According to findings presented by the University of Washington, climate change is causing a decline in the biggest colony of Magellanic penguins in the world. The researchers claim that interchanging weather conditions, ranging from rainstorms to heat, are responsible for depriving the penguin population of food, stifling breeding success and harming chick populations.
Magellanic Penguin Chicks Battle the Elements?
The Magellanic penguin (Spheniscus magellanicus) is a medium-sized, South American penguin that can grow to a height of around 15 inches. The adult penguin has a white underside and black reverse, along with distinctive black and white bands that run, horizontally, between the breast and head. Adult males of the species sound reminiscent of braying donkeys and are typically larger than females. The Magellanic penguins tend to favor breeding in reasonably dry, snow-free regions, where temperatures are temperate.
Covered in relatively soft feathers, penguin chicks struggle for survival in drenching rainfall. The size of the chicks places them in an unfortunate position; they are too large to be protected by their parents from the elements, but too young to have sprung their own waterproof feathers; as a consequence, the chicks are susceptible to hypothermia, when subjected to such weather. On the other hand, during periods of extreme heat, the young chicks are unable to reduce their body temperature by swimming in the cooling waters, again, due to the absence of waterproof feathers.
The latest data was obtained over the course of 27 years, in Argentina. The study was spearheaded by Dee Boersma, a University of Washington professor and lead author of the study, with the findings published in the Jan. 29 issue of the journal PLOS ONE, entitled Climate Change Increases Reproductive Failure in Magellanic Penguins.
Boersma was tasked with leading the field work since 1983. Her team performed their investigations into the largest breeding grounds for Magellanic penguins at Punta Tombo, in an area where 200,000 penguin couples dwell, from September to February, to give birth. Boersma indicates that the study represents the first long-term research effort to explore the relationship between climate change and chick survival rate and reproductive success.
The researchers based their findings from weather information, collected in the field and at a regional airport, as well as a series of penguin counts. The crew visited nest sites during the breeding season to inspect the nest and note its contents; the teams would then look for chicks, as they were roaming around the breeding grounds. When stumbling upon the corpse of a chick, the researchers also attempted to determine it cause of death, hunting for signs of predation, starvation or other causes of death.
Starvation and Weather Impact Penguins of Punta Tombo
Over the 27 year period, the team established that, on average, 65 percent of chicks died every year; of this percentage, approximately 40 percent of chicks died from starvation. It has been suggested that climate change is a relatively new cause of chick death; the researchers maintain that climate change was responsible for killing an average of 7 percent of chicks, per year. Some years, meanwhile, climate change was allegedly responsible for causing the deaths of up to 43 percent of all chicks.
In explaining the death toll of the penguin chicks, Boersma states that starvation and weather appeared to be the two primary causes. She states that starving chicks are increasingly likely to pass away during storms and – with rainfall and storm frequency, reportedly, increasing at the study site – the researchers are linking the deaths to climate change. Boersma spoke about creating a marine reserve to protect the vulnerable Magellanic penguins, in a recent press release.
“There may not be much we can do to mitigate climate change, but steps could be taken to make sure the Earth’s largest colony of Magellanic penguins have enough to eat by creating a marine protected reserve, with regulations on fishing, where penguins forage while raising small chicks.”
Ginger Rebstock, a University of Washington research scientist and co-author of the latest study, believes that climate change could wreak havoc on the penguin population, if storms worsen in intensity and frequency during the penguin breeding season. The team found an increase in the number of storms in the opening two weeks of each December, between 1983 and 2010. During this period, very young chicks – typically under 25 days old – are at their most vulnerable. If the down-covered young can survive beyond this dangerous period, they will produce a sufficient number of waterproof feathers to offer protection against the weather.
Since 1987, the number of penguins breeding at Punta Tombo has declined by around 20 percent. In concluding, the authors suggest that weather, starvation and predation have all taken their toll on the Magellanic penguins. They posit that penguins from other areas, from southern Chile to the Falkland/Malvinas Islands, could also be at risk from climate change.
By James Fenner