Markham's Storm-Petrel

识别特征

Markham's storm petrel is a large and slender storm petrel. As in other species of its genus, the wings are slender with tapering tips and a distinct wing bend at the carpus (wrist). The tail is deeply forked. The fresh plumage is black to sooty brown with a dull lead-gray gloss on its head, neck, and mantle. With wear, the plumage becomes browner overall. A distinct crescent-shaped, grayish bar runs diagonally over the upper side of the inner wing. The covert feathers above this bar are often brownish, while the primaries below it are often blackish, resulting in a characteristic three-colored wing pattern. The iris is brown and the bill, legs, and feet are black. The bill is shorter than in most related species, whereas the nasal tube on top of the bill is long, reaching to the mid-length of the beak. Adults have a wingspan between 49 and 54 cm (19 and 21 in) and measure between 21 and 23 cm (8.3 and 9.1 in) from the tip of the bill to the tip of the tail. Body weight is 53 g (1.9 oz) on average. Sexes are alike without morphological differences.<p>Similar birds within its range include the black storm petrel (Hydrobates melania) and the dark variety of Leach's storm petrel (Hydrobates leucorhous). It is especially difficult to distinguish from the similar-sized black storm petrel, from which it differs in having a tarsus that is much shorter than the foot, and in that the gray bar on the upper side of the wing is more distinct and reaches closer to the leading edge of the wing. Markham's storm petrel also differs in its shorter neck and more angular head, and in the more pronounced forking of the tail. From Leach's storm petrel, it differs in its more pronounced tail forking, its longer wings, and larger size. Differences in flight patterns also aid in separating these species. Markham's storm petrel typically flies leisurely and often glides with intermittent shallow wingbeats, whereas the black storm petrel glides less often and tends to use deep wingbeats. Markham's storm petrel also typically flies greater than 1 m (3.3 ft) over the ocean surface, in contrast to the black storm-petrel, which usually flies at less than one meter. Leach's storm petrel generally uses deeper wingbeats and its flight is more bouncing. <p>The calls of Markham's storm petrel have been described as series of "purrs", "wheezes", and "chatters". Adults in nests were found to vocalize when a recording of Markham's storm petrel vocalizations was played at the entrance of the nest cavity.

分类信息

The ornithologist Osbert Salvin first described Markham's storm petrel as Cymochorea markhami in 1883. The species is named after Albert Hastings Markham, a British explorer and naval officer who collected the type specimen off the coast of Peru. In 1931, the ornithologist James L. Peters thought the bird was the same species as Tristram's storm petrel (Oceanodroma tristrami), though the two were later distinguished by the size of their tarsi (the "lower leg" of a bird). Subsequently, Markham's storm petrel was for many years considered a member of the genus Oceanodroma. In 1972, the ornithologist Reginald Wagstaffe considered Tristram's storm petrel a subspecies of Markham's storm petrel, though later research recognized them as different species. <p>In 2004 and 2017, genetic analyses found that the genus Oceanodroma must be merged with the genus Hydrobates, because the only species of Hydrobates, the European storm petrel (Hydrobates pelagicus), was found to be nested within Oceanodroma (i.e., some species of Oceanodroma are more closely related to the European storm petrel than to some other species of Oceanodroma). The name Hydrobates was introduced by the ornithologist Friedrich Boie in 1822 and thus has priority over the name Oceanodroma, which was introduced by the ornithologist Ludwig Reichenbach in 1853. Therefore, all the species in Oceanodroma were transferred to Hydrobates, including Markham's storm petrel, which was accepted by the International Ornithologists' Union. The authors of the 2004 genetic study instead suggested that the species formerly in Oceanodroma should be split into smaller genera, placing Markham's storm petrel and its closest relatives in Cymochorea, but this has not been followed by subsequent studies.<p>A genetic analysis by Wallace and colleagues in 2017 found Markham's storm petrel to be the sister species of the black storm petrel. This was subsequently questioned by Alvaro Jaramillo, who argued that Wallace and colleagues mistook a specimen of the black storm petrel for Markham's storm petrel. Therefore, the relationships of Markham's storm petrel to other members of its genus remain unclear. The following cladogram shows the results of the 2017 study.<p>The northern storm petrel family, Hydrobatidae, is a group of seabirds that is highly adapted to marine environments. Hydrobates is currently recognized as the only genus; its eighteen species are predominantly found in the northern hemisphere. They differ from their southern counterparts, the Austral storm petrels (Oceanitidae), in having proportionally longer wings and shorter heads and legs. Fossils of storm petrels are rare, but have been found in Upper Miocene deposits in California; by this time, the Hydrobatidae had probably extensively radiated. Both storm petrel families are in danger globally, the IUCN classifying 48% of the species as "near threatened" or higher. Markham's storm petrel breeds in extreme habitats in the Atacama desert; this breeding ecology is shared with Elliot's storm petrel and the ringed storm petrel.<p>Separate subspecies have not been identified, but a 2019 study suggested that the difference in breeding time between populations could lead to allochronic speciation (speciation occurring due to different breeding times between populations of a species) in the future. A 2023 study found that there were three well-supported genetic clades of Markham's storm petrel, reflecting the Paracas, Arica, and Salar Grande colonies. The researcher Rodrigo Barros and colleagues described the bird as "one of the least known seabirds in the world" in 2019.

学名

Hydrobates markhami

命名信息

(Salvin, 1883)

目

Procellariiformes

科

Hydrobatidae

属

Hydrobates

分布与栖息地

Markham's storm petrel inhabits waters of the Humboldt Current in the Pacific Ocean off Ecuador, Peru, and northern Chile. As these birds spend most of their lives at sea, they are considered to be endemic to the Humboldt Current. The birds may venture as far north as southern Mexico (18°N); as far south as central Chile (30°S); and as far west as 118°W. Sightings have been reported from even farther north, off Baja California, but these might mistake Markham's storm petrel for the black storm petrel. A survey published in 2007 found that during austral autumn, the non-breeding season, the largest concentration of birds is just off the cost of Peru between Guayaquil and Lima. During spring, this concentration splits into two, with one concentration just off southern Peru and northern Chile, and a second concentration ca. 1,700 km (1,100 mi) to the west. Adults were more common within 200 km (120 mi) of the coast; subadults were more common at distances greater than 500 km (310 mi) from the coast. The birds were more common in the relatively shallow waters above the continental crust (the continental shelf) and less common in the deeper waters above the oceanic crust, and more common in areas where the surface water is cooler and saltier. As a highly pelagic species, the birds are only rarely seen from shore.<p>Despite its range, Markham's storm petrel only nests in Peru and Chile in the Atacama desert, in natural cavities in saltpeter (salt crusts rich in nitrates). The known colonies range in area from 33 to 6,100 ha (82 to 15,073 acres), with a density between 0.5 to 248 nests per hectare. They are typically located within 25 km (16 mi) of the sea, at an elevation of up to 1,080 m (3,540 ft). The nesting habitats are typically flat areas devoid of vegetation, but in 2021, a colony (Punta Patache) was discovered close to a lomas (fog oasis), being the first known colony associated with abundant vegetation. The location of a colony likely depends on favorable wind corridors where the birds can take advantage of sea-land winds when returning to the nest after nightfall and land-sea winds when returning to the sea before dawn.<p>Because the birds only return to their nests after nightfall and fly off again to sea before dawn, the detection of the breeding colonies is difficult, and their location had long been unknown. The first colony, on the Paracas Peninsula of Peru, was only reported in 1993 and is estimated at 2,300 pairs. Five more colonies, all in northern Chile, were discovered between 2013 and 2021. Two separate discoveries occurred in Chile in 2013: one of nesting sites south of the Acha valley in Arica Province and one of a recording of a bird singing. After further exploration in November 2013 based on the recording, populations of 34,684 nests in Arica, 20,000 nests in Salar Grande, and 624 nests in Pampa de la Perdiz were found in the Atacama Desert of northern Chile, as reported in a 2019 study. This translated to about ninety-five percent of the known breeding population at the time. The authors of the study noted that there are two other areas in Chile that could hold colonies based on sightings of grounded fledglings; these would then be the southernmost colonies. The first breeding site of this species in south Peru was reported from Pampa Pie de Candela in 2023.

繁殖区

PO : I. San Gallan and I. Independencia (=La Vieja, w and s of Paracas Pen., sc Peru), Atacama Desert to mts. 50 km inland between Arica and s of Iquique (n Chile)

非繁殖区

ec Pacific to coasts of s Mexico, Galápagos and c Chile

迁徙

Complete migrants

行为

Migration pattern: Complete migrants.

保护状况

Population trend: declining.

种群趋势

declining