Recent climate shifts pose a threat to species accustomed to colder habitats, disrupting their life cycles and limiting food availability. However, a decade of monitoring a gentoo penguin colony on Martillo Island in Tierra del Fuego has revealed a positive outcome. The penguins have adjusted their nesting times, enabling their chicks to escape the effects of extreme summer temperatures.
An international research team from Argentina and the UK published their findings in the journal PLOS One. The study indicates that well-fed Magellanic penguin chicks are highly susceptible to heat stress due to elevated body temperatures during digestion. Traditionally, climate changes, such as earlier blooming or breeding seasons, lead to a disconnect with food sources, hindering reproductive success.
Argentine gentoo penguins have demonstrated remarkable adaptability, capable of adjusting their nesting schedules in response to local climate conditions.
Researchers have been observing the penguin colony on Martillo Island since 2013, utilizing an automated camera trap. The camera recorded events hourly during daylight, with a particular focus on the start and end of breeding, the number of nests and chicks, and the birds’ behavior during heat waves. Ambient temperatures were measured by the camera and cross-referenced with data from a nearby meteorological station.
The data analysis confirmed that gentoo penguin chicks are indeed vulnerable to heat stress. During a three-day heatwave in January 2015, with temperatures reaching 24°C, five out of 32 chicks died from overheating within 45 minutes. At temperatures above 18°C, chicks experienced difficulty breathing, and at 20°C, most left the colony in search of shade.
Gentoo penguins have successfully adapted to these changes by initiating nesting earlier. Over the ten-year observation period, the chick-rearing season has shifted earlier by an average of two days per year. By 2023, chicks were leaving the colony 23 days earlier than in 2013. While chicks frequently suffered from heat at the beginning of the project, by the end of the observations, they had learned to avoid over 53% of critical temperatures above 20°C.
About the Author
