Wildlife Research Area Research Articles

Modelling Poaching Risk Zones in Sengwa Wildlife Research Area: A Progressive Step towards Poaching Management

Modelling Poaching Risk Zones in Sengwa Wildlife Research Area: A Progressive Step towards Poaching Management

Dynamics and determinants of human–hyaena conflicts in the surroundings of a protected area

AbstractHuman–wildlife conflicts (HWC) predominate in areas proximal to wildlife rich protected zones. Whereas herbivore driven HWC is easy to detect, the stealth, nocturnal and predacious nature of carnivores leads to human injury and fatality, livestock depredation and loss of livelihoods in communities proximal to Sengwa Wildlife Research Area (SWRA) in northwest Zimbabwe. This study aimed to: (1) determine the nature of human–hyaena conflicts (HHCs), (2) explore the drivers of HHCs and (3) investigate the spatial and temporal movement patterns of hyaenas in HHC hotspots in areas proximal to SWRA. The results indicated that prevalent HHC types include livestock depredation, property damage, harassment, nuisance and disruption of human movements around SWRA. Locals indicated removal of park fences, human settlement on wildlife migration corridors, increases in hyaena populations, easy stray livestock targets, increased poaching and removal of natural wildlife death carcasses by illegal hunters as key drivers of HHC. Hyaenas have a predetermined non‐seasonal movement pattern following traditional wildlife migration corridors through SWRA into proximal communities. Human–hyaena conflict abatement strategies should be underpinned by indigenous local knowledge of hyaena movement and hunting patterns. Integrating citizen science data and remote sensing techniques aids to track and understand movement and hunting patterns of hyaenas inside and outside of protected areas.

Spatial distribution of invasive large fever berry trees (Croton megalobotrys) in Sengwa Wildlife Research Area: Gokwe, Zimbabwe

BackgroundThe invasion of rangelands by invasive plant species is a major threat to biodiversity in most parts of Zimbabwe posing not only an ecological challenge but a growing management and eradication challenge as well. However, there is sparse information relating to the spatial distribution of these species and the conditions promoting their growth and development particularly in Sothern Africa. The study assessed the spatial distribution of the invasive large fever berry tree and associated soil type in Sengwa Wildlife Research Area. A mixed methods research design triangulating qualitative and quantitative methods was utilized. All known sites occupied by large fever berry trees were obtained from the Sengwa Wildlife Research Institute’s records on invasive plant species. Ground truthing was done for all sites and global positioning system coordinates of occupied areas were collected. Mapping of invaded areas by the large fever berry tree was done using Quantum GIS software. Coordinates were imported to show points with the large fever berry tree. Altitude of invaded areas and soil samples were also collected for soil analysis and a soil texture triangle was used to come up with the soil type associated with the growth and spread of the large fever berry trees.ResultsThe results show that the large fever berry tree occupied areas along major rivers and streams on loam soils. An area of 16.5km2 which is 4.4% of the Sengwa Wildlife Research Area is invaded by the large fever berry tree. Results further indicated that sandy- loam soils were associated with the growth and development of the large fever berry tree in Sengwa Wildlife Research Area. Veld fires were also identified as a factor influencing the spread of the large fever berry tree species in the Sengwa Wildlife Research Area.ConclusionIn conclusion, a holistic framework was developed to curb the invasion of the large fever berry tree in Sengwa Wildlife Research Area. It is recommended that further studies be conducted outside the protected area to establish soil characteristics and invasion rates in order to fully understand drivers of its invasion.

Livestock Losses and Predation Crisis in Communal Areas around Sengwa Wildlife Research Area (SWRA), Zimbabwe

Livestock Losses and Predation Crisis in Communal Areas around Sengwa Wildlife Research Area (SWRA), Zimbabwe

Effects of Prescribed Burning on Abundance of Common Herbivores in Matekenya Vlei, Sengwa Wildlife Research Area (SWRA), Zimbabwe

Effects of Prescribed Burning on Abundance of Common Herbivores in Matekenya Vlei, Sengwa Wildlife Research Area (SWRA), Zimbabwe

Spatial Distribution of Invasive Large Fever Berry Trees (Croton Megalobotrys) in Sengwa Wildlife Research Area: Gokwe, Zimbabwe

Spatial Distribution of Invasive Large Fever Berry Trees (Croton Megalobotrys) in Sengwa Wildlife Research Area: Gokwe, Zimbabwe

Topo-edaphic, Vegetation Cover and Type Influence on Spatial Distribution of Gullies in Sengwa Wildlife Research Area (SWRA), North West Zimbabwe

Gully erosion is a common phenomenon in arid and semi-arid areas and is mostly influenced by soil type, topography, vegetation type and cover. The objective of the study was to determine the effect of topo-edaphic, vegetation type and cover on gully occurrence, hence map their spatial distribution in SWRA. A conventional method was used where field visit to known gully sites was done. At each site, GPS points were marked at three points, that is, at the head site, the middle and lower end of the gully. Soil samples, gully width, depth, length, vegetation type and cover were recorded for each point where GPS coordinates were collected. GPS points were overlaid on SWRA processed vegetation, soil and topographic map for analysis on the spatial distribution of gullies. Fifty-six gullies were recorded with highly affected areas on the southwestern side of the park. Associated soils types were clay and loam of the Madumabisa mudstone, colluvial and alluvial located at altitudes below 1000 meters. Gully occurrences were sighted more in mopane dominated woodlands with few recorded in areas dominated by acacia woodlands and on the edges of miombo woodlands, which occupy the high grounds of SWRA. Gully length varied from 20m in less developed gullies to 2520m for mature gullies with volumes ranging between 52m3 and 4649.4m3. Hence, topography, soil type, vegetation cover and type influence gully location and occurrence. Future research should aim to monitor changes in gully development using remote sensing as it provides a great potential for monitoring gully changes across the landscape.

Assessment of Big Cats Abundance and Distribution in Sengwa Wildlife Research Area (SWRA): An Analysis of Multiple Methods

Large carnivores are considered key species and their presence signify health of the ecosystem. Mostly used methods to establish big cats abundance and spatial distribution in SWRA consist of spoor survey, individual observations, analysis of patrol data and interviews with safari operators. In this study, four methods were used to establish current abundance and distribution of big cats in Sengwa and to find advantages and disadvantage for each method used. To do this, spoor survey along twelve transects were done between 13th to 20th April 2020. Oral interviews with local professional hunters and park managers was done between 1st and 10th April 2020, whilst analysis of patrol reports from January 2018 to December 2019 were also done. Descriptive statistics was used for analysis of interview data. For other three methods, data were summarised in excel and quantitatively analysed. Mapping of spatial distribution of big cats from secondary data and spoor surveys were done in QGIS software. Five lion spoors and twenty-one leopard spoors were recorded during spoor survey. Two individual leopards and zero lions were also recorded. Lion spoors were mostly recorded along river valleys while leopard spoors were recorded in different habitats and terrain. Future related studies should focus on use of other survey design and combination of methods such as radio calls and camera traps as well as use of GPS enabled collars for monitoring and estimating abundance.

An Analysis of the Factors Contributing to Elephant Population Fluctuations in SWRA using Ranger-based Knowledge and Perceptions

This study aimed at examining local ranger-based knowledge and perceptions on explaining contributing factors to variations on elephant fluctuations seasonally and over a long period in Sengwa Wildlife Research Area following a massive decline of elephants by nearly 76% after the 2014 National Aerial Survey done in Sebungwe Region, Zimbabwe. Data were collected between 1st and 20th August 2020 using a purposive sampling approach administered to questionnaire to resident SWRA rangers (n = 25). Our results show that rangers considered a combination of factors that may have affected elephant fluctuations in SWRA including poaching, migration, settlement and impact of climate change. However, our results suggest that rangers had inadequate knowledge about elephant migration destinations. Moreover, mixed perceptions about the impact of trophy hunting, poaching and climate change-induced factors were recorded from the participants. The results contribute to a growing understanding of poaching, climate change, trophy hunting and human settlement on elephant behaviour. The study recommends improvement in elephant monitoring through investments in elephant collars and radio tracking to better understand elephant daily and seasonal dispersal movements.

An Analysis of the Influence of Annual Rainfall Fluctuations on Wildfire Occurrence in Protected Areas in the Northwest of Zimbabwe

The occurrence and threat from wildfires are a conservation concern in semi-arid savanna-protected areas. The risk of wildlife occurrence is uncertain under climate change scenarios. However, general predictions are that different changes are likely to occur in weather conditions in different landscapes. We sought to analyze the influence of annual precipitation on wildfire occurrence in a protected area landscape in northwest Zimbabwe. Data on annual rainfall received and wildfire occurrence for Chizarira National Park (CNP), Chirisa Safari Area (CSA), and Sengwa Wildlife Research Area (SWRA) was analyzed using regression analysis. The relationship between the annual precipitation amount received per site and the number of wildfires recorded per site showed a positive correlation only for CSA. No significant differences were observed for CNP and SWRA at a significant level of p< 0.05. The highest number of wildfires were recorded between July and November. We advance that annual rainfall is one factor among many drivers of wildfires and that this is not uniform but varies across the landscape. Effective annual precipitation contributes to high vegetation biomass production and accumulation of such biomass increases the risk of wildfires. In some instances, rainfall patterns could not explain the occurrence of wildfires. We, therefore, contend that other drivers such as human activities and natural factors are important drivers of wildfires across the three sites. The conservation implication of our finding is that robust fire management plans need to take an ecosystem approach that includes communities adjacent to protected areas.

Quantifying the wetland water balance: A new isotope-based approach that includes precipitation and infiltration

Stable isotopes have been used to quantify lake and wetland pond water loss to evaporation by applying the modified Craig and Gordon (1965) model. This model and its derivatives employ simplifying assumptions that ignore the additions of precipitation and infiltration outputs and assume evaporation is the only loss term over the prediction period. Here we develop a coupled water and isotope mass-balance model to account for precipitation additions. Our model uses physical and isotopic observations to quantify pond evaporation and infiltration losses over the ice-free period. We tested and applied the model to four wetland ponds at the St Denis National Wildlife Research Area, Saskatchewan Canada, where we have long-term datasets. Modeled infiltration rates from the ponds ranged between 0.99 and 9.2 mm/d and open water evaporation rates ranged between 0.88 and 2.8 mm/d. Both were consistent with independent estimates. Infiltration amounts were highest in the ephemeral ponds (that dry out within days or weeks of the spring melt period). In these ponds, infiltration exceeded evaporation. In permanent ponds, that is ponds that do not dry out; evaporation exceeded infiltration. Evaporation amounts were most substantial for permanent ponds that were not sheltered by topography or riparian vegetation. Overall, our coupled water and isotope mass-balance model combined with physical and isotope observations was able to quantify the spatially and temporally variable evaporation and infiltration fluxes within and between ponds.

Decline and Die-Back of Woody Plants in a Physiognomic and Floristically Complex Sebungwe Region and the Factors Modifying Mosaic Patch Landscapes at Sengwa Wildlife Area, Zimbabwe

An investigation of the status of woodlands at Sengwa Wildlife Research Area (SWRA) revealed factors influencing decline and die-back of woody plants at a time of low elephant densities. The vegetation condition of the study area in the elephant range area of the semi-arid area of northwest Zimbabwe was randomly assessed in 50 × 20 m permanently marked degraded and undegraded plots in a study area approximately 80 km2. Diversity of woody plants increased towards downstream. Percentage elephant damage was slight on undegraded plots and termite damage was three times greater on undegraded plots than degraded plots. Density of woody plants was high following a period of coppice regeneration. The results suggest regeneration of woody plants following a long period of elephant culls between 1960 and 1992 that altered forest structures. It is conceivable that other environmental agents may play the role of elephant damage in the presence of elephant densities < 1 individuals/ km2. Significant differences (p<0.05) in elephant densities (no/km2) were recorded in SWRA between 1958 and 1996, 1958 and 1993 suggesting that increasing elephant densities were negatively impacting on woody cover (%). Woody cover increased from 60% in 1993 to 70% in 1996 inside SWRA. SWRA vegetation may be on regeneration path if no adverse impacts are recorded from other environmental agents including termite activity, fungal attack (Fusarium oxysporum), Lantana camara L. invasions and drought. Epidemic die-back is not yet a common feature in the protected area. The results refute the postulation that elephant alone prevent woodland regeneration and recruitment into larger size classes by feeding on small trees. The findings suggest need to consider end to end cycle of each disturbance factor in order to accurately predict scale of vegetation change in savanna ecosystems.

Breeding bird communities at Anmon wildlife research area in the Shirakami Mountains (II)

Breeding bird communities at Anmon wildlife research area in the Shirakami Mountains (II)

Observed and modeled ecosystem isoprene fluxes from an oak-dominated temperate forest and the influence of drought stress

Ecosystem fluxes of isoprene emissions were measured during the majority of the 2011 growing season at the University of Missouri's Baskett Wildlife Research and Education Area in central Missouri, USA (38.7° N, 92.2° W). This broadleaf deciduous forest is typical of forests common in the Ozarks region of the central United States. The goal of the isoprene flux measurements was to test our understanding of the controls on isoprene emission from the hourly to the seasonal timescale using a state-of-the-art emission model, MEGAN (Model of Emissions of Gases and Aerosols from Nature). Isoprene emission rates from the forest were very high with a maximum of 53.3 mg m−2 h−1 (217 nmol m−2 s−1), which to our knowledge exceeds all other reports of canopy-scale isoprene emission. The fluxes showed a clear dependence on the previous temperature and light regimes, which was successfully captured by the existing algorithms in MEGAN. During a period of drought, MEGAN was unable to reproduce the time-dependent response of isoprene emission to water stress. Overall, the performance of MEGAN was robust and could explain 90% of the observed variance in the measured fluxes, but the response of isoprene emission to drought stress is a major source of uncertainty.

Rodents communities at Anmon wildlife research area in the Shirakami Mountains

Rodents communities at Anmon wildlife research area in the Shirakami Mountains

Genetic measures confirm familial relationships and strengthen study design

AbstractSocial structure and behavioral interactions between individuals shape basic biological processes, such as breeding; foraging and predator avoidance; movement and dispersal; and disease transmission. We used a targeted trapping strategy to capture kin groups of white‐tailed deer (Odocoileus virginianus) during 2007 and 2008 in Sandhill Wildlife Research Area, Wisconsin, USA, in order to observe social behaviors. Because inferring family relationships from observation of behavior is subjective, we used measures of genetic relatedness and parentage assignment tests to determine that our capture strategy was efficient for capturing related pairs (78% of groups contained ≥1 dyad of related animals). The results of our genetic tests verified that study animals were related; therefore, our capture strategy was successful and the assumptions of the research design were met. This demonstrates both the utility of a targeted sampling approach, and the importance of genetic techniques to verify relationships among animals, especially when kin association forms a basis for further biological study or management action. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Evaluation of the effectiveness of an early peripheral burning strategy in controlling wild fires in north‐western Zimbabwe

AbstractA review of the occurrence of wild fires in Sengwa Wildlife Research Area (SWRA), Zimbabwe, is presented for the period 1965–1993. The effectiveness and desirability of early burning of peripheral areas introduced in 1979 are evaluated. More than 75% of wild fires occurred between July and October, 48.6% of which originated from communal lands. Early burning of peripheral areas led to significant reductions in extent of areas burnt, from annual mean areas of 115 km2 (1965–1978) to 11 km2 (1979–1993) because of effective control of fires, which originated from communal lands. Some areas did not burn at all after 1979, and the overall probability of burning dropped from 0.484 to 0.187. Whilst it may be desirable to keep fires out of SWRA in the short term, fuel build‐ups increase the fire hazard resulting in negative consequences on biodiversity in the long term. Consideration should be given to combine peripheral burning with low‐intensity prescribed burning of selected blocks to keep a semblance of natural fire regimes to ensure the maintenance of biodiversity while simultaneously reducing the fire‐hazard. An integrated fire management plan should be put in place for SWRA.

Seasonal influence of rainfall and crops on home range expansion by bull elephants

'Knowledge of distribution and movement patterns in relation to their environment is essential if elephants are to be effectively managed because crop raiding is spatial and temporal in nature.' This study attempted to obtain estimates of the home ranges of elephants in Sengwa Wildlife Research Area, to establish seasonal crossing patterns into surrounding communal agricultural lands, and to examine the the concept of wet season range expansion. 7 adult and 3 subadult bulls were radio tracked during a two year period. 'Range sizes and crossing patterns out of the protected area were compared by season.' Results suggest that the concept of range expansion at the end of the wet season is correlated with the movement of elephants into agricultural lands. Knowing how and when crop raiding elephants move into subsistence agricultural areas that surround many of the protected areas is considered essential to identifying the reason why elephants and people come into conflict.

Free-ranging domestic dogs ( Canis familiaris) as predators and prey in rural Zimbabwe: threats of competition and disease to large wild carnivores

Domestic dogs ( Canis familiaris) arrived in Zimbabwe ca. 1000 years ago. Numbers of free-ranging dogs have reached unprecedented levels in communal lands (agro-pastoralist rural areas), and interact with large wild carnivores along boundaries with wildlife reserves as predators and prey. This study examined a population of 236 dogs in a 33-km 2 section of Gokwe Communal Land (GCL) bordering the Sengwa Wildlife Research Area (SWRA) in north-western Zimbabwe in 1995–1996. Dogs were found up to 6 km within the SWRA, and were the most common carnivore on the GCL–SWRA boundary. Observations of 16 radio-collared dogs showed that they were inefficient predators. Only 20 kills were recorded amongst the remaining dog population, of which three were wild ungulates. Dogs were unsuccessful predators due to their small group size (mean 1.7) and body mass (mean 14.7 kg), and the abundance of alternative food. It is therefore unlikely that they compete with large carnivores for wild prey. However, leopards ( Panthera pardus), lions ( P. leo) and spotted hyaenas ( Crocuta crocuta) preyed on dogs in GCL, removing ⩾6% of the dog population in 1993. Such predation provides ideal circumstances for disease transmission. Canid disease was prevalent in the study area; including rabies and probably distemper. The risk of infection is greatest during the dry season (May–October), when peaks in rates of disease, carnivore incursions into GCL, and predation on dogs coincided. The role of jackals ( Canis adustus and Canis mesomelas) and spotted hyaena predation of dogs is discussed in relation to disease epidemics within wildlife reserves. With a dog population growth rate of 6.5% per annum, and the prevalence of canid diseases, the conservation threat posed by dogs is escalating on communal land–wildlife reserve boundaries in Zimbabwe. Measures to control dog numbers and improve vaccination coverage of dogs are discussed.

Cyclic voles, prey switching in red fox, and roe deer dynamics – a test of the alternative prey hypothesis

Medium‐sized predators sometimes switch to alternative prey species as their main prey declines. Our objective of this study was to test the alternative prey hypothesis for a medium sized predator (red fox, Vulpes vulpes), a small cyclically fluctuating main prey (microtine voles) and larger alternative prey (roe deer fawns, Capreolus capreolus). We used long‐term time series (28 years) on voles, red fox and roe deer from the Grimsö Wildlife Research Area (59°40′N, 15°25′E) in south‐central Sweden to investigate interspecific relationships in the annual fluctuations in numbers of the studied species. Annual variation in number of roe deer fawns in autumn was significantly and positively related to vole density and significantly and negatively related to the number of fox litters in the previous year. In years of high vole density, predation on roe deer fawns was small, but in years of low vole density predation was more severe. The time lag between number of fox litters and predation on fawns was due to the time lag in functional response of red fox in relation to voles. This study demonstrates for the first time that the alternative prey hypothesis is applicable to the system red fox, voles and roe deer fawns.