Jaqueline Brummelhaus

Diet and ingestion of synthetics by Cory’s Shearwater Calonectris diomedea off southern Brazil

Cory’s Shearwater, Calonectris diomedea, is a pelagic seabird that winters in the waters off the state of Rio Grande do Sul in southern Brazil. Elsewhere, its diet is comprised mostly of fish and cephalopods, but dietary details out of the breeding season are unknown. The present study analysed the diet of Cory’s Shearwater along the coast of Rio Grande do Sul based on the stomach contents of 185 birds found dead during beach surveys between July 1997 and July 1998. Food items were classified taxonomically and non-food items were categorized. The taxa identified included the cephalopods Argonauta nodosa and Histioteuthis sp. and the fish Paralonchurus brasiliensis, Porichthys porosissimus, and Prionotus punctatus. Cephalopods were present in 97% of stomachs and fish in 33% of stomachs. Synthetic materials were found in 81% of stomachs. Our data corroborate the general ideas of Procellariiform diet during migration. The high amount of synthetic materials indicates the pollution of the marine environments of southern Brazil and we call attention to this situation.

Morphometric variation in chinstrap penguins: molecular sexing and discriminant functions in the South Shetland Islands, Antarctica

Abstract Chinstrap penguins (Pygoscelis antarcticus) show little sexual dimorphism and sexing by direct observation can be difficult. Through molecular techniques, male and female adults were identified at Stinker Point, Elephant Island, South Shetland Islands, in the 2011–12 and 2012–13 breeding seasons. In the assessment of sexual dimorphism using morphological characteristics, males were 6.0–9.4% larger than females. From the most significant morphological measurements, a discriminant function was formulated that classified 80.6% of the birds correctly. In addition, our data on bill length and depth were compared with those in the literature to evaluate sexual dimorphism between different breeding locations and to test the performance of the discriminant function. There were no differences in sexual dimorphism between breeding locations. However, the discriminant function should be used with caution because some penguins may be misclassified. Therefore, when there is doubt about the accuracy of morphometric approaches, application of molecular sexing techniques is recommended.

Biparental Care of Chinstrap Penguin: Molecular Sexing and Life History in the South Shetland Islands, Antarctica

Chinstrap penguin, Pygoscelis antarctica, breeding biology involves several distinct stages of chick rearing, in which each parent varies in their relative contribution to reproductive success. We investigated tertiary adult sex ratios using molecular sexing in breeding colonies during guard and crèche stages of chick rearing at Admiralty Bay (King George Island) and on Stinker Point (Elephant Island) in the 2010/2011 breeding season. We analyzed 52 blood samples and found this represented 31 males and 21 females. We observed that the adult sex ratio in guard and crèche stages did not vary signi cantly. However, we feel evidence did infer di erences in relative biparental care behavior between the two stages studied. us, it was possible to develop a potential hypothesis of relationship between sex ratio of adults present during di erent stages of the breeding season by molecular biology technique with Chinstrap penguin life history and gain understanding of the importance of contributions of both sexes in raising their o spring and for attaining reproductive success.

Population Fluctuation of Pygoscelis Papua and Pygoscelis Antarctica, Elephant Island, South Shetlands, Antarctica

Reproductive population size of both the Gentoo penguin (Pygoscelis papua) and Chinstrap penguin (Pygoscelis antarctica) has changed over the last decades in many sites in the South Shetlands Islands. We evaluated the population sizes of these species on Stinker Point, Elephant Island, South Shetlands, Antarctic, during the breeding season 2009, 2010 and 2011, and we compared with preterit studies. Over the last 40 years, the number of breeding pairs here have shown uctuations, with changes of up to 32%. It is possible that these uctuations are related to the variation in prey availability and/or climate change. However, additional census and demographic surveys in Elephant Island are clearly needed to determine whether the decline represents a long-term trend or random circumstantial uctuations.