A long-term study of petrels in the Galápagos Islands has shown a 90% population decline over the past 50 years. The study, published in the journal Current Biology, is the first to document such a steep decline in a seabird population in the Galápagos.

The decline is likely due to a combination of factors, including climate change, habitat loss, and introduced predators. Climate change is causing the ocean to warm, which is changing the petrels' food supply. Habitat loss is also a major factor, as the petrels' nesting sites are being destroyed by human development. Introduced predators, such as rats and cats, are also taking a toll on the petrel population.

The decline of the petrels is a serious concern, as they play an important role in the Galápagos ecosystem. Petrels are top predators, and they help to control the population of other seabirds and fish. They also disperse seeds, which helps to maintain the health of the Galápagos' plant communities.

The study's authors say that urgent action is needed to protect the petrels and other seabirds in the Galápagos. They recommend that the government create new marine protected areas, control introduced predators, and reduce the impact of climate change.

Here are some additional details about the study:

- The study was conducted by researchers from the Charles Darwin Foundation and the University of California, Santa Cruz.

- The researchers studied three species of petrels: the Galápagos petrel, the wedge-tailed petrel, and the black-capped petrel.

- The study was conducted over a period of 50 years, from 1965 to 2015.

- The researchers found that the population of Galápagos petrels declined by 94%, the population of wedge-tailed petrels declined by 89%, and the population of black-capped petrels declined by 85%.

- The researchers say that the decline is likely due to a combination of factors, including climate change, habitat loss, and introduced predators.

- The study's authors say that urgent action is needed to protect the petrels and other seabirds in the Galápagos. They recommend that the government create new marine protected areas, control introduced predators, and reduce the impact of climate change.