
Lorien Pichegru- PhD
- Acting Director at Coastal and Marine Research Institute
Lorien Pichegru
- PhD
- Acting Director at Coastal and Marine Research Institute
About
94
Publications
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Introduction
My research focuses on seabirds foraging ecology and life history traits in relation to prey availability and local competition with industrial fisheries, using animal-borne miniaturized recorders, such as GPS recorders combined with pressure sensors, cameras, etc, taped on adults breeding small chicks to determine the at-sea behaviour of several species of seabirds breeding in South Africa, endemic to the region and threatened with extinction.
Current institution
Coastal and Marine Research Institute
Current position
- Acting Director
Additional affiliations
April 2008 - December 2009
August 2013 - April 2015
January 2013 - present
Publications
Publications (94)
No-take zones may protect populations of targeted marine species and restore the integrity of marine ecosystems, but it is unclear whether they benefit top predators that rely on mobile pelagic fishes. In South Africa, foraging effort of breeding African penguins decreased by 30 per cent within three months of closing a 20 km zone to the competing...
Studies investigating how mobile marine predators respond to their prey are limited due to the challenging nature of the environment. While marine top predators are increasingly easy to study thanks to developments in bio-logging technology, typically there is scant information on the distribution and abundance of their prey, largely due to the spe...
Seismic surveys in search for oil or gas under the seabed, produce the most intense man-made ocean noise with known impacts on invertebrates, fish and marine mammals. No evidence to date exists, however, about potential impacts on seabirds. Penguins may be expected to be particularly affected by loud underwater sounds, due to their largely aquatic...
The population of the Endangered African penguin Spheniscus demersus has decreased by > 65% in the last 20 years. A major driver of this decrease has been the reduced availability of their principal prey, sardine Sardinops sagax and anchovy Engraulis encrasicolus. To date, conservation efforts to improve prey availability have focused on spatial ma...
The rapid increase in seaborn trade since the 1990s has resulted in an increase in vessel-derived noise pollution, yet there is little evidence linking these activities to a decline in many marine taxa, such as seabirds. Algoa Bay, South Africa, is a marine biodiversity hotspot, providing habitats for the largest populations of endangered African P...
Heat stress from high temperatures has been recognised as a threat to several bird species and one that is likely to increase in severity and frequency as a result of global environmental change. Many seabirds are particularly vulnerable as their adaptations to forage in cold water can make it hard for them to resist heat gain while on land. The Af...
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 p...
Opportunistic species, including some gulls (Laridae), can benefit from urbanization and increased anthropogenic food resources. Knowledge of the level of exploitation of anthropogenic resources by gulls is crucial to understand how changes in food availability might affect their populations, which in turn may impact other species. The Kelp Gull La...
The African penguin population has declined precipitously in recent decades, and if current rates of decline persist, this species could become extinct in the wild by 2035. Resource extraction of small pelagic fish prey by the purse-seine fishery around African penguin breeding colonies has been identified as a demographically meaningful threat to...
The 2023 edition of the African Litter Monitoring Manual is a guide for harmonised litter monitoring in different environments. Accounting for Africa’s limited resources, the methods are simple and feasible to empower citizen scientists, researchers and other stakeholders, with different languages and backgrounds, with the knowledge and tools neede...
Senescence is the irreversible decline in physiological functioning and survival with age. While this phenomenon has been studied in a range of different taxa, including seabirds, it has seldom been assessed for both sexes of monomorphic species, and in conservation contexts. Here, we studied the effect of age and sex on the foraging trip character...
Global biodiversity is in rapid decline, and many seabird species have disproportionally poorer conservation statuses than terrestrial birds. A good understanding of population dynamics is necessary for successful conservation efforts, making noninvasive, cost-effective monitoring tools essential. Here, we set out to investigate whether passive aco...
The likelihood of success of a marine protected area (MPA) is strongly dependent on stakeholders’ support. A concern often raised by local fishers is their lack of involvement in the design or management of a MPA and their loss of income owing to lost fishing grounds. We used Algoa Bay, South Africa, as a case study to analyse fisher’s and fish-pro...
Storms can cause widespread seabird stranding and wrecking,1,2,3,4,5 yet little is known about the maximum wind speeds that birds are able to tolerate or the conditions they avoid. We analyzed >300,000 h of tracking data from 18 seabird species, including flapping and soaring fliers, to assess how flight morphology affects wind selectivity, both at...
Decision-making with regard to saving the African penguin from extinction has been challenging for managing authorities. The penguin population had plummeted from five million breeding pairs in the early 1900s to <10 000 in 2022 placing it on the IUCN Endangered list in 2010. Despite several management interventions over the last two decades, the p...
Low-latitude penguins naturally breed in burrows dug in guano. This affords them a buffered environment that remains cool and humid, reducing the risk of hyperthermia while on land. As a conservation strategy, several versions of artificial housing units have been trialled at various breeding sites of African Penguins ( Spheniscus demersus ) around...
Kelp Gulls Larus dominicanus are widespread globally due to their ability to exploit a wide variety of resources and foraging habitats inland, in coastal areas and offshore. However, the increasing availability of anthropogenic diet items might potentially impact the health of their populations. We investigated body condition and parasite loads of...
To support sustainable growth of ocean-based economies, many countries are engaging in marine spatial planning (MSP) processes, which require robust decision-support tools. Systematic conservation planning (SCP) is commonly used in decision-making to guide spatially efficient protected area expansion. Here we contend that SCP can also be used to st...
Flying seabirds are adapted for windy environments 1,2 . Despite this, storms can cause widespread strandings and wrecks, demonstrating that these seabirds are not always able to avoid or compensate for extreme conditions 3,4,5,6,7 . The maximum wind speeds that birds can operate in should vary with morphology and flight style ⁸ , but this has been...
Fear effects of predators on prey distributions are seldom considered in marine environments , especially over large spatial scales and in conservation contexts. To fill these major gaps, we tested the Seascape of Fear Hypothesis in the Benguela marine ecosystem off South Africa. Using electronic tracking data, we showed that Cape gannets and their...
In coastal waters, nutrient supplies originate principally from allochthonous sources, such as inputs from rivers, estuaries or oceanic waters. Recently, it has been suggested that marine life contributes to the nutrient load, with penguin colonies being the largest contributor worldwide. This study aimed to quantify the nitrogen (N) and phosphorus...
Data on marine litter is crucial to guide waste management but is scarce in third-world countries such as South Africa. We established the first baseline measurement of litter accumulation on two beaches differing in public access in Port Elizabeth, Eastern Cape, the poorest province in South Africa. Four 10-day surveys were conducted on each beach...
Despite the importance of ecotourism in species conservation, little is known about the industry's effects on wildlife. In South Africa, some African penguin (Spheniscus demersus) colonies have become tourist attractions. The species is globally endangered, with population sizes decreasing over the past 40 years. As African penguin chicks are altri...
African Penguins (Spheniscus demersus) are endangered and declining seabirds which make extensive use of vocal signals for intra‐specific vocal communication. Accordingly, passive acoustic monitoring tools could be developed as robust population monitoring methods that cause minimal disturbance to the birds. In this study, we collected soundscape r...
Background:
Kelp Gulls Larus dominicanus are one of the most abundant gulls in the Southern Hemisphere and can play an important role in their ecosystem. Understanding their foraging ecology is therefore important, especially in the context of anthropogenic changes of the environment. Over 35,000 Kelp Gulls breed in South Africa but little is know...
Social information percolates through a variety of channels to influence animal decision making, with a notable effect on reproductive and feeding success. Colonial central place foragers can reduce time to locate ephemeral food patches and/or increase foraging rate by following their informed peers, parasitizing direction of returning successful f...
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 id...
Marine predators adapt their hunting techniques to locate and capture prey in response to their surrounding environment. However, little is known about how certain strategies influence foraging success and efficiency. Due to the miniaturisation of animal tracking technologies, a single individual can be equipped with multiple data loggers to obtain...
In the context of marine anthropogenic debris management, monitoring is essential to assess whether mitigation measures to reduce the amounts of waste plastic entering the environment are being effective. In South Africa, baselines against which changes can be assessed include data from the 1970s to the 1990s on microplastics floating at sea, on ma...
African Penguin Spheniscus demersus numbers have declined steadily over three generations, resulting in a loss of nearly 60% since of 1989. The breeding population reached an historic low of ~20,850 pairs in 2019. We use count data and JARA, a generalized Bayesian state-space tool for estimating extinction risk estimates under IUCN Red List Criteri...
Ecosystem‐based management of fisheries aims to allow sustainable use of fished stocks while keeping impacts upon ecosystems within safe ecological limits. Both the FAO Code of Conduct for Responsible Fisheries and the Aichi Biodiversity Targets promote these aims. We evaluate implementation of ecosystem‐based management in six case‐study fisheries...
Seabirds often have wide distribution ranges and may travel relatively long distances to breeding grounds, often crossing jurisdictional boundaries. When engaged in foraging behaviour, seabirds are prone to interact with different fisheries and suffer incidental mortality. We assessed the spatial use of foraging Magellanic penguins Spheniscus magel...
The African Penguin Spheniscus demersus is an endangered seabird endemic to southern Africa, and killing sprees by terrestrial predators have been one of the main threats for its mainland colonies. The methods employed to manage predators may differ depending on the species involved, therefore the implementation of strategies to limit the impacts o...
The Cape Gannet Morus capensis is one of several seabird species endemic to the Benguela upwelling ecosystem (BUS) but whose population has recently decreased, leading to an unfavourable IUCN Red List assessment. Application of ‘JARA’ (‘Just Another Red-List Assessment,’ a Bayesian state-space tool used for IUCN Red List assessments) to updated inf...
Social cohesion and prey location in seabirds are largely enabled through visual and olfactory signals, but these behavioural aspects could potentially also be enhanced through acoustic transfer of information. Should this be the case, calling behaviour could be influenced by different social‐ecological stimuli. African Penguins Spheniscus demersus...
African penguins (Spheniscus demersus) are pursuit-diving seabirds endemic to the coast of southern Africa. In this study, we investigate the presence of seashells and anthropogenic debris (e.g. plastic, glass, nylon) in the stomach contents of adult African penguins, as determined from sampling of live penguins through the water off-loading techni...
Understanding functional relationships between seabirds and prey can play an important role in the sustainable management of fisheries that compete for the same resources yet data linking the foraging performance of seabirds directly with concurrent information on prey supplies remain limited.
We assess the influence of prey availability on the for...
Optimal foraging theory suggests that the environment (e.g. distribution of resource patches) will shape an individual's decision to exploit the resource available or explore other locations. Together with the environment and the social context, individual characteristics such as personality have been recently discovered to affect behaviour, offeri...
In 2017, South Africa became the first African country to draft Marine Spatial Planning (MSP) legislation. The underlying legal framework supports the achievement of ecological, social and economic objectives, but a national policy to fast track the oceans economy provides a challenge for ecosystem-based approaches to MSP. During the 2018 Internati...
Fisheries compete with seabirds for vanishing marine resources, but also produce fishery waste consumed by seabirds. Marine birds may therefore avoid or seek fishing vessels, and have evolved complex, plastic behavioural responses to vessel presence. Understanding these responses is essential to the conservation of a globally declining seabird comm...
Nest usurpation is a relatively common phenomenon in birds but remains poorly documented in penguins. This behaviour may advantage bolder and aggressive individuals and influence population dynamics by affecting breeding success. African Penguins Spheniscus demersus are aggressive towards conspecifics during the breeding season when competing for t...
Colour aberrations among wild birds are of long-time interest because they are uncommon, particularly in seabirds, although recent publications have revealed varying forms of aberrations in cormorants and penguins. In African Penguins Spheniscus demersus, there have been previous sightings of abnormal plumages, particularly in Algoa Bay, South Afri...
Global forage-fish landings are increasing, with potentially grave consequences for marine ecosystems. Predators of forage fish may be influenced by this harvest, but the nature of these effects is contentious. Experimental fishery manipulations offer the best solution to quantify population-level impacts, but are rare. We used Bayesian inference t...
The concept of individual behavioural consistency has received a great deal of attention in the past 2 decades. However, the fitness benefits of being consistent in varying environmental conditions remain poorly explored. Such information is strongly relevant to our understanding of ecological processes, but also for predicting how some individuals...
Throughout the animal kingdom, individual variations in reproductive success are is commonly observed, even under similar environmental conditions. However, the mechanisms behind such differences remain unclear. The notion of behavioural consistency in animals has developed rapidly since the early 21st century and can partly explain individual diff...
Marine piscivores have evolved a variety of morphological
and behavioural adaptations, including group foraging, to
optimize foraging efficiency when targeting shoaling fish. For
penguins that are known to associate at sea and feed on
these prey resources, there is nonetheless a lack of empirical
evidence to support improved foraging efficiency whe...
Small pelagic fish play a significant role in regulating the foraging activities and
population trends of marine top predators in upwelling ecosystems, yet there is little information
on oceanographic drivers of fish assemblages at temporal and spatial scales relevant to their predators.
The survival of the Endangered African penguin Spheniscus dem...
Biased offspring sex ratio is relatively rare in birds and sex allocation can vary with environmental conditions, with the larger and more costly sex, which can be either the male or female depending on species, favoured during high food availability. Sex-specific parental investment may lead to biased mortality and, coupled with unequal production...
Breeding seabirds often need to locate prey in spatially confined search areas on short temporal scales. Ocean physical features such as thermoclines are used as foraging cues since they concentrate and thus increase the likelihood of locating prey. However, in highly variable environments, it is less well understood how these features act as forag...
Fisheries are often accused of starving vulnerable seabirds, yet evidence for this claim is scarce. Foraging energetics may provide efficient, short-term indicators of the fitness status of seabirds competing with fisheries. We used this approach in Cape gannets (Morus capensis) from Malgas Island, South Africa, which feed primarily on small pelagi...
Sustainable ecotourism requires careful management of human impacts on wildlife. Contrasting responses to the disturbance caused by ecotourism are observed across taxa and within species, because species and populations can differ in their tolerance to humans. However, the mechanisms by which tolerance develops remain unclear. Penguin colonies are...
Norwegian Northern Gannet Morus bassanus populations exhibit contrasting trends on a regional scale, with several colony extinctions having occurred in recent decades. In an attempt to understand the ecological drivers of such variability, we tested whether resource availability is a factor limiting the current development of gannetries in the Lofo...
This account presents the first known observations of Cape Gannet Morus capensis fledgling mortalities as a result of aggressive nest defence behaviour by African Penguins Spheniscus demersus. Observations were conducted in 2013 on Bird Island, Algoa Bay, South Africa ? the world's largest breeding colony of Cape Gannets. Twentyeight attacks were w...
Seabirds respond to environmental changes by adjusting their breeding and foraging strategies, but this behavioural flexibility has limits. Cape gannets Morus capensis breeding in the southern Benguela on Malgas Island off South Africa’s west coast have experienced large fluctuations in natural prey availability over the past decade, linked to envi...
Sex-biased mortality can increase the risk of extinction of threatened populations. Numbers of the Endangered African penguins Spheniscus demersus are decreasing rapidly and the smaller size of females associated with their higher foraging effort during the breeding season may put them more at risk than males. Using records from 2004-2012 from a re...
Norwegian Northern Gannet Morus bassanus populations exhibit contrasted trends at a regional scale and several colony extinctions occurred in recent decades. In an attempt to understand the ecological drivers of such variability, we tested whether resource availability is a factor limiting the current development of gannetries in the Lofoten/Vester...
African penguins Spheniscus demersus naturally breed in guano burrows which provide shelter from predators and extreme weather conditions. Past guano harvesting has removed this habitat and artificial nests of different types have been deployed, with previous research identifying variable success of these different types. We investigated climate co...
Climate change and fishing impact marine ecosystems, potentially modifying the availability of small pelagic fish to marine top predators. Some seabirds that primarily rely upon these resources have switched to feeding on fishery waste. It has therefore been argued that seabirds might become dependent upon this artificial resource.
To test this hyp...
Sexual differences in at-sea behaviour of seabirds often derive from size dimorphism and may lead to both resource partitioning and diverging threats between the sexes. Spheniscids are one of the least dimorphic of the seabird families, and the most threatened. In many instances, diet differs between the sexes in penguins, but few studies have comp...
Industrial fishing can profoundly alter marine environments, and no-take zones are an important tool to achieve sustainable fishing and re-establish ecosystem integrity. However, the potential benefits for vagile species such as top predators are still questioned. The numbers of endangered African penguins Spheniscus demersus have halved since 2004...
Drastic recent decreases in numbers of the 'Endangered' African Penguin Spheniscus demersus highlight the need for conservation efforts to reverse this trend. Habitat reduction due to former guano scraping forces penguins to breed in surface nests, which are vulnerable to predation by Kelp Gulls Larus dominicanus and to extreme weather events. Here...
Once one of the most numerous seabirds of the Benguela upwelling system, the population of Cape cormorants Phalacrocorax capensis has decreased by 60% in the last three decades and the species is listed as Near-threatened. Declines in prey availability and/or abundance brought about by recent changes in the distribution of pelagic fish stocks and i...
Using a multi-disciplinary approach, we evaluated the potential consequences of long-term contrasting prey availability on the condition Cape gannets Morus capensis. We compared breeding adults from a decreasing colony on Malgas Island off the west coast of South Africa, where the abundance of small pelagic fish has de-creased, with an increasing c...
We report co-operative group foraging in the African Penguin Spheniscus demersus. Groups of approximately 25–165 African Penguins were observed circling schools of pelagic fish, sometimes forcing them to the surface. During this behaviour 66–75% of penguins were underwater at any given time. Smaller numbers of African Penguins also joined foraging...
Knowledge on how divers exploit the water column vertically in relation to water depth is crucial to our understanding of their ecology and to their subsequent conservation. However, information is still lacking for the smaller-bodied species, due mostly to size constraints of data-loggers. Here, we report the diving behaviour of a flying diving se...
Breeding Spheniscus penguins are central place foragers that feed primarily on schooling pelagic fish. They are visual hunters, but it is unclear how they locate prey patches on a coarse scale. Many petrels and storm petrels (Procellariiformes), the penguins' closest relatives, use olfactory cues to locate prey concentrations at sea, but this has n...
Despite the large biomass of macaroni penguins Eudyptes chrysolophus in the Southern Ocean, their feeding ecology is poorly known at some important breeding localities. We investigated the diving behaviour and diet of female macaroni penguins feeding small chicks on Marion Island (468520S, 37850E), South Africa, one of the species' most northerly b...
The number of African penguins Spheniscus demersus breeding in South Africa collapsed from about 56 000 pairs in 2001 to some 21 000 pairs in 2009, a loss of 35 000 pairs (>60%) in eight years. This reduced the global population to 26 000 pairs, when including Namibian breeders, and led to classification of the species as Endangered. In South Afric...
In the southern Benguela upwelling ecosystem off the west coast of South Africa, seabird populations are decreasing dramatically because of reduced availability of pelagic fish. We tested the hypothesis that the west coast fishing industry is competing for the remaining stocks of anchovy and sardine with the largest colony of Vulnerable Cape Gannet...
Industrial-scale fisheries are often thought to reduce food availability for top predators. It is essential to estimate the spatial and temporal overlap over a fine scale between fisheries and pre- dators during their breeding season, when their energy demand is greatest and when they are most spatially constrained, in order to understand and manag...
The Cape cormorant Phalacrocorax capensis is unusual among cormorants in using aerial searching to locate patchily distributed pelagic schooling fish. It feeds up to 80 km offshore, often roosts at sea during the day and retains more air in its plumage and is more buoyant than most other cormorants. Despite these adaptations to its pelagic lifestyl...
In variable environments, organisms are bound to track environmental changes if they are to survive. Most marine mammals and
seabirds are colonial, central-place foragers with long-term breeding-site fidelity. When confronted with environmental change,
such species are potentially constrained in their ability to respond to these changes. For exampl...
Worldwide fisheries generate large volumes of fishery waste and it is often assumed that this additional food is beneficial to populations of marine top-predators. We challenge this concept via a detailed study of foraging Cape gannets Morus capensis and of their feeding environment in the Benguela upwelling zone. The natural prey of Cape gannets (...
In the context of rapid global changes, understanding the foraging mechanisms of marine top predators is crucial to determine their ability to adapt to environmental variability, in order to predict the consequences of changes on population dynamics and to define appropriate conservation measures for threatened species and the trophic webs to which...
We compared the foraging ecology of Cape gannets (Morus capensis) attending two colonies of equivalent size, yet with contrasting diet and population trends. One colony, on the west coast of South Africa, is decreasing in size and its occupants feed mainly on fishery wastes, whereas the other colony on the south coast of South Africa is growing and...
Human activities affect all trophic levels of marine food webs and threaten numerous species. The status of such populations can be assessed via monitoring of their size. However, in long-lived species as most marine top-predators, environmental stress upon a population only affects its size after several years. It has therefore been suggested that...
In the mid 1970s, the breeding populations of the migrant White Stork Ciconia ciconia were close to extinction in the northeastern region of France (Alsace). A re-introduction project was implemented, resulting in the year-round settlement of some individuals in the region, which rely on additional food supplied by humans during the winter. Today,...