Markham's Storm-Petrel Hydrobates markhami Scientific name definitions

Fernando Medrano, Benjamin Gallardo, Jacob Drucker, and Alvaro Jaramillo
Version: 3.0 — Published April 12, 2024

Photos from this Account

Markham's Storm Petrel (Hydrobates markhami). 

Small storm-petrel with long, pointed wings and a deeply forked tail. The body is entirely dark sooty brown, except for pale grayish brown upperwing coverts that form a distinct pale bar across the surface of the wings.

Markham's Storm-Petrel (Hydrobates markhami). 

Large sooty gray storm-petrel with deeply forked tail and pale grayish-brown upperwing coverts.

Possible confusion species: Black Storm-Petrel (Hydrobates melania). 

Very similar in size and appearance to Markham's Storm-Petrel; however, the Black Storm-Petrel is differentiated by a shorter bill, rounder head, longer neck, and less deeply forked tail.

Possible confusion species: Black Storm-Petrel (Hydrobates melania). 

Further set apart from Markham's Storm-Petrel by less extensive pale upperwing bar.

Markham's Storm-Petrel (Hydrobates markhami). 

Uniformly sooty gray storm-petrel with pale upperwing bar and deeply forked tail.

Possible confusion species: Leach's Storm-Petrel, Chapman's form (Hydrobates leucorhous chapmani). 

May overlap with Markham's Storm-Petrel off the coast of Ecuador. Differentiated from Leach's Storm-Petrel by having a less deeply forked tail and shorter wings.

Possible confusion species: Leach's Storm-Petrel, Chapman's form (Hydrobates leucorhous chapmani). 

Further distinguished from Markham's Storm-Petrel by smaller body size.

Natal Down in Markham's Storm-Petrel.

Natal down is thick and pale to dark, gray to brownish gray

Juvenile Markham's Storm-Petrel.

The narrow, brownish, and pointed outer primaries and narrow and tapered outer rectrices indicate Juvenile Plumage. Note also the lack of molt clines. The more worn plumage in March suggests that this bird may be from northern breeding populations.

Juvenile Markham's Storm-Petrel.

The same bird as shown to the left; note the narrow, brownish, and pointed outer primaries and narrow and tapered outer rectrices. The underwing coverts become brownish with wear.

Definitive Basic Markham's Storm-Petrel. 

Fresh Definitive Basic Plumage is sooty black above, the head, neck and mantle showing a plumbeous gloss. The median and greater wing coverts, longer scapulars, and tertials are paler, more gray brown, forming a distinct diagonal bar across the extended upperwing, broadest at the carpal joint. Remiges show molt clines, primaries becoming darker and fresher distally, and the outermost secondary (s1) is usually visibly darker and fresher than the innermost primary (p1)

Definitive Basic Markham's Storm-Petrel.

Body feathering becomes browner with wear. Flight feathers and primary coverts are almost black, the white bases of the primary shafts usually visible beyond the primary coverts. Basic outer primaries and rectrices are broader and slightly more truncate at the tips. Note also the molt cline from more worn p1 to fresher p10.

Definitive Basic Markham's Storm-Petrel.

When worn, the upperparts appear tricolored, with brownish back and lesser coverts, paler wing band with wear, and blackish flight feathers; the underparts also become browner with wear. The relatively fresh, blackish, and broad primaries and rectrices indicates Definitive Basic rather than Juvenile Plumage when body feathering is this worn.

Markham's Storm-Petrel commencing Second Prebasic Molt. 

Birds from northern breeding populations undergo the Second Prebasic Molt in September-March, 2-3 months earlier than in adults due to lack of breeding constraints. This individual has commenced molt, with p1-p3 dropped. The worn, pointed, and brown primaries are juvenile feathers indicating that this is the Second as opposed to a Definitive Prebasic Molt.

Markham's Storm-Petrel completing Second Prebasic Molt. 

Distal replacement of primaries has reached p7, and secondries have commenced molt at the tertials, s1 and s5. The extremely abraded condition of the outer primaries indicates juvenile feathers and that this is the Second Prebasic Molt. Timing is consistent with molt in birds from northern breeding populations.

Markham's Storm-Petrel undergoing Definitive Prebasic Molt. 

The broad and relatively fresh, unmolted outer primaries, secondaries, and rectrices, indicates that this is a Definitive rather than the Second Prebasic Molt. Molt reaching p6 in March is consistent with the timing of molt in northern breeding populations.

Adult Markham;s Storm-Petrel.

The bill is relatively long for a storm-petrel and hooked with prominent tubinares at the base of the culmen. At all ages the bill is black, the iris is dark brown, and the legs and feet are slate gray to blackish with black claws.

Juvenile (post fledging) Markham;s Storm-Petrel.

Bare part coloration in juveniles is the same as in adults: the bill is black, the iris is dark brown, and the legs and feet are slate gray to blackish. Claws are sharper in juveniles than in older breeding adults due to lack of digging burrows.

Adult Markham;s Storm-Petrels.

The bill is relaticvely long for a storm-petrel. In the filed, theslate to blackish webbing to the feet can be used to separate Markham's from some other storm-petrels.

Breeding habitat; Arica y Parinacota, Chile. 

Breeds in saltpeter deposits in the the Sechura and Atacama deserts.

Breeding habitat; Arica y Parinacota, Chile. 

Colonies occur in both flat areas and small hills.

Nonbreeding habitat; Chile, Chile. 

During the nonbreeding season, prefers the cool, inshore waters of the Humboldt Current. Can also be found along the Costa Rica and Southern Equatorial Currents.

Entrance to nesting cavity.

Entrances range from 5.5-18 cm wide with an average diameter of 9.33 cm.

Entrances to several nests. 

Nesting cavities are formed from the salt of saltpeter deposits.

Bird at entrance to nesting cavity.

No additional material is added to the nesting cavities.

Chick in nest under 14 days old. 

In the first two weeks of life, chicks have a rounded structure and grayish down covering the entire body.

Chick in nest, 30 days old. 

Thirty days after hatching, chicks exhibit a longer beak, growing primaries, an unfeathered rostrum, and a more elongated body shape.

Chick in nest, 60 days old. 

Sixty days after hatching, chicks may have almost or fully developed primaries and secondary, as well as a large part of the rectrices, an elongated shape, and a beak similar to an adult's.

Chick in nest, 90-100 days old. 

Chicks likely have their bodies almost completely covered with feathers. Only approximately 5 to 10% down is left, usually on the belly, flanks, back, and head

Juvenile affected by lights of Tenardita Mine.

Macaulay Library Photos for Markham's Storm-Petrel

Top-rated photos submitted to the Macaulay Library via eBird. Note: Our content editors have not confirmed the species identification for these photos.

Recommended Citation

Medrano, F., B. Gallardo, J. Drucker, and A. Jaramillo (2024). Markham's Storm-Petrel (Hydrobates markhami), version 3.0. In Birds of the World (T. S. Schulenberg, S. M. Billerman, and B. K. Keeney, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.maspet.03
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