two study areas on Antipo-
2000
des and Adams Islands and fitted regression lines of the log of the number
1800 of birds against time)
1600
1400
No. Breeding Pairs
1200
1000
800
Series1
600
Linear (Series1)
400
200
0
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Year
to their breeding grounds in New Zealand, food supply. The
the birds migrate rapidly eastwards below removal of sheep on
South Africa and Australia, traveling with Campbell Island has
the prevailing winds and circumnavigating significantly reduced
the Southern Hemisphere. These the area of suitable
long-distance movements make these breeding habitat but
populations extremely susceptible to has not yet impacted
unregulated fisheries on the high seas or on the burgeoning
traditional inshore fisheries. Less is known population of
about the movements of young birds in the Southern royal
years before they breed. albatross. An
Grey-headed mollymawks and Light- increase in marine
mantled sooty-albatrosses are rarely mammal numbers
encountered in bycatch. A decline in the
numbers of both species breeding on
has been implicated
in the loss of breeding habitat, predation Petrels
Campbell Island recorded since the 1940s and competition for food but this has not
appears to be related to movements in the been quantified. Plastic ingestion has been New Zealand has the richest diversity of
Antarctic Front causing variation in the implicated in a decline in fecundity in petrels in the world. Thirty-four species
North Pacific albatrosses. Despite the breed from Kermadec Islands in the north
presence of some regurgitated plastic (29o) to Campbell Island in the south (52o).
in New Zealand albatross colonies here The breeding species include two fulmarine
is currently no evidence of any adverse petrels (Macronectes and Daption), four
effects. Disease (which may be a result large Procellaria petrels, seven shearwaters
of global warming or transmission (Puffinus spp.), four prions (Pachyptila
from researchers) has been implicated spp.), 11 gadfly petrels (Pterodroma spp.),
in the decline of eastern yellow-nosed four storm petrels (Garrodia, Pelagodroma
mollymawk in the Indian Ocean; and two Fregetta), and two diving petrels
however, there is no evidence that (Pelecanoides). Ten of these species are
disease outbreaks have occurred in New endemic to New Zealand. The 34 species
Zealand albatross populations. There are further divided into 40 breeding
are no reports of large scale oil spills subspecies. Of these subspecies, 17 are
affecting albatrosses in New Zealand. endemic. The taxonomic status and affinity
of two petrels is still uncertain. Black and
by Paul Scofield and Paul Sagar white storm petrels seen off northern New
Paul Scofield, Zealand in recent years may be the New
Canterbury Museum, Christchurch, Zealand storm petrel (Pealeornis maoriana),
Above: Black-browed mollymawk (Thalassarche
pscofield@canterburymuseum.com last observed over a century ago. The
melanophris) and Cape Petrel (Daption capense)
Paul Sagar, population of South Georgian diving
Photo by Kerry-Jayne Wilson
National Institute of Water petrels (Pelecanoides georgicus) breeding on
& Atmospheric Research, Codfish Island (off Stewart Island) may
Below: Antipodean wandering albatross (Diomedea
P.O. Box 8602, Christchurch, be an endemic taxon. In addition to the
antipodensis)
p.sagar@niwa.co.nz breeding species, a further eight petrel
Photo by Kerry-Jayne Wilson
species regularly visit New Zealand seas
and another 15 species have been reported
as vagrants or beach-cast birds.
All New Zealand petrel species are
fully protected under the Wildlife Act
1953. However many species are at risk
of extinction. The most significant threat
is predation by introduced mammals.
Formerly the mainland had a host of
breeding species that nested from the
coastal slopes to the mountain tops.
Today only two petrel species nest only
on the New Zealand mainland with
5
no island refuges. Westland petrels scavenge behind fishing vessels. The
(Procellaria westlandica) nest in rain forest Procellaria petrels, flesh-footed shearwater
near Punakaiki and Hutton’s shearwaters (Puffinus carneipes) and sooty shearwater
(Puffinus huttoni) in two sites high up on the (Puffinus griseus) are the species most
Seaward Kaikoura Range. Tiny remnant often caught on long-lines or snared
populations of four other species nest on during trawl fishing operations. While
steep coastal cliffs around the main islands commercial fishing is the main threat,
of New Zealand. On the Chatham Islands, recreational line fishing is responsible
several petrels nest on steep coastal cliffs, for the deaths of many flesh-footed
but one species, the critically endangered shearwaters in northern waters. Set-net
Chatham Island taiko (Pterodroma magentae) fishing also impacts on petrels, especially
nests only in forested valleys on the main those species that forage close inshore.
island. All remaining petrel species now Hutton’s shearwaters, for example,
breed only on small offshore islands. have been reported in set-nets on a Above: Northern giant petrel (Macronectes halli)
The densest petrel populations are number of occasions. Migratory species Photo by Kerry-Jayne Wilson
found on islands free of introduced are exposed to fisheries impacts both
predators. Norway rats (Rattus norvegicus), during the breeding season and during Below: Westland petrel (Procellaria westlandica)
feral cats (Felis catus), stoats (Mustela their non-breeding migratory journeys. Photo by Kerry-Jayne Wilson
erminea) and feral pigs (Sus scrofa) are For example flesh-footed and sooty
the most significant predators. Ship rats shearwaters are taken in salmon gill net
(R. rattus), kiore (R. exulans), ferrets (M. fisheries from Alaska south to Oregon.
furo) and possums (Trichosurus vulpecula) Other threats include ingestion of
all impact on petrels at some sites. Weka plastics and water borne chemicals, and
(Gallirallus australis) severely impact several oil spills. These threats are a particular
of the smaller petrel species and this has problem for these species that migrate
lead to population declines on offshore to distant oceans. For example sooty
islands to which weka were introduced. shearwaters have been killed in oil
Introduced browsing mammals damage spills off North America and stomach
the petrel’s breeding habitat and trample contents of this species reveal plastic
burrows. residues probably taken during their
Introduced predators and browsers annual sojourn in the North Pacific.
have been eradicated from a number of The crowding of petrels onto the few
offshore islands, the largest being Campbell remaining predator free islands is yet
Island (11,300 ha). These eradications have another problem. On densely burrowed
removed some of the most significant islands, suitable nesting habitat is
threats to breeding seabirds and allowed scarce and intra- and inter- specific
population increase (currently about 1000-
populations to begin recovery. For example, competition for nest sites can be intense.
1100 birds).
Pycroft’s petrel (Pterodroma pycrofti) is On Rangatira Island in the Chatham Island
Habitat loss has primarily resulted from
now increasing in numbers and range on group, the rare, endemic Chatham petrel
the loss of the mainland nesting sites due
the Mercury and Chickens Island groups (Pterodroma axillaris) competes for burrows
to predation by introduced mammals. On
following removal of kiore in the early with the locally abundant broad-billed
some islands, the removal of introduced
1990’s. The eradication of rats on Little prion (Pachyptila vittata). An intensive
browsing mammals has created some new
Barrier and Codfish Islands has allowed management programme involving
problems for petrels. Regeneration of native
Cook’s petrels (P. cookii) on those islands to finding nesting burrows, converting them
plants has created dense monocultures of
breed with greater success and this species to artificial wooden nest boxes and use
sedges, vines and ferns on some islands. On
is likely to soon be down-listed from its of entrance flaps to prevent prions from
Macauley Island in the Kermadec group,
threatened ranking. entering has stabilised the small population
tall Hypolepis fern is smothering breeding
Fisheries interactions are another major of Chatham petrels. Breeding success has
areas and may be displacing the near
threat to petrels, especially the larger been raised from 10-30% in the early 1990s
endemic white-naped petrel (Pterodroma
species. The species most at risk are those to around 80%. This has lead to increased
cervicalis) from its last stronghold.
that are capable divers and regularly recruitment of young birds and a modest
Management of the vegetation may be
required until taller forest
Table 2: Petrel species of conservation concern in New Zealand
has re-established. On other
Conserva- Population trend islands, introduced weeds
tion status Scientific name Common name Population size (NZ) (past 10 years) have taken over after removal
Nationally Pterodroma magentae Chatham Island taiko 120-150 birds Slight increase of browsing mammals. For
critical Pelagodroma marina Kermadec storm petrel 100+ prs? Stable? example, on Motunau Island
albiclunis in North Canterbury, boxthorn
Pelecanoides georgicus Codfish Island South 150 birds Increasing then (Lycium ferocissimum) (a thorny
(Codfish Island) Georgian diving petrel declining
shrub capable of snaring
Nationally Pterodroma axillaris Chatham petrel 1100 birds Slight increase petrels) became established
endangered Pterodroma neglecta Kermadec petrel 5-10,000 prs Stable? and requires active control. To
Puffinus huttoni Hutton’s shearwater 150-200,000 prs Slight decrease?
our knowledge no outbreaks
Gradual Pachyptila desolata Antarctic prion Tens of thousands prs? Declining? of serious viral illnesses have
decline Procellaria cinerea Grey petrel 50-60,000 prs Declining?
occurred in petrels in New
Pterodroma cookii Cook’s petrel 50,000+ prs Declining?
Puffinus griseus Sooty shearwater Several million prs Declining Zealand.
Puffinus carneipes Flesh-footed shearwater 20,000 prs Declining? In the near future global
Range Macronectes halli Northern giant petrel 2000-3000 prs Stable
climate change may prove to
restricted Pachyptila crassirostris Chatham Island fulmar 1000-5000 prs Stable? be the major threat to petrels.
pyramidalis prion Sea temperature warming has
Pachyptila crassirostris Lesser fulmar prion 1000 prs Stable? occurred in the past century
flemingi and is likely to have caused a
Procellaria aequinoctialis White-chinned petrel 200,000+ prs Stable? decline in ocean productivity.
Procellaria parkinsoni Black petrel 5-10,000 birds Stable? Higher levels of UV light
Procellaria westlandica Westland petrel 2000-5000 prs Stable? exposure in the southern
Pterodroma cervicalis White-naped petrel 50,000+ prs Increasing? ocean due to ozone depletion
Puffinus bulleri Buller’s shearwater Several million birds Stable?
6
are predicted Seabird catch in observed sectors of the fishery (estimated total) Bycatch of Albatrosses
to impact on
chlorophyll
3500
Japan-NZ tuna
and Petrels in New
A production
and decrease
Hoki traw l Zealand Fisheries
3000 Ling Autoline
productivity Albatrosses and petrels are attracted to
at the base Squid traw l
fishing vessels to feed on discarded fish
of the food Total 4 fisheries
2500 and offal. This leads to incidental seabird
chain. Global captures particularly in trawl and longline
climate change fisheries and globally bycatch is recognised
may interrupt 2000 as one of the main threats to seabird
migration populations. Around 40 species of seabird
patterns for are known to have been caught in New
seabirds, reduce 1500 Zealand fisheries during the last 10 years.
food stocks and The predominant species caught in New
increase the Zealand fisheries are white-chinned petrel
frequency of 1000 (Procellaria aequinoctialis), grey petrel (P.
storm events. cinerea), sooty shearwater (Puffinus griseus),
Already severe white-capped mollymawk (Thalassarche
storms have 500
steadi), Salvin’s mollymawk (T. salvini),
affected some Campbell mollymawk (T. impavida) and
small islands. Buller’s mollymawk (T. bulleri). The New
For example, on 0
Zealand breeding populations of these
Codfish Island, 1999-00 2000-01 2001-02 2002-03 2003-04 2004-05 species number in the tens to hundreds of
a storm in 2003 thousands. Rarer species such as Chatham
swept out a large mollymawk (T. eremita), Westland petrel
Chatham Island taiko, Chatham petrel,
section of sand dunes along the beach at (Procellaria westlandica) and black petrel (P.
the Codfish Island population of South
Sealers Bay and destroyed 41% of the South parkinsoni) are caught in small numbers
Georgian diving petrels and Kermadec
Georgian diving petrel nest sites. The same sporadically. Little is known about seabird
storm petrel are the species at greatest risk.
storm also caused the deaths of at least capture in coastal setnet fisheries which
Two significant events in 2006 were the
15% of this tiny population of less than 150 probably affect penguins, shearwaters and
confirmation by Mike Imber and Karen
birds. shags. The extent to which these captures
Baird that Kermadec storm petrels breed
Since 1990 the development of petrel affect the population viability of New
on the summit of Haszard Island (a tiny
translocation techniques has provided the Zealand breeding seabirds is unknown,
stack off Macauley Island), and the first
opportunity for threatened species to be but research programmes are in place to
successful breeding by Chatham petrels
transferred to new safe sites and for islands address this question over the next five
on Pitt Island in more than a century. The
cleared of pests to have seabirds returned to years.
identity of “New Zealand storm petrels”
begin the process of ecosystem restoration. Monitoring of fisheries bycatch has
and whether or not they breed in northern
While the status of some threatened petrel been limited, with coverage of only a
New Zealand still needs confirmation.
species has begun to improve, there are still small portion of the fisheries potentially
Of the 40 subspecies of petrels breeding
several species that will require intensive interacting with seabirds. There is
in New Zealand, nearly half are threatened,
management to avoid extinction. The ongoing monitoring of bird captures in
declining or have restricted breeding
ranges (Table 2). The remaining 21 the large-vessel trawl fleets fishing for
species/subspecies are thought to be hoki and squid and in selected parts of the
stable or increasing in numbers following longline fisheries for tunas and ling. This
habitat improvements, and not currently monitoring has shown declines in bycatch
considered at risk. The location and rates in the ling autoline fleet following the
population size of petrel colonies in New implementation of line-weighting regimes.
Zealand is poorly known. Only a handful There has been success in reducing seabird
of species have had any work done on take in the Japan-New Zealand tuna
their population dynamics (survival and fleet over a period of several years to the
recruitment rates) and the population 35-50 birds currently caught each year.
trends for most species has not been Occasional capture of rare species in these
studied in a scientifically robust manner. longline fisheries is a continuing challenge.
Urgent work is needed on a number The number of mortalities in 2004/05 in
of species in view of the potentially the West-Coast hoki and Auckland Islands
significant changes expected in the ocean squid trawl fisheries was around 475 birds.
environment in the next 50 years (only This number does not include those birds
2-3 petrel generations). which hit trawl wires and fell into the sea.
Above: Sooty shearwater (Puffinus griseus) Review of bycatch statistics both with
Photo: Graeme Taylor by Graeme Taylor, New Zealand fisheries and internationally
Research, Development and Improvement shows that for a particular fishery,
Below: Flesh-footed shearwater (Puffinus carneipes) Division, Department of Conservation, PO recognition of the seabird bycatch problem,
Photo: Graeme Taylor Box 10420, Wellington. gtaylor@doc.govt.nz research and implementation of effective
mitigation measures often takes around
five years. This requires coordination and
cooperation across various government,
industry and environmental advocacy
sectors. International initiatives to manage
seabird bycatch include the International
Plan of Action on Seabirds promoted by
the Food and Agriculture Organisation.
New Zealand is alone in implementing
a mainly voluntary regime to manage
bycatch through its National Plan of Action
on Seabirds.
Ongoing challenges for reducing
7
seabird bycatch that affects New Zealand squid, salmon smolt and Antarctic krill
breeding species are; the reduction of offal – but a diet based on tinned sardines
and whole-fish discharge from vessels, preserved in soya oil has since been used
and the capture of New Zealand breeding successfully for six species, with fledging
species in foreign fisheries as the birds rates of up to 100%. Hand-feeding of
migrate to other areas around the globe, in chicks is labour intensive, and volunteer
particular the waters off South America and involvement in caring for the chicks has
South Africa. been a feature of most translocations.
Seven species of petrels have been
by Susan Waugh, recovered as adults at their release sites,
Fisheries Sciences, Ministry of Fisheries, with five confirmed breeding. However,
Wellington for five species; few birds (1-4) have yet
been recovered at release sites and for at
least two of these, a higher proportion
Petrel Translocations of translocated chicks have returned to
the source population. To date, only two
There are two main reasons to translocate translocations have resulted in large
petrels: as part of recovery programmes for numbers of birds returning to the release Top: Sweetwater exclosure, Alison Davis, Liz and
threatened species, and to restore their role site – 32 fluttering shearwaters on Maud Bruce Tuanui
as ecological drivers at sites from which Island, and 20 common diving petrels on Photo by Graeme Taylor
they have been extirpated. Burrowing Mana Island. While we now know how
petrels had profound effects on many to get large numbers of chicks to fledge in determine annual survival. Blood samples
New Zealand terrestrial ecosystems, both good condition, we still do not know how have been collected from all birds handled
on islands and on the mainland. Impacts to overcome the strong instinct of most since 1996. These have been used to sex
included the importation of vast quantities individuals to return to their natal colony. the birds and are currently being analysed
of marine nutrients (especially nitrates to assess genetic relationships within the
and phosphates), and the creation of a by Colin Miskelly, population. All chicks are captured in April
subterranean network of tunnels providing Wellington Conservancy, Department of or early May to be banded and measured.
living space and habitat for a diversity of Conservation, P.O. Box 5086, Wellingon. Small transmitters are attached to ensure
other animals. Eradication of introduced cmiskelly@doc.govt.nz that all chicks make it safely to sea. Every
mammals from islands or fenced mainland year a few of the fledglings need to be
sites is often a prerequisite for restoration
of petrel colonies, but predator eradication Chatham Island Taiko taken out to the coast after crash-landing in
the forest.
alone may be insufficient to guarantee The species has a precarious hold on
success. Most petrels are highly faithful to The Chatham Island taiko (Pterodroma
magentae) was rediscovered in 1978 by its existence. Mark-recapture estimates put
their natal colony, and the establishment of the population at 120-150 birds. In 2005/06,
a new colony depends on overcoming this David Crockett, solving a puzzle that
linked bird bones on the Chatham Islands the number of known breeding pairs edged
strong homing instinct. up to 15 and a record 11 chicks fledged.
The two main techniques used to attract with a petrel specimen collected at sea in
the 1860s. It took nearly ten years to locate Over ten banded chicks have now returned
petrels to new or ancestral sites are sound to the scattered colony. The main hope for
attraction, and translocations of chicks in the first breeding burrows. In 1987/88, only
three taiko breeding burrows were known, the species’ future lies with the Sweetwater
the last few weeks before fledging. Solar- Covenant, a predator proof fenced hilltop
powered sound systems that automatically at the head of the Tuku River on main
Chatham Island, 4-5 km inland in tall, wet about 500m from the coast. The site was
switch on at dusk and off at dawn gifted by landowners Bruce and Liz Tuanui
broadcast calls of species that visit their forest.
Over the last 20 years, a large team and funding for the fence was secured by
colonies at night, giving the impression the Chatham Island Taiko Trust. In October
of an active breeding colony. These had of dedicated workers and volunteers
committed to saving this enigmatic species 2006 a sound attraction unit with taiko
been installed at ten sites by 2006. Between calls was installed and the first taiko chick
1986 and 2006, ten separate attempts were from extinction have contributed to taiko
recovery. The work has entailed protection transfers to this site are planned for 2007.
made to translocate chicks of eight petrel
species in New Zealand. However, many of all known breeding colonies, finding
of these attempts were too recent to yet more breeding sites and monitoring all by Graeme Taylor,
known taiko pairs and their breeding Research, Development and Improvement
determine their success, as most petrel
activity. Division, Department of Conservation, PO Box
species do not return to land until 3-5
Department of Conservation workers 10420, Wellington. gtaylor@doc.govt.nz
years old. Several of the earlier attempts at
translocation were specifically to develop trap and poison introduced predators and
browsers and protect taiko nests. The main
seabird translocation techniques, either
target species are feral cats (Felis catus) and Black Petrel
generic, using fluttering shearwaters
(Puffinus gavia) and common diving petrels rats (Rattus sp.). Locating new burrows
has involved the cooperation of David The endemic black petrel (Procellaria
(Pelecanoides urinatrix), or as analogues for parkinsoni) once bred on coastal and inland
more threatened species, grey-faced petrel Crockett and his team of OSNZ volunteers,
conservation staff and supportive ranges of the North and upper South
(Pterodroma macroptera) for Chatham Island Islands. They are now only found on Little
taiko (P magentae), and Pycroft’s petrel (P. landowners. Every 2-3 years a radio
telemetry project involves spotlighting and Great Barrier Islands in the Hauraki
pycrofti) for Chatham petrel (P. axillaris). Gulf. The Great Barrier Island population
Other species translocated to date are black taiko as they fly inland toward their
breeding sites, capturing these birds and is estimated to be 1600 breeding pairs with
petrel (Procellaria parkinsoni), fairy prion approximately 100 pairs on Little Barrier
(Pachyptila turtur), Chatham petrel and attaching tail-mounted radio transmitters.
The birds are then tracked to pinpoint Island.
Hutton’s shearwater (Puffinus huttoni). The Great Barrier population is affected
All translocations involved hand- promising search areas. Ground teams
then head in after dark to locate the birds, by predation by rats (Rattus sp), feral cats
feeding all or some chicks, though some (Felis catus) and occasionally feral pigs
species become very fat as nestlings and hopefully at a new burrow site. In recent
years, a specially trained dog and handler (Sus scrofa). Little Barrier Island is now
need little food in their last week or so predator-free, but once had kiore (Rattus
before fledging. Translocations of diving have joined the search and have been
successful in finding new burrows. exulans) and feral cats which preyed
petrels and fairy prions have required daily heavily on the petrels. Black petrels
or twice-daily feeding of all chicks. Earlier Burrow monitoring, mainly in October
each year, has concentrated on capturing scavenge behind fishing vessels and have
translocation attempts used relatively been recorded in the bycatch of long-line
natural food such as fresh or frozen birds at the burrows for banding and to
fisheries in New Zealand waters. They
8
may also be at threat from bycatch in Paul Scofield, plied by fisherman and naturalists, birding
foreign waters during their migration Canterbury Museum, Christchurch, trips which use chum (fish waste) to attract
and wintering period in South America. pscofield@canterburymuseum.com seabirds close to the observers’ boats is a
Recent deployment of data loggers has recent development. Alternatively, perhaps
shown that during breeding black petrels their numbers are increasing following
forage more widely than expected; around Pycroft’s Petrel recent eradication of rodents from nearby
New Zealand visiting Fiordland and the islands. Whichever, it seems likely that the
Chatham Rise with some also going to The status of Pycroft’s petrel (Pterodroma population has persisted unnoticed ever
eastern Australia and Fiji. pycrofti) is representative of many New since those specimens were collected in the
We have monitored the Great Barrier Zealand breeding petrels. They once 19th century.
Island population since the 1995. During bred at Norfolk Island and probably at Confirmation that the birds seen are
this study, population estimates, breeding mainland sites in northern New Zealand, the same species as the three museum
success, mortality factors and survival rates as well as many offshore islands. With the specimens has been slow in coming, mainly
have been determined. Over 1500 adult introduction of mammalian predators the because this required the capture of birds.
birds and 1200 chicks have been banded. species became extinct on the mainland In November 2005 a bird flew into the cabin
Population models suggest that the and survived only on a few islands that of a boat anchored off Little Barrier Island.
population is in slight decline, (estimated remained free of introduced predators. The The bird was held overnight and next day
decline 2.8% per year) and that adult species can persist, at least in the medium Richard Griffiths and Karen Baird were
survival is lower than for other petrels. term, with kiore (Rattus exulans). Island there to band, measure, and photograph
Despite low adult survival, breeding surveys in the 1970’s and 1980’s located it. A further three birds were captured
success was high, with chicks fledging some breeding sites and it is likely that they in January 2006. All birds were banded,
from three quarters of eggs laid. Survival also bred on other poorly surveyed islands. measured, photographed, and fitted with
of pre-breeders is 92%, which indicates No accurate counts were ever made and a small radio-transmitter before release.
that juveniles are returning to the colony in few of these islands have been resurveyed. Unfortunately, only one bird was detected
good numbers. Other than general accounts of the breeding at sea and no signals were received from
The black petrel population appears cycle virtually nothing else is known birds on land. These captures support the
to be fairly stable, but is still at risk from of its biology. The species is threatened assertion that these birds do indeed belong
land-based threats such as rats and feral but not at immediate risk of extinction. to the same species as those museum
cats on Great Barrier Island and at sea from Pycroft’s petrel numbers have apparently specimens, and are a distinct species. The
undetermined fisheries-related mortality. increased following the eradication of birds’ identity is currently being reviewed
kiore from some islands where the petrels by the Ornithological Society of New
by Elizabeth Bell, Joanna Sim and survived. Because Pycroft’s petrel is less Zealand’s Rare Birds Committee.
Paul Scofield at risk than other small Pterodroma species Now the main priority is to discover
Elizabeth Bell, it has been used to develop translocation their breeding location, to estimate the
Wildlife Management International Limited, methodologies for use with it’s rarer population size and assess population
35 Selmes Road, Rapaura, RD3, Blenheim, congeners. Chick development, meal size trends so that protection can be ensured.
New Zealand, wmil@clear.net.nz and feeding frequencies were studied so Molecular work is also underway to
Joanna Sim, that translocated Pterodroma chicks could compare the four captured birds with the
Department of Conservation, Great Barrier be fed prior to fledging. Pycroft’s chicks museum specimens and other storm-petrel
Area Office, Port Fitzroy, Great Barrier Island, have been translocated from Red Mercury species. Fieldwork planned for the 2006/07
New Zealand, jsim@doc.govt.nz to Cuvier Island and the species used to summer involves the further capture of
develop burrow protection devices for the birds, attachment of transmitters, and
protection of the critically endangered survey of islands where they may breed.
Chatham petrel (P. axillaris). As with
most other petrels that are not under
immediate threat their status and biology
by Brent M. Stephenson
Eco-Vista: Photography & Research + Wrybill
remains little known.
Birding Tours, NZ, PO Box 8291, Havelock
North 4157. brent@eco-vista.com
by Kerry-Jayne Wilson
Bio-Protection & Ecology Division, Lincoln
University, Lincoln. wilsok@lincoln.ac.nz Penguins
Despite being an iconic group and the
New Zealand Storm Petrel subject of countless documentaries, New
Zealand penguins remain enigmatic with
Until 2003, the New Zealand storm-petrel all too much still unknown. Of the six
(NZSP) was known from only three species that breed in the New Zealand
specimens held in museums in France region (four of which are endemic), five are
and England. It was thought to be either in decline.
Above and Below: Chatham petrel
a rare colour morph of Wilson’s storm- Mammalian predators including dogs
(Pterodroma axillaris)
petrel (Oceanites oceanicus), or a distinct, (Canis familiaris), cats (Felis catus), ferrets
Photos by Graeme Taylor
but extinct species, Pealeornis maoriana. (Mustela furo) and stoats (M. erminea) are
Then in January 2003 Sav Saville and the traditional foes of mainland nesting
Brent Stephenson spotted a small black penguins and although advances in
and white storm-petrel, they suggested trap technology and dog legislation has
could be a NZSP, off Whitianga. In seen some small reduction in penguin
November 2003 a small ‘flock’ of these mortality, a solution to mainland predator
birds was seen in the Hauraki Gulf and problems is unlikely in the foreseeable
sightings of these birds in northern New future. Where there is some protection
Zealand have continued from October to from predators, blue penguins (Eudyptula
April each year. minor) can do well and there are some
Where have these birds suddenly significant populations on islands and
appeared from and are they indeed predator controlled sites. Elsewhere, their
NZSPs? Perhaps their dramatic populations are seeing slow declines and
rediscovery is an artifact of the recent localised extinctions. A growing problem
interest in pelagic bird watching. for the blue penguin, and to a limited
Although the Hauraki Gulf has been well extent the yellow-eyed penguin (Megadyptes
9
eyed penguins is a must for many of predation by cats (Felis catus). However,
the tourists that visit coastal Otago, but despite there being no evidence that chicks
the pressure of tourist numbers at some were still lost to cats, few chicks have
sites and the overcrowding of facilities fledged in the last three years.
is seeing spillover into other breeding Disease has been an issue for both
sites where, because of their value to the Stewart Island and Otago Yellow-eyed
penguin population, viewing has been populations, with the Corynebacterium
discouraged and visitor facilities, like outbreak of 2004 claiming around 50% of
hides, do not exist. all chicks. A blood parasite, formerly only
While the tourists may get a “natural” known from Fiordland crested penguins
experience there is growing evidence (Eudyptes pachyrhynchus), has also recently
that the penguins are suffering, with been identified in yellow-eyed penguins
increased levels of stress hormones on Stewart Island. The poor years of the
and reduced chick fledge weights (and late 1980’s and bio-toxin induced mass
thus lower survival) documented. The mortality event of 1989 can be linked to El
behaviour of some visitors undoubtedly Nino/southern oscillation events, but other
contributes to this, as some visitors marine factors are having unknown and
pursue penguins to get a better photo. perhaps immeasurable impacts.
Fiordland crested penguins (Eudyptes Recent research has confirmed that
pachyrhynchus) are even more susceptible yellow-eyed penguins forage almost
to human disturbance and even though exclusively on the sea floor. Some penguins
the numbers of tourists are a fraction of have been drowned in nets set on the sea
those viewing yellow-eyeds, most of the bottom even in waters up to100m deep,
Fiordland penguin colonies accessible to however information on the frequency
the public are in decline. The sensitivity of capture is sparse. Evidence is also
of these birds to disturbance has even emerging of yellow-eyed penguins foraging
seen the monitoring of breeding at some in areas of sea bed disturbed by trawling
Above: Snares crested penguin South Westland sites suspended. and dredging. The impacts, if any, of this
(Eudyptes schlegei) The Snares penguin (E. robustus) is disturbance to the penguin’s marine habitat
Photo by Dave Houston the one species that is not in decline, the are unknown.
last census in 2000 revealing a similar So if things aren’t too good on
antipodes), is coastal development. Coastal number of breeding pairs to previous the mainland, what’s going on in the
subdivisions and other developments can counts. Why they alone should have a “stronghold” of the species, the Auckland
result in a decrease the amount of suitable stable population is puzzling, but the and Campbell Islands? The truth is we
nesting habitat, an increase the numbers proximity of The Snares to the nutrient-rich don’t really know, the last census of these
of domestic dogs and raise the risk of road Southland current may be a factor. islands was carried out 15 years ago.
kills.
Habitat protection alone is not sufficient by Dave Houston by Dave Houston
to ensure the long-term viability of penguin Wellington Conservancy, Department of Wellington Conservancy, Department of
populations, as the state of the yellow- Conservation, P.O. Box 5086, Wellingon. Conservation, P.O. Box 5086, Wellington.
eyed and crested (Eudyptes sp) penguins dhouston@doc.govt.nz dhouston@doc.govt.nz
can attest. While the former, at least in
its mainland habitat is still subject to the
pressures of introduced predators, most Yellow-Eyed Penguin Shags
crested penguins live on remote sub-
Antarctic islands that are largely predator Over the last 20 years much effort has been New Zealand’s shags (cormorants) fall
free, yet all but one species are in apparent put into the conservation of the yellow- into two distinct groups. Those that
decline. eyed penguin (Megadyptes antipodes) in predominantly use freshwater or estuarine
The plight of the rockhopper penguin Otago, its principal mainland range. habitats and those that are primarily,
(Eudyptes chrysocome) is the most dramatic. Efforts, lead by the Yellow-eyed Penguin or exclusively marine. The freshwater/
Its population on Campbell Island has Trust and Department of Conservation, estuarine species also occur in Australia
collapsed from 1.6 million breeding pairs in have been focussed on the two problems and some species in other counties as
the 1940’s to just over 100,000 pairs in 1985 identified in the early 1980’s – predators well. The New Zealand populations of
and there is no evidence to indicate that and breeding habitat. Predator control is the pied (Phalacrocorax varius varius) and
the decline has halted. A similar decline ongoing at many sites, significant areas little shags (P. melanoleucos brevirostris)
in rockhoppers has also been noted on the of coastal land have been protected and are sub-species endemic to New Zealand.
Antipodes Islands and in the erect-crested the slow process of ecological restoration Within New Zealand, all four species (black
penguin (E. sclateri) population there and started, but yellow-eyed penguin numbers (P. carbo), pied, little and little black (P.
at the Bounty Islands. have not increased significantly. sulcirostris) are widespread and moderately
The reasons for the rockhopper On Stewart Island the situation is common, although the little black shag
penguin’s decline are unclear but are most worse. The first
Population trends for the yellow-eyed penguin in Otago
likely related to changes in food availability, census, completed
in 2003, revealed a 700
either from reduced marine productivity
or shifts in prey distribution. While population of just
600
natural marine and climate cycles may be 178 breeding pairs,
involved, so may human influence through alarmingly short 500
of the previous
Breeding Pairs
either global warming or fishing. Our
knowledge of the foraging ecology of these estimates of 470- 400
species is at best basic and without baseline 600 pairs. The lack
information, detecting and understanding of young and non- 300
changes is difficult. breeding birds in
Tourism has the potential to be of what appears to 200
benefit to some species, as it has been for be a population
blue penguins in Oamaru, who instead in decline saw 100
of being considered pests and accused of research and
management 0
trespass are now a valued asset. Tourism
is not always so benign. Viewing yellow- efforts focussed on 1980 1985 1990 1995 2000 2005
10breeds only in the North Island. The black population of the Stewart Island shag
shag is one of few native birds that is not increased in both range and numbers
totally protected. The most comprehensive during the 1990s but further south trends
population surveys and population and are confusing. Each with populations
breeding studies are being carried out in of about 2000 pairs, the Stewart Island
the Wellington region where black shag and Campbell Island shags are the most
and little shag numbers may have declined. secure of the New Zealand species in
Recent trends elsewhere are unknown. this genus. The Chatham shag appears
The biology of black and pied shags is to have undergone a large decline with
moderately well known but little and little counts in 2003 suggesting a population
black shags have been little studied. of only a third of that recorded in 1997.
The marine shags are all endemic to The Chatham shag is almost certainly the
New Zealand, all but one have restricted most threatened of New Zealand’s shag
distributions and most are of conservation species. Counts also suggest a decline
concern. Three taxa, spotted (Stictocarbo in the numbers of Bounty Island shags.
punctatus), blue (S. punctatus steadi) and Pitt However, for both species counts are
Island (S. featherstoni) shags are generally not strictly comparable and latter counts
placed in the genus Stictocarbo although could reflect poor breeding seasons in the
shag taxonomy is subject to ongoing debate second year counts were done. There is
and some taxonomists place all shags in little census data for any of the remaining
the genus Phalacrocorax. The spotted shag species but they appear to be small
has a discontinuous distribution from (80%) of the New Zealand
the genus Leucocarbo. The taxonomic New Zealand shags is desirable, the need population breeds between 34 and 38°S.
relationships of these species need for research is most urgently required The location of breeding sites seems related
revision but on the basis of their disjunct for the marine shags. Almost none of to sea-temperature, which determines the
distributions and variations in morphology the census, survey or research priorities availability of food for these primarily fish
each is currently treated as a separate identified for New Zealand shags in 2000 eating birds. The predominant prey species
species. Recent fossils found in parts of have been addressed. Recent counts are of Australasian gannets in New Zealand are
New Zealand not currently occupied by strongly indicative of declines in Chatham, inshore pelagic schooling fish and diurnal
Leucocarbo shags gives credence to the Pitt Island and Bounty Island shags. For squid. Differences in diet at different
view that the New Zealand king shag all three species the most optimistic counts gannetries are evident, and some seasonal
(L. carunculatus) and the Stewart Island show populations of c600 pairs. Research variation is also apparent. Gannets also
shag (L. chalconotus) are in fact variants of to determine the reasons for declines and take discards from boats, and will feed on
the same species and molecular studies ways to reverse these declines is urgently quite large flatfish at the back of trawlers.
being conducted by Martyn Kennedy at required. The New Zealand king shag is National population counts date back
the University of Otago, could result in a the rarest of the New Zealand shags but its to the 1940s and much has been published
further reduction in the number of species population is probably stable. Shags remain on their basic biology. Censuses have been
recognised. The King shag is restricted a poorly studied group whose conservation conducted in New Zealand in the 1946/47,
to the outer regions of the Marlborough needs are inadequately documented. Even 1969/70, and 1980/81 breeding seasons, and
Sounds, and the Stewart Island shag occurs easily accessible species, such as the spotted this has suggested an annual population
in Otago, Southland and Stewart Island. shag, have attracted little attention from increase of 2.3%, with the population in
The Chatham (L. onslowi), Auckland (L. researchers. Most shag colonies have not 1980/81 estimated at 46,004 breeding pairs
colensoi), Campbell (L campbelli) and Bounty been censused for at least a decade and in NZ, and 6660 in Australia. A national
(L. ranfurlyi) shags are each confined to therefore the population estimates and census was conducted in the 2000/01
those respective island groups. The diet, trends indicated here might be unreliable. breeding season, but the results of this
foraging ecology, population dynamics and are yet to be published, although results
breeding biology are not adequately known by Kerry-Jayne Wilson indicate a continued increase, with some
for any New Zealand Leucocarbo species. Bio-Protection & Ecology Division, Lincoln gannetries remaining stable. The current
The king shag is endangered with a University, Lincoln. wilsok@lincoln.ac.nz population estimate is 55,000 breeding pairs
total population of only about 645 birds. in New Zealand and 20,000 in Australia.
However, counts over the last decade With regards to population changes,
suggest the population is stable. The Otago three gannetries have been well studied,
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