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Becker M.S.,Zambian Carnivore Programme | Becker M.S.,Montana State University | Watson F.G.R.,Zambian Carnivore Programme | Watson F.G.R.,California State University, Monterey Bay | And 5 more authors.
Journal of Wildlife Management | Year: 2013

African lions (Panthera leo) are declining continent-wide, with protected area populations subject to a variety of anthropogenic effects. Zambia contains viable lion populations of considerable importance for photographic and hunting tourism, but long-term lion demographic data do not exist to guide recent management directives and population projections under different strategies. We described population size, as well as age and sex structure of lions in 3 Zambian national park populations bordering hunting areas, and found them to be male-depleted relative to other systems. We then estimated rates of adult male loss leading to male depletion in these populations and the effect of different future hunting management options on population characteristics. Predictions from matrix population models constructed within a Bayesian framework confirmed that the observed population structure was likely due to high rates of adult male loss and that instituting age limits on male harvests with quota reductions would reduce male depletion, improve tourism by providing older and more abundant males, and slightly increase population size. Reducing male mortality from wire snare poaching would also result in similar demographic impacts, and in concert with changes in hunting regulations would substantially improve the quality and quantity of adult male lions. However, model results varied depending on whether we assumed historical population stability. Predictions assuming negative historical growth rate indicated that substantially more conservative lion harvest management is warranted. We discuss the relevance of these findings for maintaining viable lion populations in and around protected areas in Zambia. Copyright © 2012 The Wildlife Society.

Watson F.G.R.,California State University, Monterey Bay | Becker M.S.,Zambian Carnivore Programme | Becker M.S.,Montana State University | Milanzi J.,Zambia Wildlife Authority | Nyirenda M.,Worldwide Fund for Nature
Regional Environmental Change | Year: 2014

Large carnivores are declining globally, with strong direct and indirect ecological impacts on protected area networks (PANs). Human encroachment on ecosystems is a global threat for large carnivores, particularly in savanna Africa, where increasing human resource demands continue to degrade the connectivity and viability PANs. Zambia has a regionally significant role in large carnivore conservation, given that it borders eight countries, includes three transfrontier conservation areas (TFCAs), and manages nearly 40 % of its land for wildlife. Deforestation in general and encroachment in particular are recognized problems in Zambian natural resource management. However, specific impacts on PANs are poorly understood owing to a lack of adequate mapping of encroachment, deriving from widespread difficulty in mapping cultivation and clearing in fire-prone savannas, and severe inaccuracy in several previous land cover data sets. Using simple manual interpretation of diverse and carefully chosen remote sensing imagery, we evaluated land use change from 1965 to 2011 in Zambia, primarily in the Luangwa Valley. We found widespread encroachment extending toward national parks from major roads as fast as 2 km/year and averaging 18 hectares per hour of daylight throughout a 159,805 km2 study area, eliminating designated buffer zones in some areas, decreasing connectivity, and potentially eliminating viable TFCAs. At current rates, Zambia’s PANs would be expected to be reduced into small isolated pockets primarily centered on national parks, with substantial human edge effects threatening the viability of wildlife populations in the region, particularly wide-ranging, low density, and threatened large carnivores such as African wild dogs, cheetah, and lion. It is thus critical that encroachment is accurately mapped across the entire region and that land use plans are developed, implemented, revised where necessary, and enforced with strong governmental support, enabling protection of these areas and the communities that depend upon them. © 2014, Springer-Verlag Berlin Heidelberg.

Halloran K.M.,University of Vermont | Murdoch J.D.,University of Vermont | Becker M.S.,Zambian Carnivore Programme | Becker M.S.,Montana State University
African Journal of Ecology | Year: 2015

Digital photography enables researchers to rapidly compile large quantities of data from individually identifiable animals, and computer software improves the management of such large datasets while aiding the identification process. Wild-ID software has performed well with uniform datasets controlling for angle and portion of the animal photographed; however, few datasets are collected under such controlled conditions. We examined the effectiveness of Wild-ID in identifying individual Thornicroft's giraffe from a dataset of photographs (n = 552) collected opportunistically in the Luangwa Valley, Zambia from March to October 2009. We assessed the programme's accuracy in correctly identifying individuals and the effect of five image quality factors on identification success: blurriness, background type and complexity, amount of sky and the presence of other giraffe. The programme correctly identified individuals in 71.6% of photographs. Background complexity was the only significant variable affecting identification success and removing background imagery reduced identification error by 52.8% (from 28.4 to 13.4%). Our results indicate higher levels of error than previously reported for Wild-ID. However, they also suggest the programme is an effective tool for quickly identifying individuals in large field datasets, especially if photograph backgrounds are removed beforehand and postanalysis visual verification is performed. © 2014 John Wiley & Sons Ltd.

Watson F.,California State University, Monterey Bay | Becker M.S.,Zambian Carnivore Programme | Becker M.S.,Montana State University | McRobb R.,South Luangwa Conservation Society | Kanyembo B.,South Luangwa Conservation Society
Biological Conservation | Year: 2013

Wire-snare poaching is fueling the rapidly growing illegal bushmeat trade in Africa's savanna ecosystems given the region's relatively abundant wildlife, increasing commercial bushmeat demand, and burgeoning human populations; thus understanding snaring dynamics is critical to addressing this crisis. Community conservation areas often border National Parks (NPs) and are intended to serve as buffer zones wherein sustainable, wildlife-based economies exist. Yet their success is poorly-evaluated, partly due to poorly-understood poaching patterns and the impact of human development in these zones. We investigated snaring patterns in Zambia's South Luangwa National Park and adjacent community Game Management Areas (GMAs) using highly-trained four-person teams to conduct 116 snare surveys at stratified random locations across approximately 6661km2 from September 2011 to November 2012. We postulated that snaring would be predicted by land use, crops, roads, and permanent water. Using novel multi-logistic models, we found decisive evidence that snaring only occurred in GMAs and immediately adjacent NP areas. Within these areas, we found substantial evidence that snaring was constrained by road proximity, moderate evidence for water constraints, and equivocal evidence for crop constraints. Snare detection rates in these areas were 60%. Evaluating finer-scale GMA snaring patterns requires more data; however strong correlation between snaring and human development in protected area buffer zones necessitates increased caution and carefully planned community development initiatives, and the adoption and enforcement of well-zoned land-use plans. Incentives aimed at increasing agricultural development in buffer zones should be redirected away from these zones to reduce encroachment and poaching and protect wildlife-based economies. © 2013 Elsevier Ltd.

Riggio J.,Duke University | Riggio J.,National Geographic Society | Jacobson A.,Duke University | Jacobson A.,National Geographic Society | And 17 more authors.
Biodiversity and Conservation | Year: 2013

We define African savannahs as being those areas that receive between 300 and 1,500 mm of rain annually. This broad definition encompasses a variety of habitats. Thus defined, savannahs comprise 13.5 million km2 and encompass most of the present range of the African lion (Panthera leo). Dense human populations and extensive conversion of land to human use preclude use by lions. Using high-resolution satellite imagery and human population density data we define lion areas, places that likely have resident lion populations. In 1960, 11.9 million km2 of these savannahs had fewer than 25 people per km2. The comparable area shrank to 9.7 million km2 by 2000. Areas of savannah Africa with few people have shrunk considerably in the last 50 years and human population projections suggest they will likely shrink significantly in the next 40. The current extent of free-ranging lion populations is 3.4 million km2 or about 25 % of savannah area. Habitats across this area are fragmented; all available data indicate that between 32,000 and 35,000 free-ranging lions live in 67 lion areas. Although these numbers are similar to previous estimates, they are geographically more comprehensive. There is abundant evidence of widespread declines and local extinctions. Under the criteria we outline, ten lion areas qualify as lion strongholds: four in East Africa and six in Southern Africa. Approximately 24,000 lions are in strongholds, with an additional 4,000 in potential ones. However, over 6,000 lions are in populations of doubtful long-term viability. Lion populations in West and Central Africa are acutely threatened with many recent, local extinctions even in nominally protected areas. © 2012 The Author(s).

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