Students, volunteers, and research staff have studied a variety of topics relating to Magellanic penguins in Punta Tombo, with the goal of changing policies to aid in their conservation. Below are just some of the past research products undertaken by the Penguin Sentinels Project.
Doctoral candidate Olivia Kane and Jeff Smith helped document and research a feather-loss disorder, first observed in captive African Penguin (Spheniscus demersus) chicks in a South African rehabilitation center in 2006. The condition was found one year later in wild Magellanic Penguin chicks in four colonies in Argentina. Two years later, it was found in African Penguin chicks in the wild. The featherless African Penguin chicks in the rehabilitation center lost their down and emerging juvenile feathers, remaining featherless for several weeks until they died or grew juvenile or adult plumage before being released. Likewise, the featherless wild Magellanic Penguin chicks lost their second coat of down, remaining featherless for several weeks; but those that survived to fledging all grew normal juvenile plumage. Featherless Magellanic Penguin chicks grew more slowly and were smaller at fledgling age than most feathered chicks. The disorder in Africa and Argentina is new, rare, and more common in a rehabilitation center in Africa than in the wild. The cause of the feather loss is unknown, but the disorder results in slower growth, smaller fledglings, and appears to increase mortality in Magellanic Penguin chicks in the wild.
During the week of August 20, 2007, Professor Boersma and her student, Elizabeth Skewgar, selected six adult male penguins from a group of oiled penguins at two coastal towns in Northern Argentina–San Clemente del Tuyú and Mar del Plata–to carry satellite transmitters during their southern migration back to their breeding colonies. They put the transmitters on healthy, robust birds in good body condition that were likely to be eager to get back to their colony to begin breeding. The point was to follow their ocean route and determine if they are going south along a well-defined route.
From 1996 to 2006 Dr. Boersma tracked breeding Magellanic penguins at Punta Tombo using satellite transmitters (n = 148 males, 57 females) to investigate the variability in foraging distance and its effects on reproductive success. Foraging distance affects reproductive success and other demographic parameters in seabirds. The time a penguin was away from its nest predicted the distance it swam during all stages of the breeding season. During incubation, penguins went 1.0 km farther from the colony for every additional hour they were away from the nest, and the distance penguins traveled predicted the mean colony reproductive success. When chicks were >30 days old, the probability of fledging 2 chicks was highest when penguins went less than 70 km from their nests. Penguins that went between 70 and 180 km from their nests were most likely to raise one chick, and the probability of losing both chicks increased with trip distance. Females and males made trips of similar distance. Penguins went farthest during incubation and stayed closest when chicks were <30 d old, requiring parents to guard them. When chicks were older, adults traveled 111 ± 5.0 km.
From the tropics to Antarctica, penguins depend on predictable regions of high ocean productivity where their prey aggregate. Increases in precipitation and reductions in sea ice associated with climate warming are affecting penguins. The largest breeding colony of Magellanic penguins, at Punta Tombo, had approximately 200,000 breeding pairs in October 2006—a decline of 22% since 1987. In the 1980s and 1990s, petroleum pollution was a major source of Patagonian penguin mortality. In 1994, tanker lanes were moved 40 kilometers (km) farther off the coast of Chubut, and the dumping of ballast water and the oiling of penguins are now rare. However, penguins are swimming 60 km farther north from their nests during incubation than they did a decade ago, very likely reflecting shifts in prey in response to climate change and reductions in prey abundance caused by commercial fishing. These temperate penguin species, marine sentinels for southern oceans, demonstrate that new challenges are confronting their populations.