Masatierra Petrel
Pterodroma defilippiana
Small but rather stocky and stout-billed petrel of subtropical eastern Pacific and Humboldt Current; not seen from mainland. One of several similar species, Masatierra is best identified by gray head and collar at sides of neck, rather stout bill, and plain grayish tail without a black tip. Much smaller than Juan Fernandez Petrel with quick wheeling flight unlike more easy and less hurried-looking flight of Juan. Also compare with Stejneger’s and Cook’s Petrels.
Identification
Masatierra petrel grows to a length of about 26 centimetres (10 in). Its cap and mask are dark grey while its forehead is white. It has dark grey plumage on its upperparts with a distinctive "M" mark, a paler grey partial collar and a white throat, belly and under wing-coverts. When seen from below, the wings have black tips and black trailing edges.
Taxonomy
- Scientific name
- Pterodroma defilippiana
- Authority
- (Giglioli & Salvadori, 1869)
- Order
- Procellariiformes
- Family
- Procellariidae
- Genus
- Pterodroma
Range and habitat
Masatierra petrel spends the greatest part of the year at sea in the eastern Pacific Ocean south of the equator where the Humboldt Current causes a major upwelling of nutrient-rich cold water. Here the bird feeds by skimming across the surface of the water and scooping up prey on the wing. It nests in two island groups off the coast of Chile. On the Desventuradas Islands, the largest colony is on San Ambrosio where more than 10,000 birds were estimated to be present in 1970. San Félix also had 150 to 200 nesting pairs at that time. On the Juan Fernández Islands, the bird is no longer believed to be nesting on Robinson Crusoe Island but Santa Clara Island had a few hundred birds present in 1991, a number not likely to increase because there is limited availability of suitable nesting sites on the island.
- Breeding range
- PO : San Ambrosio and San Felix (Desventuradas Is., far w of nc Chile) and Santa Clara (sw of Robinson Crusoe=Mas a Tierra, Juan Fernandez Is., far w of c Chile)
- Non-breeding range
- to coastal waters of s Peru and n, c Chile and to Pitcairn group (e Polynesia)
- Migration
- Complete migrants
Conservation
- Population trend
- stable
Photos
Distribution
Other Birds
Rufous-gorgeted Flycatcher
Ficedula strophiata
A bold little flycatcher of mid- to high-altitude forests with a flashing black-and-white tail. Male is brown above with a black face, white eyebrow, and orange throat patch (gorget). The female is essentially a faded version of the male with a dark gray face and a pale, largely unnoticeable gorget. Usually perches at middle levels, sallying from its perch to catch flying insects. Often joins mixed-species feeding flocks.
Peregrine Falcon
Falco peregrinus
Sleek, fast-flying large falcon. Always look for a grayish back in adults, long wings that almost reach the tail tip, and powerful but slender build. Dark mark below each eye varies in shape and size. Juveniles are more heavily patterned below than adults, and can be quite brownish above. Patterning varies considerably across a wide global range, with back color ranging from pale gray in Central Asian “Red-capped” to slaty-blue across much of northern Eurasia North America, to almost black in Asian “Shaheen.” Chases prey down at high speeds with continuous powerful wingbeats. Becoming increasingly common in parts of range, especially in cities, where they can nest on tall buildings and feed on pigeons. Adaptable, and can be seen in a wide range of habitats; often encountered in areas with steep cliffs, as well as around coastal mudflats and open areas with shorebirds.
White-throated Shrike-Tanager
Lanio leucothorax
Large, long-tailed tanager with heavy hooked bill. Striking plumage is reminiscent of an oriole: yellow body with black head, black wings, white throat, and white shoulder patch. Female brown with paler throat and yellow belly. Note especially bill shape and habitat. Found in forests, usually at moderate heights, often in pairs leading a mixed-species flock.
Start Your Bird Watching Journey
Identify a bird outdoors and keep the field guide close for your next observation.