Isla Partida Norte and Isla Rasa
The full moon set and the Sea Voyager glided over southerly swells in morning fog to Isla Partida Norte, a small island in the Midriff Region of the Sea of Cortez. Here Zodiac riders discovered whitened columnar basalt formations protruding from productive seas – black volcanic geometry painted by generations of seabirds processing prodigious ocean resources.
Flocks of elegant terns danced over the water, squeaking, dangling in the air, facing into the wind, dropping from a hovering flutter to a piercing plunge, to lift silvery fish from the sea. The sleek birds shuttle the fresh seafood to their hyper-dense breeding colonies ashore. They pluck prey from shoals of sardines and anchovies that swim, school, and gulp zooplankton, as we observed snorkeling.
Nearly all the world’s population of elegant terns and Heermann’s gulls nest on small low-lying Isla Rasa, where we visited this afternoon. We observed the jam-packed squawking terneries from an overlook, after slowly slaloming through gull nest sites. We could see speckled eggs and tiny helpless spotted chicks beneath devoted parents. The eggs only began to hatch five days ago (three weeks late this year) and we witnessed shells being chipped open by protruding egg teeth and chicks shaking themselves out of their eggshells. A few precocious young, now days old, stumbled about their nest area.
We navigated the trail between meowing gulls on near nests and large cairns of cobbles assembled years ago by guano hunters (to possibly increase nesting habitat). In the last decade, the rodents introduced by these harvesters were completely eradicated (e-rat-icated?) and the birds’ breeding success has risen dramatically.
Isla Rasa’s scientist and guardian, Enriquetta Velarde, says the worst threat now to the island and the birds is a proposal to place a series of marinas throughout the gulf; she fears that an increase in unchecked and reckless visits would result in disruption of the breeding colonies. As it is, in El Niño years, sea temperatures rise, ocean productivity drops, and seabird reproduction crashes.
Lindblad Expeditions continues to be a leading private supporter of the research and conservation efforts on Isla Rasa, work that is successfully helping to sustain the world’s populations of these two seabirds.
The full moon set and the Sea Voyager glided over southerly swells in morning fog to Isla Partida Norte, a small island in the Midriff Region of the Sea of Cortez. Here Zodiac riders discovered whitened columnar basalt formations protruding from productive seas – black volcanic geometry painted by generations of seabirds processing prodigious ocean resources.
Flocks of elegant terns danced over the water, squeaking, dangling in the air, facing into the wind, dropping from a hovering flutter to a piercing plunge, to lift silvery fish from the sea. The sleek birds shuttle the fresh seafood to their hyper-dense breeding colonies ashore. They pluck prey from shoals of sardines and anchovies that swim, school, and gulp zooplankton, as we observed snorkeling.
Nearly all the world’s population of elegant terns and Heermann’s gulls nest on small low-lying Isla Rasa, where we visited this afternoon. We observed the jam-packed squawking terneries from an overlook, after slowly slaloming through gull nest sites. We could see speckled eggs and tiny helpless spotted chicks beneath devoted parents. The eggs only began to hatch five days ago (three weeks late this year) and we witnessed shells being chipped open by protruding egg teeth and chicks shaking themselves out of their eggshells. A few precocious young, now days old, stumbled about their nest area.
We navigated the trail between meowing gulls on near nests and large cairns of cobbles assembled years ago by guano hunters (to possibly increase nesting habitat). In the last decade, the rodents introduced by these harvesters were completely eradicated (e-rat-icated?) and the birds’ breeding success has risen dramatically.
Isla Rasa’s scientist and guardian, Enriquetta Velarde, says the worst threat now to the island and the birds is a proposal to place a series of marinas throughout the gulf; she fears that an increase in unchecked and reckless visits would result in disruption of the breeding colonies. As it is, in El Niño years, sea temperatures rise, ocean productivity drops, and seabird reproduction crashes.
Lindblad Expeditions continues to be a leading private supporter of the research and conservation efforts on Isla Rasa, work that is successfully helping to sustain the world’s populations of these two seabirds.
