THREATENED SPECIES SCIENTIFIC COMMITTEE Established under the Environment Protection and Biodiversity Conservation Act 1999

The Minister’s delegate approved this conservation advice on 01/10/2015

Conservation Advice

Pterodroma heraldica

Herald petrel

Conservation Status

Pterodroma heraldica (Herald petrel) is listed as Critically Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth) (EPBC Act). The species is eligible for listing as Critically Endangered as, prior to the commencement of the EPBC Act, it was listed as Critically Endangered under Schedule 1 of the Endangered Species Protection Act 1992 (Cwlth). Garnett et al., (2011) reviewed the conservation status of the Herald petrel and considered it to be Vulnerable. The Threatened Species Scientific Committee are using the findings of Garnett et al., (2011) to consider whether reassessment of the conservation status of each of threatened listed under the EPBC Act is required.

Description

The gadfly petrels (: Pterodroma spp.) are a group of highly oceanic , comprising some 30 species, that are complex in plumage and (Nelson 1980). Found throughout the ocean basins of the world, they are widely distributed in the tropics and sub-tropics, but with some species breeding in the subantarctic zone (Warham 1990). They are adapted to a highly aerial and oceanic life, and possess short sturdy bills adapted for seizing soft prey at the surface, and unusual helicoidally twisted intestines. The function of the twisted intestines is obscure but believed to assist in digesting marine that have an unusual biochemistry (Imber 1985, Kuroda 1986). They also show complex markings on the face and wings that are thought to serve as interspecific recognition characters (Murphy and Pennoyer 1952).

As a group, gadfly petrels vary considerably in size (160-525 g, Warham 1990). The Herald petrel (Pterodroma heraldica) is a medium to large-sized , (280.450 g; Gardner et al., 1985), and 34-39 cm long with a wingspan of 80-100 cm (Marchant and Higgins 1990). Their plumages are well described in the literature (Marchant and Higgins 1990), and both species are polymorphic, possessing both light and dark morphs. For both species the genders and young birds are similar in appearance. The Herald petrel and Round petrel are both tropical/sub-tropical species and are considered to be closely related (Imber 1985; Brooke et al., 1996; Brooke et al., 2000). Historically they have been considered by some authors to be conspecific e.g. Warham (1990).

There is taxonomic uncertainty regarding the Pterodroma arminjoniana/heraldica type petrel that was recorded on North Keeling Island in the 1980s. Further, there have been no records since that time, despite recent attempts to locate birds. Breeding has never been confirmed on Cocos (Keeling) Island. Garnett et al., (2011) believe the found on Cocos (Keeling ) Island and identified as P. arminjoniana by Garnett and Crowley (2000) is likely to be P. heraldica.

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Distribution and Habitat

The Herald petrel breeds in winter on Raine Island and possibly other small cays in the Coral Sea, (Garnett and Crowley 2000; Garnett et al., 2011). However, despite regular surveys of the Herald, Coringa and Magdelaine Cays of the Coral Sea over the last 15 years, Herald petrels have not been recorded breeding (B.Baker unpublished).

The Australian population has been estimated at 10-25 breeding birds (Garnett and Crowley 2000; Garnet et al., 2011). There are no estimates of former abundance for the Australian population.

Since its discovery in 1959, Herald petrels have been recorded breeding irregularly in small numbers until 1987, once more in June 2002 when only one breeding pair was observed, and not again, though winter visits to the island have been few (Batianoff and Cornelius 2005). A total of 22 birds have been banded, but rarely are more than a few pairs found on any one visit.

Extralimitally, it breeds on a number of other in the Pacific Ocean including Easter Island, French Polynesia, the Cook Islands, the Pitcairn group; and the Tonga group (BirdLife 2004; Murphy and Pennoyer 1952). It forages in surrounding waters, mostly south of the Equator (Marchant and Higgins 1990). The global population is estimated at 150 000 mature individuals (Birdlife International 2015).

The distribution of this species is not known to overlap with any EPBC Act-listed threatened ecological community.

The Department of the Environment has prepared survey guidelines for Australia's threatened birds. The survey guidelines are intended to provide guidance for stakeholders on the effort and methods considered appropriate when conducting a presence/absence survey for birds listed as threatened under the EPBC Act. http://www.environment.gov.au/resource/survey- guidelines-australias-threatened-birds-guidelines-detecting-birds-listed-threatened

Threats

Herald petrels breeding on Raine Island are threatened by the potential introduction of feral predators. At this stage, feral predators are not considered an immediate threat as none occur on Raine Island. Appropriate quarantine measures should be put in place at all breeding sites to minimise this threat.

Small populations such as these of the Herald petrel will always be susceptible to stochastic events such as storms and cyclones. Cyclones have the potential to have serious effects on the vegetation and wildlife of Raine Island. A cyclone database maintained by the Bureau of Meteorology shows that a number of cyclones have regularly but unpredictably affected Raine Island.

Conservation Actions

Conservation and Management Actions

Habitat Loss, Disturbance and Modification • Maintain appropriate quarantine measures enforced by management authorities at Raine Island to maintain a barrier to feral predators.

Survey and Monitoring priorities

• Continue monitoring the species, and adapt management actions if population changes (decreases or increases) necessitate them.

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Information and research priorities

• Determine the taxonomic affinity of the Pterodroma arminjoniana/heraldica type petrel that was recorded on Cocos (Keeling) Island in the 1980s. • Determine the population size and breeding success of Herald petrel on Raine Island.

This list does not necessarily encompass all actions that may be of benefit to the Herald petrel, but highlights those that are considered to be of highest priority at the time of preparing the Approved Conservation Advice.

References cited in the advice Batianoff GN, Cornelius NJ (2005) Birds of Raine Island: population trends breeding behaviour and nesting habitats. Proceedings of the Royal Society of Queensland 112: 1-29.

BirdLife International. (2004). Threatened birds of the world 2004. CD-ROM. Cambridge, U.K: BirdLife International.

BirdLife International (2015) Species factsheet: Pterodroma heraldica. Downloaded from http://www.birdlife.org on 17/06/2015.

Brooke, M. de L. and Rowe, G. (1996). Behavioural and molecular evidence for specific status of dark and light morphs of the Herald Petrel Pterodroma heraldica. Ibis 138: 420-432.

Brooke, M. de L., Imber, M.J. and Rowe, G. (2000). The occurrence of two surface-breeding species of Pterodroma on Round Island, Indian Ocean. Ibis 142: 154-158.

Gardner, A.S., Duck, C.D. & Greig, S. (1985). Breeding of the , Pterodroma arminjoniana on Round Island, Mauritius. Ibis 127: 517-522.

Garnett S, Crowley GM (2000) The Action Plan for Australian Birds 2000. Environment Australia, Canberra. Garnett ST, Szabo JK, Dutson G (2011) The Action Plan for Australian Birds 2010. CSIRO Publishing, Melbourne. Imber, M.J. (1985). Origins, phylogeny and taxonomy of the glad-fly petrels, Pterodroma spp. Ibis 127: 197-229.

Kuroda, N. (1986). On the intestinal twistings in gadfly-petrels and comparative notes on the digestive tract in . Japanese Journal of Ornithology 35: 1-14.

Marchant S, Higgins PJ (Eds) (1990) Handbook of Australian, New Zealand and Antarctic Birds. Volume 1: Ratites to Ducks. Oxford University Press, Melbourne. Murphy, P.C and Pennoyer, J.M. (1952). Larger petrels of the genus Pterodroma. American Museum Novitates 1580: 1-43.

Nelson, B. (1980). Seabirds their biology and ecology. Hamlyn: London. Warham J. (1990). The petrels: Their ecology and breeding systems. Academic Press: London.

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