Mottled petrel

{{Short description|Species of bird}} {{Speciesbox | image = Mottled Petrel 0A2A3403.jpg | status = NT | status_system = IUCN3.1 | status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=BirdLife International |date=2018 |title=''Pterodroma inexpectata'' |volume=2018 |article-number=e.T22697963A132615071 |doi=10.2305/IUCN.UK.2018-2.RLTS.T22697963A132615071.en |access-date=12 November 2021}}</ref> | genus = Pterodroma | species = inexpectata | authority = (J. R. Forster, 1844) | synonyms = ''Procellaria inexpectata'' J. R. Forster, 1844

''Procellaria raolensis'' Bonaparte, 1857 (''nomen novum'')

''Procellaria gularis'' Peale, 1848

''Procellaria affinis'' Buller, 1874

''Aestrelata fisheri'' Ridgway, 1883

''Aestrelata scalaris'' Brewster, 1896

''Procellaria lugens'' Mathews, 1912

''Pterodroma neglus'' Mathews, 1928 (''nomen novum'')

''Pterodroma inexpectata thompsoni'' Mathews, 1915 | range_map = Pterodroma inexpectata map.svg }}

The '''mottled petrel''' ('''''Pterodroma inexpectata''''') or '''kōrure''' is a species of seabird and a member of the gadfly petrels. It usually attains {{convert|33|to(-)|35|cm|in|abbr=on}} in length with a {{convert|74|to(-)|82|cm|in|abbr=on}} wingspan.

This species is highly pelagic, rarely approaching land, except to nest and rear young. The mottled petrel feeds mostly on fish and squid, with some crustaceans taken. It is a transequatorial migrant, breeding in the islands of New Zealand, and migrating to the Bering Sea, concentrating in the Gulf of Alaska and the Aleutian Islands.

It was previously found on mainland New Zealand North and South Islands, but is now only found on smaller off-shore islands near Fiordland, Stewart Island and Snares Islands, with the largest populations on Codfish Island, Big South Cape Island and the Snares Islands.<ref>{{Cite Q|Q106839633}}</ref>

The mottled petrel uses burrows and rock crevices to nest in. It was formerly more numerous than today. The species' numbers have been and continue to be affected by predation by introduced mammals. Chicks have been reintroduced to Maungaharuru, hills 24 km from the sea, in Hawke's Bay.<ref>{{cite news |title=Korure settling into new home |first=Kaysha |last=Brownlie |url= http://www.nzherald.co.nz/hawkes-bay-today/news/article.cfm?c_id=1503462&objectid=11624414 |newspaper=Hawke's Bay Today |date=18 April 2016 |access-date=23 April 2016}}</ref>

== Breeding == The breeding behaviour of the mottled petrel is similar to that of the sooty shearwater (''Adrenna grisea'').<ref name=":0">{{Cite journal |last=Richdale |first=L. E |date=1964 |title=NOTES ON THE MOTTLED PETREL ''PTERODROMA INEXPECTATA'' AND OTHER PETRELS |journal=IBIS |volume=106 |issue=1 |pages=110–114|doi=10.1111/j.1474-919X.1964.tb03684.x }}</ref> Adults return to the nesting islands in late October.<ref name=":1">{{Cite journal |last1=Warham |first1=John |last2=Keeley |first2=Bruce |last3=Wilson |first3=Graham J. |date=1997 |title=Breeding of the Mottled Petrel |journal=The Auk |volume=94 |issue=1 |pages=1–17|doi=10.1093/auk/94.1.1 |doi-broken-date=12 July 2025 }}</ref> The beginning of the breeding season ranges between November 21 to December 10th with the laying season lasting nineteen days.<ref name=":0" /> They breed on many islands, including Whero Island, Big South Cape Island, and Snaves Island.<ref name=":0" /> Big South Cape Island, located off Stewart Island, holds most of the population of New Zealand's mottled petrel.<ref name=":0" />

Nests can be found in secluded burrows surrounded by vegetation containing only a single egg.<ref name=":0" /> The eggs of the mottled petrel are relatively large in proportion to the size of the bird.<ref name=":0" /> The mean length of the eggs being 58.6mm ± 1.5, with a mean width of 42.7mm ± 0.77, and a mean weight of 53.2g ± 3.2.<ref name=":0" /> This makes the adult bird only six times heavier than the egg.<ref name=":0" /> The incubation period lasts around fifty-four days, with the last of the eggs hatching mid-February.<ref name=":0" />

Parent birds only return to their nests at night after their egg has hatched.<ref name=":0" /> Chicks are brooded for two days.<ref name=":1" /> They fledge when they are 90–105 days old, the last of the chicks departing in June.<ref name=":1" /> The weight of the chicks increased by 66grams within six days.<ref name=":0" /> Both parents feed their chick, and the chicks are fed at night.<ref name=":0" />

== Migration == The mottled petrel is the only gadfly petrel that is seen far south in the Antarctic and Pacific Arctic waters.<ref name=":2">{{Cite journal |last=Harper |first=Peter C. |date=1987 |title=Feeding behaviour and other notes on 20 species of Procellariiformes at sea |journal=Notornis |volume=34 |issue=3 |pages=169–192}}</ref> They migrate at a steady, fast pace, they start heading north in May and the migratory period lasts about 1.5 months.<ref name=":3">{{Cite journal |last1=Nakamura |first1=Kazue |last2=Tanaka |first2=Yutaka |date=1997 |title=Distribution and migration of two species of Petrel in the North Pacific Ocean |journal=Journal of the Yamashina Institute for Ornithology |volume=9 |issue=1 |pages=112–120|doi=10.3312/jyio1952.9.112 }}</ref>,<ref>{{Cite journal |last1=Hamo |first1=Ogii |last2=Newcomer |first2=Michael W. |last3=Fujimara |first3=Hitoshi |last4=Shiratori |first4=Senichi |date=1999 |title=Seasonal Distribution of the Mottled Petrel |journal=Bull. Fac. Fish. Hokkaido Univ |volume=50 |issue=2 |pages=45–59}}</ref> They are seen migrating to different areas in the north pacific, depending on water temperature and where their prey is most abundant.<ref name=":3" /> ''P. inexpectata'' migrate alone or in pairs, showing their solitary nature.<ref name=":3" />

== Foraging and Feeding == ''P. inexpectata'' feast alone, not joining in with other species, and they feed at night.<ref name=":2" /> They eat fish, squid, and krill, and forage by surface seizing tactics.<ref name=":2" /> Mottled petrels cope with prey limitations better than other breeding procellariforms.<ref>Sagar, Rachel. 2019. "Foraging Ecology & Conservation Physiology of the Mottled Petrel, Pterodroma inexpectata, with Applications for Maximising the Success of Petrel Conservation."</ref>

Mottled petrels have a high latitude foraging niche along the edge of the Antarctic pack ice during breeding season.<ref name=":4">Sagar, Rachael L., Antje Leseberg, Ken Hunt, Kahori Nakagawa, Brendon Dunphy, and Matt J. Rayner. 2015. "Optimising translocation efforts of Mottled Petrels (Pterodroma inexpectata): growth, provisioning, meal size and the efficacy of an artificial diet for chicks." ''Emu - Austral Ornithology'' 115 (2): 137-145.</ref> They also tend to go on long foraging trips.<ref name=":4" /> <gallery> File:Pterodroma inexpectata (AM LB4282).jpg|alt=Pterodroma inexpectata mount from the collection of Auckland Museum|''Pterodroma inexpectata'', Auckland Museum collection </gallery>

==References== {{Reflist}} * "National Geographic" ''Field Guide to the Birds of North'' ''America'' {{ISBN|0-7922-6877-6}} *'' Seabirds, an Identification Guide'' by Peter Harrison, (1983) {{ISBN|0-7470-1410-8}} *''Handbook of the Birds of the World Vol 1'', Josep del Hoyo editor, {{ISBN|84-87334-10-5}} *"National Audubon Society" ''The Sibley Guide to Birds'', by David Allen Sibley, {{ISBN|0-679-45122-6}}

==External links== *{{Commons category-inline}} *[http://www.birdweb.org/birdweb/bird/mottled_petrel Mottled petrel profile] - Birdweb.org *[http://nzbirdsonline.org.nz/species/mottled-petrel Mottled Petrel, New Zealand Birds Online]

mottled petrel Category:Birds of the South Island mottled petrel mottled petrel

Mottled petrel

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