dc.contributor.author | Gaglio, D | |
dc.contributor.author | Cook, TR | |
dc.contributor.author | Sherley, RB | |
dc.contributor.author | Ryan, PG | |
dc.date.accessioned | 2018-05-08T12:43:29Z | |
dc.date.issued | 2018-04-07 | |
dc.description.abstract | Seabirds use several methods to transport food to their chicks; most species carry food in their stomachs or crops, but some terns and auks carry prey in their bills. Terns usually only carry one prey item at a time, limiting the rate at which they can provision their chicks, and restricting their effective foraging range. However, some terns do occasionally carry multiple prey, which should offer a selective advantage, but there are very few studies investigating the factors influencing the occurrence of multi-prey loading. We investigated the occurrence of multi-prey loads in provisioning Greater Crested Terns (Swift Tern) Thalasseus bergii bergii breeding on Robben Island, South Africa. Of 24 173 loads photographed, 1.3% comprised multiple prey items. Up to 11 fish were carried at once, but most multi-prey loads contained two Anchovies Engraulis encrasicolus, the most common prey item for this population of terns. Mixed species prey were recorded for the first time in a tern. Multi-prey loads occurred more frequently during mid- and late-provisioning, presumably because large chicks can cope with multiple prey, and have higher energetic requirements than small chicks. Mean standard length of Anchovies in multi-prey prey loads was less than Anchovies in single loads, possibly suggesting terns compensate for smaller prey sizes by bringing multiple prey back to their chick. The orientation of multiple Anchovies in a tern’s bill tended to be the same, suggesting that they were captured from polarised fish schools. At least some multi-prey loads were caught in a single dive. | en_GB |
dc.description.sponsorship | Our research was supported by a
Department of Science and Technology–National Research
Foundation grant to the Centre of Excellence at the FitzPatrick
Institute of African Ornithology, the Leiden Conservation
Foundation (RBS) and our institutes. SANParks and Robben
Island Museum provided logistical support and access to the tern
colonies. This research was approved by SANParks (CONM1182),
the Department of Environmental Affairs (RES2013/24,
RES2014/83 and RES2015/65) and the animal ethics committee of
the University of Cape Town (2013/V3/TC). | en_GB |
dc.identifier.citation | 2018: 1 - 5 | en_GB |
dc.identifier.doi | 10.2989/00306525.2018.1439116 | |
dc.identifier.uri | http://hdl.handle.net/10871/32754 | |
dc.language.iso | en | en_GB |
dc.publisher | Taylor & Francis / National Inquiry Services Centre (NISC) | en_GB |
dc.rights.embargoreason | Under embargo until 10th April 2019 in compliance with publisher policy. | en_GB |
dc.rights | Copyright © NISC (Pty) Ltd | en_GB |
dc.title | How many can you catch? Factors influencing the occurrence of multi-prey loading in provisioning Greater Crested Terns | en_GB |
dc.type | Article | en_GB |
dc.identifier.issn | 0030-6525 | |
dc.description | This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record. | en_GB |
dc.identifier.journal | Ostrich | en_GB |