Browsing by Author "Waller, Lauren J."

Now showing 1 - 6 of 6
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    Applying science to pressing conservation needs for penguins
    (Wiley-Blackwell, 2020) Waller, Lauren J.; Boersma, P. Dee; Borboroglu, J. P.G.
    More than half of the world's 18 penguin species are declining. We, the Steering Committee of the International Union for Conservation of Nature Species Survival Commission Penguin Specialist Group, determined that the penguin species in most critical need of conservation action are African penguin (Spheniscus demersus), Galápagos penguin (Spheniscus mendiculus), and Yellow-eyed penguin (Megadyptes antipodes). Due to small or rapidly declining populations, these species require immediate scientific collaboration and policy intervention. We also used a pairwise-ranking approach to prioritize research and conservation needs for all penguins. Among the 12 cross-taxa research areas we identified, we ranked quantifying population trends, estimating demographic rates, forecasting environmental patterns of change, and improving the knowledge of fisheries interactions as the highest priorities. The highest ranked conservation needs were to enhance marine spatial planning, improve stakeholder engagement, and develop disaster-management and species-specific action plans. We concurred that, to improve the translation of science into effective conservation for penguins, the scientific community and funding bodies must recognize the importance of and support long-term research; research on and conservation of penguins must expand its focus to include the nonbreeding season and juvenile stage; marine reserves must be designed at ecologically appropriate spatial and temporal scales; and communication between scientists and decision makers must be improved with the help of individual scientists and interdisciplinary working groups.
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    The conservation status and population decline of the African penguin deconstructed in space and time
    (Wiley-Blackwell, 2020) Waller, Lauren J.; Sherley, Richard B.; Crawford, Robert J.M.
    Understanding changes in abundance is crucial for conservation, but population growth rates often vary over space and time. We use 40 years of count data (1979–2019) and Bayesian state-space models to assess the African penguin Spheniscus demersus population under IUCN Red List Criterion A. We deconstruct the overall decline in time and space to identify where urgent conservation action is needed. The global African penguin population met the threshold for Endangered with a high probability (97%), having declined by almost 65% since 1989. An historical low of ~17,700 pairs bred in 2019. Annual changes were faster in the South African population (−4.2%, highest posterior density interval, HPDI: −7.8 to −0.6%) than the Namibian one (−0.3%, HPDI: −3.3 to +2.6%), and since 1999 were almost −10% at South African colonies north of Cape Town. Over the 40-year period, the Eastern Cape colonies went from holding ~25% of the total penguin population to ~40% as numbers decreased more rapidly elsewhere. These changes coincided with an altered abundance and availability of the main prey of African penguins. Our results underline the dynamic nature of population declines in space as well as time and highlight which penguin colonies require urgent conservation attention.
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    Descriptive epidemiology of and response to the high pathogenicity avian influenza (h5n8) epidemic in South African coastal seabirds, 2018
    (Wiley, 2023) Roberts, Laura C.; Abolnik, Celia; Waller, Lauren J.
    High pathogenicity avian infuenza (HPAI) clade 2.3.4.4b H5N8 virus was detected in coastal seabirds in late 2017 in South Africa, following a devastating epidemic in the commercial poultry and ostrich industries. By May 2018, the infection had been confrmed in ffteen seabird species at 31 sites along the southern coast, with the highest mortality recorded in terns (Family Laridae, Order Charadriiformes). Over 7,500 positive or suspected cases in seabirds were reported. Among those infected were three endangered species: African penguins (Spheniscus demersus Linnaeus, 1758), Cape cormorants (Phalacrocorax capensis Wahlberg, 1855), and Cape gannets (Morus capensis Lichtenstein, 1823). Te scale and impact of this outbreak were unprecedented in southern African coastal seabirds and raised logistical challenges in resource allocation, risk mitigation, and outbreak response. It required the collaboration of multiple stakeholder groups, including a variety of government departments and nongovernmental organizations. With another HPAI outbreak in South African seabirds in 2021 and major incursions in seabird species in the northern hemisphere in 2022, it is vital to share and consolidate knowledge on the subject. We describe the epidemic, the lessons learned, and recommendations for developing contingency plans.
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    The effects of anthropogenic disturbance upon African penguin colonies
    (University of Western Cape, 2020) Miller, Rebecca Jane; Maneveldt, Gavin W.; Pichegru, Lorien; Sherley, Richard B.; Waller, Lauren J.
    African penguin (Spheniscus demersus) mainland colonies are a popular tourist attraction in the Western Cape of South Africa. The African penguin population is in decline and the species is listed as endangered on the International Union for the Conservation of Nature (IUCN) Red List. This thesis aimed to investigate the impact of ecotourism upon African penguin colonies by comparing two colonies of differing levels of tourist visitation in the Western Cape in 2017. The high visitation colony is a mainland colony where ecotourism activities take place (Stony Point), and the low visitation colony is an island colony where ecotourism does not occur (Robben Island). As well as inter-colony comparisons, nests at the high visitation colony within areas of differing exposure levels were also compared.
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    Factors that influence cape fur seal predation on Cape gannets at Lambert’s bay, South Africa
    (PeerJ, 2022) Strydom, Zanri; Waller, Lauren J.; Brown, Mark
    Seabird populations experience predation that can impact their breeding density and breeding success. The Cape gannet Morus capensis is endemic to the Benguela upwelling ecosystem and is classified as Endangered by the IUCN. They are affected by several threats, including predation by the Cape fur seal Arctocephalus pusillus pusillus. Many fledglings succumb to predation during their maiden flight across waters around the island. To curb predation, the selective culling of individual predatory seals was implemented in 2014, 2015, and 2018. Our first study objective was to determine if selective culling of Cape fur seals significantly reduced predation probability on Cape gannets. We tested whether predation probability in 2014, 2015, and 2018 was affected by fish biomass, gannet fledgling numbers, and/or the presence/absence of selective culling.
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    Nest-type associated microclimatic conditions as potential drivers of ectoparasite infestations in African penguin nests
    (Springer Nature, 2020) Waller, Lauren J.; Espinaze, Marcela P.A.; Hui, Cang
    Nest design and characteristics can influence the microclimatic conditions in the nest. Nest-dwelling ectoparasites are sensitive to temperature and moisture and as such the conditions in the nest can influence parasite infestations. The endangered African penguin (Spheniscus demersus) breeds in different nest types and as yet little is known with regard to the microclimate and parasite infestation within these nests. This study characterized the microclimatic conditions in natural open, natural covered (with vegetation) and artificial nests, and assessed the relationship between nest characteristics (type, age, distance from the coast, orientation and entrance opening) and in-nest ectoparasite infestations and the health of African penguins in Stony Point, South Africa. Penguins (50 adults and 192 chicks) and their nests (n = 308) were sampled in 2016 and 2017.