Amy Buren - Academia.edu (original) (raw)
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Papers by Amy Buren
Polar Biology, 2006
The taxonomy of rockhopper penguins, Eudyptes chrysocome (Forster 1781), is contentious. Some aut... more The taxonomy of rockhopper penguins, Eudyptes chrysocome (Forster 1781), is contentious. Some authorities recognise three subspecies based on morphological differences and geographical separation of breeding populations while others suggest that morphological differences support classifying rockhopper penguins as two distinct species. The taxonomy of rockhopper penguins is of more than academic interest as breeding colonies worldwide have declined markedly in size since the 1930s and rockhopper penguins are currently listed as vulnerable by the IUCN. We compared the genetic distances between three mitochondrial gene regions from the three putative rockhopper penguin subspecies with the distances between various penguin sister species to clarify the taxonomy and systematics of rockhopper penguins. Genetic distances between the rockhopper penguin taxa, relative to other closely related penguin species, support reclassifying the three rockhopper penguin subspecies as species. Reclassification of rockhopper penguins as three species could result in their conservation status being upgraded from vulnerable to endangered.
Journal of Ethology, 2006
Game theory models predict that fighting ability should be more important in contest outcome when... more Game theory models predict that fighting ability should be more important in contest outcome when the payoffs of winning are high for both contestants, and ownership should be more important when payoffs are low. Male Magellanic penguins (Spheniscus magellanicus) provide an opportunity to test these predictions in a natural setting because payoffs of winning are higher for penguins fighting before egg laying and lower for penguins fighting after egg laying, allowing the prediction of differences in who should win and lose. We watched an area of approximately 2000 Magellanic penguin nests from 1992 to 1996 at Punta Tombo breeding colony, Argentina; we quantified fighting behavior, banded contestants, measured their body size (here used as an index of fighting ability), determined ownership status when possible, and monitored their reproductive success. We determined that male Magellanic penguins fought for nests and mates. As theory predicts, before egg laying, body size difference was more important than ownership as a predictor of contest outcome and fight duration. After egg laying, owners won fights, and size did not predict who won or how long they fought. Our comparisons of nest ownership, nest quality, and chicks fledged by winners and losers suggested that our predictions on the change in benefits of winning before and after egg laying were correct. We conclude that game theory models are useful in predicting who won or lost fights in male Magellanic penguins and that ultimate benefits of winning fights are related to fitness.
Polar Biology, 2006
The taxonomy of rockhopper penguins, Eudyptes chrysocome (Forster 1781), is contentious. Some aut... more The taxonomy of rockhopper penguins, Eudyptes chrysocome (Forster 1781), is contentious. Some authorities recognise three subspecies based on morphological differences and geographical separation of breeding populations while others suggest that morphological differences support classifying rockhopper penguins as two distinct species. The taxonomy of rockhopper penguins is of more than academic interest as breeding colonies worldwide have declined markedly in size since the 1930s and rockhopper penguins are currently listed as vulnerable by the IUCN. We compared the genetic distances between three mitochondrial gene regions from the three putative rockhopper penguin subspecies with the distances between various penguin sister species to clarify the taxonomy and systematics of rockhopper penguins. Genetic distances between the rockhopper penguin taxa, relative to other closely related penguin species, support reclassifying the three rockhopper penguin subspecies as species. Reclassification of rockhopper penguins as three species could result in their conservation status being upgraded from vulnerable to endangered.
Journal of Ethology, 2006
Game theory models predict that fighting ability should be more important in contest outcome when... more Game theory models predict that fighting ability should be more important in contest outcome when the payoffs of winning are high for both contestants, and ownership should be more important when payoffs are low. Male Magellanic penguins (Spheniscus magellanicus) provide an opportunity to test these predictions in a natural setting because payoffs of winning are higher for penguins fighting before egg laying and lower for penguins fighting after egg laying, allowing the prediction of differences in who should win and lose. We watched an area of approximately 2000 Magellanic penguin nests from 1992 to 1996 at Punta Tombo breeding colony, Argentina; we quantified fighting behavior, banded contestants, measured their body size (here used as an index of fighting ability), determined ownership status when possible, and monitored their reproductive success. We determined that male Magellanic penguins fought for nests and mates. As theory predicts, before egg laying, body size difference was more important than ownership as a predictor of contest outcome and fight duration. After egg laying, owners won fights, and size did not predict who won or how long they fought. Our comparisons of nest ownership, nest quality, and chicks fledged by winners and losers suggested that our predictions on the change in benefits of winning before and after egg laying were correct. We conclude that game theory models are useful in predicting who won or lost fights in male Magellanic penguins and that ultimate benefits of winning fights are related to fitness.