Correction to ‘Bayesian inference reveals positive but subtle effects of experimental fishery closures on marine predator demographics'

Sherley, Richard B.; Barham, Barbara J.; Campbell, Kate J.; Crawford, Robert J. M.; Grigg, Jennifer; Horswill, Catharine; McInnes, Alistair; Morris, Taryn L.; Pichegru, Lorien; Steinfurth, Antje; Weller, Florian; Winker, Henning; Votier, Stephen C.

doi:10.1098/rspb.2021.2129

Cited by 8 publications

(1 citation statement)

References 10 publications

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“…While historically driven by egg collection and guano scraping (Crawford et al, 2018;Frost et al, 1976), current declines are predominantly attributed to reduced prey availability (Crawford et al, 2011;Sherley et al, 2020). Shifting geographic distributions of sardine (Sardinops sagax) and anchovy (Engraulis encrasicolus), the main prey of African penguins, apparently exacerbated by competition with fisheries, has been linked to both reduced survival (Robinson et al, 2015;Sherley, Abadi, et al, 2014) and lower breeding success (Crawford, Barham, et al, 2006;Sherley et al, 2013Sherley et al, , 2021. However, population growth of seabirds can also be influenced by the proportion of the population that breeds each year (Cam et al, 1998;Le Bohec et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Intercolony variation in reproductive skipping in the African penguin

Leith

Grigg

Barham³

et al. 2022

Ecology and Evolution

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In long‐lived species, reproductive skipping is a common strategy whereby sexually mature animals skip a breeding season, potentially reducing population growth. This may be an adaptive decision to protect survival, or a non‐adaptive decision driven by individual‐specific constraints. Understanding the presence and drivers of reproductive skipping behavior can be important for effective population management, yet in many species such as the endangered African penguin (Spheniscus demersus), these factors remain unknown. This study uses multistate mark‐recapture methods to estimate African penguin survival and breeding probabilities at two colonies between 2013 and 2020. Overall, survival (mean ± SE) was higher at Stony Point (0.82 ± 0.01) than at Robben Island (0.77 ± 0.02). Inter‐colony differences were linked to food availability; under decreasing sardine (Sardinops sagax) abundance, survival decreased at Robben Island and increased at Stony Point. Additionally, reproductive skipping was evident across both colonies; at Robben Island the probability of a breeder becoming a nonbreeder was ~0.22, versus ~0.1 at Stony Point. Penguins skipping reproduction had a lower probability of future breeding than breeding individuals; this lack of adaptive benefit suggests reproductive skipping is driven by individual‐specific constraints. Lower survival and breeding propensity at Robben Island places this colony in greater need of conservation action. However, further research on the drivers of inter‐colony differences is needed.

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Section: Introductionmentioning

confidence: 99%

Intercolony variation in reproductive skipping in the African penguin

Leith

Grigg

Barham³

et al. 2022

Ecology and Evolution

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Decades of artificial nests towards African penguin conservation—Have they made a difference?

Pichegru,

Sherley,

Malan

et al. 2024

Ecol Sol and Evidence

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African penguins are among the most threatened seabird species globally and an African Penguin Biodiversity Management Plan (BMP) published in 2013 guides conservation strategies to prevent their extinction. To counter the impact of past guano exploitation which reduced the nesting habitat of these burrowing seabirds, rendering them vulnerable to predators and extreme weather events, a suite of artificial nests was deployed in various colonies over the past decades with varying success. The BMP called for new nest designs to maximise breeding output. This study assesses African penguin breeding success over the past 14 years in four types of artificial nests and in natural nests at all major colonies in South Africa. Overall, artificial nests outperformed natural nests and successfully increased breeding output of African penguins by 16.5% (95% CI: 6.7–26.2). No design was, however, consistently most effective across locations. For example, fibreglass nests had the poorest hatching success of all nest types at one colony (Bird Island), but outperformed cement nests at another (Boulders Beach). The latest design of double‐layered ceramic nests tended to perform better than other artificial nests, although not consistently at all colonies and occupancy rates were low in some areas. Practical implication. The deployment of artificial nests proved to be a successful conservation measure for African penguins although the variety of habitats in the different colonies seems to have prevented a one solution‐fits‐all approach. The consistent poor breeding output in some areas in all nest types (<30% at the mainland colony in Simons' Town and the islands in Algoa Bay) further calls for colony‐specific conservation strategies beyond artificial nests, while the continuous decline in African penguin numbers globally calls for broader measures urgently, primarily increasing access to their forage fish prey.

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The Decline and Conservation Status of the African Penguin

Grigg

Sherley

2022

Imperiled: The Encyclopedia of Conservation

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Correction to ‘Bayesian inference reveals positive but subtle effects of experimental fishery closures on marine predator demographics'

Cited by 8 publications

References 10 publications

Intercolony variation in reproductive skipping in the African penguin

Intercolony variation in reproductive skipping in the African penguin

Decades of artificial nests towards African penguin conservation—Have they made a difference?

The Decline and Conservation Status of the African Penguin

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