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 Storm-petrel may refer to one of two bird families, both in the order Procellariiformes, once treated as the same family. The two families are: * Northern storm petrels (''Hydrobatidae'') are found in the Northern Hemisphere, although some speci ...

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

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.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 else ...

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 In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...

. Examination of the

mtDNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA ...

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

islet An islet is a very small, often unnamed island. Most definitions are not precise, but some suggest that an islet has little or no vegetation and cannot support human habitation. It may be made of rock, sand and/or hard coral; may be permanen ...

s in the Azores, with most breeding occurring on the Baixo and Praia islets off the coast of

Graciosa Graciosa Island () (literally "graceful" or "enchanting" in Portuguese) is referred to as the ''White Island'', the northernmost of the Central Group of islands in the Azores. The ovular Portuguese island has an area of , a length of and a width ...

. Like in all

Procellariiformes Procellariiformes is an order (biology), order of seabirds that comprises four family (biology), families: the albatrosses, the Procellariidae, petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still call ...

, 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;
HTML abstract
/ref>

Conservation

The species has a low reproductive output due to competition with other burrowing

petrel Petrels are tube-nosed seabirds in the bird order Procellariiformes. Description The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group (all except the albatross f ...

s, and some years, the young and some prospectors are preyed upon by the

long-eared owl The long-eared owl (''Asio otus''), also known as the northern long-eared owlOlsen, P.D. & Marks, J.S. (2019). ''Northern Long-eared Owl (Asio otus)''. In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook o ...

. 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 Birds of the Azores Endemic fauna of the Azores Monteiro's storm petrel