In 1854, an American ship captain discovered what fortune seekers were finding on remote islands throughout the Pacific and Caribbean: guano, accumulated in quantities worth mining. Bird droppings, rich in nitrogen and phosphorus, were among the most valuable agricultural commodities of the 19th century. Systematic collection began almost immediately. When the Dutch and Venezuelan governments found out, both protested. The Dutch sent a warship; its captain found Americans loading guano and informed them that the Netherlands considered Aves its territory. In 1857, three Boston men -- Shelton, Samson, and Tappan -- formally annexed the island under the recently passed Guano Islands Act of 1856, which authorized American citizens to claim uninhabited islands containing guano deposits. The Venezuelans objected. The Administrator of Sint Eustatius, meanwhile, granted his own guano concession to a Baltimore firm at two and a half guilders per ton, arguing that the inhabitants of Statia and Saba had used the island "longer than anyone can remember." Businessmen on Dutch Sint Maarten filed competing claims. A tiny sand spit had become the center of an international legal tangle.

Faced with overlapping claims they could not resolve themselves, the Dutch and Venezuelan authorities agreed on an unusual solution: they would ask a mutually acceptable sovereign to arbitrate. Queen Isabella II of Spain took the case and ruled in 1865 in Venezuela's favor. Her judgment, however, acknowledged the longstanding rights of inhabitants from Sint Eustatius, Saba, and Sint Maarten to fish in the waters around Aves -- the central concern for the Dutch, who accepted the ruling. Some Dutch historians later suggested that Isabella's advisors may have confused Isla de Aves with the Las Aves Archipelago, a different group of islands lying between Bonaire and Los Roques much closer to the Venezuelan coast. Whether or not the confusion was real, the ruling stood. American guano miners returned from 1878 to 1912, working the deposits until supplies were exhausted. President Joaquin Crespo included Isla de Aves in Venezuela's 1895 territorial reorganization, and in 1950 the Venezuelan Navy dispatched two patrol boats and a transport to formally establish control.

Under the United Nations Convention on the Law of the Sea, the distinction between a "rock" and an "island" carries enormous consequences. A rock grants its owner a twelve-nautical-mile economic zone. An island grants 200 nautical miles. Venezuela claims Isla de Aves is a normal island, which projects its exclusive economic zone deep into the Caribbean and establishes maritime boundaries with the United States, France, and Dominica. In 1978, Venezuela used Aves as its reference point to agree on a maritime boundary with the U.S. between the island and Puerto Rico, making Aves the closest Venezuelan territory to American soil -- roughly 163 miles from Saint Croix. France accepted a boundary at longitude 62 degrees 48 minutes 52 seconds west, dividing Aves from Guadeloupe and Martinique. In 2006, Dominica's Prime Minister Roosevelt Skerrit visited Caracas and stated that Aves belonged to Venezuela, effectively ending the last active claim. A scientific naval base named Simon Bolivar, built on stilts partially in the water on the island's lee side, has been permanently staffed since 1978.

Beneath the geopolitics, Isla de Aves remains what its name promises: a place for birds. BirdLife International has designated the island and its surrounding waters an Important Bird Area for its significant populations of brown noddies and sooty terns. Green sea turtles nest on its beaches. The island's low profile, which makes it so vulnerable to hurricanes, also makes it a hazard to navigation -- many ships have wrecked on its barely visible shores over the centuries. Venezuelan authorities have considered engineering solutions to protect the island from erosion, driven less by ecological concern than by the legal reality that if Aves disappears beneath the waves, Venezuela's 200-nautical-mile claim may disappear with it. In 2006, an amateur radio expedition reached the island after 14 years of planning, making over 42,000 contacts during a weeklong stay under the rare ITU prefix YV0. One member of the expedition suffered a fatal heart attack. Even visiting this place, it seems, carries risk.