Sam M Ferreira

Dr. Sam M Ferreira

orcid

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 June 2015 in PLOS ONE
Verified
Journal Article
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SFSam M Ferreira
Sam M Ferreira
CGCathy Greaver
Cathy Greaver
GKGrant A Knight
Grant A Knight
MKMike H Knight
Mike H Knight
ISIzak P J Smit
Izak P J Smit
DPDanie Pienaar
Danie Pienaar
The onslaught on the World’s rhinoceroses continues despite numerous initiatives aimed at curbing it. When losses due to poaching exceed birth rates, declining rhino populations result. We used previously published estimates and growth rates for black rhinos (2008) and white rhinos (2010) together with known poaching trends at the time to predict population sizes and poaching rates in Kruger National Park, South Africa for 2013. Kruger is a stronghold for the south-eastern black rhino and southern white rhino. Counting rhinos on 878 blocks 3x3 km in size using helicopters, estimating availability bias and collating observer and detectability biases allowed estimates using the Jolly’s estimator. The exponential escalation in number of rhinos poached per day appears to have slowed. The black rhino estimate of 414 individuals (95% confidence interval: 343-487) was lower than the predicted 835 individuals (95% CI: 754-956). The white rhino estimate of 8,968 individuals (95% CI: 8,394-9,564) overlapped with the predicted 9,417 individuals (95% CI: 7,698-11,183). Density- and rainfall-dependent responses in birth- and death rates of white rhinos provide opportunities to offset anticipated poaching effects through removals of rhinos from high density areas to increase birth and survival rates. Biological management of rhinos, however, need complimentary management of the poaching threat as present poaching trends predict detectable declines in white rhino abundances by 2018. Strategic responses such as anti-poaching that protect supply from illegal harvesting, reducing demand, and increasing supply commonly require crime network disruption as a first step complimented by providing options for alternative economies in areas abutting protected areas.

27 September 2012 in PLOS ONE
Verified
Journal Article
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SFSam M Ferreira
Sam M Ferreira
JBJudith M. Botha
Judith M. Botha
MEMegan C. Emmett
Megan C. Emmett
White rhinoceros (rhinos) is a keystone conservation species and also provides revenue for protection agencies. Restoring or mimicking the outcomes of impeded ecological processes allows reconciliation of biodiversity and financial objectives. We evaluate the consequences of white rhino management removal, and in recent times, poaching, on population persistence, regional conservation outcomes and opportunities for revenue generation. In Kruger National Park, white rhinos increased from 1998 to 2008. Since then the population may vary non-directionally. In 2010, we estimated 10,621 (95% CI: 8,767–12,682) white rhinos using three different population estimation methods. The desired management effect of a varying population was detectable after 2008. Age and sex structures in sink areas (focal rhino capture areas) were different from elsewhere. This comes from relatively more sub-adults being removed by managers than what the standing age distribution defined. Poachers in turn focused on more adults in 2011. Although the effect of poaching was not detectable at the population level given the confidence intervals of estimates, managers accommodated expected poaching annually and adapted management removals. The present poaching trend predicts that 432 white rhinos may be poached in Kruger during 2012. The white rhino management model mimicking outcomes of impeded ecological processes predicts 397 rhino management removals are required. At present poachers may be doing “management removals,” but conservationists have no opportunity left to contribute to regional rhino conservation strategies or generate revenue through white rhino sales. In addition, continued trends in poaching predict detectable white rhino declines in Kruger National Park by 2016. Our results suggest that conservationists need innovative approaches that reduce financial incentives to curb the threats that poaching poses to several conservation values of natural resources such as white rhinos.

16 January 2019 in PLOS ONE
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Journal Article
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SFSam M Ferreira
Sam M Ferreira
NRNikki Le Roex
Nikki Le Roex
CGCathy Greaver
Cathy Greaver
Unrelenting poaching to feed the illegal trafficking of rhinoceros (rhino) horn remains the principle threat to the persistence of south-central black and southern white rhino that live in the Kruger National Park (Kruger), South Africa. Other global environmental change drivers, such as unpredictable climatic conditions, impose additional uncertainties on the management and persistence of these species. The drought experienced in Kruger over the 2015/2016 rainy season may have affected rhino population growth and thus added an additional population pressure to the poaching pressure already occurring. Under drought conditions, reduced grass biomass predicts increased natural deaths and a subsequent decrease in birth rate for the grazing white rhino. Such variance in natural death and birth rates for the browsing black rhino are not expected under these conditions. We evaluated these predictions using rhino population survey data from 2013 to 2017. Comparisons of natural deaths and birth rates between pre- (2013/2014 and 2014/15), during- (2015/2016) and post-drought (2016/2017) periods in Kruger showed increased natural mortality and decreased births for white rhino, but no significant changes for black rhino, supporting our predictions. As a result, despite reduced poaching rates, the total mortality rate of white rhino remains significantly higher than the birth rate. Decreased poaching, decreased natural deaths and no apparent drought effects in black rhino resulted in a lower total mortality rate than the estimated birth rate in 2017. Active biological management and traditional anti-poaching initiatives together therefore represent the most likely way to buffer the impacts of decreased population growth through climate change and wildlife crime on the persistence of rhinos.

7 December 2020 in AMBIO
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Journal Article
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DCDonna-Maree Cawthorn
Donna-Maree Cawthorn
AKAlexandra Kennaugh
Alexandra Kennaugh
SFSam M Ferreira
Sam M Ferreira
The COVID-19 pandemic is a global crisis emanating both from a virus (SARS-CoV-2) and from the drastic actions to contain it. Here, we reflect on the immediate responses of most world powers amid the pandemic chaos: totalitarian surveillance and nationalist isolation. Drawing on published literature, we consider measures such as wildlife-use bans, lockdowns and travel restrictions, along with their reverberations for people, economies and the planet. Our synthesis highlights significant shortfalls of applying command-and-control tactics in emergencies. For one, heavy-handed bans risk enormous unintended consequences and tend to fail if they lack legitimacy or clash with people’s values. Furthermore, reactive and myopic strategies typically view the pandemic as a stand-alone crisis, rather than unravelling the complex interplay of nature-society interactions through which zoonotic diseases originate. A return to adaptive management approaches that recognise root causes and foster socio-ecological resilience will be essential to improve human and planetary health and mitigate future pandemics.

30 June 2012 in Pachyderm
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Journal Article
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SFSam M Ferreira
Sam M Ferreira
BOBenson Okita-Ouma
Benson Okita-Ouma
African rhinos are suffering a new poaching onslaught for their high-priced horns. Despite intensified anti-poaching activities, the number of rhinos poached per day has continued to increase since 2008. Between 2010 and 2011 more than 1.5% of the African rhino population was poached each year: a higher percentage is projected for 2012. This trend in increased poaching will reverse overall positive rhino population growth in the long term. In response, a rhino emergency summit comprising representatives of rhino range States, the private sector, government officials and non-governmental organizations met in Nairobi during April 2012. Following this meeting, we propose an integrated framework directed at reducing the demand-and-supply ratio associated with the use of rhino horn. The framework is envisaged to guide short- as well as medium- to long-term responses by range States directed at reducing the incentives for poaching and ensuring the persistence of rhinos. Les rhinocéros d’Afrique souffrent d’une nouvelle offensive de braconnage à cause du prix élevé de leurs cornes. En dépit de l’intensification des activités anti-braconnage, le nombre de rhinocéros braconnés par jour n’a cessé d’augmenter depuis 2008. Entre 2010 et 2011, plus de 1,5% de la population des rhinocéros d’Afrique ont été braconnés chaque année alors qu’on prévoit un pourcentage encore plus élevé pour 2012. Cette tendance à l’augmentation du braconnage va renverser la croissance positive de la population des rhinocéros dans le long terme. Pour cette raison, un sommet d’urgence comprenant les représentants des Etats de l’aire répartition de rhinocéros, le secteur privé, les responsables gouvernementaux et les organisations non-gouvernementales s’est tenu à Nairobi au mois d’avril 2012. Suite à cette réunion, nous proposons un cadre intégré visant à réduire le rapport de la demande et de l’offre associé à l’utilisation de la corne de rhinocéros. Le cadre est prévu pour guider à court, à moyen et à long termes les réponses des Etats de l’aire de répartition destinées à réduire les motivations pour le braconnage et assurer la persistance des rhinocéros.

7 February 2018 in Ecological Applications
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Journal Article
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THTimothy C. Haas
Timothy C. Haas
SFSam M Ferreira
Sam M Ferreira
Conservation management is of increasing importance in ecology as most ecosystems nowadays are essentially managed ecosystems. Conservation managers work within a political‐ecological system when they develop and attempt to implement a conservation plan that is designed to meet particular conservation goals. In this article, we develop a decision support tool that can identify a conservation policy for a managed wildlife population that is both sustainable and politically feasible. Part of our tool consists of a simulation model composed of interacting influence diagrams. We build, fit, and use our tool on the case of rhino horn trafficking between South Africa and Asia. Using these diagrams, we show how a rhino poacher's belief system can be modified by such a policy and locate it in a perceived risks‐benefits space before and after policy implementation. We statistically fit our model to observations on group actions and rhino abundance. We then use this fitted model to compute a politically feasible conservation policy.