Colleen T Downs

Colleen T Downs
University of KwaZulu-Natal | ukzn · School of Life Sciences

BSc Hons PhD MEd

About

529
Publications
126,422
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5,533
Citations
Introduction
Skills and Expertise
Additional affiliations
July 1994 - present
University of KwaZulu-Natal
Position
  • Chair

Publications

Publications (529)
Article
African forests have been negatively affected because of human impacts. The use of forest products is high for lower-income communities. Excessive logging alters the forest patch structure and composition, causing degradation. In addition, increases in bushmeat hunting for sustenance and trade result in increased pressures on forest mammalian speci...
Article
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Many of the world’s most biodiverse regions are found in the poorest and second most populous continent of Africa; a continent facing exceptional challenges. Africa is projected to quadruple its population by 2100 and experience increasingly severe climate change and environmental conflict—all of which will ravage biodiversity. Here we assess conse...
Article
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Alien invasive plant species are a major problem globally, threatening ecosystem functioning and biodiversity. Native bird species facilitate their spread through mutualistic relationships. Studies of seed dispersal of alien invasive plants are important for effective management. In the present study, we investigated the role of native bird species...
Article
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Invasive alien plant species have been identified as a major threat to biodiversity and the relationship with native avian dispersers may increase their invasion potential. The impact of invasive plant species needs to be quantified using comparable assessment tools across different habitats and species to allocate limited resources to high-priorit...
Article
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Context Forest loss and fragmentation are major drivers of biodiversity decline globally. However, with the widely recognised notion that biodiversity is multifaceted, few studies have assessed the responses of different diversity metrics to forest landscape changes. Objectives Here, we used a multifaceted approach to assess the effects of landsca...
Article
Anthropogenic habitat conversion through urban sprawl is driving mesocarnivores to modify their behaviour and ecology. Thorough knowledge of their feeding ecology is fundamental in understanding the pressures imposed on mesocarnivores by urbanisation. The diet of the water mongoose Atilax paludinosus has been studied in natural habitats of KwaZulu-...
Article
The Rose-ringed Parakeet Psittacula krameri (Scopoli, 1769) has become invasive in several countries, including South Africa, mainly through the pet trade releases and escapees. We conducted an online questionnaire survey targeting the residents in Durban, eThekwini Municipality, KwaZulu-Natal, South Africa. We aimed to determine the distribution,...
Article
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Urbanisation has increasingly encroached on numerous bird species' natural habitats, generally negatively affecting their persistence. Furthermore, increased human-wildlife interactions may benefit or be detrimental to the long term persistence of these species. The Spotted Thick-knee (Burhinus capensis), a ground-nesting species, persists in some...
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Non‐native species have been translocated from their native to new geographic ranges through the pet trade. Consequently, some become threatened with extinction, while some establish and become invasive. We surveyed 117 physical pet stores across South Africa between September 2018 and September 2019 to determine avian species composition, availabi...
Article
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Invasive alien plants can use animal-plant interactions to increase their invasiveness. This study investigated the role of frugivorous birds in seed dispersal, germination success and germination time of the alien plant Pyracantha angustifolia (Franch.) C.K. Schneid. (Rosaceae) in South African high elevation grasslands. We monitored which bird sp...
Preprint
Full-text available
Resource selection functions are among the most commonly used statistical tools in both basic and applied animal ecology. They are typically parameterized using animal tracking data, and advances in animal tracking technology have led to increasing levels of autocorrelation between locations in such data sets. Because resource selection functions a...
Article
Full-text available
With open-access publishing authors often pay an article processing charge and subsequently their article is freely available online. These charges are beyond the reach of most African academics. Thus, the trend towards open-access publishing will shift the business model from a pay-wall model, where access to literature is limited, to a pay-to-pub...
Article
Protected areas are intended as tools in reducing threats to wildlife and preserving habitat for their long-term population persistence. Studies on ranging behavior provide insight into the utility of protected areas. Vultures are one of the fastest declining groups of birds globally and are popular subjects for telemetry studies, but continent-wid...
Article
Four anguillid eel species occur in the western Indian Ocean rivers of Africa: Anguilla bengalensis, Anguilla bicolor, Anguilla marmorata and Anguilla mossambica. These catadromous fishes face multiple stressors, including habitat alteration and deterioration, barriers to migration, pollution and the adverse impacts of alien species, but knowledge...
Article
The sale of live non‐native animals has become a social norm and is of global concern. The pet trade industry has become one of the main pathways where non‐native small mammals are introduced worldwide. We conducted a questionnaire survey in South African pet shops from September 2018 to September 2019 to gain insights into non‐native small mammali...
Presentation
Full-text available
I present some first results from my PhD showcasing the significant impact water sources and infrastructure inside a large savannah protected area has on various bird diversity metrics.
Article
Anthropogenic activities have resulted in habitat loss and fragmentation across different landscapes. Anthropogenic land-uses adjacent to forest patches may further influence the movement and occupancy of a species. Therefore, we investigated how dominant land-uses, i.e. grassland, human settlement and commercial exotic timber plantations surroundi...
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Globally, the threats of habitat loss and disease on amphibian survival have necessitated the creation of ex-situ insurance populations as a conservation tool. We initiated a captive breeding project to create an insurance population for the endangered Pickersgill's reed frog (Hyperolius pickersgilli Raw, 1982) at the Johannesburg Zoo from parents...
Article
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Changes to natural environments as a consequence of human population growth are a major threat to biodiversity. Natural habitat modifications, changes in vegetation structure and habitat characteristics have resulted in decreased species richness and functional diversity in wildlife populations. Species’ distributions, abundance and persistence are...
Article
Figs (Ficus spp.) are a diverse taxon of woody plants that play keystone ecological roles. They provide nutritional and aseasonal fruit crops that are consumed by many frugivores, often in times of fruit scarcity. In a mutually beneficial relationship, the plants also benefit from seed dispersal by birds and mammals away from the parent plants enha...
Article
The ever-increasing human population, globalisation, and desire to keep pets have resulted in the translocation of many species into non-native environments. As a result, some of the non-native reptile species have been introduced to South Africa through the pet trade. However, little is known about the extent of trade in reptiles via online and ph...
Article
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The increase in anthropogenic stress on river ecosystems is of growing concern globally as demand for water increases and freshwater ecosystem degradation occurs. Understanding how the species respond to these stressors is important to manage ecosystem functioning, the conservation of species and the ecosystem services they provide. We used radio t...
Article
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Background and Aims For the first time in Africa, two freshwater turtle species (hereafter terrapin) presence and temporal activity in their habitats were investigated using radio telemetry. Methods Telemeter tags were attached to Pelusios sinuatus ( n = 10) at Ndumo Reserve and Pelomedusa galeata ( n = 10) at Tala Reserve. Pelusios sinuatus tagge...
Article
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Tourism can be a powerful tool for wildlife conservation if well controlled and responsibly managed. Apex predators constitute particularly attractive subjects for tourism, but simultaneously they may generate conflict with local communities. Harpy Eagles Harpia harpyja are the largest eagle species and are highly sought-after by ecotourists. The l...
Article
Low-cost uncrewed aerial vehicles (UAVs) have become ubiquitous, and advanced UAV systems are affordable for many field ecologists and wildlife managers. Many hobbyist UAVs have been applied to ecological studies, but proprietary software limits their widespread application with little quantification with regards to their accuracy and efficiency in...
Article
Increasing beach sediment loss from erosion and high levels of crab Ocypode spp. predation are threatening turtle nests and nesting habitat. The 900 m long beach on Cousine Island, Seychelles, supports a nesting population of approximately 70–130 hawksbill turtle Eretmochelys imbricata nests each season. Seasonal and storm-related erosion and accre...
Article
Documenting phylogenetic diversity for conservation practice allows elucidation of ecosystem functioning and processes by highlighting the commonality and divergence of species' functional traits within their evolutionary context. Conserving distinct evolutionary histories has intrinsic value, and the conservation of phylogenetically diverse commun...
Article
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Understanding population trends is important when managing wildlife in protected areas. The common hippopotamus, Hippopotamus amphibius (hereafter hippo), is an iconic African species that, in South Africa, is mainly restricted to protected areas. Ndumo Game Reserve (NGR), South Africa, was established as a sanctuary for hippos in 1924. However, NG...
Article
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Larger carnivores often trigger human-wildlife conflicts that arise from perceived threats to humans and domestic animals’ safety, which generate the need for management and removal strategies. These issues become especially challenging when humans and wildlife coexist close to one another, for example, in urban landscapes. African Crowned Eagles (...
Article
en Historically, Cousine Island was used for agriculture and harvesting various seabird eggs, but following restoration efforts initiated in the 1990s, it has become an important nesting area for Seychelles seabirds. White-tailed tropicbird (Phaethon lepturus), white tern (Gygis alba), and lesser (Anous tenuirostris) and brown noddy (Anous stolidus...
Article
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Urbanisation has caused significant alterations to ecosystems, generally resulting in decreased biodiversity. However, certain animal species persist and thrive in urban environments by making use of available opportunities, anthropogenic resources, infrastructure and increased ambient and surface temperatures. These species are known as urban expl...
Article
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The pet trade is one of the main pathways of introduction of several mammals worldwide. In South Africa, non-native mammalian species are traded as pets, and so far, only four of these species are considered invasive. We used a list of 24 companion mammalian species compiled from a previous study. We selected a subset of 14 species for species dist...
Preprint
With open-access publishing authors pay an article processing charge and subsequently their article is freely available online. These charges are beyond the reach of most African academics. Thus, the trend towards open access publishing will shift the business model from a pay-wall model, where access to literature is limited, to a pay-to-publish o...
Article
Land-use change is one of the greatest threats to biodiversity. It is predicted that conversion of land and habitats will increase rapidly over the next few decades in Africa. Over the years, these changes potentially reduced the capacity of ecosystems to sustain food production for vertebrates. Ficus species (Moraceae), commonly known as figs, occ...
Article
Full-text available
Vultures provide crucial ecological, economic, and cultural benefits, yet many Old World populations are declining. The illegal trade in vultures for traditional medicines (known as muthi in South Africa) is widely regarded as an important threat to the conservation of African vultures, but there are relatively few studies on the acquisition and tr...
Article
The degradation of freshwater ecosystems can be attributed to stressors associated with the increased demand for water and other aquatic resources. Freshwater ecosystems face such challenges in supporting agriculture, industry, and high-density urban areas in KwaZulu-Natal (KZN) province, South Africa. In this study, the presence of fish species an...
Article
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Within South Africa, the St. Lucia Basin, comprising the White Mfolozi, Black Mfolozi, Mfolozi Hluhluwe-Mkuze sub-basins, is an ecologically important region. However, the river ecosystems and their inherent biota, especially the ichthyofauna, are inadequately studied. Considering the anthropogenic land-use change currently occurring and the concom...
Article
Full-text available
Understanding the biological response to increasing anthropogenic stressors is an important consideration to make when evaluating ecosystem well-being. Among aquatic ecological indicators, fish are effective as they are mobile and can be monitored relatively easily. The socio-economically important uMngeni River in South Africa is a highly regulate...
Article
Anthropogenic land transformation, especially agriculture and urban development, are the leading causes of natural land cover loss and ultimate decline in environmental functionality and connectivity in KwaZulu-Natal Province, South Africa. However, recent developments in the form of housing estates with conservation and environmental management in...
Preprint
Full-text available
Invasive alien plants can use animal-plant interactions to increase their invasiveness. This study investigated the role of frugivorous birds in seed dispersal and germination of the alien plant Pyracantha angustifolia (Rosaceae) in South African high elevation grasslands. We monitored which bird species fed on the fruit of the invasive P. angustif...
Article
Open access to the scholarly literature is crucial for African academics but, without urgent action, the move from paywall to pay-to-publish wall will continue to disenfranchise researchers. In an unpublished study, we looked at the 40 journals with the highest impact factors in our field (ecology), and found that the average article-processing c...
Article
African vulture populations are currently in rapid decline, due to a range of anthropogenic factors. These include intentional and unintentional poisoning; degradation, fragmentation, and loss of habitat; and the killing of vultures to obtain body parts for use in traditional medicine. Consequently, people living in rural communities adjacent to pr...
Article
Full-text available
Apex predators are widely threatened globally and generally considered a priority on the conservation biology agenda. The harpy eagle, Harpia harpyja, is an apex predator threatened by habitat loss and persecution and a flagship species for Neotropical conservation. We investigated the roles of social, economic and environmental factors related to...
Article
Full-text available
Rose-ringed parakeets Psittacula krameri are one of the most widely distributed urban avian invader species present in~35 countries with population sizes increasing. These parakeets were introduced to South Africa as part of the pet trade, and feral populations have established in several urban areas since and are of concern. We, therefore, conduct...
Article
Full-text available
Apex predators are threatened globally, and their local extinctions are often driven by failures in sustaining prey acquisition under contexts of severe prey scarcity. The harpy eagle Harpia harpyja is Earth's largest eagle and the apex aerial predator of Amazonian forests, but no previous study has examined the impact of forest loss on their feedi...
Article
Full-text available
Little is documented on the population demographics and morphometrics of wild freshwater turtles (hereafter terrapins) in South Africa. From February 2016 to October 2019, we trapped and recorded morphometric and biological data for serrated hinged terrapins Pelusios sinuatus (n = 97) and marsh terrapins Pelomedusa galeata (n = 51) in KwaZulu-Natal...
Article
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Fish telemetry is a widely established technique in developed countries. However, in underdeveloped regions, its use is generally lacking. We briefly present common fish telemetry methods used globally and then reviewed their use in African inland freshwater ecosystems. We highlight telemetry studies' progress in African inland waters and evaluate...
Article
Full-text available
Four freshwater eel species (Anguilla spp.) occur in southern African rivers that are increasingly anthropogenically modified. Information on movements, habitat use and overlap by African eels is needed for their conservation. We carried out a preliminary investigation of the spatial ecology of three eel species in the Thukela River, South Africa,...
Article
The relationship between mistletoes and their host trees constitutes one of the unique host–parasite interactions in ecosystems. Most West African studies have reported on the parasitic nature of the relationship between Tapinanthus dodoneifolius mistletoes and Parkia biglobosa trees. However, there is little on bird species’ use and subsequent dis...
Article
The fleshy fruits of exotic Opuntia ficus-indica (L.) Mill and Opuntia robusta (Haw.) Haw (Cactaceae family) are consumed and dispersed by many vertebrates, which likely influences their invasion success. We tested whether seed ingestion by Pied Crows (Corvus albus) and other smaller birds (African Pied Starling Lamprotornis bicolor and the Red-eye...
Article
In the original publication, the figure 2 was processed incorrectly during the typesetting and publication process. The correct figure is provided in this correction. The original article has been corrected.
Article
Urbanisation is rapidly transforming natural landscapes with consequences for biodiversity. Little is documented on the response of African wildlife to urbanisation. We reviewed case studies of vertebrate species’ responses to urbanisation in KwaZulu-Natal, South Africa to determine trends. Connected habitat mosaics of natural and anthropogenic gre...
Article
en Admission records of rescued birds are an important source of information for tracking the prevalence of human‐related threats to wildlife. In this study, we used admission records from January 2015 to December 2016 to review the causes for raptor admissions to a raptor rehabilitation centre in Pietermaritzburg, South Africa, and to determine fa...
Article
South Africa's communal rangelands constitute ~25% of the country's land cover and are largely managed for livestock grazing. These habitats play an important role in rural livelihoods and cultural practices. Using semi-structured interviews, we documented indigenous local ecological knowledge (LEK) held by rural dwellers linked to natural resource...
Article
Full-text available
Technology is transforming societies worldwide. A major innovation is the emergence of robotics and autonomous systems(RAS), which have the potential to revolutionize cities for both people and nature. Nonetheless, the opportunities and challenges associated with RAS for urban ecosystems have yet to be considered systematically. Here, we report the...
Article
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Urbanisation is rapidly transforming natural habitats with the potential to benefit synanthropic species, especially mesocarnivore species. Knowledge of the spatio-temporal ecology of mongoose species in an urban matrix is limited. Consequently, we examined the home range and habitat use of water mongoose (Atilax paludinosus, n = 14) in an urban ma...
Article
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Nature is experiencing degradation and extinction rates never recorded before in the history of Earth.1,2 Consequently, continuous large-scale monitoring programmes are critical, not only to provide insights into population trends but also to aid in understanding factors associated with altering population dynamics at various temporal and spatial s...
Article
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The urban landscape is a complex mosaic of costs and benefits for urban wildlife. Although many species may adapt and thrive in the urban mosaic, the complexity of this landscape can be stressful and have health implications for urban wildlife, raising concerns for zoonosis and biodiversity. In this study, we assessed how human–primate interactions...