74 research outputs found

    Factors that influence cape fur seal predation on Cape gannets at Lambert’s bay, South Africa

    Get PDF
    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

    Initial evaluation of the care and rehabilitation success of Cape Cormorants Phalacrocorax capensis rescued from Robben and Jutten islands, South Africa, in January 2021

    Get PDF
    The population of the endangered Cape Cormorant Phalacrocorax capensis more than halved over the last three decades (BirdLife International 2018a). In January 2021, nearly 2 000 Cape Cormorant chicks were found abandoned, suffering from dehydration and heat stress, at two important nesting sites. The chicks were rescued and rehabilitated by the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB, Cape Town, South Africa). About half (53.7%) of the cormorant chicks were successfully rehabilitated and released back into the breeding colonies. This study found a direct link between the initial body mass of cormorant chicks admitted to the rehabilitation centre and their probability of surviving during rehabilitation, with birds that were initially heavier having a greater probability of eventual release. Most cormorant chicks that died (80.7%) did so within the first 5 days of admission. This rescue required SANCCOB to care for and rehabilitate the largest number of Cape Cormorant chicks that has ever been admitted to its rehabilitation centre at one time, making it the first rescue of its kind. Despite the presumably limited positive impact on overall population numbers of Cape Cormorants, the rescue campaign improved SANCCOB’s preparedness to respond successfully to future disaster events and to deal with different species, both locally and globally

    Hand-rearing, release and survival of african penguin chicks abandoned before independence by moulting parents

    Get PDF
    The African penguin Spheniscus demersus has an ‘Endangered’ conservation status and a decreasing population. Following abandonment, 841 African penguin chicks in 2006 and 481 in 2007 were admitted to SANCCOB (Southern African Foundation for the Conservation of Coastal Birds) for hand-rearing from colonies in the Western Cape, South Africa, after large numbers of breeding adults commenced moult with chicks still in the nest. Of those admitted, 91% and 73% respectively were released into the wild. There were veterinary concerns about avian malaria, airsacculitis and pneumonia, feather-loss and pododermatitis (bumblefoot). Post-release juvenile (0.32, s.e. = 0.08) and adult (0.76, s.e. = 0.10) survival rates were similar to African penguin chicks reared after oil spills and to recent survival rates recorded for naturally-reared birds. By December 2012, 12 birds had bred, six at their colony of origin, and the apparent recruitment rate was 0.11 (s.e. = 0.03). Hand-rearing of abandoned penguin chicks is recommended as a conservation tool to limit mortality and to bolster the population at specific colonies. The feasibility of conservation translocations for the creation of new colonies for this species using hand-reared chicks warrants investigation. Any such programme would be predicated on adequate disease surveillance programmes established to minimise the risk of disease introduction to wild birds

    Nest-type associated microclimatic conditions as potential drivers of ectoparasite infestations in African penguin nests

    Get PDF
    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

    Descriptive epidemiology of and response to the high pathogenicity avian influenza (h5n8) epidemic in South African coastal seabirds, 2018

    Get PDF
    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

    Population-Level Compensation Impedes Biological Control of an Invasive Forb and Indirect Release of a Native Grass

    Get PDF
    The intentional introduction of specialist insect herbivores for biological control of exotic weeds provides ideal but understudied systems for evaluating important ecological concepts related to top-down control, plant compensatory responses, indirect effects, and the influence of environmental context on these processes. Centaurea stoebe (spotted knapweed) is a notorious rangeland weed that exhibited regional declines in the early 2000s, attributed to drought by some and to successful biocontrol by others. We initiated an experiment to quantify the effects of the biocontrol agent, Cyphocleonus achates, on Ce. stoebe and its interaction with a dominant native grass competitor, Pseudoroegneria spicata, under contrasting precipitation conditions. Plots containing monocultures of each plant species or equal mixtures of the two received factorial combinations of Cy. achates herbivory (exclusion or addition) and precipitation (May–June drought or “normal,” defined by the 50-year average) for three years. Cy. achates herbivory reduced survival of adult Ce. stoebe plants by 9% overall, but this effect was stronger under normal precipitation compared to drought conditions, and stronger in mixed-species plots compared to monocultures. Herbivory had no effect on Ce. stoebe per capita seed production or on recruitment of seedlings or juveniles. In normal-precipitation plots of mixed composition, greater adult mortality due to Cy. achates herbivory resulted in increased recruitment of new adult Ce. stoebe. Due to this compensatory response to adult mortality, final Ce. stoebe densities did not differ between herbivory treatments regardless of context. Experimental drought reduced adult Ce. stoebe survival in mixed-species plots but did not impede recruitment of new adults or reduce final Ce. stoebe densities, perhaps due to the limited duration of the treatment. Ce. stoebe strongly depressed P. spicata reproduction and recruitment, but these impacts were not substantively alleviated by herbivory on Ce. stoebe. Population-level compensation by dominant plants may be an important factor inhibiting top-down effects in herbivore-driven and predator-driven cascades

    Sport Chaplains and Social Workers: A Theoretical Understanding of a Necessary Component of an Interprofessional Collaborative Practice in Sport in the United States

    Get PDF
    Holistic care of athletes is a growing area of research and practice. Yet, there is still much to consider as attention to this matter continues to expand. Specifically, what are the different theoretical perspectives of each profession working together towards the holistic care of athletes? The theoretical understanding between professions is essential for effective interprofessional teams—what some scholars have termed interprofessional cultural competence. The purpose of this paper is thus to provide the theoretical underpinnings for collaboration between sport chaplains and social workers, both emerging professions within interprofessional care in sport. This paper presents the unique partnership of sport chaplains and social workers in the spiritual care of athletes. Furthermore, it seeks to clarify the theoretical foundations of each profession, and how then these professions can then work together most effectively. Suggestions and ethical considerations are also given for best practices in the execution of this collaboration

    A simple contagion process describes spreading of traffic jams in urban networks

    Full text link
    The spread of traffic jams in urban networks has long been viewed as a complex spatio-temporal phenomenon that often requires computationally intensive microscopic models for analysis purposes. In this study, we present a framework to describe the dynamics of congestion propagation and dissipation of traffic in cities using a simple contagion process, inspired by those used to model infectious disease spread in a population. We introduce two novel macroscopic characteristics of network traffic, namely congestion propagation rate \b{eta} and congestion dissipation rate {\mu}. We describe the dynamics of congestion propagation and dissipation using these new parameters, \b{eta}, and {\mu}, embedded within a system of ordinary differential equations, analogous to the well-known Susceptible-Infected-Recovered (SIR) model. The proposed contagion-based dynamics are verified through an empirical multi-city analysis, and can be used to monitor, predict and control the fraction of congested links in the network over time.Comment: 10 pages, 8 figure

    Urofaecal glucocorticoid metabolite concentrations in African penguin (Spheniscus demersus) chick populations experiencing different levels of human disturbance

    Get PDF
    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 altricial and unable to move away from anthropogenic stressors, it is important to evaluate the effect of tourist activities on baseline glucocorticoid levels as a measure of potential disturbance. Chicks at three study sites within two breeding colonies (Robben Island, Stony Point), with varying levels of exposure to tourism (low/moderate/high) were monitored. Urofaecal samples were collected to determine urofaecal glucocorticoid metabolite (ufGCM) concentrations as an indication of baseline stress physiology. Morphometric measurements were taken to compare body condition between sites. Penguin chicks experiencing low, infrequent human presence had significantly higher mean (± standard deviation) ufGCM levels [1.34 ± 1.70 ÎŒg/g dry weight (DW)] compared to chicks experiencing both medium (0.50 ± 0.40 ÎŒg/g DW, P = 0.001) and high levels of human presence (0.57 ± 0.47 ÎŒg/g DW, P = 0.003). There was no difference in chick body condition across sites. These results suggest that exposure to frequent human activity may induce habituation/desensitization in African penguin chicks. Acute, infrequent human presence was likely an important driver for comparatively higher ufGCM levels in chicks, though several other environmental stressors may also play an important role in driving adrenocortical activity. Nevertheless, as unhabituated chicks experiencing infrequent anthropogenic presence showed significantly higher ufGCM levels, managers and legislation should attempt to minimize all forms of activity around important breeding colonies that are not already exposed to regular tourism. Although the results of this study are crucial for developing enhanced conservation and management protocols, additional research on the long-term effect of anthropogenic activities on African penguin physiology is required.Department of Biodiversity and Conservation Biology, African National Research Foundation and Earthwatch Institute.http://conphys.oxfordjournals.orgdm2022Mammal Research InstituteZoology and Entomolog

    The impact of the COVID-19 pandemic on children’s conduct problems and callous-unemotional traits

    Full text link
    The COVID-19 pandemic has dramatically altered family life, but whether family exposures to and worries about the COVID-19 pandemic has impacted child conduct problems (CP) and callous-unemotional (CU) traits is unknown. Thus, we evaluated 303 parents (Mage = 38.04; SD = 5.21; 92.4% biological mothers) and children (Mage = 6.43; SD = 2.13; 51.8% female) during a four-month period early in the pandemic. We examined associations between parental exposures to COVID-19, parental worries about the pandemic, harsh and warm parenting practices, and child CP and CU traits. Although more parental worries were not directly related to parenting practices, more worry about COVID-19 was specifically related to higher levels of child CP, particularly parental worries about themselves or family members contracting the virus. Our findings add to a growing literature demonstrating the burden that the pandemic has placed on families and its implications for children’s mental health.Published versio
    • 

    corecore