Monteiro's storm petrel (''Hydrobates monteiroi'') is a

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...

species from the storm petrel

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Hydrobatidae Northern storm petrels are seabirds in the genus ''Hydrobates'' in the family Hydrobatidae, part of the order Procellariiformes. The family was once lumped with the similar austral storm petrels in the combined storm petrels, but have been split ...

. The

cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

was once considered to be conspecific with the

band-rumped storm petrel The band-rumped storm petrel, Madeiran storm petrel, or Harcourt's storm petrel (''Hydrobates castro'') is of the storm petrel family Hydrobatidae. Description The band-rumped storm petrel is 19–21 cm in length with a 43–46 cm wi ...

.M. Bolton, A.L. Smith, E. Gomez-Diaz, V.L. Friesen, R. Medeiros, J. Bried, J.L. Roscales & R.W. Furness (2008) "Monteiro's Storm Petrel ''Oceanodroma monteiroi'': a new species from the Azores" ''Ibis'' 150 (4): 717–727 The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

Taxonomy

The existence of a separate species was first hinted at by the discovery of two distinct breeding seasons of ''Hydrobates'' storm-petrels in the Azores. Both populations were initially thought to be of band-rumped storm petrels; however, one population breeds during the cool season, and the other during the hot season. A closer study of these two breeding populations found differences in their

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

and moult. Examination of the mtDNA found that the two populations were indeed genetically isolated, and the hot-season-breeding population was elevated to full species rank, ''Hydrobates monteiroi'', Monteiro's storm petrel. The species is named for biologist Dr Luis Monteiro, who was the first to notice morphological and acoustic differences between the two seasonal populations from the Azores. It was formerly defined in the genus ''

Oceanodroma Northern storm petrels are seabirds in the genus ''Hydrobates'' in the family Hydrobatidae, part of the order Procellariiformes. The family was once lumped with the similar austral storm petrels in the combined storm petrels, but have been split ...

'' before that genus was synonymized with '' Hydrobates''.

Breeding

Monteiro's storm petrel is only known to breed on a few islets in the Azores, with most breeding occurring on the Baixo and

Praia Praia (, Portuguese language, Portuguese for "beach") is the capital and largest city of Cape Verde.

islets off the coast of Graciosa. Like in all

Procellariiformes Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are of ...

, a single egg is laid and is incubated by both parents. Laying occurs between late April and early July (in contrast to the band-rumped storm petrel, which on these islands lays between October and December). The earliest chicks hatch in June and the last chicks fledge by October. The young will return to the colony from 2 years old onwards.Bried, J., & Bolton M. 2005. An initial estimate of age at first return and breeding in Madeiran Storm Petrels ''Oceanodroma castro''. Atlantic Seabirds 7: 71-74.

Foraging ecology

The species is thought to forage in the local seas all year round, possibly near the breeding sites; this is in contrast to the band-rumped storm petrel, which disperses to the West

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

. The diet of Monteiro's storm-petrel is unknown, but analyses of stable isotopes in the feathers suggest that it differs from that of the band-rumped storm petrel as well. Monteiro's storm-petrels feed at the sea surface, but they can also forage underwater by performing shallow dives of on average.Bried, Joël (2005) Diving ability of the Madeiran Storm Petrel. ''Waterbirds'' 28(2): 162–166. DOI:10.1675/1524-4695(2005)028 162:DAOTMS.0.CO;
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Conservation

The species has a low reproductive output due to competition with other burrowing petrels, and some years, the young and some prospectors are preyed upon by the long-eared owl. The species has been assessed as Vulnerable by the IUCN because of its small population (estimated at 250–300 breeding pairs in 1999 and 328–378 pairs in 2016) and restricted breeding range.

References

{{Taxonbar, from=Q1261907

Monteiro's storm petrel Monteiro's storm petrel (''Hydrobates monteiroi'') is a seabird species from the storm petrel family, Hydrobatidae. The cryptic species was once considered to be conspecific with the band-rumped storm petrel.M. Bolton, A.L. Smith, E. Gomez-Diaz, ...

Birds of the Azores Endemic fauna of the Azores