Vegetation gradients around artificial water points in the Central Kalahari Game Reserve of Botswana

Vegetation was assessed in plots sited at varying distances along two line transects radiating from each of nine artificial water points. Environmental variables such as distance from water point, soil type and ground cover were related to grass species composition. Grass species composition in calcrete soils differed significantly from that found in sandy soils. On calcrete soils, distance from water point did not have a significant effect on species composition. On sandy soils, distance from water point had a significant effect on species composition at two of the nine water points sampled. At these two water points, grass species that are usually associated with disturbed areas dominated close to the water points while those that dominated far from the water points were those that are usually associated with undisturbed sites. The results therefore indicate that there was no severe degradation of habitat around water points.     

Experiential Autochthony in the Okavango Delta,Botswana

The white Batswana of the Okavango identify as African, are strongly nationalistic and express deep senses of belonging to the social and physical environments of their birth and upbringing. Yet, claims to belonging by white people to extra-European territories are often perceived as inauthentic at best and neocolonial at worst. This raises the question of how the empirical realities of such connections can be analytically rendered without threatening or appropriating indigenous identities. Through making a case for the heuristic utility of the concept of experiential autochthony, I argue that emplacement and belonging can be fruitfully explored for migrant and settler groups.     

Black-backed jackal exposure to rabies virus, canine distemper virus, and Bacillus anthracis in Etosha National Park, Namibia

Canine distemper virus (CDV) and rabies virus (RABV) occur worldwide in wild carnivore and domestic dog populations and pose threats to wildlife conservation and public health. In Etosha National Park (ENP), Namibia, anthrax is endemic and generates carcasses frequently fed on by an unusually dense population of black-backed jackals (Canis mesomelas). Using serology, phylogenetic analyses (on samples obtained from February 2009-July 2010), and historical mortality records (1975-2011), we assessed jackal exposure to Bacillus anthracis (BA; the causal bacterial agent of anthrax), CDV, and RABV. Prevalence of antibodies against BA (95%, n = 86) and CDV (71%, n = 80) was relatively high, while that of antibodies against RABV was low (9%, n = 81). Exposure to BA increased significantly with age, and all animals >6 mo old were antibody-positive. As with BA, prevalence of antibodies against CDV increased significantly with age, with similar age-specific trends during both years of the study. No significant effect of age was found on the prevalence of antibodies against RABV. Three of the seven animals with antibodies against RABV were monitored for more than 1 yr after sampling and showed no signs of active infection. Mortality records revealed that rabid animals are destroyed nearly every year inside the ENP tourist camps. Phylogenetic analyses demonstrated that jackal RABV in ENP is part of the same transmission cycle as other dog-jackal RABV cycles in Namibia.     

Zoogeography of the herpetofauna of Botswana and its management implications

A taxonomic analysis of data reveals that there are more reptilian than amphibian species in Botswana and that the number of reptilian species generally decreases from the mesic north to the arid southern part of the country. Squamates (lizards and snakes) compose the majority of the reptilian fauna. An analysis of community reveals that the area of Botswana north of the 22° parallel is the most important in terms of faunal diversity, and thus special consideration in terms of fauna conservation and management is warranted. Results show that climatic conditions in Botswana have profound affects on the distribution of herpetofaunal species.

Résumé

Une analyse taxonomique des données révèle qu'il y a plus d'espèces de reptiles que d'amphibiens au Botswana et que le nombre d'espèces de reptiles diminue généralement du nord vers le sud aride du pays. Les squamates (lézards et serpents) composent la majeure partie de la faune reptilienne. Une analyse des communautés révèle que la partie du Botswana au nord du 22^e parallèle est la plus importante en terme de diversité faunistique et que ceci justifie une considération spéciale pour la conservation et la gestion de la faune. Les résultats montrent que les conditions climatiques au Botswana affectent profondément la distribution des espèces de reptiles.     

内蒙古赛罕乌拉自然保护区4 种小型食肉目动物的食性构成的初步分析

为了解同域分布动物的食物竞争关系,采用样线法收集粪便样品,依据残遗物鉴别物种的方法,于2007年8 ～12 月对赛罕乌拉国家级自然保护区的赤狐、狗獾、香鼬和豹猫的食物构成进行比较。结果表明:赤狐取食所有15 类食物,并捕食小型鼬类;在赤狐粪样(n =70) 中出现率较大的植物(32.6% )以重量比率计算时其贡献极大下降(0.02% ),而出现率较低的草兔和鸟类重量比率较高(草兔65.4% , 鸟类22.9% ), 相对重要值的计算表示,赤狐的食物构成均一。狗獾(n = 64)以取食昆虫和植物果实为主(出现率29.3% 和57.8% )。香鼬(n =14)集中取食鼠类(出现率73.7% ,相对重量99.8% ),豹猫(n = 11) 则以鸟类居多(出现率27.8% ,相对重量69.0% )。食物生态位的宽度以赤狐最大(0.2),其次为豹猫(0.07)。根据食物生态位的重
叠度分析,赤狐与狗獾(O = 0.99)和豹猫(O = 0.7)以及狗獾与豹猫(O = 0.6)的种间竞争较强, 但在主要食物上出现分离,实现捕食者之间的共存。赤狐对香鼬的捕食可能限制了其种群的发展。     

“震前半小时山林突然鸦雀无声”——唐家河保护区纪实

那一刻,连猴子都吓着了! 一大堆从山顶一直垮塌到公路上的大石头、泥土和横七竖八的断树挡住了去路,我们只好下车徒步前行。刚刚走了几十米,又是一堆更大的垮塌物堆在路上．唐家河国家级自然保护区管理处的副处长鲜方海告诉我们,地震后路都抢通了,这是这两天又垮下来的,现在已进入雨季．还会不断地垮。     

“周围的山都像是在放炮，激起许多土柱子”——白水江保护区纪实

“地震来时,我正带着一台照相机和一台摄像机站在跌水崖环路边的一个向外突出的陡崖上面,这个山是东西走向的,我面朝北．背后就是青川的唐家河保护区,我站的这个地方是大熊猫觅食时常走的路的上方,因为在竹林里想拍到大熊猫实在太难了．经过几年的摸索,我们发现这里是拍摄大熊猫的好地方。     

Activity, feeding behaviour and diet of Ogcocephalus vespertilio in southern west Atlantic

The Brazilian batfish Ogcocephalus vespertilio is a nocturnal and early morning predator on bottom invertebrates, staying stationary and hidden in rock holes, crevices or among bottom rocks during the day. While active, it searches for prey walking along the bottom with the help of its specialized paired fins, with the illicium protracted and oscillating or exploring the substrate. The prey are either snapped up from the bottom, after visual detection, or dug out with use of the mouth and rostrum. It feeds on crustaceans (hermit crabs, true crabs, shrimps, amphipods, porcelain crabs, isopods and mysid shrimps), molluscs (snails, sea slugs and clams), polychaete worms (mostly Errantia) and echinoderms (sea urchins and brittle stars).     

丹顶鹤春迁期觅食栖息地多尺度选择——以双台河口保护区为例

双台河口保护区是世界濒危鸟类丹顶鹤大陆种群西线群体不同生活史阶段的重要栖息地。2008-2010年3-4月,采用定点观察法、二维坐标法、方差分析、因子分析等方法对保护区内春迁期丹顶鹤觅食栖息地的多尺度选择进行了监测分析。研究结果表明：(1)春迁期,该保护区丹顶鹤觅食栖息地选择包括2个尺度3个选择,即大生境尺度内觅食生境类型选择和小生境尺度内觅食区选择、觅食微生境选择;(2)觅食生境类型偏好选择芦苇沼泽(90.00%),也偶选玉米地、泥滩、草甸等生境;(3)觅食区选择通过宏生境因子和干扰因子来判定,宏生境因子包括明水面、堤坝和火烧地,距离均在30m以内;干扰因子包括居民区和油田等强干扰因子和道路等弱干扰因子,均采取远离的方式进行回避,居民区保持在1km以上,油田保持在2km以上,道路保持在300-500m;(4)觅食微生境选择通过微生境因子来判定,包括植被高度、植被密度、植被直径等,选择盖度小(<5%)且植被高度小于喙长的区域觅食。     

The multidimensional nature of biodiversity and social dynamics and implications for contemporary rural livelihoods in remote Kalahari settlements, Botswana

Despite rapid socio-economic development in Kalahari drylands, contemporary research suggests that biodiversity remains important as a component of the complex portfolio of livelihood strategies, as a real and perceived safety net in times of stress, and a key factor of cultural identity. The degree to which the spatially and temporally dynamic nature of biodiversity in drylands influences livelihoods is, however, little studied, particularly in socially complex contemporary rural settlements. Greater understanding in this area is required to allow better-informed design and implementation of rural development, poverty alleviation and conservation initiatives. This is particularly true in the light of predicted increases in environmental dynamism with climate change. An interdisciplinary approach was used in two environmentally and socially distinct dryland settlements in Botswana, to investigate the extent to which the dynamic biodiverse setting influences contemporary rural livelihoods. Results illustrate that biodiversity, particularly its dynamics, is of critical contemporary importance to rural settlement livelihoods, particularly in times of inner settlement scarcity. Entitlements to biodiversity dynamics were, however, bound up by complex settlement-specific social, economic and political factors. Unless such contextual within-settlement dynamics are understood, the relative importance of biodiversity in rural development and poverty alleviation strategies in contemporary Kalahari drylands may be undermined.     

Artificial diet delivery system for Philaenus spumarius,the European vector of Xylella fastidiosa

Artificial diets represent an essential tool for investigations on the intimate relationship between plant pathogens and their vectors. Previous research failed in devising an artificial diet delivery system for the meadow spittlebug Philaenus spumarius, to date considered the most important vector of the bacterium Xylella fastidiosa in Europe. Here, we describe a new delivery “tube system” by which we succeeded in artificial feeding of P. spumarius with holidic diets (one sucrose diet and two amino acids diets). Spittlebug probing and feeding behaviour on either the tube system or a traditional “flat system” realized out of a small Petri dish filled with diet and covered with stretched Parafilm^® were observed in real time by video‐EPG (Electrical Penetration Graph), in order to assess the occurrence of ingestion and excretion. Moreover, we evaluated P. spumarius survival on either the tube system filled with the two holidic diets that gave the best EPG results or an empty tube system serving as control. Contrary to the flat system, where just brief stylet insertions through the Parafilm^® were recorded, the spittlebug ingested the artificial diets when delivered with the tube system. Survival on the diets provided with the tube system was significantly greater than the control, with no differences between the diets tested. Furthermore, the tube system was suitable also for another spittlebug species shown to be a competent vector of X. fastidiosa, that is Neophilaenus campestris. The tool we devised opens new perspectives for investigations on X. fastidiosa/spittlebugs interactions, as well as for the functional analysis of mutant X. fastidiosa strains in respect to insect colonization and transmission.     

云南省纳帕海自然保护区越冬黑颈鹤的集群特征

2004年10月-2005年5月,在云南纳帕海自然保护区采用定点扫描法对越冬黑颈鹤(Grus nigricollis)的集群类犁和集群大小进行了观察.结果表明黑颈鹤夜间集群夜栖,形成较大的夜栖群,平均群体大小为67.9只(16-157,n=17):按照有无灰鹤加入,又将其分为同种集群和混种集群两种类型,其中同种集群的黑颈鹤数量占整个越冬种群的65.3%.在白昼,黑颈鹤以家庭鹤、集群鹤及特殊群体3种类型活动,家庭鹤和集群鹤的平均大小分别为2.7只(2-4,n=145)和16.1只(3-65,n=1017).黑颈鹤的集群大小并不稳定,在日内和月份间均有明显变化(P=0.000＜0.05).存越冬期,最大集群形成于12月,其次为11月和1月;在日内,早上8时集群最大,随后减小并保持相对稳定,18时黑颈鹤开始向夜栖地靠拢,使得集群再次开始增大.随后观察中还发现,黑颈鹤的家庭解体过程开始于3月底,当幼鹤被成鹤驱逐离群后,逐渐加入集群鹤活动,从而使得家庭鹤和集群鹤的大小和组成发生改变.黑颈鹤的集群大小和组成受自身状况、种内关系、天气、食物等多种因素的共同影响,随时间和季节变动而发生变化,是对自身、种群和环境条件变化的综合反映.     

Intake,feeding behaviour,digestibility, performance,carcass characteristics and meat quality of lambs fed different levels of semi-purified glycerine in the diet

The aim of this study was to evaluate the effect of different inclusion levels of semi-purified glycerine in the diet of feedlot lambs on feeding behaviour, nutrient intake and digestibility, carcass characteristics, meat quality and in vitro degradability. Thirty-two Dorper × (Texel × Suffolk) crossbred intact male lambs (22.2 ± 5.51 kg) were fed glycerine (90% purity) at 0, 120, 240 or 360 g/kg dry matter (DM) in a total mixed ration with a roughage to concentrate ratio of 40:60 for 84 d. In vitro degradability was not affected by glycerine supplementation. Feeding behaviour and digestibility of DM, crude protein and fibre and production performance were similar among treatments. Ether extract digestibility was lower at the highest inclusion level. Glycerine level had no effect on ruminal pH, carcass characteristics and meat quality, except for subcutaneous fat thickness which was lower for lambs fed glycerine at 240 and 360 g/kg DM. Scores for unpleasant taste, unpleasant odour, succulence and softness of meat were not affected by dietary glycerine level. These data suggest that there are no adverse effects on carcass quality and performance when semi-purified glycerine is provided up to 360 g/kg DM in the diet of growing lambs fed a forage to concentrate ratio of 40:60.