المؤلفون: Bar-David, Shirli, Bar-David, Israel, Cross, Paul C., Ryan, Sadie J., Knechtel, Christiane U., Getz, Wayne M.

المصدر: Ecology; Sep2009, Vol. 90 Issue 9, p2467-2479, 13p

مصطلحات موضوعية: HOME range (Animal geography), AFRICAN buffalo, HABITATS, GLOBAL Positioning System, ANIMAL ecology, RECURSION theory, FOURIER analysis, WILDLIFE conservation

مصطلحات جغرافية: KRUGER National Park (South Africa), SOUTH Africa

مستخلص: Abstract. Recent developments of automated methods for monitoring animal movement, e.g., global positioning systems (GPS) technology, yield high-resolution spatiotemporal data. To gain insights into the processes creating movement patterns, we present two new techniques for extracting information from these data on repeated visits to a particular site or patch ("recursions"). Identification of such patches and quantification of recursion pathways, when combined with patch-related ecological data, should contribute to our understanding of the habitat requirements of large herbivores, of factors governing their space-use patterns, and their interactions with the ecosystem. We begin by presenting output from a simple spatial model that simulates movements of large-herbivore groups based on minimal parameters: resource availability and rates of resource recovery after a local depletion. We then present the details of our new techniques of analyses (recursion analysis and circle analysis) and apply them to data generated by our model, as well as two sets of empirical data on movements of African buffalo (Syncerus caffer): the first collected in Klaserie Private Nature Reserve and the second in Kruger National Park, South Africa. Our recursion analyses of model outputs provide us with a basis for inferring aspects of the processes governing the production. of buffalo recursion patterns, particularly the potential influence of resource recovery rate. Although the focus of our simulations was a comparison of movement patterns produced by different resource recovery rates, we conclude our paper with a comprehensive discussion of how recursion analyses can be used when appropriate ecological data are available to elucidate various factors influencing movement. Inter alia, these include the various limiting and preferred resources, parasites, and topographical and landscape factors. [ABSTRACT FROM AUTHOR]

: Copyright of Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: OOSTHUIZEN, W. CHRIS, CROSS, PAUL C., BOWERS, JUSTIN A., HAY, CRAIG, EBINGER, MICHAEL RYAN, BUSS, PETER, HOFMEYR, MARKUS, CAMERON, ELISSA Z.

المصدر: Journal of Wildlife Management; Jan2009, Vol. 73 Issue 1, p149-153, 5p, 1 Chart, 1 Map

مصطلحات موضوعية: ANIMAL immobilization, AFRICAN buffalo, WILDLIFE monitoring, ANIMAL population estimates, ANIMAL mortality, REGRESSION analysis, TUBERCULOSIS in cattle, EQUIPMENT & supplies

مصطلحات جغرافية: KRUGER National Park (South Africa), SOUTH Africa

مستخلص: Capturing, immobilizing, and fitting radiocollars are common practices in studies of large mammals, but success is based on the assumptions that captured animals are representative of the rest of the population and that the capture procedure has negligible effects. We estimated effects of chemical immobilization on mortality rates of African buffalo (Syncerus caffer) in the Kruger National Park, South Africa. We used a Cox proportional hazards approach to test for differences in mortality among age, sex, and capture classes of repeatedly captured radiocollared buffalo. Capture variables did not improve model fit and the Cox regression did not indicate increased risk of death for captured individuals up to 90 days postcapture [exp (β) = 1.07]. Estimated confidence intervals, however, span from a halving to a doubling of the mortality rate (95% CI=0.56-2.02). Therefore, capture did not influence survival of captured individuals using data on 875 captures over a 5- year period. Consequently, long-term research projects on African buffalo involving immobilization, such as associated with research on bovine tuberculosis, should result in minimal capture mortality, but monitoring of possible effects should continue. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Wildlife Management is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Gorsich EE; Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA., Ezenwa VO; Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA., Cross PC; U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, MT, 59715, USA., Bengis RG; Department of Agriculture, Forestry and Fisheries, Directorate of Animal Health, State Veterinary Office, Skukuza, 1350, South Africa., Jolles AE; Department of Biomedical Sciences, Oregon State University, Corvallis, OR, 97331, USA.

المصدر: The Journal of animal ecology [J Anim Ecol] 2015 Jul; Vol. 84 (4), pp. 999-1009. Date of Electronic Publication: 2015 Mar 18.

نوع المنشور: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.

بيانات الدورية: Publisher: Blackwell Country of Publication: England NLM ID: 0376574 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1365-2656 (Electronic) Linking ISSN: 00218790 NLM ISO Abbreviation: J Anim Ecol Subsets: MEDLINE

مواضيع طبية MeSH: Fertility*, Brucella abortus/*pathogenicity , Brucellosis/*veterinary , Buffaloes/*microbiology, Animals ; Brucellosis/epidemiology ; Brucellosis/microbiology ; Cross-Sectional Studies ; Female ; Longitudinal Studies ; Male ; Population Dynamics ; Pregnancy ; Seroepidemiologic Studies ; South Africa ; Survival Analysis

مستخلص: Chronic infections may have negative impacts on wildlife populations, yet their effects are difficult to detect in the absence of long-term population monitoring. Brucella abortus, the bacteria responsible for bovine brucellosis, causes chronic infections and abortions in wild and domestic ungulates, but its impact on population dynamics is not well understood. We report infection patterns and fitness correlates of bovine brucellosis in African buffalo based on (1) 7 years of cross-sectional disease surveys and (2) a 4-year longitudinal study in Kruger National Park (KNP), South Africa. We then used a matrix population model to translate these observed patterns into predicted population-level effects. Annual brucellosis seroprevalence ranged from 8·7% (95% CI = 1·8-15·6) to 47·6% (95% CI = 35·1-60·1) increased with age until adulthood (>6) and varied by location within KNP. Animals were on average in worse condition after testing positive for brucellosis (F = -5·074, P < 0·0001), and infection was associated with a 2·0 (95% CI = 1·1-3·7) fold increase in mortality (χ(2)  = 2·039, P = 0·036). Buffalo in low body condition were associated with lower reproductive success (F = 2·683, P = 0·034), but there was no association between brucellosis and pregnancy or being observed with a calf. For the range of body condition scores observed in the population, the model-predicted growth rate was λ = 1·11 (95% CI = 1·02-1·21) in herds without brucellosis and λ = 1·00 (95% CI = 0·85-1·16) when brucellosis seroprevalence was 30%. Our results suggest that brucellosis infection can potentially result in reduced population growth rates, but because these effects varied with demographic and environmental conditions, they may remain unseen without intensive, longitudinal monitoring.
(© 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.)

المؤلفون: LaBeaud AD; Children's Hospital Oakland Research Institute, Oakland, CA, USA. alabeaud@chori.org, Cross PC, Getz WM, Glinka A, King CH

المصدر: The American journal of tropical medicine and hygiene [Am J Trop Med Hyg] 2011 Apr; Vol. 84 (4), pp. 641-6.

نوع المنشور: Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.

بيانات الدورية: Publisher: American Society of Tropical Medicine and Hygiene Country of Publication: United States NLM ID: 0370507 Publication Model: Print Cited Medium: Internet ISSN: 1476-1645 (Electronic) Linking ISSN: 00029637 NLM ISO Abbreviation: Am J Trop Med Hyg Subsets: MEDLINE

مواضيع طبية MeSH: Buffaloes*, Epidemics/*veterinary , Rift Valley Fever/*veterinary , Rift Valley fever virus/*immunology, Animals ; Antibodies, Viral/blood ; Climate ; Rain ; Rift Valley Fever/blood ; Rift Valley Fever/epidemiology ; Rift Valley Fever/immunology ; Rift Valley Fever/transmission ; Seroepidemiologic Studies ; South Africa/epidemiology ; Time Factors

مستخلص: Rift Valley fever virus (RVFV) is an emerging biodefense pathogen that poses significant threats to human and livestock health. To date, the interepidemic reservoirs of RVFV are not well defined. In a longitudinal survey of infectious diseases among African buffalo during 2000-2006, 550 buffalo were tested for antibodies against RVFV in 820 capture events in 302 georeferenced locations in Kruger National Park, South Africa. Overall, 115 buffalo (21%) were seropositive. Seroprevalence of RVFV was highest (32%) in the first study year, and decreased progressively in subsequent years, but had no detectable impact on survival. Nine (7%) of 126 resampled, initially seronegative animals seroconverted during periods outside any reported regional RVFV outbreaks. Seroconversions for RVFV were detected in significant temporal clusters during 2001-2003 and in 2004. These findings highlight the potential importance of wildlife as reservoirs for RVFV and interepidemic RVFV transmission in perpetuating regional RVFV transmission risk.

المؤلفون: Wolhuter J; Department of Nature Conservation, Tshwane University of Technology, Pretoria 0001, South Africa., Bengis RG, Reilly BK, Cross PC

المصدر: Journal of wildlife diseases [J Wildl Dis] 2009 Apr; Vol. 45 (2), pp. 502-4.

نوع المنشور: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.

بيانات الدورية: Publisher: Wildlife Disease Association Country of Publication: United States NLM ID: 0244160 Publication Model: Print Cited Medium: Print ISSN: 0090-3558 (Print) Linking ISSN: 00903558 NLM ISO Abbreviation: J Wildl Dis Subsets: MEDLINE

مواضيع طبية MeSH: Buffaloes*/microbiology , Buffaloes*/parasitology, Mite Infestations/*veterinary , Skin Diseases, Parasitic/*veterinary, Age Factors ; Animals ; Animals, Wild/microbiology ; Animals, Wild/parasitology ; Brucellosis/complications ; Brucellosis/epidemiology ; Brucellosis/veterinary ; Cattle ; Female ; Male ; Mite Infestations/epidemiology ; Mite Infestations/pathology ; Pregnancy ; Prevalence ; Rift Valley Fever/complications ; Rift Valley Fever/epidemiology ; Rift Valley Fever/veterinary ; Severity of Illness Index ; Skin Diseases, Parasitic/epidemiology ; Skin Diseases, Parasitic/pathology ; South Africa/epidemiology ; Tuberculosis, Bovine/complications ; Tuberculosis, Bovine/epidemiology

مستخلص: We investigated the relationship between prevalence and severity of clinical signs of Demodex cafferi infection in free-ranging African buffalo (Syncerus caffer) and other factors such as age, sex, pregnancy status, and concomitant infections with bovine tuberculosis (BTB), Rift Valley fever (RVF), and brucellosis (BA). Approximately half of 203 buffalo examined in this study had clinical signs of demodicosis (cutaneous nodules); younger age classes had the highest prevalence and severity of lesions (chi(2)=21.4, df=6, P=0.0015). Nodules were generally limited to the head and neck region, but in severe cases were present over the entire animal. We found no significant association between clinical severity of the Demodex infection and gender, pregnancy status, or infection with BTB, RVF, or BA.

المؤلفون: Getz WM; Department of Environmental Science, Policy and Management, University of California, Berkeley, California, United States of America. getz@nature.berkeley.edu, Fortmann-Roe S, Cross PC, Lyons AJ, Ryan SJ, Wilmers CC

المصدر: PloS one [PLoS One] 2007 Feb 14; Vol. 2 (2), pp. e207. Date of Electronic Publication: 2007 Feb 14.

نوع المنشور: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.

بيانات الدورية: Publisher: Public Library of Science Country of Publication: United States NLM ID: 101285081 Publication Model: Electronic Cited Medium: Internet ISSN: 1932-6203 (Electronic) Linking ISSN: 19326203 NLM ISO Abbreviation: PLoS One Subsets: MEDLINE

مواضيع طبية MeSH: Homing Behavior* , Statistics, Nonparametric*, Ecology/*statistics & numerical data, Animals ; Buffaloes ; Demography ; Geographic Information Systems ; South Africa

مستخلص: Parametric kernel methods currently dominate the literature regarding the construction of animal home ranges (HRs) and utilization distributions (UDs). These methods frequently fail to capture the kinds of hard boundaries common to many natural systems. Recently a local convex hull (LoCoH) nonparametric kernel method, which generalizes the minimum convex polygon (MCP) method, was shown to be more appropriate than parametric kernel methods for constructing HRs and UDs, because of its ability to identify hard boundaries (e.g., rivers, cliff edges) and convergence to the true distribution as sample size increases. Here we extend the LoCoH in two ways: "fixed sphere-of-influence," or r-LoCoH (kernels constructed from all points within a fixed radius r of each reference point), and an "adaptive sphere-of-influence," or a-LoCoH (kernels constructed from all points within a radius a such that the distances of all points within the radius to the reference point sum to a value less than or equal to a), and compare them to the original "fixed-number-of-points," or k-LoCoH (all kernels constructed from k-1 nearest neighbors of root points). We also compare these nonparametric LoCoH to parametric kernel methods using manufactured data and data collected from GPS collars on African buffalo in the Kruger National Park, South Africa. Our results demonstrate that LoCoH methods are superior to parametric kernel methods in estimating areas used by animals, excluding unused areas (holes) and, generally, in constructing UDs and HRs arising from the movement of animals influenced by hard boundaries and irregular structures (e.g., rocky outcrops). We also demonstrate that a-LoCoH is generally superior to k- and r-LoCoH (with software for all three methods available at http://locoh.cnr.berkeley.edu).