PUERTO AYORA, ECUADOR – In the humid Galápagos highlands, surrounded by tall scalesia trees, biologist Carolina Proaño has her head to the ground, checking nests for signs of new eggs or recent visits. She has long been trying to save the Galápagos petrel, a critically endangered black and white seabird known for making its nest in the ground and returning to the same spot every year during mating season.
On her family farm on the island of Santa Cruz, Proaño has marked out a safe area for the petrels’ nests and tries to attract them by playing a recording of their calls on a loudspeaker. She then monitors the area using camera traps.
But a few months ago, Proaño visited the site and found two adult petrels dead in front of their nests. They had been attacked by stray dogs, introduced to the islands by humans and a growing menace to the local biodiversity.
“I nearly died [of shock],” says Proaño.
While reviewing camera trap images, she also spotted a cat lurking around the petrel nesting area. “I am seeing introduced species that are obviously a response to population growth,” she says. “It’s terrible.”
Ecuador’s Galápagos archipelago is known for its wide variety of unique and endemic species, such as large tortoises and the blue-footed booby, and their cohabitation with humans. But over the years, environmental and human-induced pressures have created challenges for the archipelago’s conservation initiatives and local populations.
The spike in tourism and population growth in recent years have been the main challenges. Both have risen steadily since 1959, when the Galápagos national park was created. The park protects 97% of the archipelago and leaves only 3% available to be inhabited by humans.
In 2023, nearly 330,000 visitors passed through the islands, a 23% increase from the previous year. Today, about 29,000 people live on the four inhabited islands, mainly to service the tourism industry.
For Proaño, the problem is not humans’ existence in this unique ecosystem, but the way people live and travel as if it were any other town or city.
One of the biggest repercussions has been the arrival of alien species. These include deliberate introductions to feed local demand for pets such as dogs and cats, which are often abandoned and are known to attack birds and baby iguanas and eat their eggs. It also includes bugs and parasites unintentionally introduced via cargo boats bringing building materials and food, as about 75% of the Galápagos’ food supply comes from the mainland.
The parasitic fly Philornis downsi has been particularly deadly for Galápagos birds, as it lays its eggs in nests, killing or debilitating hatchlings. It has been associated with the decline of the mangrove finch and medium tree finch, endemic birds already critically endangered.
Dozens of insects, such as various fire ants, wasps, and scale insects, have also been introduced and found to be highly invasive.
“It’s super complicated to maintain biosecurity control,” says Proaño. “There is not enough personnel or even a quarantine place to inspect everything that arrives here.”
Kimberley Michelle Brown 