century, posing further threats to the Galapagos penguin. If the pattern of El Niño events from 1965-2004 continues, there is a 30% chance of extinction for the Galapagos penguin. If the frequency of strong El Niño events were to double over this same time period, the chance of extinction would be 80%. Disease Another potential threat to the Galápagos penguin is disease. Preliminary studies, such as one conducted in 2001, found no evidence of Avian malaria or Marek’s disease in Galápagos penguin populations. Despite these findings, the researchers recommended further observations, citing the death of 800 chickens in the Galápagos Islands from Marek’s disease, the presence of mosquitos known to carry Avian malaria, and the known impacts of these diseases on other endemic bird populations in Hawaii. Later, a 2009 study revealed the presence of a species of Plasmodium in Galápagos penguins, the parasite genus that causes Avian malaria. The presence of this parasite suggests that diseases are able to travel from other populations to the isolated Galápagos penguin communities. Further research suggests that cross-species transmission may occur between endemic Galápagos species and migratory birds such as the Bobolink. Understanding how these diseases reach the Galápagos Islands and transmit between its bird species is a focus for developing conservation strategies for endangered species such as the Galápagos penguin. Other Other threats include humans harvesting penguins for oil and other products, competition with fisheries for krill and other fish, habitat loss, increased predation from invasive species, bycatch, and pollution. On Isabela Island, humans may be contributing to the decline of this species due to introduced cats, dogs, and rats which attack penguins, destroy nests, and spread disease. Other threats on land include crabs, snakes, rice rats, Galápagos hawks, and short-eared owls. While in the water, predators include sharks, fur seals, and sea lions. They also face the hazards of unreliable food resources and volcanic activity. Illegal fishing activity may interrupt the penguins' nesting, and they are often caught in fishing nets by mistake. These impacts are particularly threatening because of the population structure of the Galápagos penguin. The Galápagos penguin consists of two geographic subpopulations, but studies suggest that there is sufficient gene flow between these populations to treat them together when considering conservation strategies. Additionally, the Galápagos penguin demonstrates relatively low genetic diversity, making it especially vulnerable to disease, predation, and other environmental changes. References External links Galápagos penguins from