independent. Newly hatched chicks have downy feathers that do not become waterproof until the chicks grow into juveniles. The juvenile plumage, attained by thirty days after a chick hatches, is dark brown or gray above and white below. These feathers are mainly needed to protect the chicks from the strong sun rather than keep them warm. Bermudian naturalist Louis L. Mowbray was the first to successfully breed the Galápagos penguins in captivity. Population Galápagos penguins have a lifespan ranging from 15 to 20 years, but because of environmental factors and predation, their life expectancy is reduced. They are listed on the IUCN Red List of Threatened Species as Endangered, and as of 2018 there are around 1,200 mature penguins left. It is currently the rarest penguin species (a status often falsely attributed to the yellow-eyed penguin). Conservation El Niño and climate change The Galápagos penguin is a particularly vulnerable bird species due to its limited range on the Galápagos Islands. With a population of only about 1800, it remains on the endangered species list, and its population will likely fluctuate strongly in response to anthropogenic changes in the region. The primary danger to the Galapagos penguin is the climate phenomena known as El Niño. In 1982-83 and 1997–98, two strong El Niño events resulted in Galapagos penguin population declines of 77% and 65%, respectively. Additionally, the years 1965-66, 1968–69, 1972–73, 1976, 1986–87, 1991–92 and 1993 all had relatively weak El Niño events which were associated with slow population recovery. Conversely, during La Niña events when sea surface temperatures are lower than normal and the climate patterns shift, Galapagos penguin populations begin to recover. Anthropogenic climate change has been shown to increase frequency and intensity of El Niño events beyond levels of natural variability which negatively impacts the Galapagos penguin. Warmer temperatures caused by El Niño are associated with poorer female condition and lower adult bodyweights. The warmer temperatures of El Niño events result in a decrease in upwelling of the cold nutrient rich waters which decreases phytoplankton productivity and results in bottom up trophic disruptions that reduce the food availability for the Galapagos penguin. This lack of food leads to poor breeding success and a disproportionate female death rate, causing population decline and disrupting future recovery by creating uneven sex ratios in the populations. Predictive models suggest future El Niño events will increase in frequency and severity over the next