Vol.:(0123456789) 1 3 Polar Biology https://doi.org/10.1007/s00300-018-2326-1 SHORT NOTE A brown Adélie Penguin Pygoscelis adeliae breeding at King George Island, Maritime Antarctica Júlia Victória Grohmann Finger 1  · César Rodrigo dos Santos 1  · Luiz Liberato Costa Corrêa 1  · Antônio Coimbra de Brum 1  · Maria Virginia Petry 1,2 Received: 16 February 2018 / Revised: 13 April 2018 / Accepted: 20 April 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Plumage aberrations are rare in penguin species. Tracking their occurrence is helpful to understand the efects of these phe- notypes on the life history of penguins, especially on mating, breeding, and foraging success. We registered a brown Adélie Penguin Pygoscelis adeliae at Turret Point, King George Island, Maritime Antarctica, during the middle of the 2017/2018 breeding season. The individual was brooding one chick in a nest located in the center of the colony and its partner was by its side. Both chick and partner showed normal plumage, reafrming the recessive character of brown mutations. A breeding aberrant bird nesting in the center of the colony indicates that the brown coloration does not seem to afect mate selection, but we could not verify if it afects breeding success. This is the third published record for Adélie Penguins following a gap of 40 years. We stress, however, that possible misclassifcations of brown aberrations in literature might be causing an underestimation of its occurrence rate in bird populations. Keywords Adélie Penguin · Pygoscelis adeliae · Spheniscidae · Color aberration · Eumelanin · King George Island Introduction In birds, “brown” is a phenotype resulting from a mutation in a recessive gene located on the sex-related Z-chromo- some (van Grouw 2006, 2013). In this mutation, the pigment eumelanin responsible for black, gray, and brown colors in feathers sufers a qualitative reduction due to its incomplete oxidation during synthesis. That is, the amount of pigment granules (melanosomes) remains unafected but the aspect of the color changes (van Grouw 2006). Feathers that are originally black turn to brown, while reddish, yellowish, and plain brown colors do not change because the pigment pheomelanin is not afected (van Grouw et al. 2011; van Grouw 2013). In some cases, the bill and the tarsal skin may also look paler (Wilson 1907; van Grouw 2013). Brown mutations have been registered for several pen- guin species such as the Gentoo Penguin Pygoscelis papua (Forrest and Naveen 2000; Juáres et al. 2011), King Pen- guin Aptenodytes patagonicus (Van Wyk 1995; Voisin et al. 2002), Magellanic Penguin Spheniscus magellanicus (Petry et al. 2017), and for Adélie Penguins as well (Wilson 1907; Novatti 1959). Even though such cases of color aberrations are rare, they are not unusual for Adélies. Other mutations, such as leucism (Stirling 1969; Nishikawa et al. 2000), isa- bellinism (Everitt and Miskelly 2003), dilution (Bellisio 1967), and melanism (Falla 1937) have also been registered for the species. Tracking the occurrence of plumage aberrations is help- ful to understand the efects of these phenotypes on the life history of penguins, especially on mate selection and breeding success. Implications on mating and breeding are expected especially for penguin species with colored- ornamented feathers used in sexual signaling such as King Penguins (Stonehouse 1960; Pincemy et al. 2009). However, for exclusively black and white species, such as Adélie and Chinstrap Penguins, perhaps the greatest implication might be a reduction in foraging efciency. This could happen if the aberration provokes loss of the countershading efect and * Júlia Victória Grohmann Finger victoriafnger@hotmail.com 1 Laboratório de Ornitologia e Animais Marinhos, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil 2 INCT-APA - National Institute of Science and Technology - Antarctic Environmental Research, Rio de Janeiro, RJ 21941-902, Brazil