Ben Hoffman

Bio: Ben Hoffman is an academic researcher from University of KwaZulu-Natal. The author has contributed to research in topics: Wildlife management & Tyto. The author has an hindex of 2, co-authored 7 publications receiving 18 citations.

Causes of admissions to a raptor rehabilitation centre in KwaZulu-Natal, South Africa

Abstract: With many species of southern African raptors becoming increasingly threatened, records from rehabilitation centres can give an indication of the threats faced by birds of prey in particular areas and to particular species. Thus, admissions records from a raptor rehabilitation centre in KwaZulu-Natal, South Africa, were analysed for trends. Over eight years (2004–2011), 547 birds from 39 raptor species were admitted to the centre. The majority of individuals were spotted eagle-owls (16.6%), western barn owls (15.2%) and yellow-billed kites (9.7%). The most frequent known causes of injury to raptors were motor vehicle accidents and injuries caused when birds flew into buildings. There was no significant difference in admissions of motor vehicle collision cases between seasons. People generally waited 3.8 days before bringing injured raptors in to the centre, and approximately half of the birds admitted were fed within that time, highlighting a need for public education regarding the general diets of raptor...

Causes of admission to a raptor rehabilitation centre and factors that can be used to predict the likelihood of release

Abstract: 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 factors that can be used to predict the outcome of rehabilitation. During the study period, 242 raptors were admitted to the centre, representing 33 species. The major causes of admission were collision‐related injuries (52%), grounded birds (12%) and orphaned chicks (10%). The most common casualties were spotted eagle‐owl Bubo africanus (23%), yellow‐billed kite Milvus migrans aegyptius/parasitus (12%), jackal buzzard Buteo rufofuscus (10%) and western barn owl Tyto alba (10%). The rehabilitation centre had a release rate of 48%. Reason for admission was a significant predictor of the outcome of rehabilitation while other variables were not. Raptors with no severe injuries such as orphaned chicks and grounded birds were more likely to have successful rehabilitation treatment than raptors suffering from collision injuries. Wildlife rehabilitators can use the results of the present study to develop triage guidelines for raptors admitted to rehabilitation centres.

Reintroduction of captive-bred African Grass-Owls Tyto capensis into natural habitat

Abstract: This study represents the first attempt to determine post-release survival of a captive-bred owl in Africa. We released six captive-bred African Grass-Owls Tyto capensis into suitable habitat and, ...

Surviving the Urban Jungle: Anthropogenic Threats, Wildlife-Conflicts, and Management Recommendations for African Crowned Eagles

Abstract: 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 (Stephanoaetus coronatus) are powerful forest raptors that breed within the metropolitan green-space system of Durban and Pietermaritzburg, South Africa. Negative human-wildlife interactions can occur because eagles occasionally predate on pets, and provisioning domestic stock to nest sites has previously been quantified. Here, wildlife management becomes critical, usually aimed at reducing or eliminating causes of economic or social harm, but have to be balanced against conservation goals regarding threatened species. In this study, we (i) identified causes of harm or loss of Crowned Eagles because of injuries (n = 53 incidents; 31 mortalities); and (ii) describe interactions with negative perceptions to human livelihoods, particularly concerning predation on pets and livestock. Anthropogenic causes of mortality were more likely to be reported than remote natural deaths, which provides important opportunities for mitigation measures. Most avoidable are electrocution on utility poles, persecution via gunshot wounds and poisoning (targeted or secondary), while collisions with anthropogenic structures, such as glass panes, vehicles and fence wires, are more challenging to mitigate. Of 44 verified Crowned Eagle versus pets and livestock conflicts, we documented 19 dog attacks (2012 – 2020), with detrimental impacts on social perception and acceptance of urban eagles. Pet and livestock conflicts were primarily associated with juveniles and immature eagles (83%). Of these, 19% occurred during September alone, which marks the end of the post-fledging dependency period; 70% occurred outside the breeding season. We provide management recommendations regarding various categories of Crowned Eagle human-wildlife interactions. For example, activities such as rehabilitation and falconry can coordinate to achieve a high standard of public support and conservation outcomes for Crowned Eagles. Finally, we discuss different management intervention strategies, including rehabilitation, falconry, re-wildling processes, and lethal control of specific ‘problem’ individuals towards achieving the goal of sustainable, healthy Crowned Eagle populations that coexist with humans in urban landscapes.

Ranging behaviour of Long-crested Eagles Lophaetus occipitalis in human-modified landscapes of KwaZulu-Natal, South Africa

Abstract: The ranging behaviour of raptors in human-altered environments, such as agricultural and suburban landscapes, is becoming increasingly important for conservationists in the context of unprecedented...

Evolutionary effects of alternative artificial propagation programs: implications for viability of endangered anadromous salmonids

Abstract: Most hatchery programs for anadromous salmonids have been initiated to increase the numbers of fish for harvest, to mitigate for habitat losses, or to increase abundance in populations at low abundance. However, the manner in which these programs are implemented can have significant impacts on the evolutionary trajectory and long-term viability of populations. In this paper, we review the potential benefits and risks of hatchery programs relative to the conservation of species listed under the US Endangered Species Act. To illustrate, we present the range of potential effects within a population as well as among populations of Chinook salmon (Oncorhynchus tshawytscha) where changes to major hatchery programs are being considered. We apply evolutionary considerations emerging from these examples to suggest broader principles for hatchery uses that are consistent with conservation goals. We conclude that because of the evolutionary risks posed by artificial propagation programs, they should not be viewed as a substitute for addressing other limiting factors that prevent achieving viability. At the population level, artificial propagation programs that are implemented as a short-term approach to avoid imminent extinction are more likely to achieve long-term population viability than approaches that rely on long-term supplementation. In addition, artificial propagation programs can have out-of-population impacts that should be considered in conservation planning.

Episodic outbreaks of small mammals influence predator community dynamics in an east African savanna ecosystem

Abstract: Little is known about the dynamics of small mammals in tropical savanna: a critical gap in our understanding of Africa's best known ecosystems. Historical evidence suggested small mammals peak in abundance (outbreak) in Serengeti National Park (SNP), as in agricultural systems. We asked 1) what are bottom–up drivers of small mammals and 2) do predators have top–down effects? We documented dynamics of small mammals, birds of prey, and mammalian carnivores in SNP and agricultural areas. We used climatic fluctuations and differences between unmodified and agricultural systems as perturbations to examine trophic processes, key to understanding responses to climate change and increasing human pressures. Data were derived from intermittent measures of abundance collected 1968–1999, combined with systematic sampling 2000–2010 to construct a 42-year time series. Data on abundance of black-shouldered kites (1968–2010), eight other species of rodent-eating birds (1997–2010), and 10 carnivore species (1993–2010) were also collated. Outbreaks occurred every 3–5 years in SNP, with low or zero abundance between peaks. There was a positive relationship between rainfall in the wet season and 1) small mammal abundance and 2) the probability of an outbreak, both of which increased with negative Southern Oscillation Index values. Rodent-eating birds and carnivores peaked 6–12 months after small mammals. In agricultural areas, abundance remained higher than in natural habitats. Abundances of birds of prey and mammalian carnivores were extremely low in these areas and not related to small mammal abundance. Small mammals are an important food resource for higher trophic levels in the Serengeti ecosystem. Changes in climate and land use may alter their future dynamics, with cascading consequences for higher trophic levels, including threatened carnivores. Although outbreaks cause substantial damage to crops in agricultural areas, small mammals also play a vital role in maintaining some of the diversity and complexity found in African savanna ecosystems.

Communal farmers of Namibia appreciate vultures and the ecosystem services they provide

Abstract: Ecosystem services are cited as one of the many reasons for conserving declining vulture populations in Africa. We aimed to explore how communal farmers in Namibia perceive vultures and the ecosystem services they provide, with special focus on cultural and regulating ecosystem services. We surveyed 361 households across Namibia’s communal farmlands and found that over two-thirds of households liked vultures and found them useful, stating that they were harmless and useful for locating dead livestock. The minority of households who disliked vultures believed that they were killing their livestock. Poisoning was the main cause of vulture mortalities reported by farmers. While poisoning appears to be a concern for vultures in the communal farmlands, it appears that cultural use of vulture body parts is a minimal threat. We found that few farmers knew of cultural beliefs about vultures or uses for body parts; most farmers believed these beliefs and practices to be outdated. It is further promising that commu...

Final outcome of raptors admitted to the Tafira Wildlife Rehabilitation Center, Gran Canaria Island, Spain (2003–2013)

Abstract: espanolEn este estudio se analizan los resultados de la rehabilitacion de aves rapaces silvestres admitidas en el Centro de Rehabilitacion de Fauna Silvestre de Tafira en la isla de Gran Canaria, Espana, desde 2003 hasta 2013, mediante un sistema de auditoria de la calidad basado en los indices generales y clasificados (por causa de admision) de las cuatro categorias de disposicion final, el tiempo hasta la muerte y el tiempo de permanencia como indicadores de calidad. Las categorias de disposicion final fueron: eutanasia (Er ) = 19,78%, mortalidad no asistida durante la hospitalizacion (Mr ) = 22,20%, liberacion (Rr ) = 57,57% y cautividad permanente (Cr ) = 0,46%. Teniendo en cuenta la especial vulnerabilidad de las especies de rapaces insulares y el alto indice de Rr conseguido, los resultados de este estudio ponen de relieve la importancia de los centros de rehabilitacion de fauna silvestre en el tratamiento medico de las aves heridas y la consiguiente liberacion de las aves rehabilitadas. EnglishThe outcomes of wild raptors admitted to the Tafira Wildlife Rehabilitation Center in Gran Canaria Island, Spain, from 2003 to 2013 were analyzed using a quality auditing system based on the crude and stratified (by causes of admission) rates of four final outcome categories, time until death and length of stay as quality indicators. The outcome categories were: euthanasia (Er = 19.78%); unassisted mortality during hospitalization (Mr = 22.20%); release (Rr = 57.57%); and permanent captivity (Cr = 0.46%). Taking into account the particular vulnerability of insular raptor species and the high Rr achieved, findings from this study emphasize the importance of wildlife rehabilitation centers for the medical management of injured raptors and the subsequent release of rehabilitated individuals into the wild.

Causes of admissions to a raptor rehabilitation centre in KwaZulu-Natal, South Africa

Abstract: With many species of southern African raptors becoming increasingly threatened, records from rehabilitation centres can give an indication of the threats faced by birds of prey in particular areas and to particular species. Thus, admissions records from a raptor rehabilitation centre in KwaZulu-Natal, South Africa, were analysed for trends. Over eight years (2004–2011), 547 birds from 39 raptor species were admitted to the centre. The majority of individuals were spotted eagle-owls (16.6%), western barn owls (15.2%) and yellow-billed kites (9.7%). The most frequent known causes of injury to raptors were motor vehicle accidents and injuries caused when birds flew into buildings. There was no significant difference in admissions of motor vehicle collision cases between seasons. People generally waited 3.8 days before bringing injured raptors in to the centre, and approximately half of the birds admitted were fed within that time, highlighting a need for public education regarding the general diets of raptor...