Fulmar prion

Pachyptila crassirostris (Mathews, 1912)

New Zealand status: Native

Conservation status: Naturally Uncommon

Geographical variation: Three subspecies, all extant: fulmar prion P. c. crassirostris (At Risk/Naturally Uncommon); Chatham fulmar prion P. c. pyramidalis (At Risk/Naturally Uncommon); lesser fulmar prion P. c. flemingi (At Risk/Naturally Uncommon).

Fulmar prion. Adult. Bounty Islands, October 2012. Image © Paul Sagar by Paul Sagar

Fulmar prion. Adult. Bounty Islands, October 2012. Image © Paul Sagar by Paul Sagar

The fulmar prion is a poorly known species that is only easily seen by visiting its remote island breeding sites. It is usually only identifiable in the hand. The species is very similar to the abundant fairy prion but is separable on the basis of its chunkier bill. The specific name crassirostris means ‘thick billed’ in Latin. The fulmar prion breeds only at five southern island groups. Like most petrels it spends most of its life at sea, but its pelagic distribution is poorly known.

Identification

Prions are small petrels. The fulmar prion, like other prions, is blue-grey above with a black 'M' marking between the wing tips, a black tail tip and a white supercilium. Underneath it is largely white. Its bill is mainly bluish-grey; its legs and feet are blue with paler webs and greyer claws. Immatures appear similar.

Of the three subspecies, the Chatham form of fulmar prion is the largest, the lesser fulmar prion is the smallest, and the nominate form is of intermediate size.

Voice: the fulmar prion is a noisy bird at the nesting colonies both in flight and on the ground, with males giving a four-note call described as what-not-to do and females giving a more slurred, cooing three note call coore-corr-corr . Unlike other prion species, fulmar prions on the Bounty Islands are vocal by day but silent at night.

Similar species: the fulmar prion is separable from most other prion species by its relatively small body and bill size and its more pronounced black tail tip. However it shares these characteristics with the fairy prion and can usually only be separated from this species in the hand on the basis of its more robust bill and slightly darker tail tip.

Distribution and habitat

The nominate subspecies nests at the Bounty Islands and The Snares (Rima and Toru in the Western Chain); the Chatham Islands subspecies nests on The Pyramid and the Forty-Fours; the lesser fulmar prion nests at the Auckland Islands (Ewing, Ocean and Rose), Heard Island, and probably McDonald Island.

Fulmar prions are commonly seen offshore from their breeding colonies during the breeding season, and the species may be fairly sedentary around its nesting islands in winter, however little is known about its pelagic range as fulmar prions are difficult to identify at sea. It has been seen in the south Tasman Sea, near Stewart Island, east of the South Island, and well east of the Chatham islands at 50˚S 156˚W. Fulmar prions rarely reach mainland New Zealand coasts, and are an extreme vagrant to Tasmania.

Population

The total New Zealand population is probably less than 40,000 pairs, including about 30,000 pairs at the Bounty Islands, up to 400-600 pairs at The Snares, 1,000-5,000 pairs at the Chatham Islands, and less than 1,000 pairs at the Auckland Islands. Outside the New Zealand region, more than 10,000 pairs nest at Heard Island.

At the Bounty Islands the population forms "a subterranean population wherever suitable habitat" occurs (Robertson & van Tets 1982).

Threats and conservation

The fulmar prion is confined to nesting on offshore islands free of introduced predators. There is no evidence to show that the species formerly had a wider nesting range, although fossil remains have been identified from Chatham and Pitt Islands. Many current nesting sites remain vulnerable to invasion by rats which would have the potential to eliminate populations. Serious pollution incidents, such as oil spills, near breeding sites are also a potential threat. Subantarctic skuas kill some birds on the breeding grounds.

Breeding

Fulmar prions breed in dense to loose concentrations; at several sites they breed among nesting albatrosses. The breeding biology has not been studied in detail but it is assumed to be very similar to that of the closely related fairy prion, with a breeding season from October to February. At the Bounty Islands, partly incubated eggs were found on 19 November. At The Snares, eggs have been found from 13 October to 21 November, hatching peaks in mid December, large downy chicks were seen on 19 January, and fledglings probably leave in early February. At the Chatham islands incubation was underway from early to mid December. At Heard Island, eggs have been found from 23 November to 20 December, with hatching estimated to be in late December to early January, and fledglings departing from 17 February for 1 week.

Nests are normally in natural crevices, rock piles, scree slopes and caves rather than burrows. Like all petrels, only a single egg is laid.

Behaviour and ecology

Fulmar prions are unusual among prion species for visiting their nest sites in broad daylight at some colonies (Bounty Islands and The Snares), including performing acrobatic courtship displays and intraspecific fighting on the surface of the colonies. Over the Bounty Islands, flocks will pursue and mob predatory gulls or skuas. However at most colonies (Chatham, Auckland and Heard Islands), fulmar prions are mainly active ashore nocturnally.

Food

Fulmar prions probably catch most of their food close to their breeding islands during the day. They have been seen pecking small items off the sea surface and making brief, shallow dives. Prey consists of a range of small marine invertebrates, varying seasonally, including: crustaceans, juvenile barnacles, salps, pyrosomes, cephalopods and various floating molluscs, and the occasional fish. Chatham Island birds appear to feed mainly on adult barnacles, while birds at The Snares eat mainly crustaceans (euphausiids and amphipods).

Websites

http://www.birdlife.org/datazone/speciesfactsheet.php?id=3919

References

Downes, M.C.; Ealey, E.H.M.; Gwynn, A.M.; Young, P.S. 1959. The birds of Heard Island. ANARE Reports, Series B, Vol. 1, Antarctic Division, Melbourne.

Ealey, E.H.M. 1954. Analysis of stomach contents of some Heard Island birds. Emu 54: 204-210.

Fleming, C.A. 1939. Birds of the Chatham Islands Part 1. Emu 38: 380-413.

Fleming, C.A.; Baker, A.N. 1973. The Snares Western Chain. Notornis 20: 37-45.

Gill, B.J.; Bell, B.D.; Chambers, G.K.; Medway, D.G.; Palma, R.L.; Scofield, R.P.; Tennyson, A.J.D.; Worthy, T.H. 2010. Checklist of the Birds of New Zealand, Norfolk and Macquarie Islands, and the Ross Dependency, Antarctica (4th edition). Ornithological Society of New Zealand & Te Papa Press, Wellington.

Harper, P.C. 1980. The field identification and distribution of the prions (genus Pachyptila), with particular reference to the identification of storm-cast material. Notornis 27: 235-286.

Heather, B.D.; Robertson, H.A. 1996. The field guide to the birds of New Zealand. Viking, Auckland.

Imber, M.J. 1981. Diets of stormpetrels Pelagodroma and Garrodia and of prions Pachyptila (Procellariiformes). Pp. 63-88 in Cooper, J. (ed.). Proceedings of the Symposium on Birds of the Sea and Shore. African Seabird Group, Cape Town. 

Marchant, S.; Higgins, P.J. (Eds.) 1990. Handbook of Australian, New Zealand and Antarctic birds. Vol. 1, ratites to ducks. Oxford University Press, Melbourne.

Miskelly, C.M. 1984. Birds of the Western Chain, Snares Islands, 1983-84. Notornis 31: 209-223.

Miskelly, C.M.; Sagar, P.M.; Tennyson, A.J.D.; Scofield, R.P. 2001. Birds of the Snares Islands, New Zealand. Notornis 48: 1-40.

Robertson, C.J.R.; van Tets, G.F. 1982. The status of birds at the Bounty Islands. Notornis 29: 311-336.

Sagar, P.M. 1977. Birds of the Western Chain, Snares Islands, New Zealand. Notornis 24: 178-183.

Taylor, G.A. 2000. Action plan for seabird conservation in New Zealand. Part A: threatened seabirds. Threatened Species Occasional Publication No.16. Department of Conservation, Wellington.

Tennyson, A.J.D.; Mayhill, R.C.; Clark, G.S. 1993. A visit to The Pyramid and the Murumurus, Chatham Islands.  Tane 34: 171-179.

Tennyson, A.J.D.; Bartle, J.A. 2005. A scientific name for fulmar prions nesting at Auckland and Heard Islands. Notornis 52: 47-55.

Woehler, E.J. 2006. Status and conservation of the seabirds of Heard Island. Pp. 128-165 in Green, K.; Woehler, E. (eds). Heard Island: Southern Ocean sentinel. Surrey Beatty & Sons, Sydney.

Recommended citation

Tennyson, A.J.D. 2013. Fulmar prion. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz

Fulmar prion

Breeding season
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Egg laying dates
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun

Fulmar prion

Social structure
monogamous
Breeding season
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Nest type
scrape
Nest description
Shallow scrape or hollow in rock debris sometimes lined with feathers.
Nest height (mean)
0.00 m
Clutch size (mean)
1
Mean egg dimensions (length)
46.00 mm
Mean egg dimensions (width)
33.00 mm
Egg colour
White
Egg laying dates
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Interval between eggs in a clutch
Not applicable
Incubation length (mean)
Unknown
Nestling type
altricial
Nestling period (mean)
Unknown
Age at fledging (mean)
Unknown
Age at first breeding (typical)
Unknown
Maximum longevity
Unknown
Maximum dispersal
At least several hundred km

Chatham fulmar prion

Social structure
monogamous
Breeding season
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Nest type
burrow, rock crevice
Nest description
Small bowls largely built out of vegetation, concealed in rock crevices or under rocks, occasionally in holes beneath albatross nests and in soil burrows.
Nest height (mean)
0.00 m
Maximum number of successful broods
Unknown
Clutch size (mean)
1
Mean egg dimensions (length)
46.00 mm
Mean egg dimensions (width)
33.00 mm
Egg colour
White
Egg laying dates
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Interval between eggs in a clutch
Not applicable
Incubation length (mean)
Unknown
Nestling period (mean)
Unknown
Age at fledging (mean)
Unknown
Age at first breeding (typical)
Unknown
Maximum longevity
Unknown
Maximum dispersal
Possibly several hundred km

Lesser fulmar prion

Social structure
monogamous
Breeding season
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Nest type
rock crevice
Nest description
In costal rocky crevices or made of small stones among rocks
Nest height (mean)
0.00 m
Clutch size (mean)
1
Egg laying dates
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
Interval between eggs in a clutch
Not applicable
Incubation length (mean)
Unknown
Nestling type
altricial
Nestling period (mean)
Unknown
Age at fledging (mean)
Unknown
Age at first breeding (typical)
Unknown
Maximum longevity
Unknown
Maximum dispersal
Probably several thousand km