Oviparity in Two South African Skinks of the Genus Mabuya,With Notes on Hatching

This study was conducted as part of the interdisciplinary biodiversity project BIOTA and describes small mammal communities on two differently managed farmlands (cattle and game farm) in Namibia over the course of one year. Species diversity, density and activity are discussed and compared to data on vegetation parameters, and on grazing and trampling effects by large herbivores. Small mammal abundance was related to vegetation cover on both farm areas. Species composition differed between the cattle and the game farm. These differences and the dominance structure are discussed in the view of different grazing techniques of cattle and wild ungulates.     

The effects of fire-breaks on plant diversity and species composition in the grasslands of the Loskop Dam Nature Reserve,South Africa

There is a dearth of knowledge on the effects of annual burning of fire-breaks on species composition, plant diversity and soil properties. Whittaker's plant diversity technique was used to gather data on species composition and diversity in four grassland communities on the Loskop Dam Nature Reserve (LDNR). The study demonstrated that fire-beaks did not have a negative effect on plant diversity and an increase was even noted in various diversity parameters in the grassland on abandoned cropland. Fire-breaks were changing the species composition, as three of the four communities illustrated a clear separation in species composition between fire-break and unburnt plots. There was not a strong association between specific species and the fire-break or unburnt plots, except for Themeda triandra and Tristachya leucothrix, known for their association with and without fire, respectively. The change in species composition was not negatively affecting range condition. Carbon and nitrogen concentrations were slightly lower in the fire-break than unburnt soils, but the reduced concentrations were unlikely to cause severe soil degradation in fire-break zones. From a management perspective, fire-breaks appear to be a sustainable management tool as they are not adversely affecting plant diversity or range condition in the grassland association on LDNR.     

Reproductive biology of a pride of lions on Karongwe Game Reserve,South Africa

The reproductive biology of a pride of lions (Panthera leo) was studied on the 8500 ha Karongwe Game Reserve from 1999 to 2005. Over this period, the pride consisted of between four and 11 lions with a paired coalition of adult males during the first three years and a single adult male for the next three years. We recorded shorter than normal interbirth intervals, high birth rates of 1.3 cubs/lioness/year, very high cub survival rates, and subadults leaving the pride at young ages. This translated into substantially faster growth rates than are typical in large lion populations in ecologically similar circumstances such as Kruger National Park, but are similar to those of lions in Serengeti National Park. These demographic characteristics were probably induced initially by a lack of intense intraspecific competition and high prey availability, but population stability was maintained through the removal of young subadults by management. Interestingly, variability in conception rates between lionesses resulted in lower growth rates than have been found in other similar reintroduced lion populations. These demographic traits characterize many of the small reintroduced lion populations, and call for appropriate management to avoid the consequences of high predator densities.     

The impacts of season and livestock management strategy on the quality of diets selected by goats and sheep in the semi-arid rangelands of Namaqualand,South Africa

Access to good-quality forages is one of the major limitations to livestock production in semi-arid pastoral systems. This study aimed to determine whether there are differences in the nutritional quality of diets selected by herded and free-ranging goat and sheep flocks utilising Namaqualand Granite Renosterveld vegetation during the wet and dry seasons. Plant samples collected along the grazing routes of livestock were dried and analysed for their fibre, condensed tannin, total phenolic and mineral nutrient contents. The study showed that a large variety of forages were on offer and livestock groups selected different diets of which some were different to the total diet on offer. In general, significant deficiencies in phosphate, protein and energy in the diets selected by herded and free-ranging goats and sheep were observed in both wet and dry season. The quality of the diets selected by herded and free-ranging livestock was also found to be different from each other, with herded livestock generally selecting more nutrient-dense diets. Herding, therefore, allows livestock to access better-quality forage in the Namaqualand Granite Renosterveld rangeland, where it is generally poor.     

Effect of stocking density on vegetation and animal performance within the semi-arid shrublands of the Karoo,South Africa

As the primary land use in the Karoo, extensive small-stock farming contributes significantly towards the agricultural economy of the region. However, the sustainability of this practice has been questioned for many years. This led to the establishment of a long-term stocking-density trial in 1988 at the Carnarvon Research Station. The trial was designed on a three-camp rotational grazing system under four stocking densities (8, 7, 5.5 and 4 ha SSU^–1). Following continuous treatment over 28 years, the results from a once-off assessment in February 2016 portrayed no significant differences between treatments with regard to plant height, cover, species diversity, ecological and grazing index scores. Animal production varied among treatments where the mean production per hectare was found to be the highest under the high stocking-density treatment. Due to the absence of historical data, the results from this study are not conclusive with regards to changes in the vegetation dynamics over time and therefore does not lend itself to making conclusions concerning stocking densities. It can, however, be concluded that the vegetation of the Western Upper Karoo is remarkably resilient to the perceived higher stocking densities set at the time, on condition that an appropriate grazing management strategy is applied.     

南非克鲁格斯多普禁猎区珠鸡的社群组织

1982年3月至1984年2月,在南非豪登省的克鲁格斯多普禁猎区(Krugersdorp Game Reserve),通过翼标观察对珠鸡(Numida meleagris)的社群组织进行了研究.珠鸡必须以社群的方式才能在野外存活,而集群(7-10只珠鸡)并非随机组成.地位最高的雄鸟(雄鸟A)是群体日常活动的核心,例如决定觅食方向等.地位较高的雄鸟(雄鸟A和B)密切协作以驱赶闯入者.在繁殖期,繁殖雌鸟与高地位雄鸟的结合更为紧密.尽管雄鸟中存在明显的等级差异,但群内争斗频率很低,这些争斗只是在维系群体稳定时才发生.雌性成鸟始终位于优势雄鸟和亚成体之间,以免受天敌伤害.但优势雄鸟与其配偶暂时离开群体进行繁殖时,次优势雄鸟(雄鸟B)成为集群中心,其余个体聚集在其周围以保持集群的稳定.大多数成鸟都协助抚育优势雄鸟的雏鸟.珠鸡的集群具有监视天敌的作用,以保障其在地表植被有限的环境中觅食并在冬季最大限度地获得食物.     

A note on endoparasites of wild ostriches (Struthio camelus) in the Mokolodi Nature Reserve,Gaborone, Botswana

A study was undertaken to investigate the prevalence of endoparasites of wild ostriches at Mokolodi Nature Reserve, Gaborone, over a 7-month period. Large numbers of strongyle eggs were recovered from faecal material in April and September and a decline in the strongyle egg counts was evident during June and July. Noteworthy was the absence of helminth eggs in faecal samples collected from chicks and coccidia oocysts from any of the ostriches.     

Determinants of the occurrence of a native encroacher species,Pechuelloeschea leubnitziae (wild sage), in the eastern Okavango Delta,Botswana

Although indigenous to southern Africa, Pechuel-loeschea leubnitziae is considered a problematic weed as it forms dense monotypic stands in the grasslands and woodlands of the Okavango Delta, Botswana, and is associated with veld degradation and a dominance of shade-tolerant, poor-quality grass species. Generalised linear modelling was used to determine the effect of the following environmental conditions on the likelihood of occurrence of P. leubnitziae: type of land use, vegetation type, burning history, total woody species density, soil pH and soil texture. There was no difference in P. leubnitziae presence under wildlife, large livestock and small livestock land use (p = 0.227). Only vegetation type (p<0.001) and total woody species density (p<0.001) significantly affected P. leubnitziae occurrence, with the species being rare in dense mopane woodlands and most likely to occur in mixed thornveld and mixed broadleaf woodland, although this likelihood decreased with increasing total woody species density. A single burn had no effect on P. leubnitziae occurrence, but repeated burning should be investigated as a means to reduce the vigour and recoppicing success of P. leubnitziae.     

Small mammal community succession on the beach of Dongting Lake,China after the Three Gorges Project

Although the Three Gorges Project (TGP) may have affected the population structure and distribution of plant and animal communities, few studies have analyzed the effect of this project on small mammal communities. Therefore, the present paper compares the small mammal communities inhabiting the beaches of Dongting Lake using field investigations spanning a 20‐year period, both before and after the TGP was implemented. Snap traps were used throughout the census. The results indicate that the TGP caused major changes to the structure of the small mammal community at a lake downstream of the dam. First, species abundance on the beaches increased after the project commenced. The striped field mouse (Apodemus agrarius) and the Norway rat (Rattus norvegicus), which rarely inhabited the beach before the TGP, became abundant (with marked population growth) once water was impounded by the Three Gorges Reservoir. Second, dominant species concentration indices exhibited a stepwise decline, indicating that the community structure changed from a single dominant species to a more diverse species mix after TGP implementation. Third, the regulation of water discharge release by the TGP might have caused an increase in the species diversity of the animal community on the beaches. A significant difference in diversity indices was obtained before and after the TGP operation. Similarity indices also indicate a gradual increase in species numbers. Hence, a long‐term project should be established to monitor the population fluctuations of the Yangtze vole (Microtus fortis), the striped field mouse and the Norway rat to safeguard against population outbreaks (similar to the Yangtze vole outbreak in 2007), which could cause crop damage to adjacent farmland, in addition to documenting the succession process of the small mammal community inhabiting the beaches of Dongting Lake.     

Effects of disturbance on small mammal community structure in the New Jersey Pinelands, USA

We compared small mammal community composition among undisturbed habitats and habitats disturbed by military operations on Warren Grove Gunnery Range (WGR) in the New Jersey Pinelands. WGR is one of the largest tracts of protected land within this globally rare ecosystem. Disturbance in the form of fire, mowing, soil disruption and logging has had a large effect on small mammal occurrence and distribution. Of the 14 small mammal species that occur in the Pinelands, 9 live on WGR, including large populations of the southern bog lemming (Synaptomys cooperi Baird, 1858) and meadow jumping mouse [Zapus hudsonius (Zimmermann, 1780)]. Simpson's Index of Diversity was 0 for most disturbed sites and was generally greater in wetlands than in uplands. White-footed mouse [Peromyscus leucopus (Rafinesque, 1818)] was the most common species on WGR and had a dominant effect on species diversity and community similarity indices. It dominated upland habitats and was the only species to occur in several disturbed habitats, whereas all 9 species occurred in wetlands. Principal components analysis indicated that most variation in species diversity was explained by disturbance and differences between upland and wetland habitats, due to presence of white-footed mice in disturbed and upland sites. Meadow jumping mice, southern bog lemmings and red-back voles [Myodes gapperi (Vigors, 1830)] were positively correlated with wetland habitats, and pine voles [Microtus pinetorum (Le Conte, 1830)], short-tail shrews [Blarina brevicauda (Say, 1823)] and eastern chipmunks [Tamias striatus (Linnaeus, 1758)] were associated with uplands. Habitat heterogeneity at WGR, including extensive undisturbed wetlands and uplands supported a rich diversity of small mammal species.     

Habitat use and home range of black-backed jackals (Canis mesomelas) on farmlands in the Midlands of KwaZulu-Natal,South Africa

Black-backed jackals (Canis mesomelas) are an abundant mesopredator on farmlands (croplands and rangelands) across South Africa. Given their adaptability in a changing anthropogenic landscape, knowledge of spatial movements can provide important ecological information on the species. We captured, collared and monitored five black-backed jackals in the Midlands of KwaZulu-Natal to determine their home range and habitat use in farmlands. The 95% fixed kernel (95% FK) home range sizes were large, showing a marked seasonal variation in movement. One adult male dispersed 150?km over two seasons (winter and spring) and thereafter settled into a home range that it maintained. Transient home ranges of males and juveniles were larger than resident home ranges. The mean resident home ranges (95% FK) across seasons for adult males, adult female and juvenile males were 11.4 ± 4.3 km², 5.6 ± 0.36?km² and 2.15 ± 0.45?km², respectively. The mean transient home ranges (95% FK) of all the seasons for adult and juvenile males were 1 181.93 ± 575.81 km² and 104.27 ± 35.64?km², respectively. Adult jackal preferred croplands in spring, summer and autumn but avoided croplands in winter. Variable habitat use and large home ranges in our study confirmed the species’ ability to adapt to agricultural areas.     

Influence of food availability,plant productivity,and indigenous forest use on ranging behavior of the endangered samango monkey (Cercopithecus albogularis schwarzi), in the Soutpansberg Mountains,South Africa

Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long‐term adaptability to an increasingly human‐dominated landscape. The aim of this study was to determine and compare the influence of ground‐based food availability, remotely sensed plant productivity, and indigenous forest use on the ranging patterns of the endangered samango monkey (Cercopithecus albogularis schwarzi). We collected monthly ranging data on two habituated samango monkey groups, from February 2012 to December 2016, from our field site in the Soutpansberg Mountains, South Africa. We used linear mixed models to explore how food availability, plant productivity, and indigenous forest use influenced monthly ranging patterns, while controlling for group size, number of sample days and day length. We found that as more areas of high plant productivity (derived from remotely sensed EVI) were incorporated into the ranging area, both total and core monthly ranging areas decreased. In addition, both total ranging area and mean monthly daily path length decreased as more indigenous forest was incorporated into the ranging area. However, we found no effect of either ground‐based food availability or remotely sensed plant productivity on ranging patterns. Our findings demonstrate the behavioral flexibility in samango monkey ranging, as samangos can utilize matrix habitat during periods of low productivity but are ultimately dependent on access to indigenous forest patches. In addition, we highlight the potential of using remotely sensed areas of high plant productivity to predict ranging patterns in a small ranging, forest‐dwelling guenon, over ground‐based estimates of food availability.     

The effects of topo-edaphic variables and cultivation on the woody vegetation of Weenen Nature Reserve,KwaZulu-Natal

The soil types and woody vegetation of Weenen Nature Reserve (WNR), KwaZulu-Natal, were described. Mispah, overlying shale, and Shortlands, overlying dolerite were the most common of 18 the soil forms encountered. Six vegetation types were identified by TWINS PAN which differed in slope, aspect, land-use history, species richness and tree density. Vegetation types ranged from species-rich, dense 'Coddia rudis-Dombeya cymosa Closed Woodland' overlying dolerite and occurring on steep north-east facing slopes that had never been cultivated, to previously cultivated, species-poor 'Acacia sieberiana Open Woodland' on flat topography, overlying shale. Ordination analyses further described the main associated floristic-environmental gradient from steep slopes supporting a high diversity of broad leaved species through to species-poor, flatter areas with an abundance of microphyllous plants. A second main gradient described was from uncultivated sites on steep slopes of usually dolerite-derived soils through to flat, previously cultivated land on shallow soils overlying shale. Topo-edaphic variables and previous cultivation, which were confounded, were therefore the main determinants of floristic variation in WNR, whereas fire had no influence. Half of the dominant woody species exhibited a reverse-J size structure, indicating relatively constant population change. A number of species had a preponderance of individuals in the smallest (0.5–1.5m height) size class, owing possibly to recruitment during the exceptional wet season of 1995/6, and/or the inability of individuals to escape the 'fire-trap'. Several, mostly Acacia, species appear to have recruited intermittently. The vegetation changes of this system will have an affect on browse availability. The woody vegetation of WNR appears to be changing in response to successional processes and management influences.     

The potential negative impacts of the classical swine fever virus on wild boar population in Gifu prefecture,Japan

There is a possibility that classical swine fever (CSF) virus outbreak has negative impacts on wild boar. To adequately manage native wild boar populations, wildlife managers need to gather the field data on wild boar and implement population management practices. We aimed to report the relative abundance index of wild boar before and after this outbreak. Our results showed that relative abundance index declined from 2017 (8.88 wild boars/100 trap days) to 2019 (2.03 wild boars/100 trap days), because of the negative impact of this virus and continuous culling programs. Although the eradication risk from the synergistic effect is low, wildlife managers need to consider the relationship between the trade-off between the risk of CSF and the conservation ecology risk of native species eradication.     

辽宁双台河口国家级自然保护区1991-2012年间丹顶鹤种群数量迁徙动态监测(英文)

为了解丹顶鹤的种群动态趋势,我们自1991年至2012年在中国东北双台河口国家级保护区开始监测迁徙的丹顶鹤(Grus japonensis)。研究结果表明,春季丹顶鹤一般在3月1日左右到达,而秋季最后离开日在11月8日左右。经22年的观察,春季迁徙丹顶鹤集群的高峰期为3月10–20日,春季的停歇期为25天左右。比较历年春季最高值,在1990年代,数量为400只左右,至2000年数量超过800只,之后有一短期种群数量在600–800只间波动。随之种群数量开始下降,至近年我们观察到每年春季的峰值数量为400只左右。我们的观察结果与越冬地研究结果相似——丹顶鹤种群自2000年来呈下降趋势。我们认为目前亟待加强对丹顶鹤的保护和管理,以维持和改善其栖息地质量。     

>Utilization of shallow subtidal bays associated with warm temperate rocky shores by the late-stage larvae of some inshore fish species,South Africa

>This work describes the utilization of shallow, subtidal bays, associated with rocky shores, by the late-stage larvae and early juveniles of some common inshore fishes. Larval and early juvenile fishes were collected in seven small bays (30–50 m wide) between Port Alfred (33°36’S, 26°53’E) and Hamburg (33°17’S, 27°29’E), using a modified, beach seine net (500 µm mesh). Four bays were sampled weekly during peak fish spawning (September–November 2004) to firstly assess whether larval fishes occur in these previously-unstudiedhabitats and secondly, to assess the extent of this utilization in terms of species occurrence, abundance and potential nursery function. An additional three replicate bays, situated >50 km away near Bira were used for comparison. In total, 14 fish families represented by 26 taxa were recorded but the catch was dominated by a small suite of common species. Bays were extensively utilized by Sparidae (>Diplodus capensis >and >Sarpa salpa>), and to a lesser extent by Clinidae (>Clinus superciliosus>), Mugilidae (>Liza >spp.) and Kyphosidae (>Neoscorpis lithophilus>). Mean CPUE of larvae was high and exceeded 900 individuals per seine haul. Larval abundance peaked at 4000 larvae per haul and at these times, was dominated only by the two sparid species. Abundance of sparid larvae exceeds that recorded for these species in surf zones, estuaries or the shallow nearshore habitatssampled to date in temperate South Africa by an order of magnitude. Larval abundance was significantly higher during new moon sampling throughout the study period, but was not significantly different between repeated samples collected per site on each fieldtrip. The length-frequency of larvae utilizing the bays was dominated by postflexion stages ranging 7–14 mm SL. Length-frequency distribution of >Diplodus, Sarpa, Clinus, Sparodon, Neoscorpis >was indicativeof grow-out and use of bays as interim nurseries. The nursery function of these bays is supported by gut analysis of a sub-sample of the dominant species, >Diplodus capensis, >which showed that these larvae were actively feeding in the area, predominantly on copepods. This work prompts further research on shallow habitats associated with rocky shores particularly the shelter and feeding role that these under-studied habitats are playing in the early life history of coastal fishes.     

Effects of animal activity on the absorption rate of soils in the southern Karoo,South Africa

The rates of absorption into various microsites in Karoo soils were compared. The absorption of water by hard, bare intershrub soils was significantly increased by the presence of emergence holes of adult cicadas (Homoptera: Cicadidae) and near nest‐mounds of the harvester ant Messor capensis. Both these insects play an important role in raising the amount of water that penetrates into the soil after rains. Absorption rates were also high in the soils of heuweltjie mounds but were reduced by sustained use of an area by sheep and were particularly poor on sheep paths.     

基于CVM的兴隆山自然保护区非使用价值评估

采用条件价值评估法（CVM）,对甘肃省兴隆山国家级自然保护区的非使用价值及其主要影响因素进行评估与分析。研究表明,1）兴隆山自然保护区的非使用价值为9.21×10.7 元·年-1,其中存在价值、遗产价值和选择价值分别占44.02%、42.39%和13.59%;2）支付意愿与被调查者对兴隆山自然保护区保护费的支付态度以及对景观的满意度呈正相关;3）利用Logit和Probit模型,得出年龄和经济收入是影响支付态度的两个最重要的因素,而其中被调查者的年龄因素对于支付意愿所产生的影响大于其经济收入。     

草地畜牧业对晴隆县农业产业结构的影响

草地畜牧业不仅对生态恢复具有重要影响,而且对区域经济发展具有积极作用.本研究以贵州省晴隆县为研究对象,分析草地畜牧业对晴隆县土地利用,种植业,畜牧业和农、林、牧业产值的影响.结果表明,种草养畜后耕地减少和养羊产业的发展,促进了晴隆县农业产业结构的有效调整.一是促进土地利用结构由坡耕地向栽培草地合理转变;二是种植业压粮扩...