Breeding

The species exhibits allochrony, whereby different populations have markedly different breeding phenologies (23 Barros, R., F. Medrano, H. V. Norambuena, R. Peredo, R. Silva, F. de Groote and F. Schmitt (2019) Breeding phenology, distribution and conservation status of Markham's Storm-Petrel Oceanodroma markhami in the Atacama Desert. Ardea 107: 75–84. Close ). Even within colonies, breeding is not synchronous among pairs. In the colonies of Paracas, Arica, and Salar de Quiña, territory marking happens between April and August, and egg-laying starts for some pairs in April but continues for other pairs until August. Given the protracted period of territory marking and egg-laying, the chick-rearing stage occurs between July and January, and the fledglings leave the nest between October and January, with small numbers of birds fledging in February (23 Barros, R., F. Medrano, H. V. Norambuena, R. Peredo, R. Silva, F. de Groote and F. Schmitt (2019) Breeding phenology, distribution and conservation status of Markham's Storm-Petrel Oceanodroma markhami in the Atacama Desert. Ardea 107: 75–84. Close , 32 Medrano, F., R. Silva, R. Barros, D. Terán, R. Peredo, B. Gallardo, P. Cerpa, F. de Groote, P. Gutiérrez, and I. Tejeda (2019). Nuevos antecedentes sobre la historia natural y conservación de la golondrina de mar negra (Oceanodroma markhami) y la golondrina de mar de collar (Oceanodroma hornbyi) en Chile. Revista Chilena de Ornitología 25:21-30. Close ).

In the colonies of Caleta Buena (also known as Pampa Perdiz), Salar Grande, and Salar de Navidad, which are only 140-240 km south of the Arica colony, breeding activity starts with pairs marking territories between November and January. Egg-laying occurs between November and (presumably) March. Chick rearing occurs between January and April, with fledglings leaving the nest between March and June (23 Barros, R., F. Medrano, H. V. Norambuena, R. Peredo, R. Silva, F. de Groote and F. Schmitt (2019) Breeding phenology, distribution and conservation status of Markham's Storm-Petrel Oceanodroma markhami in the Atacama Desert. Ardea 107: 75–84. Close , 32 Medrano, F., R. Silva, R. Barros, D. Terán, R. Peredo, B. Gallardo, P. Cerpa, F. de Groote, P. Gutiérrez, and I. Tejeda (2019). Nuevos antecedentes sobre la historia natural y conservación de la golondrina de mar negra (Oceanodroma markhami) y la golondrina de mar de collar (Oceanodroma hornbyi) en Chile. Revista Chilena de Ornitología 25:21-30. Close ).

The reasons behind the allochrony between the colonies are unclear, but it could be related to ecological divergence. More information is needed to understand if both populations use the same resources and areas.

Microhabitat

Colonies are built into crevices and holes in saltpeter deposits, on sloping ground within 25 km of the ocean (2 Brooke, M. (2004). Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. Close , 26 Jahncke, J. (1993). Primer informe del área de anidación de la Golondrina de la Tempestad Negra Oceanodroma markhami (Salvin, 1883). In Memoria del X Congreso Nacional de Biología, Lima, Peru, 2–7 agosto 1992 (E. Castillo de Maruenda, Editor) Colegio de Biólogos del Perú, Lima. pp. 339–343. In Spanish. Close , 23 Barros, R., F. Medrano, H. V. Norambuena, R. Peredo, R. Silva, F. de Groote and F. Schmitt (2019) Breeding phenology, distribution and conservation status of Markham's Storm-Petrel Oceanodroma markhami in the Atacama Desert. Ardea 107: 75–84. Close , 32 Medrano, F., R. Silva, R. Barros, D. Terán, R. Peredo, B. Gallardo, P. Cerpa, F. de Groote, P. Gutiérrez, and I. Tejeda (2019). Nuevos antecedentes sobre la historia natural y conservación de la golondrina de mar negra (Oceanodroma markhami) y la golondrina de mar de collar (Oceanodroma hornbyi) en Chile. Revista Chilena de Ornitología 25:21-30. Close ).

Structure and Composition

Birds lay their egg inside the saltpeter cavities without any additional material (26 Jahncke, J. (1993). Primer informe del área de anidación de la Golondrina de la Tempestad Negra Oceanodroma markhami (Salvin, 1883). In Memoria del X Congreso Nacional de Biología, Lima, Peru, 2–7 agosto 1992 (E. Castillo de Maruenda, Editor) Colegio de Biólogos del Perú, Lima. pp. 339–343. In Spanish. Close , 23 Barros, R., F. Medrano, H. V. Norambuena, R. Peredo, R. Silva, F. de Groote and F. Schmitt (2019) Breeding phenology, distribution and conservation status of Markham's Storm-Petrel Oceanodroma markhami in the Atacama Desert. Ardea 107: 75–84. Close ). These cavities are formed by salt. In some cases, birds may breed between the old mummies of failed fledglings.

Dimensions

In Paracas, the entrance has an average diameter of 9.33 cm, with a range of 5.5–18 cm (26 Jahncke, J. (1993). Primer informe del área de anidación de la Golondrina de la Tempestad Negra Oceanodroma markhami (Salvin, 1883). In Memoria del X Congreso Nacional de Biología, Lima, Peru, 2–7 agosto 1992 (E. Castillo de Maruenda, Editor) Colegio de Biólogos del Perú, Lima. pp. 339–343. In Spanish. Close ). In Arica, the entrance has an average width of 9.8 cm and a height of 6.4 cm, and the nest is located 53.8 cm from the entrance (Gallardo et al., unpublished data).

Size

The mean size of eggs is 32.2 x 24.2 mm (n = 155; 26 Jahncke, J. (1993). Primer informe del área de anidación de la Golondrina de la Tempestad Negra Oceanodroma markhami (Salvin, 1883). In Memoria del X Congreso Nacional de Biología, Lima, Peru, 2–7 agosto 1992 (E. Castillo de Maruenda, Editor) Colegio de Biólogos del Perú, Lima. pp. 339–343. In Spanish. Close ).

Color and Surface Texture

White (26 Jahncke, J. (1993). Primer informe del área de anidación de la Golondrina de la Tempestad Negra Oceanodroma markhami (Salvin, 1883). In Memoria del X Congreso Nacional de Biología, Lima, Peru, 2–7 agosto 1992 (E. Castillo de Maruenda, Editor) Colegio de Biólogos del Perú, Lima. pp. 339–343. In Spanish. Close ).

Clutch Size

Only a single egg is laid (26 Jahncke, J. (1993). Primer informe del área de anidación de la Golondrina de la Tempestad Negra Oceanodroma markhami (Salvin, 1883). In Memoria del X Congreso Nacional de Biología, Lima, Peru, 2–7 agosto 1992 (E. Castillo de Maruenda, Editor) Colegio de Biólogos del Perú, Lima. pp. 339–343. In Spanish. Close ).

Incubation Period

In Paracas, incubation averages 47 days (range 37-70 days, n = 28; 26 Jahncke, J. (1993). Primer informe del área de anidación de la Golondrina de la Tempestad Negra Oceanodroma markhami (Salvin, 1883). In Memoria del X Congreso Nacional de Biología, Lima, Peru, 2–7 agosto 1992 (E. Castillo de Maruenda, Editor) Colegio de Biólogos del Perú, Lima. pp. 339–343. In Spanish. Close ).

Parental Behavior

Both the male and female share incubation duties. In Paracas, incubation shifts lasted three days or less (26 Jahncke, J. (1993). Primer informe del área de anidación de la Golondrina de la Tempestad Negra Oceanodroma markhami (Salvin, 1883). In Memoria del X Congreso Nacional de Biología, Lima, Peru, 2–7 agosto 1992 (E. Castillo de Maruenda, Editor) Colegio de Biólogos del Perú, Lima. pp. 339–343. In Spanish. Close ). No details on the breeding colonies in Chile.

Condition at Hatching

When chicks hatch, they are covered in gray down feathers.

Growth and Development

The following description is based on unpublished data by B. Gallardo et al.: When the chicks hatch, they can usually be observed next to or under their parent (the pair is never found when the egg hatches) and sometimes have eggshells stuck to their down; most have closed eyes and fragile necks. In the first two weeks, the most evident changes are the general growth of the body, adopting a more rounded structure but maintaining the grayish down that covers the entire body. Near 30 days after hatching, they lose down from the face and begin to show the first pins in the primaries, which will later become their first flight feathers. After 30 days of hatching, the primaries are growing, with pins on the rectrices, an unfeathered rostrum, a longer beak, and a more elongated general structure. After 60 days of life, 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. At least 90-100 days after hatching, individuals may have their bodies almost completely covered with feathers and approximately 5 to 10% down, especially on the belly, flanks, back, and head, allowing them to leave the nest for the first time.

Sex Ratios and Sex Allocation

Information is needed.

Both parents incubate the egg and take part in rearing the chicks (23 Barros, R., F. Medrano, H. V. Norambuena, R. Peredo, R. Silva, F. de Groote and F. Schmitt (2019) Breeding phenology, distribution and conservation status of Markham's Storm-Petrel Oceanodroma markhami in the Atacama Desert. Ardea 107: 75–84. Close ).

This species, as all known storm-petrels, does not breed cooperatively (39 Winkler, D. W., S. M. Billerman, and I. J. Lovette (2020). Northern Storm-Petrels (Hydrobatidae), version 1.0. In Birds of the World (S. M. Billerman, B. K. Keeney, P. G. Rodewald, and T. S. Schulenberg, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.hydrob1.01 Close ).

Unknown but very unlikely.

Departure from the Nest

Chicks take 90-110 days between hatching and fledging (Gallardo et al., unpublished data).