Factors influencing the foraging behaviour of African Penguins (Spheniscus demersus) provisioning chicks at Robben Island, South Africa by Kate Campbell Student number: RBNKAT008 Thesis presented for the Degree of Doctor of Philosophy (PhD) Department of Biological Sciences Faculty of Science UniversityUNIVERSITY ofOF CAPE Cape TOWN Town Supervised by Professor Les G. Underhill Co-supervised by: Dr. Richard B. Sherley Dr. Antje Steinfurth Dr. Rob J. M. Crawford December 2016 The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgement of the source. The thesis is to be used for private study or non- commercial research purposes only. Published by the University of Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University of Cape Town DECLARATION I, Katrina (Kate) Jane Campbell, formerly Robinson, hereby declare that this thesis and the work on which this thesis is based is my original work (except where acknowledgements indicate otherwise) and that neither the whole work nor any part of it has been, is being, or is to be submitted for another degree in this or any other university. I authorise the University to reproduce for the purpose of research either the whole or any portion of the contents in any manner whatsoever. SIGNED:_____________________________Signature Removed KATRINA JANE CAMPBELL DATE:______________________________11 December 2016 ii "COURAGE IS NOT THE ABSENCE OF FEAR, BUT THE TRIUMPH OVER IT." ‒ TATA NELSON ROLIHLAHLA MADIBA MANDELA “SHE HAD HEARD IT SAID THAT HUMANS ARE SUPPOSED ONLY TO USE ABOUT A TENTH OF THEIR BRAINS, AND THAT NO ONE WAS VERY CLEAR WHAT THE OTHER NINE-TENTHS WERE FOR, BUT SHE HAD CERTAINLY NEVER HEARD IT SUGGESTED THAT THEY WERE USED FOR STORING PENGUINS.” DOUGLAS ADAMS – LONG DARK TEA TIME OF THE SOUL "MY FAVOURITE IMAGE OF KNOWLEDGE IS THE OLD ONE OF A CANDLE BURNING ON A DARK NIGHT; THE BRIGHTER THE FLAME THE WIDER THE VAULT OF THE UNKNOWN BEHIND IT [...] WHATEVER THE SPECIES, NO LONGER NEED WE WAVE GOODBYE TO OUR BIRDS ON THE SHORELINE. NOW AT LAST WE HAVE THE TECHNOLOGY TO FOLLOW THEM TO SEA." BERNARD STONEHOUSE – PENGUIN BIOLOGY iii FOR THE PENGUINS iv ABSTRACT PhD Thesis: Factors influencing the foraging behaviour of African Penguins (Spheniscus demersus) provisioning chicks at Robben Island, South Africa by Kate Campbell December 2016 Urgent and effective conservation is needed to halt the declines of endangered African Penguins. A purse-seine fisheries closure zone was in place out to 20 km around Robben Island for three years. It provided an opportunity to investigate penguin foraging behaviour in relation to estimated local prey abundance and other factors without the confounding variable of local fishing. Penguins provisioning chicks were equipped with GPS temperature depth devices for a foraging trip. Dive data (N = 75) and GPS tracks (N = 78) were collected from 78 penguins. Of those, 14 penguins were at-sea within two days of a fine-scale hydro-acoustic pelagic fish survey. Diet sampling, breeding success and chick body condition monitoring took place in the colony. Nests were followed to outcome. Morphological indicators were developed for sex determination and body condition. Intrinsic factors, brood mass, prey abundance, wave height and direction were explored in respect to foraging behaviour. Kernel density analysis identified foraging areas, confirming consistent use of the closure area. Annual differences in foraging effort were explained by variation in local prey abundance. The time the penguins spent diving and the distance travelled from the colony were negatively related to local prey abundance. There was greater variation in foraging distance when prey abundance was lower. Foraging areas and dive behaviour were similar for the sexes. The survival of chicks in the foraging study did not differ from chicks monitored in the colony for breeding success (control chicks). The trips of penguins with nesting success (N = 44) were on average 4.5 km closer to the colony than the penguins that had nesting failure (N = 21). Chick body condition in the colony was positively related to the Anchovy (Engraulis encrasicolus) mass percentage in the diet and the local pelagic fish abundance; condition was predicted to vary by 245% over the range of local fish abundance observed during the study period (0.5 to 187 thousand tonnes). Identifying ways to avoid depletion of prey resources around penguin colonies is important for conservation of the species. v ACKNOWLEDGMENTS FUNDING A tremendous thank you to all funding sources. This research was part of the Ma-Re BASICS (Marine Research in the Benguela and Agulhas Systems for supporting Inter-disciplinary Climate-change Science) programme. Bursary money for this research was provided by the Leiden Conservation Foundation, Marine Research Institute (Ma-Re) at the University of Cape Town and by the South African Research Chair in Marine Ecology and Fisheries. Special thanks to Tom and Kathy Leiden for their generosity to this project and African Penguin research. The logger devices were funded by National Research Foundation (NRF) and provided by the Department of Environmental Affairs, Oceans and Coasts Branch (DEA). Thanks to the 8th International Penguin Conference for travel funding and to the Animal Demography Unit for funding my registration to the 2nd World Seabird Conference; attending those conferences provided insight and momentum. Finances for measurement equipment, scales and callipers, were provided by the Chick Bolstering Project. African Penguin morphological data collection is from research conducted over the years funded by many sponsors: BirdLife South Africa, Charl van der Merwe Trust, Chick Bolstering Project, SANCCOB, Ma-Re Marine Research Institute, Leiden Conservation Foundation, International Fund for Animal Welfare (IFAW), Hans Hoheisen Charitable Trust, the National Lottery Distribution Trust Fund (NLDTF). the National Research Foundation as well as the sponsors of the zoos and aquaria listed below. DATA I acknowledge the wave data supplied by the CSIR, Stellenbosch, which was collected on behalf of the Transnet National Port Authority (TNPA). Thanks to Ursula von Saint Ange with her assistance with wave data. Weather data for Robben Island were provided from the South African Weather Service. Thanks to Phumudzo Tharaga and Dawn Mahlobo for their assistance with the data requests. The South African Navy Hydrographic Office provided the bathymetry data around Robben Island. The Department of Agriculture, Forestry and Fisheries (DAFF) conducted and analysed the hydro-acoustic surveys and provided small pelagic catch data. I am extremely appreciative for their work and the opportunity to collaborate with Janet Coetzee, Dagmar Merkle, Johan Rademan and Carl van der Lingen. Their assistance provided insight to the fisheries and ecological dynamics of the system. The success of simultaneous penguin tracking and fine-scale fish surveys is largely due to their cooperation and willingness to communicate with me in the field. DEA provided penguin diet, morphological and annual census data of African Penguins. I am grateful to all the DEA staff that collect and manage the African Penguin data sets; special thanks to Azwianewi Makhado, Leshia Upfold, Bruce Dyer, Sagwadi Felicia Maluleke and Rob Crawford. Leshia Upfold assisted with the request for the raw diet sample data sheets. Thanks to Bruce Dyer for providing African Penguin post-mortem morphological measurements that were collected after the MV Treasure oil spill. The Earthwatch Penguin Project collected the chick condition and breeding success data at Robben Island. The time and dedication of all participants and facilitators past and present are greatly appreciated. The multiple measurements of chicks that fledged in 2004 were collected by Sandra Bouwhuis. Barbara Barham and Richard Sherley assisted with chick survival data processing of control chicks and provided input on the survival analysis. The African Penguin morphological data sets were provided from several sources. SANCCOB provided adult morphological measurements and post-mortem data sets. African Penguin Namibian vi measurements from Mercury and Halifax islands, were provided by Katrin Ludynia, Jessica Kemper, Rian Jones and the African Penguin Conservation Project. The Ministry of Fisheries and Marine Resources, Lüderitz, Namibia provided logistical support and permission for them to work on the islands. In South Africa penguin measurements were provided from DEA, CapeNature, SANCCOB, Percy FitzPatrick Institute of African Ornithology and Animal Demography Unit, Department of Biological Sciences, University of Cape Town and in particular from: Shannon Hampton, Katrin Ludynia, Nola Parsons, Lorien Pichegru, Richard Sherley, Antje Steinfurth, Marlene Van Onselen and Leshia Upfold. Gayle Sirpenski, African Penguin Species Survival Plan (SSP) coordinator, supplied the captive African Penguin measurements. Zoos and aquaria provided captive African Penguin morphometrics from: Adventure Aquarium, Caldwell Zoo, Cheyenne Mountain Zoological Society, Como Zoo, Dallas Zoo, Georgia Aquarium, Henson Robinson Zoo, Jenkinson's Aquarium, Knoxville Zoological Gardens, Monterey Bay Aquarium, Mystic Aquarium, Newport Aquarium, Northeastern Wisconsin Zoo, Omaha's Henry Doorly Zoo, Racine Zoo, Tautphaus Park Zoo, Toledo Zoo, and Utah's Hogle Zoo. I am grateful to all the staff, students and