Ecological and anthropogenic effects on the density of migratory and resident ungulates in a human‐inhabited protected area

Understanding the influence of environmental conditions and people on ungulate density and distribution is of key importance for conservation. We evaluated the effects of ecological and anthropogenic factors on the density of migratory wildebeest and zebra and resident oribi in Zambia's Liuwa Plain National Park where human settlements were present. We conducted transect surveys from 2010 to 2013 using distance sampling methods and then developed a set of 38 candidate models to describe results and predict density. Models included the effects of variables in three classes: environmental (year, season, vegetation, predominant grass height, burn, water presence), predation risk (hyaena density) and anthropogenic (distance to park boundary and settlements). Densities ranged from 6.2 to 60.8 individuals km^?2 for wildebeest, 1.1 to 14.5 individuals km^?2 for oribi and 1.8 to 8.1 individuals km^?2 for zebra. The most complex models were strongly supported for all three species. The magnitude and sign of variable effects differed among species, indicating that local densities of wildebeest, oribi and zebra are affected by a complex set of anthropogenic and ecological factors. Results reveal resource partitioning among ungulate species and indicate that predation risk and proximity to humans affect ungulate distributions with implications for managing migrations in the Greater Liuwa Ecosystem.     

The density and biomass of large mammals in Lake Nakuru National Park

Over the past 70 years, human activity has severely limited the diversity and movements of large mammals in the region of Lake Nakuru National Park, Kenya. Game counts were begun in April 1970 to assess the status of those species remaining. The density of large mammals per km² was found to be 64.20±8.86 (mean ±S.D.) and the biomass density of the six major species in kg/km² was 6298±801. The biomass was most heavily concentrated in the grassland-woodland area south of the lake. Defassa water-buck was the dominant species accounting for 76% of the biomass density. The probable reasons for their dominance are: (1) favourable habitat; (2) decreased competition; (3) reduced predation; (4) control of poaching; and (5) non-migratory habits. Future management may ultimately depend on the relationship of waterbuck to the food resources available.     

黄河三角洲自然保护区湿地植被生物量空间分布及其影响因素

以黄河三角洲自然保护区为研究区域,以野外实测湿地植被地上生物量数据、Landsat-8影像数据和土壤各因子检测数据为数据源,通过分析各遥感因子与实测植被生物量的相关关系,建立生物量模型,进行生物量的定量反演。通过研究生物量与土壤、水环境因子的关系,筛选影响生物量的关键因子,进而分析生物量的空间分布规律。结果表明:湿地植被地上生物量的干重与各遥感因子的相关性较高;以NDVI、EVI、MSAVI、DVI、RVI、Band1、Band2、Band3、Band4、Band6共10个因子作为自变量建立的反演模型最优;反演计算的生物量干重分为5个等级区,最低的1级区和最高的5级区面积较小,为82.23、72.16 km2,分别占研究区湿地植被总面积的13.35%、11.71%。生物量干重适中的2、3、4级区所占面积较大,为211.99、136.39、113.29 km2,分别占研究区湿地植被总面积的34.41%、22.14%、18.39%;在各环境因子中水深对芦苇生物量干重影响最大,土壤含水率对碱蓬生物量干重影响最大,水、盐条件是导致优势种植被生物量干重出现空间分异的主导因素;植被生物量干重呈现由陆向海减小,由黄河河道两岸向外递减的趋势。     

Population densities,group size and biomass of ungulates in a lowland tropical rainforest forest of the eastern Himalayas

Large ungulate population monitoring is a crucial wildlife management tool as ungulates help in structuring and maintaining the large carnivore populations. Reliable data on population status of major ungulate prey species are still non-existent for most of the protected areas in the Indian part of the eastern Himalayan biodiversity hotspot. Twenty transects were monitored over a period of three years (2009–2011) totaling 600 km with an average length of 2 km. The estimated mean density of ungulates was 17.5 km⁻² with overall density of 48.7 km⁻². The wild pig Sus scrofa had the highest density (6.7 ± 1.2 km⁻²) among all the prey species followed by barking deer Muntiacus muntjak (3.9 ± 0.6 km⁻²), sambar Rusa unicolor (3.8 ± 0.5) and gaur Bos gaurus (3.5 ± 0.9 km⁻²). The estimated total ungulate biomass density was 2182.56 kg km⁻². This prey biomass can support up to 7.2 tigers per 100 km⁻². However, with two other sympatric carnivores sharing the same resources, the actual tiger numbers that can be supported will be lower. The estimated minor prey species was 31 km⁻² significantly 30.6% crop damages were reported by wild pig (p = 0.01) and 35.4% was elephant (p = 0.004). This data on ungulate densities and biomass will be crucial for carnivore conservation in this understudied globally significant biodiversity hotspot.     

乌兰布和沙漠东北缘荒漠-绿洲过渡带植被地上生物量估算

干旱区荒漠植被地上生物量是植被生长状况评价与荒漠化监测的重要指标。在乌兰布和沙漠东北缘的荒漠-绿洲过渡带选取典型区,基于地面调查数据构建主要植物种的异速生长方程,对样方内的植被地上生物量进行估算;基于样方调查数据和Quick Bird影像数据,分别建立植被指数与人工固沙林和荒漠植被地上生物量的回归模型,并对研究区植被地上生物量进行估算。结果表明:植冠体积V是较好的预测变量,所得荒漠植物异速生长方程精度较高,能够满足样方内荒漠植被地上生物量估算需要;采用RVI对数模型估算人工固沙林地上生物量的效果最好(R~2=0.72,RMSEP=56.15),采用RVI线性模型估算荒漠植被地上生物量的效果最好(R~2=0.82,RMSEP=15.07);研究区内荒漠植被和人工固沙林的单位面积地上生物量分别为90.73g/m~2和105.28g/m~2。该研究可以为荒漠化监测和荒漠植被遥感信息提取提供参考。     

黑龙江省东完达山地区东北虎猎物种群现状及动态趋势

猎物种群丰度是限制虎分布和数量的关键因子,因此猎物种群密度监测和估算是虎保护的重要内容之一。应用采用大样方法,地理信息系统技术和多元统计分析,研究了黑龙江东完达山东部地区东北虎猎物种群(马鹿、狍子和野猪)现状及动态变化趋势。结果表明:研究地区马鹿的种群平均密度为(0.2010±0.0270)只/km²、狍子的平均种群密度为(0.4980±0.0436)只/km²、野猪的平均种群密度为(0.3423±0.0275)只/km²。单因素方差分析表明,在相同生境下,3种有蹄类密度在在阔叶混交林中和杂木林中差异极为显著;不同的生境,3种猎物的猎物的密度也存在着显著差异。相关分析表明马鹿密度和野猪密度程正相关,而马鹿密度和狍子密度、狍子密度和野猪密度则不相关。 同1989年该地区东北虎猎物种群相比:1989-2002年的13 a时间内马鹿的年平均递减率为13.48%、狍子的年平均递减率为12.69%、野猪的年平均递减率为1.89%。     

Do Orthoptera Need Human Land use in Central Europe? The Role of Habitat Patch Size and Linear Corridors in the Białowieża Forest, Poland

We studied Orthoptera, Dermaptera, and Blattodea of the Białowieża Forest (Poland) in order to assess (1) the minimum patch size of open habitat necessary for each species, (2) the role of linear corridors as habitat, and (3) the impact of herbivores on diversity by comparing the fauna at periods of different ungulate densities. Many species occurred in the farthest clearings from the forest edge to arable land. Two third of species occurred in clearings smaller than 10,000 m². Dry linear corridors of 10–40 m width and wet linear corridors of 100–200 m width had a species richness that corresponded to that of clearings of about 10,000 m². Four species disappeared from the Białowieża Forest when ungulate density decreased from 20 individuals/km² (3000 kg/km² biomass) at the beginning of the 20th century to 10 individuals/km² (1000 kg/km²) at the end of the 20th century. We conclude that most Orthoptera, Dermaptera, and Blattodea species could survive in Central Europe if human land use was replaced by intensive grazing and browsing by wild herbivores.     

Boots on the ground: in defense of low-tech,inexpensive, and robust survey methods for Africa’s under-funded protected areas

Protected area managers need reliable information to detect spatial and temporal trends of the species they intend to protect. This information is crucial for population monitoring, understanding ecological processes, and evaluating the effectiveness of management and conservation policies. In under-funded protected areas, managers often prioritize ungulates and carnivores for monitoring given their socio-economic value and sensitivity to human disturbance. Aircraft-based surveys are typically utilized for monitoring ungulates because they can cover large areas regardless of the terrain, but such work is expensive and subject to bias. Recently, unmanned aerial vehicles have shown great promise for ungulate monitoring, but these technologies are not yet widely available and are subject to many of the same analytical challenges associated with traditional aircraft-based surveys. Here, we explore use of inexpensive and robust distance sampling methods in Kafue National Park (KNP) (22,400 km²), carried out by government-employed game scouts. Ground-based surveys spanning 101, 5-km transects resulted in 369 ungulate group detections from 20 species. Using generalized linear models and distance sampling, we determined the environmental and anthropogenic variables influencing ungulate species richness, density, and distribution. Species richness was positively associated with permanent water and percent cover of closed woodland vegetation. Distance to permanent water had the strongest overall effect on ungulate densities, but the magnitude and direction of this effect varied by species. This ground-based approach provided a more cost-effective, unbiased, and repeatable method than aerial surveys in KNP, and could be widely implemented by local personnel across under-funded protected areas in Africa.     

Disturbance-Mediated Apparent Competition Decouples in a Northern Boreal Caribou Range

The most widely reported threat to boreal and mountain populations of woodland caribou (Rangifer tarandus caribou; caribou) involves habitat- or disturbance-mediated apparent competition (DMAC). With DMAC, natural and anthropogenic disturbances that increase the abundance of deciduous-browsing cervids (e.g., moose [Alces alces], deer [Odocoileus spp.]) are thought to promote predator (especially wolf [Canis lupus]) numbers, which heightens predation risk to caribou. We know most about the effects of DMAC on caribou where the species is under threat by anthropogenic activities in relatively productive southern boreal and mountain systems. Yet, >60% of extant boreal caribou range in North America consists of northern shield and taiga ecoregions of low productivity where caribou may compete with only 1 ungulate species (moose) in the context of DMAC. In this environment, we know very little of how DMAC acts as a limiting factor to caribou. In Saskatchewan, Canada, from 2014–2018, using a combination of vegetation sampling, aerial surveys, and telemetry data (n = 38 wolves), we searched for evidence of DMAC (trends in data consistent with the hypothesis) in an 87,193-km² section of the Western Boreal Shield, a poorly productive but pristine region (0.18% of land cover classed as an anthropogenic feature) with a historically high fire-return interval (47% of stands aged <40 years). Despite the high levels of disturbance, moose density was relatively low (47 moose/1,000 km²), likely because of the scarcity of deciduous or mixed-wood stands and low abundance of deciduous browse in the young conifer stands that dominated the landscape. In contrast, boreal caribou density was relatively high for the species (37 caribou/1,000 km²). Wolf density (3.1 wolves/1,000 km²) and pack sizes ( = 4.0 wolves/pack) were low and resident (established) territories were large ( = 4,360 km²; 100% minimum convex polygon). The low density of wolves mirrored the low (standardized) ungulate biomass index (UBI; moose + boreal caribou) of the study area (0.36 UBI/km²). We conclude that wolf and hence caribou populations were not responding in accordance with the outcomes generally predicted by DMAC in our study area because the requisite strong, positive response to fire of deciduous-browse and alternate-prey abundance was lacking. As a limiting factor to caribou, DMAC is likely modulated at a macroecological scale by factors such as net primary productivity, a corollary to the general hypothesis that we advance here (i.e., primary productivity hypothesis of DMAC). We caution against managing for caribou based on the presumption of DMAC where the mechanism does not apply, which may include much of boreal caribou range in the north. © 2020 The Wildlife Society.     

Evaluating Methods for Counting Cryptic Carnivores

ABSTRACT Numerous techniques have been proposed to estimate carnivore abundance and density, but few have been validated against populations of known size. We used a density estimate established by intensive monitoring of a population of radiotagged leopards (Panthera pardus) with a detection probability of 1.0 to evaluate efficacy of track counts and camera-trap surveys as population estimators. We calculated densities from track counts using 2 methods and compared performance of 10 methods for calculating the effectively sampled area for camera-trapping data. Compared to our reference density (7.33 ± 0.44 leopards/100 km²), camera-trapping generally produced more accurate but less precise estimates than did track counts. The most accurate result (6.97 ± 1.88 leopards/100 km²) came from camera-trap data with a sampled area buffered by a boundary strip representing the mean maximum distance moved by leopards outside the survey area (MMDMOSA) established by telemetry. However, contrary to recent suggestions, the traditional method of using half the mean maximum distance moved from photographic recaptures did not result in gross overestimates of population density (6.56 ± 1.92 leopards/100 km²) but rather displayed the next best performance after MMDMOSA. The only track-count method comparable to reference density employed a capture-recapture framework applied to data when individuals were identified from their tracks (6.45 ± 1.43 leopards/100 km²) but the underlying assumptions of this technique limit more widespread application. Our results demonstrate that if applied correctly, camera-trap surveys represent the best balance of rigor and cost-effectiveness for estimating abundance and density of cryptic carnivore species that can be identified individually.     

Carbon stock loss from deforestation through 2013 in Brazilian Amazonia

The largest carbon stock in tropical vegetation is in Brazilian Amazonia. In this ~5 million km² area, over 750 000 km² of forest and ~240 000 km² of nonforest vegetation types had been cleared through 2013. We estimate current carbon stocks and cumulative gross carbon loss from clearing of premodern vegetation in Brazil's ‘Legal Amazonia’ and ‘Amazonia biome’ regions. Biomass of ‘premodern’ vegetation (prior to major increases in disturbance beginning in the 1970s) was estimated by matching vegetation classes mapped at a scale of 1 : 250 000 and 29 biomass means from 41 published studies for vegetation types classified as forest (2317 1‐ha plots) and as either nonforest or contact zones (1830 plots and subplots of varied size). Total biomass (above and below‐ground, dry weight) underwent a gross reduction of 18.3% in Legal Amazonia (13.1 Pg C) and 16.7% in the Amazonia biome (11.2 Pg C) through 2013, excluding carbon loss from the effects of fragmentation, selective logging, fires, mortality induced by recent droughts and clearing of forest regrowth. In spite of the loss of carbon from clearing, large amounts of carbon were stored in stands of remaining vegetation in 2013, equivalent to 149 Mg C ha^?1 when weighted by the total area covered by each vegetation type in Legal Amazonia. Native vegetation in Legal Amazonia in 2013 originally contained 58.6 Pg C, while that in the Amazonia biome contained 56 Pg C. Emissions per unit area from clearing could potentially be larger in the future because previously cleared areas were mainly covered by vegetation with lower mean biomass than the remaining vegetation. Estimates of original biomass are essential for estimating losses to forest degradation. This study offers estimates of cumulative biomass loss, as well as estimates of premodern carbon stocks that have not been represented in recent estimates of deforestation impacts.     

Monitoring ungulates in steep non-forest habitat: a comparison of faecal pellet and helicopter counts

Faecal pellet counts have been widely used to monitor the abundances of introduced ungulates in New Zealand, but ground-based sampling cannot be conducted safely in the steep non-forest habitats that are common in New Zealand's Southern Alps. Helicopter counts may be an effective technique for monitoring ungulates in steep non-forest habitat. We evaluated the relationship between faecal pellet and helicopter counts of ungulates (primarily feral goat Capra hircus) at 12 non-forest sites in the Southern Alps. Within each site we counted the numbers of ungulates from a helicopter on three occasions and the number of intact faecal pellets along 30 transects. Mean observed densities of feral goats derived from helicopter counts ranged from 0.0 to 20.2 km^?2. There was a positive curvilinear (concave down) relationship between faecal pellet and helicopter counts. Compared with faecal pellet counts, helicopter counts were cheaper, could identify ungulate species and provided estimates of absolute density. Helicopter counts are a cost-effective method for monitoring ungulates in the steep non-forest habitats of New Zealand's Southern Alps.     

The effect of landscape structure on the distribution of brown hare Lepus europaeus in farmlands of Germany and Poland

Habitat management should be an important part of the brown hare (Lepus europaeus) conservation, but the habitat requirements of this species are not fully recognised. The aim of our research was to estimate these requirements by analysing the effect of various agricultural landscape structure features on the distribution of hares in five agricultural areas in Germany and Poland. The local density of hares was assessed in the spring and autumn of 2006 by using the method of spotlight–strip counts on 9–15 subareas in each research region. The structure of agricultural landscape has been described for each subarea: the share of grain, other crops and grasses as well as the density of crop edges and uncultivated places with wild vegetation. The density of hares was considerably higher in Germany than in Poland (18.8–48.4 vs. 4.1–9.5 indiv./km²). The hare density was positively correlated with non-grain crops in an area, with crop edges in two areas and with wild vegetation without trees in two areas, and negatively correlated with grassfields in two areas. The occurrence of wild vegetation without trees affected the hare density only in the study areas, where this habitat was relatively rare (<3 km/km²). It was suggested that proper projects aimed at habitat management for brown hares should be elastic, i.e. the projects should be modified depending on the structure of local landscapes. Moreover, the protection and creation of structures with wild vegetation among cropland seem to be considerable methods of brown hare or generally wildlife conservation; therefore, such measures should be an important part of agro-environmental packages.     

Spatial-temporal character of vegetation cover and its influence factors in the Shule River Basin China,during 1985–2011

Abstract

Vegetation coverage is an important indicator of the terrestrial ecosystems, and it provides crucial significance for evaluation and analysis of vegetation change. The Shule River Basin is a typical ecological fragile region in the inland of Northwest China. We used vegetation coverage index as given in Technical Specifications for Assessment of Ecological Environment. Geographic information system (GIS) spatial analysis was used to analyze the temporal and spatial features of vegetation cover in the Shule River Basin and its influencing factors from 1986 to 2011. The results showed that vegetable cover is very low in most areas of Shule River Basin with only the upstream parts of the oasis and watershed haven high vegetation cover. The average vegetation coverage index increased from 6.78 to 8.31 during 1986–2011. An area of 59,998?km² in the Shule River Basin has unchanged vegetation coverage index and this account for 51.7% of watershed areas for the period of the study. Also, an area of 31,721?km² recorded an increased vegetable cover, accounting for 27.3% while an area of 24,372?km² decreased vegetation cover which accounts for 21.0%. There was different correlation between vegetation cover and annual precipitation in the Shule River Basin.     

京津冀地区城市化对植被覆盖度及景观格局的影响

定量研究了2000—2010年,京津冀地区植被覆盖度及其景观格局的动态变化,揭示了城市化进程对植被景观的干扰过程及生态质量的影响。结果表明:(1)2000—2010年,城市化进程显著是京津冀城市群土地变化的一大特点,人工表面面积从2000年的1.79×10~4km~2增加至2.16×10~4km~2,增幅高达21.16%;(2)京津冀平均植被覆盖度呈增加趋势但不显著(P=0.46),存在明显的时空动态差异。在覆盖度结构上形成了以中低和中植被覆盖度为主导的格局;(3)从景观空间格局变化来看,中低、高覆盖度区域植被景观更加破碎,而低、中等覆盖度区域的植被面积增加,景观破碎度减小;尤其是低植被覆盖度为主的城市区域,景观格局变化幅度大,表现为绿地面积有所增加,景观破碎化程度降低,生态质量有所改善;(4)在整个研究区范围,城市化对区域植被覆盖度存在负面影响,表现为城市化程度与区域平均植被覆盖度存在负相关(P=0.08);但是在低植被覆盖度的区域(主要为城市区域),城市化程度与植被覆盖面积呈显著正相关(P0.001),表明城市区域在城市化进程中植被覆盖面积有所提高,生态质量有所改善,与城市化过程中,日益重视城市绿地的建设有关。     

Impacts of cattle grazing on forest structure and raptor distribution within a neotropical protected area

Uncontrolled cattle grazing is frequent in protected areas across the tropics but its effect on habitat structure and biodiversity is poorly known. We used generalized additive models to examine the precise relationships between cattle grazing intensity, vegetation structure, and raptor occurrence and richness across 39 1-km² plots within the North West Biosphere Reserve, Peru. Cattle grazing was widespread and intensity was negatively correlated with average canopy height and percentage of vegetation cover at 5–15 m. Raptors were influenced by cattle density but they were probably more strongly influenced by canopy and sub-canopy characteristics. Raptor species responded differently to increasing cattle density: presence of species that hunted or searched for food in open habitats increased with cattle density, while presence of range restricted species that hunted from perches, and declining species decreased. Moderate cattle densities (20–60 cows km^?2) may actually benefit some raptor species and help to maintain the high raptor diversity in the study area. Reserve authorities should, however, act to reduce cattle densities in some areas, which can exceed 120 cows km^?2, that seriously affect some key raptor species, and cause forest to be converted to permanent cattle pasture.     

A comparison of two mountain gorilla habitats in Bwindi Impenetrable National Park, Uganda

Bwindi Impenetrable National Park, Uganda, is a small protected area (331 km²) within which there is large climatic and altitudinal variation. Therefore we compared habitat types and forest composition between two locations to investigate differences that may influence ecological conditions for large mammals, including endangered mountain gorillas. We demonstrate that there is considerable intersite variation in habitat types and spatial and temporal availability of vegetation resources of which the most apparent are the differences in species composition of plants and fruit availability. Buhoma (the lower altitude site) has a greater diversity of plant species and higher tree and shrub densities, yet has a much lower density of herbaceous vegetation eaten by gorillas compared with Ruhija. Fruit availability is significantly higher throughout the year in Buhoma compared with Ruhija. Both sites exhibit seasonal variation in fruit availability although they do not follow the same seasonal pattern, perhaps because of inherent asynchronous phenological differences amongst individual tree species. The results of this study are important because distribution and abundance of both terrestrial herbaceous vegetation and fruit resources are believed to influence aspects of feeding ecology for large mammals.     

东帕米尔高原盘羊分布与栖息地植被覆盖时空变化

2010年8月—2013年10月调查了东帕米尔高原马可·波罗盘羊(Ovis ammon polii)的分布,首次分析了2000—2010年盘羊栖息地植被覆盖时空变化。走访当地野生动物保护部门和牧民确定大概研究区域的基础上,采用经典样线法调查盘羊分布区域和分布特征,利用遥感影像技术估算2000—2010年盘羊分布区域的植被覆盖度变化。结果显示,马可·波罗盘羊主要分布在东帕米尔高原的塔什库尔干野生动物自然保护区、布伦口、木吉、吉根、哈拉峻和哈拉布拉克等地海拔在3200—520m米河谷或沟谷,分布区面积为4.70万km2。栖息地植被退化严重,在2000—2010年间适宜盘羊栖息地植被覆盖区面积由10382.63 km2下降到4444.55 km2,平均每年593.81 km2植被面积丧失。结果发现马可·波罗盘羊实体1611只,分布密度为0.99只/km2;据栖息地适宜植被覆盖面积估算,盘羊数量在3000—3500只之间,其中塔什库尔干野生动物自然保护区分布密度最大,为2.01只/km2,其他区域分布密度相对较低。全球气候变化、人为干扰、超载过牧、围栏放牧和矿业开采等因素导致马可·波罗盘羊生境遭到严重破坏,建议一方面建立红色生态区和生态补偿机制实施就地保护策略;另一方面启动实施迁地和离体保护措施,拓宽保护策略,提高保护效果。     

Response of native ungulates to drought in semi‐arid Kenyan rangeland

The distribution and abundance of native ungulates were measured on commercially managed, semi‐arid rangeland in central Kenya over a 3‐year period that encompassed severe drought and above‐average rainfall. Native ungulate biomass density averaged 5282 kg km^?2 over the study and was dominated by elephant (Loxodonta africana), impala (Aepyceros melampus) and dik‐dik (Madoqua kirkii). Biomass density of domestic cattle (Bos taurus) averaged 2280 kg km^?2 during the study. Responses of native ungulates to severe drought were variable. Impala densities were similar to or greater than densities for similar habitat in protected areas, and varied from 12 to 16 km^?2 during and following the drought to 24–29 km^?2 following above‐average rainfall. Dik‐dik densities were also greater than densities reported for protected areas and were surprisingly stable throughout the study despite the wide annual fluctuations in rainfall. Elephant migrated out of the region during drought but were present at high densities (2.9–5.2 km^?2) during wet seasons, consistent with telemetry studies emphasizing the importance of Acacia bushland habitat on commercial rangelands for the migratory portion of the Laikipia–Samburu elephant population. Results show that substantial densities of native browsing and mixed‐feeding ungulates can occur on rangeland managed for commercial beef production and suggest that the capacity for ungulates to move over large spatial scales (>100 km²) and to shift distributions in response to locally variable thunderstorms may be important for sustaining these populations.     

Group size, density and biomass of large mammals in the Réserve de Faune du Petit Loango, Gabon

Group size, density and biomass of large‐bodied diurnal mammal species in the Réserve de Faune du Petit Loango, Gabon (now Parc National de Loango) was determined over a 12‐month period using standard line‐transect methods. Petit Loango encompasses a range of distinct habitat types, including coastal scrub, savanna, swamps and disturbed and mature forest. Such intact coastal habitats are increasingly rare on the Central‐West African coastline. Faecal censusing indicated highest forest elephant (Loxodonta africana cyclotis) and buffalo (Syncerus caffer nanus) ecological densities at the extreme coast (2.48 and 1.29 km⁻² respectively), probably reflecting high intensity of use of this habitat. Ape density was comparable with that at other Central African study sites at 1.01 individuals km⁻². Mean total biomass of diurnal primates, elephants and other ungulates over the 20 km² site was 3290 kg km⁻². Forest elephants and red river hogs (Potamochoerus porcus) constituted the bulk of the biomass, at 67% and 14% respectively. Primates made up 5% of the biomass. This is the first estimation of mammal density and biomass over an annual cycle at a Central African coastal site, and provides baseline data for long‐term studies in such habitats and to aid habitat and wildlife management decisions.