Year: 2002
Type: dissertation
Abstract: Movements, survival, age of first recorded breeding and the success of rehabilitating oiled African Penguins were investigated using re-sightings of flipper-banded birds. Seventeen penguin colonies between Algoa Bay and Lambert’s Bay, South Africa, were visited between March 1995 and October 1999. Flipper-band numbers were read using binoculars and a telescope and recorded along with details of the activity of the banded birds. All sightings of banded penguins were entered into a database, providing details of 11 623 birds. The database was investigated for incidences of movements of penguins between different breeding colonies and for evidence of emigration and immigration. For birds of known age, i.e. those banded as chicks, the age at which they were first recorded breeding was calculated. The computer program MARK was used to evaluate annual survival rates for adult penguins and for those in their first year of life. The proportion of hand-reared, orphaned chicks that survived to breeding age was compared to that of naturally fledged chicks. Annual and long-term survival of oiled, cleaned and released penguins was compared to that of penguins that had not been oiled. African Penguins were found to travel up to 1910 km in their first two years of life. Most travelled west and north along the coast. Adult penguins also visited other colonies to moult and to forage. Two percent of the penguins banded as chicks that were re-sighted alive had settled to breed at non-natal colonies. Fourteen percent were recorded breeding at natal colonies. Of 5968 penguins that were banded in adult plumage and subsequently re-sighted alive, eight were found to have attempted to breed at more than one locality. Breeding by African Penguins at more than one locality has not been previously recorded. All eight penguins had been cleaned and released following a major oil spill in 1994. Emigration of young penguins is considered to be the means by which the mainland colonies of The Boulders and Stony Point were established. The mean age of first recorded breeding of African Penguins was found to be between four and five years old. Mean annual adult survival was estimated to be 0.81 for birds banded at Robben and Dassen Islands, and ranged between 0.10 and 0.80, averaging 0.35, for first year birds. Hand-reared orphaned chicks survived equally well in the wild as naturally fledged chicks and similar proportions returned to breed. Annual survival rates of penguins that had been oiled, cleaned and released were similar to those of penguins that had not been oiled. Long-term survival of rehabilitated penguins was equal to that of non-treated birds. Rehabilitation of oiled African Penguins is considered to be a worthwhile conservation tool for a species that is still undergoing a long-term decline. STATUS OF PUBLISHED CHAPTERS IN THIS THESIS CHAPTER THREE: Movements of African Penguins to and from The Boulders, South Africa This chapter formed the part for which I was mainly responsible of the following paper: Crawford, R.J.M., Shannon, L.J., Whittington P.A. & Murison, G. 2000. Factors influencing growth of the African penguin colony at Boulders, South Africa, 1985– 1999. S. Afr. J. Mar. Sci. 22: 111–119. RJMC initiated and wrote most of the sections of the published paper and coordinated the fieldwork. LJS assisted with collection of data and information from The Boulders. GM contributed data from her field study and wrote the section on nesting success in 1998. PAW collected much of the data on flipper-band re-sightings and wrote the sections on inter-colony movements in the results and discussion, which form the substance of this chapter of the thesis. CHAPTER NINE: A comparison of long-term survival of rehabilitated African Penguins with that of non-oiled penguins and other species of seabirds Published as: Whittington, P.A. 1999. The contribution made by cleaning oiled African Penguins Spheniscus demersus to population dynamics and conservation of the species. Mar. Ornithol. 27:177-180. CHAPTER TEN: Establishment, growth and conservation of a mainland colony of African Penguins at Stony Point, Betty’s Bay, South Africa. Published as: Whittington, P.A., Hofmeyr, J.H. & Cooper, J. 1996. Establishment, growth and conservation of a mainland colony of Jackass Penguins Spheniscus demersus at Stony Point, Betty’s Bay, South Africa. Ostrich 67: 144-150. PAW: Performed the data analyses, wrote the entire text and produced the figures and tables. JHH: Was responsible for the bulk of the fieldwork, with help from the Stony Point Advisory Committee, collected and collated the data and provided background information. JC Provided additional reference material and background information, largely based on his personal experience with this colony in the years immediately following its establishment.
Author: Phil Whittington
Language: English
Topic: Avian ecology and behavior
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W618863587