{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/17653"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/17653","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Breeding Jackass Penguins as pelagic predators","abstract":"The foraging of breeding Jackass Penguins Spheniscus demersus was studied in and around southwestern Cape Province, Saldanha Bay (33⁰ S, 18⁰ E), South Africa. Penguins are difficult to observe at sea. Hence, I devised a number of new techniques for studying the foraging behaviour of Jackass Penguins at sea. I built electronic and autoradiographic remote-sensing devices to measure swimming speed, distance travelled and time spent at each depth by foraging Jackass Penguins. Penguin swimming speed was reduced in proportion to the cross-sectional area of the devices, and results derived from birds wearing the devices had to be interpreted accordingly. Penguins do not regurgitate their stomach contents when handled, so I constructed a wet-offloading stomach pump which extracted 100% of the stomach contents. Using this pump, I determined that the rate of digestion of fish and squid by Jackass Penguins differed. Care is needed in diet interpretations where both fish and squid are major food items.","abstract_html":"The foraging of breeding Jackass Penguins Spheniscus demersus was studied in and around southwestern Cape Province, Saldanha Bay (33⁰ S, 18⁰ E), South Africa. Penguins are difficult to observe at sea. Hence, I devised a number of new techniques for studying the foraging behaviour of Jackass Penguins at sea. I built electronic and autoradiographic remote-sensing devices to measure swimming speed, distance travelled and time spent at each depth by foraging Jackass Penguins. Penguin swimming speed was reduced in proportion to the cross-sectional area of the devices, and results derived from birds wearing the devices had to be interpreted accordingly. Penguins do not regurgitate their stomach contents when handled, so I constructed a wet-offloading stomach pump which extracted 100% of the stomach contents. Using this pump, I determined that the rate of digestion of fish and squid by Jackass Penguins differed. Care is needed in diet interpretations where both fish and squid are major food items.","abstract_has_math":false,"creators":["Wilson, Rory Paul"],"institution":"Percy FitzPatrick Institute of African Ornithology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Siegfried, Roy"],"committee_chairs":[],"committee_members":[],"year":1986,"date_issued":"1986","date_published":"1986","updated_at":"2026-07-22T22:23:06Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/17653","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Siegfried, Roy"]},{"key":"dc:creator","label":"Author","values":["Wilson, Rory Paul"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-03-11T14:25:46Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-03-11T14:25:46Z"]},{"key":"dc:date.issued","label":"Date","values":["1986"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Percy FitzPatrick Institute of African Ornithology"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Doctoral Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["PhD"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/17653"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Bibliography: pages 187-191."]},{"key":"dc:description.abstract","label":"Abstract","values":["The foraging of breeding Jackass Penguins Spheniscus demersus was studied in and around southwestern Cape Province, Saldanha Bay (33⁰ S, 18⁰ E), South Africa. Penguins are difficult to observe at sea. Hence, I devised a number of new techniques for studying the foraging behaviour of Jackass Penguins at sea. I built electronic and autoradiographic remote-sensing devices to measure swimming speed, distance travelled and time spent at each depth by foraging Jackass Penguins. Penguin swimming speed was reduced in proportion to the cross-sectional area of the devices, and results derived from birds wearing the devices had to be interpreted accordingly. Penguins do not regurgitate their stomach contents when handled, so I constructed a wet-offloading stomach pump which extracted 100% of the stomach contents. Using this pump, I determined that the rate of digestion of fish and squid by Jackass Penguins differed. Care is needed in diet interpretations where both fish and squid are major food items."]},{"key":"dc:title","label":"Title","values":["Breeding Jackass Penguins as pelagic predators"]}]}],"canonical_facts":{"dc:contributor.advisor":["Siegfried, Roy"],"dc:creator":["Wilson, Rory Paul"],"dc:date.accessioned":["2016-03-11T14:25:46Z"],"dc:date.available":["2016-03-11T14:25:46Z"],"dc:date.issued":["1986"],"dc:description":["Bibliography: pages 187-191."],"dc:description.abstract":["The foraging of breeding Jackass Penguins Spheniscus demersus was studied in and around southwestern Cape Province, Saldanha Bay (33⁰ S, 18⁰ E), South Africa. Penguins are difficult to observe at sea. Hence, I devised a number of new techniques for studying the foraging behaviour of Jackass Penguins at sea. I built electronic and autoradiographic remote-sensing devices to measure swimming speed, distance travelled and time spent at each depth by foraging Jackass Penguins. Penguin swimming speed was reduced in proportion to the cross-sectional area of the devices, and results derived from birds wearing the devices had to be interpreted accordingly. Penguins do not regurgitate their stomach contents when handled, so I constructed a wet-offloading stomach pump which extracted 100% of the stomach contents. Using this pump, I determined that the rate of digestion of fish and squid by Jackass Penguins differed. Care is needed in diet interpretations where both fish and squid are major food items."],"dc:identifier.uri":["http://hdl.handle.net/11427/17653"],"dc:language.iso":["eng"],"dc:publisher.department":["Percy FitzPatrick Institute of African Ornithology"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["Breeding Jackass Penguins as pelagic predators"],"dc:type":["Doctoral Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["PhD"]},"updated_at":"2026-07-22T22:23:06Z"}