Swinhoe's Storm-Petrel Hydrobates monorhis Scientific name definitions

18–20 cm (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ); 25·6–53·5 g (2 Choi, C.-Y., Nam, H.-Y., Park, J.-G. and Lee, K.-G. (2011). Swinhoe’s Storm Petrels (Oceanodroma monohris) show no apparent sexual dimorphism in size and color. Orn. Sci.. 10: 145–149. Close ); wingspan 44–50 cm (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ). Medium-sized dark brownish storm-petrel with notched tail  , small head  , and some white shafts at base of primaries. Dark sooty-brown to dark grey-brown plumage, often greyer on head and neck  , paler on upperwing panel  across outer and central median coverts, all greater coverts and tips of tertials; this panel is not small but often weakly defined  ; white shafts at base of 5–6 outer primaries visible on upperwing at close range; iris dark brown; bill black; legs and feet black. Sexes alike, female averages slightly larger in wing and tail measurements but differences not statistically significant (2 Choi, C.-Y., Nam, H.-Y., Park, J.-G. and Lee, K.-G. (2011). Swinhoe’s Storm Petrels (Oceanodroma monohris) show no apparent sexual dimorphism in size and color. Orn. Sci.. 10: 145–149. Close ). Juvenile similar to adult, but will be in fresh plumage during boreal autumn/winter when adult heavily worn or in wing moult (1 Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, New Jersey, USA. Close ). Slightly smaller and smaller-headed than H. markhami and H. melania, tail notched rather than forked, while head often looks greyer rather than blacker compared to body colour; differs from H. tristrami and apparently dark-rumped individuals of H. leucorhous in smaller head, slimmer general appearance , notched rather than forked tail  , narrower wing with often less contrasting bar on its upper surface (though latter character variable) usually not reaching to bend of wing, at close range also by pale shafts at exposed bases of outer five (or six) primaries, and from former also by smaller size.

Tropical Indian and W Pacific Oceans: breeds from Japan (islets off Kyushu and Honshu) W to Yellow Sea off China and Korea, and N to extreme SE Russia. Recent records suggest possible breeding in N Atlantic.

Marine and normally pelagic, but also occurs in coastal waters. Breeds on small offshore islands, on Kutsujima Is, Japan, within evergreen forest dominated by Machilus thunbergii, with Camellia japonica and Ilex integra trees (5 Sato, F., Karino, K., Oshiro, A., Sugawa, H. and Hirai, M. (2010). Breeding of Swinhoe’s Storm-Petrel Oceanodroma monorhis in the Kutsujima Islands, Kyoto, Japan. Marine Orn.. 38(2): 133–136. Close ); off Korea, vegetation on breeding islands is typically dominated by Carex boottiana (2 Choi, C.-Y., Nam, H.-Y., Park, J.-G. and Lee, K.-G. (2011). Swinhoe’s Storm Petrels (Oceanodroma monohris) show no apparent sexual dimorphism in size and color. Orn. Sci.. 10: 145–149. Close ).

Migrates S & W to winter in N Indian Ocean (W to off Somalia) and Arabian Sea; irregular in Red Sea, straggling N to Eilat in Gulf of Aqaba (Jan 1958, Sept 2001, Apr 2003, Sept 2016) (6 Yosef, R., Rydberg-Heden, M. and Nikolajsen, R. (2003). Second record of Swinhoe’s Storm-petrel Oceanodroma monorhis at Eilat, Israel. Sandgrouse. 25(2): 150–151. Close , 7 Granit, B. and Smith, J.P. (2004). Another Swinhoe’s Storm-petrel Oceanodroma monorhis at Eilat. Sandgrouse. 26(1): 51–53. Close , 8 Ławicki, L., and A. B. van den Berg (2016). WP reports. Dutch Birding 38(6):393–408. Close ). Recorded off Oman between late May and late Dec, usually in small numbers, but once c. 100 (Nov 1997) following a cyclone (9 Eriksen, J., and R. Victor (2013). Oman Bird List: the Official List of the Birds of the Sultanate of Oman. Seventh edition. Sultan Qaboos University, Muscat, Oman. Close ). Off SW India, records (not all of them confirmed) are available from most months, mainly Mar–Oct (10 Vivek Chandran, A., Praveen, J., Sreenivasan, P.P., Nameer, P.O. and Dilip, K.G. (2011). Swinhoe’s Storm-petrel Oceanodroma monorhis and other pelagic birds from the Thrissur coast, Kerala. Indian Birds. 7(3): 73–74. Close , 11 Praveen, J., R. Jayapal, and A. Pittie (2013). Notes on Indian rarities–1: Seabirds. Indian Birds 8(5):113–125. Close ). Commonest storm-petrel in Strait of Malacca (12 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ), where pronounced eastbound passage observed in Sept–Oct, westbound in Apr–May (13 Rajathurai, S. (1996). The birds of Batam and Bintan Islands, Riau Archipelago. Kukila 8:86–113. Close , 14 Rajathurai, S. (1997). First record of White-faced Storm-petrel in the Riau Archipelago. Kukila. 9: 175–176. Close ) (exceptionally until late Jun) (15 Robson, C. (2014). From the field. BirdingASIA. 21:121–127. Close ), with large numbers recently confirmed moving through neighbouring Singapore Strait in Sept–Nov and May (exceptionally mid Jun), including single-day maxima of 510 and 470 in mid Sept (16 Poole, C.M., Davison, G.W.H. and Rajathurai, S. (2014). Marine surveys to study the movements of seabirds through the Singapore Strait 289189–28913. Forktail. 30: 5–9. Close ), and has been claimed as far E as between Ambon and Buru (Sept) (17 Lansley, P. S., C. Lester, and S. Dashper (2011). Bird observations in the south Moluccas, Indonesia, in 2009 with new migration, breeding and altitudinal records. BirdingASIA 15:68–70. Close ) and Tayandu Is (Aug), Maluku (Indonesia) (18 Johnstone, R. E., and S. (B.) van Balen (2013). The birds of the Kai and Tayandu Islands, Maluku region, Indonesia. Western Australian Naturalist 29(1):11–56. Close ), as well as between Tanahjampea and Pantar, at S edge of Banda Sea (Oct) (19 Robson, C. (2012). From the field. BirdingASIA. 18: 112–119. Close ). Single unaccepted record off SE Alaska in Aug 2003 (20 Howell, S. N. G., I. Lewington, and W. Russell (2014). Rare Birds of North America. Princeton University Press, Princeton, NJ, USA. Close ) and one definite record in the Philippines (off Palawan, May 2013) (21 Jensen, A. E., T. H. Fisher, and R. O. Hutchinson (2015). Notable new bird records from the Philippines. Forktail 31:24–36. Close ). Occurrences in NE Atlantic  , where first identified in 1983 (although an 1829 Madeira record is sometimes attributed to this species) (22 Morrison, S.J. (1998). All-dark petrels in the North Atlantic. British Birds. 91(12): 540–560. Close ) and genetic and vocal analyses were used to confirm identity of some birds on caught on land (23 Cubitt, M., Carruthers, M. and Zino, F. (1992). Unravelling the mystery of the Tyne petrels. Birding World. 5(11): 438–442. Close , 24 Dawson, R. (1992). Blood, sweat and petrels. Birding World. 5(11): 443–444. Close ), now widely assumed to indicate presence of (presumably) tiny breeding population there, rather than being vagrants from Pacific breeding colonies that had entered the Atlantic via Cape of Good Hope (as was originally postulated) (25 Bourne, W. R. P. (1992). Debatable British and Irish seabirds. Birding World 5(10):382–390. Close ) or crossed from the Red Sea to Mediterranean overland (26 King, J. and Minguez, E. (1994). Swinhoe’s Petrel: the first Mediterranean record. Birding World. 7(7): 271–273. Close ); some NW European records of dark-rumped storm-petrels that have been suggested to have involved present species subject to considerable controversy, most notably a bird off SW England in Aug 1988, which has been variously attributed to present species, H. tristrami, H. matsudairae or even Bulwer’s Petrel (Bulweria bulwerii) (22 Morrison, S.J. (1998). All-dark petrels in the North Atlantic. British Birds. 91(12): 540–560. Close , 27 Garner, M. and Mullarney, K. (2004). A critical look at the evidence relating to ‘the Chalice petrel’. British Birds. 97(7): 336–345. Close , 28 Earp, W. (2005). ‘The Chalice petrel’ revisited British Birds. 98(1): 43–44. Close , 29 Flood, R. L. (2009). ‘All-dark’ Oceanodroma storm-petrels in the Atlantic and neighbouring seas. British Birds 102(7):365–385. Close ). Northernmost European records on Fair Isle (Scotland), in Aug 2013 (30 Nightingale, B. and Hussey, H. (2013). Recent reports. British Birds 106(9):560–562. Close ). Recently (since 1993) also recorded four times off E North America (Jun to mid Aug), during pelagic trips from Cape Hatteras, North Carolina (31 Howell, S. N. G., and J. B. Patteson (2008). A Swinhoe’s Petrel off North Carolina, USA and a review of dark storm-petrel identification. Birding World 21(6):255–262. Close , 20 Howell, S. N. G., I. Lewington, and W. Russell (2014). Rare Birds of North America. Princeton University Press, Princeton, NJ, USA. Close ), and there are possible records of this species from as far S as off Mauritania (Jan 1990) (32 Bourne, W.R.P. (2010). Dark-rumped storm-petrels and others. British Birds. 103(1): 65–66. Close ).

No information available on diet. Feeds mainly on wing by dipping; does not patter. In Maldives, has been observed scavenging in company of feeding pod of false killer whales (Pseudorca crassidens) (33 Anderson, R. C., and M. Baldock (2001). New records of birds from the Maldives with notes on other species. Forktail 17:67–73. Close ).

Two main vocalizations, a purring call given from within burrow (and presumably also ground), which is given only by males (very similar to that of H. tristrami) (34 Marks, J.S. and Leasure, S.M. (1992). Breeding biology of Tristram’s Storm-Petrel on Laysan Island. Wilson Bull.. 104(4): 719–731. Close ), and sexually dimorphic chattering call (longer and more complex than in H. leucorhous) (23 Cubitt, M., Carruthers, M. and Zino, F. (1992). Unravelling the mystery of the Tyne petrels. Birding World. 5(11): 438–442. Close ) given in flight and on ground, in which male sounds cover a broad frequency range whereas females possess clear harmonic structure (35 Taoka, M. and Okumura, H. (1990). Sexual differences in flight calls and the cue for vocal sex recognition of Swinhoe’s Storm-Petrels. Condor. 92(3): 571–575. Close , 12 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Studies suggest that it is the harmonic structure of the chattering call, rather than its rhythm, that serves as the cue for sex recognition (35 Taoka, M. and Okumura, H. (1990). Sexual differences in flight calls and the cue for vocal sex recognition of Swinhoe’s Storm-Petrels. Condor. 92(3): 571–575. Close ). Silent at sea.

Very poorly known. Starts Apr, with egg-laying in May–Jun, sometimes as late as early Jul (12 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Forms loose colonies; nests in burrows. Clutch single egg.

Not globally threatened. Currently considerd Near Threatened. Much work required to determine population sizes and trends, main threats and conservation requirements. Global population speculated to perhaps number anything between 30,000 and > 130,000 pairs (12 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close , 5 Sato, F., Karino, K., Oshiro, A., Sugawa, H. and Hirai, M. (2010). Breeding of Swinhoe’s Storm-Petrel Oceanodroma monorhis in the Kutsujima Islands, Kyoto, Japan. Marine Orn.. 38(2): 133–136. Close ). Largest known colony on Verkhovsky I, S of Vladivostok, with c. 7500–8370 pairs, with c. 100 additional pairs on small nearby islands; substantial predation by crows (Corvus) and migrating owls (Asio), but no mammals; frequent visits by tourists resulted in many nest losses, until protection of island in 1984. Only other known colony off Russia, on Karamzin I, also in Sea of Japan, numbers just 30–40 pairs (12 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ). Minimum 5000 pairs in Japan, on islands off Honshu, Shikoku and Kyushu, including from N to S, Okino-shima (180 pairs), Oki-shoto (unknown numbers), Kutsujima Is (c. 3800 pairs in late 2000s), Hachijo-jima, Izu Is (< 200 pairs), Nanatsu-shima (unconfirmed), Sangan-jima (< 200 pairs), Benten-jima (colony probably extinct) (5 Sato, F., Karino, K., Oshiro, A., Sugawa, H. and Hirai, M. (2010). Breeding of Swinhoe’s Storm-Petrel Oceanodroma monorhis in the Kutsujima Islands, Kyoto, Japan. Marine Orn.. 38(2): 133–136. Close ), and possibly also in Ryukyu Is (12 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ); little known of populations in China (off Shandong, Guangdong), off Taiwan (36 Brazil, M. (2009). Field Guide to the Birds of East Asia: Eastern China, Taiwan, Korea, Japan and Eastern Russia. Christopher Helm, London, UK. Close ) and off S & W Korean Peninsula, where there is an estimated 7900–11,890 pairs on Chi’lbal I (12 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close ) and c. 112,000 pairs on Kugul I (5 Sato, F., Karino, K., Oshiro, A., Sugawa, H. and Hirai, M. (2010). Breeding of Swinhoe’s Storm-Petrel Oceanodroma monorhis in the Kutsujima Islands, Kyoto, Japan. Marine Orn.. 38(2): 133–136. Close ). Also known to breed on Guguldo Is, off Korea (2 Choi, C.-Y., Nam, H.-Y., Park, J.-G. and Lee, K.-G. (2011). Swinhoe’s Storm Petrels (Oceanodroma monohris) show no apparent sexual dimorphism in size and color. Orn. Sci.. 10: 145–149. Close ). Recent survey for seabirds on islands off Zhejiang coast (China) failed to discover any evidence of the species breeding there (37 Fan, Z., Chen, C., Chen, S., Chan, S. and Lu, Y. (2011). Breeding seabirds along the Zhejiang coast: diversity, distribution and conservation. Chinese Birds. 2(1): 39–45. Close ) and only breeding site off Guangdong harbours only c. 100 pairs (5 Sato, F., Karino, K., Oshiro, A., Sugawa, H. and Hirai, M. (2010). Breeding of Swinhoe’s Storm-Petrel Oceanodroma monorhis in the Kutsujima Islands, Kyoto, Japan. Marine Orn.. 38(2): 133–136. Close ), but 2500 birds were ringed on Dagong I, off Qingdao, Shandong, during recent surveys; this island is also subject to some tourist pressures (38 Cai, Z.J. (1998). [A study on breeding and migration of Swinhoe’s Storm-Petrel]. Chinese J. Zool.. 33(1): 19–22. (In Chinese). Close ). In Japan, colony on Koyashima I, Okino-shima, decimated by accidentally introduced brown rats (Rattus norvegicus) and has still to fully recover, despite subsequent removal of the rats (5 Sato, F., Karino, K., Oshiro, A., Sugawa, H. and Hirai, M. (2010). Breeding of Swinhoe’s Storm-Petrel Oceanodroma monorhis in the Kutsujima Islands, Kyoto, Japan. Marine Orn.. 38(2): 133–136. Close ). Possibly also breeds in NE Atlantic, e.g. on Salvagem Grande (Madeira), where one was trapped each Aug over three consecutive years in 1990s (including once with brood patch) (39 Zino, F. (1999). Madeiran seabirds and missing limbs. British Birds. 92(9): 485. Close ), or the Canaries (one caught ashore with a brood patch in 2009) (40 Gutiérrez, R. and Lorenzo, J.A. (2010). Swinhoe’s Storm-petrels in Spanish waters. British Birds. 103(1): 66. Close ), but perhaps also the Azores (where species only recently recorded, Aug 2012) (41 van den Berg, A. B., and M. Haas (2012). WP reports. Dutch Birding 34(5):320–335. Close ) or Cape Verdes (where it is still unknown) (42 Bretagnolle, V., Carruthers, M., Cubitt, M., Bioret, F. and Cuillandre, J.P. (1991). Six captures of a dark-rumped, fork-tailed storm-petrel in the northeastern Atlantic. Ibis. 133(4): 351–356. Close ), and there is also a record (Jul 1994) of one in a colony of H. pelagicus on an islet off Benidorm (Spain) in the Mediterranean (26 King, J. and Minguez, E. (1994). Swinhoe’s Petrel: the first Mediterranean record. Birding World. 7(7): 271–273. Close ). Records from Selvagem Grande include two potential pairs found and sound recorded in 2008 at different sites, one of them duetting in a burrow, but capture/recapture patterns suggest that a possible breeding population is small and likely not self-sustaining; moreover, the high haplotypic diversity of the sampled individuals (six during 2007–2013) suggests that most were immigrants (43 Silva, M.C., Matias, R., Ferreira, V., Catry, P. and Granadeiro, J.P. (2015). Searching for a breeding population of Swinhoe’s Storm-petrel at Selvagem Grande, NE Atlantic, with a molecular characterization of occurring birds and relationships within the Hydrobatinae. Journal of Ornithology. 157(1): 117–123. Close ).