Santiago Island — Lava Fields, Fur Seals, and Darwin's Campsite

The Black Sand Beach and Coastal Trail

Puerto Egas is named for Héctor Egas, who operated a salt extraction company here in the 1960s. The venture ultimately failed — as every human settlement attempt on Santiago has — and the national park reclaimed the site. What remains is a black sand beach fringed by volcanic rock, with two trails leading into two entirely different landscapes.

The coastal trail follows the shoreline south through a series of rocky benches and tidal pools toward the fur seal grottos at the trail’s end. Along the way: marine iguanas sunning on the flat black lava, American oystercatchers (among the most vividly colored shorebirds in the archipelago) picking through the pools, and the near-constant activity of the intertidal zone — sally lightfoot crabs, hermit crabs, small fish trapped by the receding tide. The light here, with the dark rock and green water, is extraordinary in the early morning.

The inland trail, approximately 3 km long, leads to Salt Mine Crater — a volcanic depression with a seasonal salt-water lagoon at the base where flamingos are sometimes seen. Galápagos hawks patrol the slopes. The hike rewards visitors willing to leave the shoreline.

Fur Seal Grottos: Meeting a Different Animal

The grottos at the end of the Puerto Egas coastal trail are where you encounter the Galápagos fur seal (Arctocephalus galapagoensis) — and immediately understand why it is not a sea lion.

The difference matters and is visible. The Galápagos fur seal is smaller than the sea lion: females average 1.3 m and 27 kg; males reach 1.5 m and 64 kg. Its head is broader and shorter, with larger, more bulging eyes adapted for dim-light hunting. Its ears protrude more noticeably. Its front flippers are proportionally larger — built for scrambling up the rocky, wave-cut ledges of the grottos, not for gliding through sandy shallows.

Fur seals are nocturnal hunters, diving at night to catch fish and squid in the marine reserve. During the day they rest in shaded, rocky recesses — the grottos provide exactly this: cool, dark overhangs above tide-washed rock. They are far less visible than sea lions precisely because their preferred habitat is the rugged, shaded coastline that most tourists pass by quickly. At Puerto Egas, the trail brings you directly to them.

The Galápagos fur seal is listed as Endangered. Its population declined catastrophically due to commercial hunting in the 19th century; the population has since recovered but remains vulnerable to El Niño events that disrupt prey availability. The grottos at Puerto Egas are one of the most reliable places in the archipelago to observe them at close range.

Tidal Pool Life

The tidal pools along the Puerto Egas coastline support a rich intertidal community: four-eyed blennies, various gobies, sea urchins, and the ever-present sally lightfoot crab (Grapsus grapsus) — whose scarlet and orange carapace against the black lava is one of the most photographed colour contrasts in the Galápagos. Reef herons wait motionless at pool edges. At high tide, the pools flush and refill; at low tide, they hold small worlds.

How the Damage Happened

Goats, pigs, and donkeys were introduced to Santiago in the 1800s — brought by sailors who used the island as a provisioning stop, left deliberately to breed as a future food source for shipwrecked crews. The intention was practical. The consequence was catastrophic.

Feral goats are among the most destructive invasive species on island ecosystems worldwide. They are indiscriminate browsers, consuming seedlings, bark, and ground cover without the selectivity of native herbivores that evolved alongside the plants. On Santiago, which had no land predator capable of controlling them, goat populations exploded. Over decades, they destroyed the natural woodlands of the island’s higher elevations, converting diverse forest into grassland. The cover that land iguanas, tortoises, and native birds depended on was stripped away. By the time systematic study of the damage began, the island was profoundly degraded.

Pigs compounded the damage differently: they are effective nest destroyers, rooting out tortoise eggs and consuming them. The giant tortoise population of Santiago had been reduced to approximately 500 animals by the time the Galápagos National Park was established in 1959 — and nesting was largely unsuccessful because pigs found and raided the nests. Rangers built rock walls around natural nests as a stopgap measure.

Project Isabela: The Largest Eradication of Its Kind

Project Isabela, initiated in 1997 as a joint program of the Galápagos National Park (GNPS) and the Charles Darwin Foundation (CDF), set out to eliminate goats, pigs, and donkeys from three islands: northern Isabela, Santiago, and Pinta. Santiago was used as the testing ground — a large island (58,465 ha) where novel techniques could be developed and proved before being deployed on even larger Isabela.

The pig eradication on Santiago began first. More than 18,000 pigs were removed, and the island was declared pig-free in 2000 (confirmed 2004 officially). Goat eradication began in earnest in 2001, combining ground hunting, aerial hunting by helicopter, and an innovation that became a model for conservation worldwide: the Judas goat.

Judas goats — captured animals fitted with radio-telemetry collars and released — exploited the sociability of goats against the remaining population. Because goats seek out other goats, a Judas goat would lead hunters to hidden, hard-to-find groups in dense vegetation or remote terrain. More than 200 Judas goats were eventually deployed on Santiago. The last feral goat was removed from the island in 2005. In 2006, Santiago was declared free of all large introduced mammals.

The Numbers

79,579 goats were removed from Santiago Island over 4.5 years at a total cost of approximately US$6.4 million. This was, at the time, the largest island goat eradication ever attempted by number of animals and by island area. The achievement established both the feasibility and the methodology for subsequent eradications across the Galápagos archipelago and, later, around the world.

Source: Aerial and ground-based methods for eradication — Carrion et al. (2011), PLoS ONE, https://pmc.ncbi.nlm.nih.gov/articles/PMC3092746/ | Galápagos Conservancy, Project Isabela — https://www.galapagos.org/conservation/project-isabela/

The Recovery

Recovery of Santiago’s vegetation after goat eradication has been rapid and visible. Native plant species suppressed or eliminated by decades of browsing have re-established across the island’s higher elevations. Some endemic species found only on Santiago — previously at risk of local extinction — are now recovering. The giant tortoise population is stabilising. The Santiago rice rat (Nesoryzomys swarthi), considered extinct until a remnant population was rediscovered on the island’s eastern coast in 1997, has survived.

The Santiago goat eradication stands as one of the conservation world’s genuine triumphs — a case study in what large-scale, methodologically rigorous intervention can achieve when institutions commit to it. It is also a permanent rebuke to the argument that island ecosystems damaged by invasive species are beyond recovery.

One challenge remains: Rubus niveus, an invasive blackberry that the goats had inadvertently kept in check, has expanded since eradication. It currently covers 28 hectares and could spread across the entire humid zone of Santiago without active management. The story of Santiago’s restoration is not finished.