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Black Petrel

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The Black Petrel is a threatened endemic bird of New Zealand, this is an informative booklet outlining the threats that are reducing the number of Black Petrels.
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1 The Black Petrel An endemic bird of New Zealand
Transcript
Page 1: Black Petrel

1

The

Blac

k Pe

trel

An

ende

mic

bird

of N

ew Z

eala

nd

Page 2: Black Petrel

Cont

ents

Page 3: Black Petrel

 3   Ecology Behaviour

 7   Population

 9   Breeding

13   Threats

19   Conservation

21   Bibliography

Page 4: Black Petrel

IntroductionThe Black Petrel is a medium sized

petrel, which is an endemic seabird of

New Zealand. They are listed as vulnerable

(VU D2 on the IUCN Red List) with only

around 2000 breeding pairs remaining

which are restricted to the islands of Great

Barrier and Little Barrier, New Zealand. Their

restricted habitat, predation from feral cats

and rodents combined with the uncertain

impacts from long-line fishing have all

contributed to the Black Petrel’s vulnerability.

Efforts are being made to better monitor

the population of the birds and continuing

research contributes to the understanding

of the birds which is key to preserving the

population of Black Petrel’s.

FamilyThere are 66 species in the petrel family,

and all spend most of their lives at sea where

they feed on a variety of planktonic animals,

squid and fish.

The genus Procellaria consists of five

species of medium to large petrels of which

Feeding Behaviour Black Petrel birds are a colonial

burrow-nesting, annually -breeding species

that can live to the age of thirty. Black

Petrel’s predominantly live an oceanic

lifestyle, which makes their behaviour

difficult to study.

Black Petrel’s feeding behaviour involves

surface feeding and diving in groups. It has

been recorded that they can dive down

further than 10 m in search of food. Its diet

is dominated by squid and supplemented by

tunicates, crustaceans and cyclostomes.

the Black Petrel, Procellaria parkinsoni, is

the smallest. The order which the Black

Petrel belongs to; Procellariiformes, are

referred to as ‘tubenoses’ because of their

unique bills which allows them to excrete salt

water through their nostril leaving the water

for them to drink.

IdentificationBlack Petrel’s are medium sized petrel’s,

46 cm in size, weighing roughly 700 grams,

with a wingspan of 1 m.

The male and female Black Petrel’s entire

plumage is sooty black in colour, with the

feathers of their back and mantle narrowly

edged with a lighter shade. Their iris’ are

also black along with their feet and legs.

The contrasting feature of the bird is its bill,

which is yellowish-grey, shaded with black

tip on adults or a blue-grey on juveniles.

Their legs and feet are also black in colour.

The young is first thickly covered with sooty

down, which eventually turns into the adult

plumage of black feathers.

Ecol

ogy

Beha

viou

r Black Petrel’s are listed as vulnerable as

there are only around 2,000 breeding pairs

remaining in the world.

3

Page 5: Black Petrel

TaxonomyOrder Procellariiformes

Family Procellariidae

Genus Procellaria

Species Procellaria

parkinsoni

Common name Black Petrel

Maori name Taiko

Other names Parkinson’s Petrel

:

Page 6: Black Petrel

5

HabitatBlack Petrel are seabirds which can spend

years on end out at sea surviving even the

most resilient storms, returning to land only

for breeding.

Black Petrel once bred widely in the

mountains over the North Island and the

North West of Nelson in New Zealand. By

the 1960s the Black Petrel had disappeared

from the mainland because with the growing

population of New Zealand came the

replacement of forests with farmland and

introduction of rats, cats, stoats and other

predators. Little and Great Barrier Islands in

the Hauraki Gulf to the east of Auckland are

the birds only remaining breeding habitats.

The foraging range of Black Petrel is

around New Zealand and extends out to

Western Australia. Research shows the birds preferentially forage on the continental shelf

or at seamounts. The Black Petrel migrates

east to the eastern Pacific Ocean between

the Galápagos Islands, northern Peru and

southern Mexico for New Zealand’s winter.

Ecol

ogy

Beha

viou

r

New Zealand

Australia

Page 7: Black Petrel

Breeding site

Foraging Range

Migration

Great Barrier Island

Little Barrier Island

Auckland

Galápagos Islands

Mexico

Peru

Page 8: Black Petrel

60

80

100

7

Little Barrier IslandOn Little Barrier, it was abundant in the late

1800s but the population was decimated,

mainly by feral cats, until predators were

eradicated in 1980. The Little Barrier Island

colony was originally monitored between

1971 and 1983 and the total breeding

population was estimated to be between 50

and 100 pairs. After the feral cat eradication,

in order to supplement the colony, 249

chicks from Great Barrier Island were

transferred to Little Barrier Island between

1986 and 1990 and the Little Barrier colony

was then monitored annually until 2000.

The Little Barrier Island population is

now thought to be gradually increasing, but

further research is needed to create more

accurate estimates of the population on

Little Barrier Island.

Great Barrier IslandBlack Petrels were first officially recorded on

Great Barrier Island in 1960, but had been

observed by earlier naturalists and harvested

by the local Maoris before this time. At this

time no census or population estimate was

given. From surveys in the late 1970s the

population was thought to be 500 –1,000

breeding pairs, but recent surveys suggest

the population is more than 1,300 breeding

pairs and between 3,551 – 5,021 individuals.

However, a subsample of 100 burrows

monitored for 10 years or more indicated a

slight decrease in population size between

1996 and 2006. The mean probability of

recapture from one year to the next was

78.36%. Additional extensive surveys are

needed to gain a better estimate of the whole

island population and to determine trends for

the total population with more confidence.

Analyses of both juvenile and adult survival

are ongoing. The mean survival of adult

birds estimated to date is 77.9%, which is

considerably lower than other petrels of

similar size. This contrasts with an estimate

of juvenile Black Petrels survival (over three

years of age) of 92.3%, which is very high.

Analysis of 421 birds of known sex suggested

that there was no significant difference

between male and female adult survival.

The low adult survival could be due to low

detectability of birds that move out of the

study area, but this hypothesis needs to be

further investigated.

Total Population Black Petrel breed on Great and Little Barrier

Islands, New Zealand, where the total

population is 1,300 and 100 breeding pairs

respectively, equating to a total population of

an estimated 5,000 individuals. The estimate

of 1,300 pairs on Great Barrier Island is lower

than previously thought but probably reflects

improved information rather than a decline,

however it is not a complete survey and

although it covers the majority of the island’s

population further research is needed to

assess the true population size.

The overall estimate of the total population

of Black Petrel, including the Black Petrel’s

out at sea, is around 10,000 individual birds.

Probability of Survival and Recapture of the Black Petrel

1996 1998 2000 2002 2004

Pro

port

ion

Survival

Recapture

Popu

latio

n

1.0

0.8

0.6

Page 9: Black Petrel

Distribution of Black Petrel’sBlack Petrel’s are estimated to have a population of 10,000 with

only 28% of them being recorded inhabiting Little and Great

Barrier Island, while the rest of them remain out to sea.

200 Black Petrel

Birds out to sea

Birds on land

The overall estimate of the total population

of Black Petrel is around 10,000 birds.

Page 10: Black Petrel

Bree

ding

9

Breeding HabitatBlack Petrel’s breed in only two colonies:

approximately 1,300 annual pairs on Great

Barrier Island, and approximately 100 annual

pairs on Little Barrier Island. The summit of

Mount Hobson is the main breeding area on

Great Barrier Island for them.

Breeding CycleBlack Petrels nest in burrows, usually above

400 m in altitude, and within 50 m either

side of ridge lines. They are an annually

breeding species, with each breeding cycle

lasting about nine months. The breeding

season starts in October, when males

prepare burrows and try to attract a mate.

Most eggs are laid in December, and the

peak period for hatching is early February

(the typical incubation period is 57 days).

Chick rearing takes about 107 days, with the

chicks fledging in May/June at about three

months old. During the breeding season

adults forage mostly to the west and east of

northern New Zealand. Both adult and

newly fledged birds spend the winter off the

west coast of North and South America.

The youngest bird recorded returning to the

Great Barrier Island colony was three years

of age and first breeding has been recorded

at five years at this site. The youngest bird

recorded returning to the Little Barrier Island

colony was five years of age with first

breeding recorded there at six years.

Success RateThe mean age of first breeding for Black

Petrel is estimated to be 6.7 years. Before

this, new adults spend an average of

1.2 years in the colony as pre-breeders, with

only 3% skipping the pre-breeder phase.

Of birds that appear in the study area as

pre-breeders and survive to breed, only 68%

do so in the study area. Once birds start

breeding, their annual survival rate is 0.89,

80% breed each year, and of those, 77%

are successful (i.e., produce a fledgling).

Survival rates before the pre-breeder stage

are not well determined because we can’t

distinguish mortality from emigration (birds

that breed in an area away from where they

were hatched).

A number of Great Barrier Island study

burrows has been monitored intensively

since the 1995 / 96 breeding season allowing

for breeding success, juvenile and adult

survival to be determined for this period.

Breeding success varies from 69% to 84%

(chicks fledged from eggs laid), with an

average of 76% of burrows fledging a chick.

Jan

Mar

May

Jul

Sept

Nov

Annual Breeding Cycle

At colonies

Egg laying

Incubating

Chick rearing

Black Petrels only lay a single egg each

breeding season.

Page 11: Black Petrel

Fledged

Predated

Unknown

Breeding Success of EggsBreeding success of breeding season (2006),

representing the percentages of outcomes of the

257 eggs laid that year.

Breeding Success of ChicksBreeding success from 2006 breeding season,

showing the percentages of outcomes of the 186

chicks that hatched from 257 eggs.

1.0

0.8

0.6

0.4

0.2

0.01996 2000 2004 2008

Pro

port

ion

The proportion of breeding outcomes

Hatched

Crushed

Predated

Disappeared

Dead Embryo

Bred successfully

Didn’t breed

Failed breeding

Page 12: Black Petrel
Page 13: Black Petrel

The vulnerability and elusive lifestyles of the Black Petrel has made them notoriously difficult to study.

Page 14: Black Petrel

13

No Black Petrels

Breeding area before introduced predators

Current breeding area

Reduced Breeding Habitat of the Black Petrel

Thre

ats

Page 15: Black Petrel

Rat and Feral Cat PredationIntroduced cats decimated the Little Barrier

Island population, killing up to 100% of

fledglings in some years, and taking adults.

Introduced cats cause minor interference on

Great Barrier Island, but breeding success

is high (80% in 2004 /5). Rats are present

on Great Barrier Island but have little effect

on this species. Rats were eradicated from

Little Barrier Island in 2004. Rats, stray dogs,

feral pigs, along with the cats, may also be a

threat on Great Barrier Island.

There were three incidents of cat predation

(1.5%) on chicks, while rats predated 0.5%

of the eggs laid within the study burrows in

the 2006 season. Predation by cats occurred

in three different areas – Palmers Track,

Kauri Dam, and the Summit. Juvenile petrels

are vulnerable to feral cat predation as soon

as they leave the burrows to strengthen

wings and practise flying. Ten chicks have

been predated by cats over the past five

seasons. It is important to continue control

the cat population with trapping in the area.

Eggs are more likely to be predated by rats.

PeopleA recent estimate indicates that about 6640

people visit Mount Hobson on Great Barrier

Island, each year, which has little or no direct

impact on the breeding success of the Black

Petrel. The construction of raised walkways

around the summit has decreased damage

to the environment, and burrows. However,

serious erosion continues to occur along the

summit ends of the South Fork and Palmers

Tracks. Extended walkway construction in

these areas is recommended. This should be

done with full consultation with the authors

to prevent the accidental destruction of

burrows, since certain places along these

tracks have high burrow densities.

Climate ChangeEl Niño fluctuations may also affect the

population in this zone. The species is

potentially threatened by climate change

because it has a geographically bounded

distribution: its altitudinal distribution

falls entirely within 1,000m of the highest

mountain top within its range (621m).

15

12

9

6

3

0

Number of Predated Eggs and ChicksThe average number of eggs laid per year is

166 with an average of 133 hatched chicks

1997 1998 1999 2000 2001 2002 2003 2004

Num

ber

of e

ggs

or c

hick

s

Some years all the fledglings on Little

Barrier Island have been killed by cats.Chicks

Eggs

Page 16: Black Petrel

Thre

ats

15

Recreational FishingIn New Zealand, participation in recreational

fishing is high. A recent survey estimated

that 19.5% of the adult population go

saltwater fishing during a year, with 2.5% of

the adult population (81,000 people) fishing

at least once during a week, catching 25,000

tonnes annually. It is estimated 4.81 (4.41

to 5.23) million hours of fishing from trailer

boats in northeastern New Zealand, where

the Black Petrel lives.

A boat ramp survey was carried out

in collaboration with Blue Water Marine

Research during the summer of 2007–08.

During the survey, 763 interviews were

conducted (654 on the northeast coast, and

109 in Otago). This survey has provided the

first quantitative information on the rates

of seabird capture by recreational fishers,

as well as information on the nature of the

interactions. Across all the survey, 47%

of fishers recalled witnessing a bird being

caught at some stage in the past, and there

were 21 birds caught on the day of the

interview. This was equivalent to a capture

rate of 0.22 (95% c.i: 0.13 to 0.34) birds per

100 hours of fishing. Observers on 57 charter

trips also recorded seabird captures, with a

capture rate of 0.36 (95% c.i: 0.09 to 0.66)

birds per 100 fisher hours, similar to the

rate found during the boat ramp surveys.

Although the number of interactions is high,

the birds were reported as unharmed in 77%

of the capture incidents that were recalled.

This results in 11,500 (6,600 to 17,200) birds

hooked or tangled each year, some of which

will be Black Petrels.

Non-commercial fisheries involve many

individual participants and are geographically

spread out. The lack of centralisation makes

data collection difficult, and to date there

has been no systematic study of the impacts

of recreational fishing on seabirds. The

intensity of recreational fishing creates a

small rate of interactions between individual

fishers and birds, which may have an

impact on the population level. The near

shore region is where recreational fisheries

are concentrated. Until recently, Ministry of

Fisheries observers have typically not been

placed on the smaller vessels that target

inshore species, and the impacts of fishing

on Black Petrels that are largely unknown.

Type of seabirds caught

45

35

25

15

5

Per

cent

age

of to

tal b

irds

caug

ht

Seagull

Shag

Petrel

Gannet

Albatross

Other

Page 17: Black Petrel

19.5% of New Zealanders engage in fishing as a

recreational hobby every year.

44.9% of total bird caught were Petrels, some of

which will be Black Petrels.

60% of fishing trips over 5 km from shore

attracted petrels, 30% within 5 km and only 10%

within an Estuary area in the North Island.

Per

cent

age

of in

cide

nts

Capture MethodCapture method that caught birds as a percentage

of the total number of incidents.

Tangled Internally Hooked Externally Hooked

80

60

40

20

Seagull

Shag

Petrel

Gannet

Albatross

Type of seabirds caught

Page 18: Black Petrel

Thre

ats

17

Capture location

Locations of Black Petrel Captures

Between 1997 and 2009, 49 Black Petrel captures

were recorded commercial fisheries.

Page 19: Black Petrel

Commercial FishingSeabirds are caught in a range of fisheries,

and the management of fisheries to ensure

the long-term viability of seabirds requires

an understanding of the risks to their

sustainability. In order to evaluate whether

the viability of seabirds is jeopardised by

fisheries by-catch, the number of annual

kills needs to be compared with the capacity

of the populations to replace those losses.

Recent research by Dragonfly studied 64

species, of seabirds where the Black Petrel

clearly stood out as the species the most at

risk from commercial fishing activities within

the New Zealand Exclusive Economic Zone.

With an average number of annual potential

kills estimated to be nearly 10 times higher

than the Potential Biological Removal index,

the study suggests that the Black Petrel

species should become the primary subject

of more detailed research and management.

Fishing is a big industry in New Zealand

with 1,278 commercial fishing vessels

registered which export $1.42 billion worth of

seafood every year.

Black Petrel’s often scavenge the fishing

boat waste, and are caught by commercial

longliners in New Zealand waters.

Most observed captures were close to

Black Petrel’s breeding grounds, primarily in

the bottom longline snapper fishery, but also

in the bottom longline bluenose fishery, and

in inshore trawl fisheries. From 29 observed

captures, we estimated that between 663

and 1289 birds may have potentially been

killed each year in the period 2003 to 2009.

These kills exceeded the Potential Biological

Removal index, which was estimated to be

between 64 and 157 mortalities per year.

There was no significant difference in the

vulnerability to capture, the number of

potential kills, or in the risk ratio of Black

Petrel between the periods of 2003–04 to

2005–06 and 2006–07 to 2008–09.

Black Petrel are also vulnerable to capture

by fisheries, especially longline fishing,

during migration to the east Pacific off

Ecuador and Peru where it is a near-obligate

associate of small crustaceans.

Black Petrel

NZ King Shag

Salvin’s Albatross

Yellow-Eyed Penguin

Gibson’s Albatross

Spotted Shag

Pitt Island Shag

Soft Plumaged Petrel

Bounty Island Shag

Sooty Shearwater

Kerm Petrel

Campbell Island Shag

Antarctic Prion

Masked Booby

Common White Tern

Risk Ratio (kills / PBR)Risk ratio (total annual potential kills / PBR) for a sample of the studied birds.

The threshold where the number of potential bird kills equals the PBR is

represented by the vertical black line.

0 0.1 1 2.5 5 10

Page 20: Black Petrel

19

ProtectionBlack Petrels are specifically covered by the

International Agreement on the Conservation

of Albatrosses and Petrels (2001) which

obliges signatories to reduce incidental

mortality, control detrimental non-native

species, protect critical habitats and support

research into the highlighted species.

Current MeasuresThe Department of Conservation and Wildlife

Management International Limited have

been taking steps to preserve the population

of Black Petrel’s for many years. Cats were

eradicated on Little Barrier Island by 1980.

Between 1986 and 1990, 249 fledglings

were transferred from Great Barrier to

Little Barrier Island in an attempt to boost

population size. Follow-up monitoring

indicates mixed results. The colony on Little

Barrier is monitored every breeding season

to assess breeding success. An ongoing

long-term population study of Black Petrel

was initiated on Great Barrier in 1996. This

study will assist in identifying the effects

very important for determining national

and international fisheries risk for the

Black Petrel. Increasing awareness of both

recreational and commercial fisheries of

the threat they pose to the Black Petrel

and their vulnerability to being captured is

also a priority. Also explaining solutions to

fishermen that reduce the problem like using

weighted line and being careful with disposal

of offal is needed. Further developing

mitigation devices and techniques that

minimise fisheries by-catch, is also a priority.

If monitoring indicates that any predators

are causing a decline in population on Great

Barrier Island then appropriate management

strategies will take place to resolve this. The

eradication of rats from Little Barrier Island is

another current target.

that long-line fishing, rat and cat predation,

and habitat disturbance may have on

the population. The population estimate

has been updated, ensuring that any

population changes will be detected in time

to implement the appropriate management

strategies. The main objective of the study is

to undertake an annual census of the Black

Petrel population on Great Barrier Island

via burrow monitoring and the banding of

adults and fledglings to determine adult

mortality, breeding success and recruitment.

More accurate research will ensure the

preservation of the Black Petrel species.

Proposed MeasuresThere are plans to complete an accurate

census of both islands and continue to

monitor Great Barrier Island populations

annually to determine trends, and assess

breeding success. From this research

follow-up reports of mainland breeding sites

will be generated to analyse data. Accurate

foraging and distribution information is also

Cons

erva

tion Black Petrel clearly stood out as the

species the most at risk from commercial

fishing activities in New Zealand.

Page 21: Black Petrel

Black Petrel Study BurrowsLocation of the Black Petrel study burrows and census grids within the study

site on Great Barrier Island, that are annually monitored by DoC.

Shortcut track

Kauri Dam Track

Southern Fork Track

Mt Hobson

Palmers Track

N

Page 22: Black Petrel

21

American Birding. (2006). Black Petrels (2006). Retrieved 2 March 2011, from

www.aba.org/birding/v38n6p64w1.pdf

Arkive (n.d.). Black Petrel (Procellaria parkinsoni). Retrieved March 17, 2011 from:

www.arkive.org/parkinsons-petrel/procellaria-parkinsoni/

Bird Life International. (n.d.) Parkinson’s Petrel Procellaria parkinsoni. Retrieved

March 5, 2011 from: www.birdlife.org/datazone/speciesfactsheet.php?id=3923

Chambers, S. (2007). New Zealand Birds: An identification guide. Auckland:

Reed Books

Cometti, R. (1986). Little Barrier Island: New Zealand’s foremost wildlife sanctuary.,

Hong Kong: Hodder & Stoughton Ltd.

Department of Conservation. (2001). Preliminary modelling of Black Petrel

(Procellaria parkinsoni) to access population status. Retrieved March 5, 2011 from:

www.doc.govt.nz/upload/documents/science-and-technical/dsis2.pdf

International Union for Conservation of Nature and Natural Resources. (n.d.). The

IUCN Red List of Threatened Species. Retrieved March 17, 2011 from: Procellaria

parkinsoni www.iucnredlist.org/apps/redlist/details/144872/0

Ministry of Fisheries. (2010). Fisheries Risk to the Population viability of Black Petrel.

Retrieved March 13, 2011 from: http://kea.massey.ac.nz/search~S4?/Xblack+petrel

&searchscope=4&SORT=DZ/Xblack+petrel&searchscope=4&SORT=DZ&SUBKEY=

black%20petrel/1%2C5%2C5%2CB/c856740911&FF=Xblack+petrel&1%2C1%2C

%2C1%2C0

Bibl

iogr

aphy

Ministry of Fisheries. (2010). New Zealand Fisheries at a Glance, Seabirds:

The Problem. Retrieved March 5, 2011 from: www.fish.govt.nz/en-nz/

Fisheries+at+a+glance/default.htm

New Zealand Birds. (n.d.) Black petrel. Retrieved March 7, 2011 from: www.nzbirds.

com/birds/blackpetrel.html

Ocean Wanderers. (n.d.). (Parkinson’s) Black Petrel (Procellaria parkinsoni).

Retrieved March 18, 2011 from: www.oceanwanderers.com/ParkBlkPet.html

Ombler, K. (2007). Where to Wathc Birds in New Zealand. Auckland: New Holland

Publishers

PLos One. (n.d.) Black Petrels (Procellaria parkinsoni) Patrol the Ocean Shelf-Break:

GPS Tracking of a Vulnerable Procellariiform Seabird. Retrieved March 7, 2011 from

www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0009236

Victoria University of Wellington. (n.d.). A History of Birds in New Zealand; Procellaria

parkinsoni (Black Petrel). Retrieved March 6, 2011 from: www.nzetc.org/tm/

scholarly/tei-BulBird-t1-g1-t2-body-d106.html

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