IS Ql . BI . 3 . W 5 I 1993 REPORT WORKSHOP ON RESEARCHER - SEABIRD INTERACTIONS JULY 15 - 17 , 1993 MONTICELLO , MINNESOTA , USA

Banding and Implant Studies of Pygoscelis Penguins Susan G. Trivelpiece and Wayne Z. Trivelpiece Polar Oceans Research Group, Department of Biology, Montana State University, Bozeman, Montana 59717, USA Although bands have been used on penguins since the early 1900s, it was not until demographic studies were undertaken in the 1960s and 1970s that the problems of band loss and mortality due to bands were addressed. Ainley et a/. (1983) calculated a 28% band induced mortality rate among the Cape Crozier Adelie Penguin (Pygoscelis adeliae) population. These findings resulted in a new, enlarged band design to accommodate the swelling of the flippers during molt. We subsequently attempted to determine the extent of band loss and mortality due to these new bands. Our double-banding study from 1984/85 to 1985/86 resulted in the discovery that double-banded birds (i.e., with one band on each flipper) had higher mortality rates than those with only single bands. 31% of the double-banded Adelie and Gentoo Penguins (P. 1ll!Illil!), and 32% of the Chinstrap Penguins (P. antarctica) returned versus 39%, 56%, and 44% of the single-banded Adelie, Gentoo, and Chinstrap Penguins, respectively. In addition, Gentoo Penguin chicks were doubleand single-banded at the same time. Differences in survival between these two groups showed dramatic differences; only one of the 200 double-banded birds returned as a one-year-old, versus 84 of the 800 single-banded birds. We hypothesized that silver flipper bands might be acting as "flashers", thereby putting double-banded birds at greater risk to predation by Leopard Seals (Hydrurga leptonyx). To test this hypothesis, Adelie Penguins were double-banded with black bands, silver bands, and black and silver bands in 1987/88. The following season (1988/89), no differences were found in survival among these groups (20%, 21%, and 26%, respectively). However, single-banded black and single-banded silver birds had significantly higher survival rates than double-banded birds (39% and 44%, respectively). These results suggest that flipper bands affect survival in penguins. To test this hypothesis, we have initiated a study of Adelie Penguin male survival using implanted transponders. Results of this experiment will help us to determine the extent of band loss and band induced mortality in penguins. Cited and Related References: 4, 5, 16,21, 34,77, 82,88,94