{"id":116481,"date":"2022-01-11T07:53:10","date_gmt":"2022-01-11T11:53:10","guid":{"rendered":"https:\/\/birdfinding.info\/?p=116481"},"modified":"2022-01-13T09:48:33","modified_gmt":"2022-01-13T13:48:33","slug":"band-rumped-storm-petrel","status":"publish","type":"post","link":"https:\/\/birdfinding.info\/band-rumped-storm-petrel\/","title":{"rendered":"Band-rumped Storm-Petrel"},"content":{"rendered":"\t\t
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\u00a9 David M. Bell<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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\u00a9 Annie B. Douglas \/ Cascadia Research Collective<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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\n\t\t\t\nhttps:\/\/birdfinding.info\/wp-content\/uploads\/2022\/01\/XC304615-Band-rumped-Storm-Petrel-Oceanodroma-castro.mp3<\/a><\/audio>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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\u00a9 James Bradley<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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Birdfinding.info \u21d2<\/em><\/strong>\u00a0 A widespread species, or species group, that is locally common in a few areas, but generally scarce across most of its wide distribution in warm waters of the Atlantic and Pacific Oceans.\u00a0 The winter-breeding North Atlantic form, \u201cGrant\u2019s\u201d<\/strong><\/a>, is common around the Azores, Madeira, and Canary Islands from August to April, and fairly common in U.S. Gulf Stream waters and the Gulf of Mexico from May to August, when the summer-breeding \u201cMadeiran\u201d<\/strong><\/a> replaces it in Madeira and the Canaries.\u00a0 In the South Atlantic, the \u201cGulf of Guinea\u201d<\/strong><\/a> and \u201cSt. Helena\u201d<\/strong><\/a> forms are locally common around the remote islands where they breed.\u00a0 In the Pacific, \u201cDarwin\u2019s\u201d<\/strong><\/a> is common year-round in the Gal\u00e1pagos, and both \u201cHawaiian\u201d<\/strong><\/a> and \u201cJapanese\u201d<\/strong><\/a> can sometimes be found in waters adjacent to their breeding areas from April or May to November.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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Band-rumped Storm-Petrel<\/strong><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Hydrobates castro<\/em><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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Family: Hydrobatidae<\/a><\/strong><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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Breeds on tropical and subtropical islands in the Atlantic and Pacific Oceans; disperses to warm waters of both oceans.<\/strong><\/p>

Under its current (2022) classification, the Band-rumped Storm-Petrel consists of seven or more distinct forms that are potentially separate species: two that breed in the North Atlantic; two in the South Atlantic; and one each in the western, central, and eastern Pacific.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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Approximate global distribution of the various forms of Band-rumped Storm-Petrel.\u00a0 \u00a9 BirdLife International 2018<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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\u201cGrant\u2019s Storm-Petrel\u201d<\/strong><\/a> (ssp. nova): breeds in the Azores, Madeira, Selvagens, Canaries, and Berlengas (beside Portugal) from August to April.<\/p>

\u201cMadeiran Storm-Petrel\u201d<\/strong><\/a> (castro<\/em>): breeds on Madeira, the Selvagens, and Canaries from late March to October.<\/p>

\u201cGulf of Guinea Storm-Petrel\u201d<\/strong><\/a> (ssp. nova): breeds in mountain forests of S\u00e3o Tom\u00e9, apparently year-round.<\/p>

\u201cSt. Helena Storm-Petrel\u201d<\/strong><\/a> (helena<\/em>): breeds on islets around Ascension and St. Helena in seasonally segregated populations\u2014from April to September and from October to March.<\/p>

\u201cJapanese Storm-Petrel\u201d<\/strong><\/a> (kumagai<\/em>): breeds on islets along the northeastern coast of Honshu from May to November.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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\u201cHawaiian Storm-Petrel\u201d, H. c. cryptoleucurus<\/em>, near known breeding colony along the Na Pali Coast of Kauai.\u00a0 (August 23, 2012.) \u00a0\u00a9 Andre Raine<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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\u201cHawaiian Storm-Petrel\u201d<\/strong><\/a> (cryptoleucurus<\/em>): breeds on the main Hawaiian Islands (known mainly from Kauai and the Big Island) from April to November.<\/p>

\u201cDarwin\u2019s Storm-Petrel\u201d<\/strong><\/a> (bangsi<\/em>): breeds in the Gal\u00e1pagos in seasonally segregated populations\u2014from May to October and from December to May.<\/p>

Nonbreeding.<\/em><\/strong>\u00a0 Although incompletely known, the available evidence indicates that a large portion of the \u201cGrant\u2019s Storm-Petrel\u201d population\u2014perhaps the majority\u2014migrates west during April and May to spend the summer months in the Gulf of Mexico and Gulf Stream waters east of North America, where they molt and recover their strength, then depart around August.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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The other three Atlantic forms are not known to migrate.\u00a0 Based on the molt-stage of some individuals and side-by-side comparisons with the predominant \u201cGrant\u2019s\u201d, some of the band-rumped-type storm-petrels that occur each year in the Gulf Stream have been speculatively identified as \u201cMadeiran\u201d, but most such identifications are questionable\u2014due to the difficulty of ruling out juvenile and first-year \u201cGrant\u2019s\u201d, as well as Monteiro\u2019s Storm-Petrel<\/strong><\/a>, which breeds around the same time as \u201cMadeiran\u201d (but on different islands) and has similar molt timing.\u00a0\u00a0Birds from \u201cSt. Helena\u201d populations apparently disperse widely in the tropical mid-South Atlantic.\u00a0 Band-rumped-type storm-petrels presumed to belong to these populations have been observed between approximately 21\u00b0 South and the Equator.\u00a0 The \u201cGulf of Guinea\u201d form may be entirely sedentary.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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\u201cJapanese Storm-Petrel\u201d, H. c. kumagai<\/em>, seems to be the most likely identification (although \u201cHawaiian\u201d, cryptoleurus<\/em>, is also somewhat likely) of band-rumped-type storm-petrels found in the Coral Sea during March and April\u2014such as this one, Australia\u2019s first documented record of Band-rumped Storm-Petrel.\u00a0 (Offshore from Southport, Queensland, Australia; April 8-9, 2016.)\u00a0 Birdline Australia<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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All three Pacific forms appear to migrate or disperse over long distances.\u00a0 The \u201cJapanese\u201d and \u201cHawaiian\u201d populations apparently vacate the breeding grounds from November to April.\u00a0 Recent records of band-rumped-type storm-petrels in the Tasman and Coral Seas during March and April likely to pertain to one or both of these forms\u2014as both are generally absent from their known ranges at that time of year, and are therefore seem likely to migrate a substantial distance away from their breeding grounds.\u00a0 Finally, nonbreeding \u201cDarwin\u2019s\u201d apparently disperses widely in the eastern Pacific, as it has been found regularly north to Costa Rican and Panamanian waters, south to the latitudes of southern Peru and west across the Pacific past the longitude of Easter Island.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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Identification<\/strong><\/span><\/p>

A medium-large storm-petrel that is dark-brown overall, with an even white band across the rump that usually extends partway down the sides of the rump to the undertail.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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The distinct forms, or cryptic species, are visually indistinguishable under most circumstances from one another and from other \u201cband-rumped-type\u201d storm-petrels recently recognized as separate species: i.e., Monteiro\u2019s<\/strong><\/a> and Cape Verde<\/strong><\/a>.\u00a0 (See Notes<\/u><\/strong> below for a comparison of Atlantic band-rumped-type storm-petrels, including Monteiro\u2019s and Cape Verde.)<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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Band-rumped-types strongly resemble storm-petrels of other groups (such as Elliot\u2019s,\u00a0Wilson\u2019s<\/strong><\/a> and Leach\u2019s<\/strong><\/a>), and are best distinguished by their characteristic flight pattern: which is comparatively steady and stable, often gliding on flat wings like a shearwater.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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\u201cGrant\u2019s Storm-Petrel\u201d, H. c.<\/em> ssp. nova\u2014likely this form, in fresh plumage to begin the breeding season.\u00a0 (Banco de la Concepci\u00f3n, Canary Islands, Spain; September 2, 2017.) \u00a0\u00a9 Miguel Rouco<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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\u201cDarwin\u2019s Storm-Petrel\u201d, H. c. bangsi<\/em>, showing typical pattern and gliding flight posture.\u00a0 (Offshore south of Isla San Crist\u00f3bal, Gal\u00e1pagos, Ecuador; November 25, 2019.) \u00a0\u00a9 David M. Bell<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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The white rump-band varies somewhat in width and the extent to which it continues down the sides of the rump to the undertail coverts.\u00a0 These aspects vary within each form, and therefore have limited value in field identification of the forms\u2014although some forms apparently tend to have narrower rump-bands (\u201cGulf of Guinea\u201d) or more extensive white on the undertail (\u201cSt. Helena\u201d).<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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\u201cGrant\u2019s Storm-Petrel\u201d, H. c.<\/em> ssp. nova\u2014likely this form, in fresh plumage to begin the breeding season\u2014note the exceedingly narrow white rump-band, a feature that seems to be subject to individual variation, not diagnostic of any North Atlantic form in the Band-rumped complex.\u00a0 (Banco de la Concepci\u00f3n, Canary Islands, Spain; August 17, 2014.) \u00a0\u00a9 Miguel Rouco<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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\u201cSt. Helena Storm-Petrel\u201d, H. c. helena<\/em>, ventral view showing white extending far down the sides of the undertail.\u00a0 (Offshore from St. Helena; April 18, 2018.) \u00a0\u00a9 John & Jemi Holmes<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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As a general rule, the tails of all forms have a shallow notch, but this feature varies within each form, and its appearance varies widely depending on posture and angle of view.\u00a0 In some cases, the same tail may appear notched, square-tipped, or even wedge-shaped.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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\u201cMadeiran Storm-Petrel\u201d, H. c.<\/em> castro<\/em>, with tail appearing notched in this posture.\u00a0 (Offshore from Bugio, Madeira; June 8, 2011.) \u00a0\u00a9 Simon Colenutt<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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\u201cMadeiran Storm-Petrel\u201d, H. c.<\/em> castro<\/em>, with tail appearing wedge-shaped in this posture.\u00a0 (Offshore from Bugio, Madeira; June 8, 2011.) \u00a0\u00a9 Simon Colenutt<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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Juveniles and freshly molted adults have the most pronounced wingbars.\u00a0 On juveniles the bar appears white.\u00a0 On adults returning to the breeding grounds, the bar is blond.\u00a0 With feather-wear, the bar diminishes and can disappear entirely by the time the next molt begins.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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\u201cGrant\u2019s Storm-Petrel\u201d, H. c.<\/em> ssp. nova, in worn plumage, molting its flight feathers, a condition that is effectively diagnostic of a post-breeding adult \u201cGrant\u2019s\u201d at this season.\u00a0 (Offshore from Cape Hatteras, North Carolina; June 1, 2015.) \u00a0\u00a9 Michael Todd<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t

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\u201cHawaiian Storm-Petrel\u201d, H. c. cryptoleucurus<\/em>, with heavily worn wing-coverts showing weak diagonal bars.\u00a0 (Offshore from Kailua-Kona, Big Island, Hawaii; July 23, 2016.) \u00a0\u00a9 Annie B. Douglas \/ Cascadia Research Collective<\/a><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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Voice.<\/em><\/strong>\u00a0 Two types of calls are heard at breeding colonies: chattering and purring.\u00a0 The sounds are broadly similar from one population to another, but differences in patterns have been instrumental to understanding the relationships among similar-looking forms.<\/p>

Among the North Atlantic forms, the calls of \u201cGrant\u2019s\u201d and \u201cMadeiran\u201d are intermediate in length and complexity between the simpler Monteiro\u2019s and more elaborate Cape Verde. \u00a0Recordings are sparse or unavailable for most of the South Atlantic and Pacific populations, and would certainly illuminate the ongoing taxonomic review.<\/p>

\u201cMadeiran\u2019s\u201d chatter call is squeaky (like rapid rubbing of a fingertip on wet glass):