Picaflor de Arica

Picaflor de Arica is a natural monument in northern Chile's Arica y Parinacota Region, established to protect the critically endangered Chilean woodstar hummingbird (Eulidia yarrellii), known locally as the picaflor de Arica. The protected area covers riparian corridors and small oasis habitats in the valleys near the city of Arica, where the species' entire known range is concentrated. With an estimated global population of fewer than 1,000 individuals, the Chilean woodstar is one of the most threatened hummingbirds in the world, and this natural monument represents the primary government response to the acute conservation need for the species.

The Chilean woodstar (Eulidia yarrellii) is the monument's defining species, with males displaying a striking purple-violet gorget. The species inhabits riparian thickets and gardens in the Azapa, Lluta, Vitor, and Camarones valleys within a narrow latitudinal range around Arica. Females are cryptically patterned and often overlooked. The hummingbird depends critically on flowering plants for nectar, particularly native Tecoma fulva (Peruvian trumpet vine) and garden ornamentals. Sympatric hummingbirds include the more abundant Peruvian sheartail. The riparian corridors also support Peruvian pelicans, Inca terns, and various resident and migrant landbirds associated with the lomas (fog oases) and river margins.

The monument protects oasis and riparian vegetation in one of the world's driest desert regions. Native riparian plants include Tessaria integrifolia (aromo macho), Pluchea chingoyo, and Phragmites australis reed beds along the rivers Azapa and Lluta. Tecoma fulva provides critical nectar resources for the Chilean woodstar and is the focus of restoration planting efforts. Invasive tamarisk (Tamarix spp.) and various agricultural plants have altered native riparian structure in many valley sections. The adjacent Atacama Desert is essentially plantless except for isolated lomas communities on coastal slopes where fog precipitation supports seasonal wildflowers including Nolana spp. and tillandsias.

The protected areas lie within the hyperarid Atacama Desert, one of the driest non-polar regions on Earth. The valleys cut through the Coastal Cordillera and the western Andean foothills, exposing Precambrian basement rocks overlaid by Mesozoic marine sediments and Cenozoic volcanic material from the high Andes. The Azapa and Lluta valleys are antecedent river valleys that have incised through uplifted terrain, maintaining their courses as the Andes rose. Alluvial fans and terraces along the valley floors provide the substrates for agricultural oases. The extreme aridity results from the Andes rain shadow, cold Humboldt Current upwelling, and stable subtropical high-pressure systems.

The Arica area records some of the world's lowest rainfall, averaging less than 1 mm per year in the city itself. Mean temperatures range from 14°C in winter to 22°C in summer, moderated by the cold Humboldt Current. Persistent coastal fog (camanchaca) occasionally provides moisture to coastal slopes but rarely penetrates the interior valleys. The Bolivian Winter (invierno boliviano) brings episodic afternoon thunderstorms to the high Andes between December and March, occasionally generating flash floods in valley bottoms. Winds are generally light, with sea breezes common in afternoons. The exceptional aridity and thermal stability make the area one of the most extreme desert climates in South America.

The Azapa and Lluta valleys have been continuously inhabited for over 9,000 years, making this one of the longest settlement sequences in the Americas. Pre-Inca cultures including the Chinchorro (famous for their mummification practices), Tiwanaku-affiliated groups, and later the Inca Empire maintained agricultural oases in the valleys using sophisticated irrigation systems fed by Andean rivers. Spanish colonizers founded the city of Arica in 1541, and the valleys became important supply routes for silver mining operations in Potosí. Following the War of the Pacific (1879–1884), Arica and its hinterlands passed from Peru to Chile. The valleys remain productive agricultural areas cultivating olives, tomatoes, and fruits.

Picaflor de Arica Natural Monument was established by Chile's Corporación Nacional Forestal (CONAF) in direct response to scientific documentation of the Chilean woodstar's catastrophic population decline during the 1990s and 2000s. Surveys revealed the species had lost approximately 80% of its range within a generation due to habitat destruction, pesticide use, and competition from the introduced Oasis hummingbird (Rhodopis vesper). The monument designation aims to provide legal protection for key nesting and foraging sites within the valleys. Conservation programs include habitat restoration with native flowering plants, community education, and monitoring of population trends.

The primary visitor experience involves birdwatching excursions to the Azapa Valley, beginning at the San Miguel de Azapa archaeological museum and continuing along the valley floor where Chilean woodstar sightings are most likely. Early morning hours at flowering Tecoma shrubs offer the best opportunities to observe this rare hummingbird. The Lluta Valley provides additional habitat patches. Arica's coastal attractions, including the historic morro headland fortress and Chinchorro mummy exhibits at the regional museum, complement a visit. The broader Arica y Parinacota Region offers access to Lauca National Park and the high Andean altiplano with flamingo-studded salt lakes.

Arica city serves as the base for visiting the monument, with well-developed hotel, restaurant, and transport infrastructure. The city is accessible by air with regular flights from Santiago (approximately two hours) or by road on the Pan-American Highway. Rental cars and guided birdwatching tours are available in Arica. The Azapa Valley is reached via the Ruta 11 highway, which also continues to the Bolivian border. No dedicated visitor center exists within the natural monument boundaries; birdwatchers typically conduct self-guided walks along the valley agricultural roads or hire local ornithological guides. The Arica San Miguel de Azapa Museum provides archaeological context for the region.

The Chilean woodstar faces existential threats from agricultural pesticide use that kills the insects and flowers it depends upon, habitat loss from urban expansion in the Azapa and Lluta valleys, and competition from introduced hummingbird species. A major conservation concern is the possibility that Picaflor de Arica may hybridize with or be outcompeted by the more adaptable Oasis hummingbird. CONAF, Birdlife International, and Chilean ornithological NGOs collaborate on population monitoring, nest protection programs, and pesticide reduction outreach with valley farmers. Habitat restoration programs planting native flowering species have been implemented at several sites. The monument's small size relative to the species' mobility requires landscape-scale conservation cooperation across the entire valley system.