Systematics Audubon's shearwater

1 systematics

1.1 lherminieri clade (atlantic ocean, caribbean)
1.2 persicus clade (west indian ocean)
1.3 bailloni clade (indian , pacific oceans)
1.4 undetermined

systematics

audubon s shearwater belongs puffinus sensu stricto group of mid-sized , small shearwaters, related genus calonectris. taxonomy of species extremely confusing. listed subspecies of p. assimilis (the little shearwater), not appear closely related. rather, p. lherminieri seems belong ill-resolved clade including such species little shearwater, manx shearwater (p. puffinus) or black-vented shearwater (p. opisthomelas).

the little-known heinroth s shearwater (p. heinrothi) considered subspecies of either audubon s or little shearwater. though member of close-knit group, actual relationships remain uncertain due lack of specimens.

audubon s shearwater has around 10 subspecies. several have @ 1 time or been suggested constitute separate species. example, galápagos islands population has turned out distinct species, galápagos shearwater (p. subalaris); apparently related christmas shearwater (p. nativitatis) , constitutes ancient lineage without other close relatives in genus. other taxa assigned little shearwater , later moved audubon s. analysis of mtdna cytochrome b sequence data – of limited value in procellariiform birds – indicates @ least 3 major clades can distinguished:

the lherminieri clade (atlantic ocean, caribbean)

puffinus lherminieri lherminieri lesson, 1839 – breeds throughout caribbean, on bahamas , formerly on bermuda; ranges throughout caribbean , north american atlantic coast southern canada, vagrants having been recorded off north-eastern canada. small breeding colony found in 1993 in itatiaia islands off vila velha (espírito santo, brazil) belongs subspecies. includes loyemilleri.
barolo shearwater, p. baroli (bonaparte, 1857) – breeds on azores , canary islands (east atlantic); ranges throughout east atlantic around (but north of) tropic of cancer.
boyd s shearwater, puffinus boydi mathews, 1912 – breeds on cape verde islands (east atlantic); ranges throughout east atlantic around (but south of) tropic of cancer.

the former 2 have more white on face , bluish feet little shearwater, formerly placed many taxonomists consider both boyd s , barolo shearwaters distinct species, depending on whether biogeography , morphological differences or genetic similarity considered more significant, , other lineages considered distinct p. lherminieri in particular treatment. southern caribbean birds separated p. l. loyemilleri, not distinct.

the persicus clade (west indian ocean)

puffinus lherminieri persicus



puffinus lherminieri persicus hume, 1837 – breeds on khuriya muriya islands (arabian sea); ranges throughout arabian sea.
puffinus lherminieri temptator louette & herremans, 1985 – breeds on mohéli (comoros); ranges in w indian ocean around northern end of madagascar.

these form distinct clade indicated mtdna sequences, , have time been proposed distinct species, persian shearwater (p. persicus). molecular data alone, seems warranted, ranges of 2 taxa quite far apart, separated forms of third clade. quite obvious on basis of such contradicting data presently available, no decision can taken regarding taxonomic status of these birds. possibly, form distinct species separated third clade different circannual rhythm, known other procellariiform birds. phenotypically distinct, longer bill, dark rump, , more extensive dark on underwing, including mottling in white area.

if p. bailloni accepted distinct species p. persicus not, latter group have included in p. bailloni.

the bailloni clade (indian , pacific oceans)

puffinus lherminieri bailloni (bonaparte, 1857) – breeds on mascarene islands (sw indian ocean); ranges throughout sw indian ocean north of tropic of capricorn, , vagrant birds seen off south africa belong subspecies. includes atrodorsalis.
puffinus lherminieri dichrous finsch & hartlaub, 1867 – breeds throughout central polynesia , possibly melanesia (pacific) , nw indian ocean arabian sea; ranges throughout w indian ocean around equator, , in c pacific equatorial region tropic of capricorn. includes colstoni, nicolae, polynesiae , maybe gunax; vagrants seen off australia belong dichrous or gunax (if valid), while vagrants recorded guam , rota (marianas) might dichrous or bannermani.

this group confusing of all. subspecies dichrous occurs in 2 areas appear separated whole of indonesia , seas surrounding it; pacific subpopulation includes proposed subspecies polynesiae (ta‘ū, american samoa) , possibly gunax (see below), whereas geographically separated indian ocean subpopulation contains birds formerly separated nicolae (nw indian ocean, aldabra maldives) , colstoni (aldabra, arabian sea).

audubon s shearwater puffinus lherminieri bailloni of reunion island.

there appear no significant genetical or morphological differences between these birds, quite amazing given pacific , indian ocean subpopulations must have been isolated long time, , no less 3 unequivocally distinct subspecies (bailloni, persicus , temptator) occur within range of indian ocean dichrous. on other hand, supposed species mascarene shearwater (p. atrodorsalis) inseparable morphologically , genetically bailloni.

clearly, mechanism blocking gene flow @ work, remains unknown – though remarked above, separate breeding seasons seem reasonable assumption , tentatively supported available field data. in addition, entirely mysterious why such mechanism should apply in rather limited , ecologically homogeneous north-western indian ocean range, not in ecologically more diverse , far larger pacific range of dichrous.

these unresolved problems notwithstanding, clade – possibly including preceding 1 – has been proposed constitute separate species, tropical shearwater or baillon s shearwater, puffinus bailloni.

undetermined

puffinus lherminieri bannermani mathews & iredale, 1915 – breeds on ogasawara islands (nw pacific); ranges throughout nw pacific japanese waters equatorial region. vagrants recorded guam , rota (marianas) might dichrous or bannermani.
puffinus lherminieri gunax mathews, 1930 – breeds on banks islands of vanuatu (sw pacific); ranges throughout sw pacific between equatorial region , tropic of capricorn. might belong in dichrous; vagrants seen off australia belong either taxon.

these taxa not included in recent studies due lack of material. case of gunax seems straightforward – can possibly said in absence of new data, belongs bailloni clade either distinct subspecies, or, more likely, yet synonym of dichrous.

the case of more distinct bannermani, range of parapatric of pacific dichrous, more complicated. has time been proposed distinct species, bannerman s shearwater (p. bannermani). in absence of more recent data investigate claim, status continues altogether unresolved, though case being @ least distinct subspecies in bailloni clade seems good.