Higher impact of female than male migration on population structure in large mammals

We simulated large mammal populations using an individual-based stochastic model under various sex-specific migration schemes and life history parameters from the blue whale and the Asian elephant. Our model predicts that genetic structure at nuclear loci is significantly more influenced by female than by male migration. We identified requisite comigration of mother and offspring during gravidity and lactation as the primary cause of this phenomenon. In addition, our model predicts that the common assumption that geographical patterns of mitochondrial DNA (mtDNA) could be translated into female migration rates (Nmf) will cause biased estimates of maternal gene flow when extensive male migration occurs and male mtDNA haplotypes are included in the analysis.     

Trends in woody vegetation cover in the Kruger National Park, South Africa, between 1940 and 1998

Changes in the cover and density of shrubs and trees were assessed from aerial photographs (1940, 1974 and 1998) as well as from fixed-point photographs taken in 1984 and 1996 in the Kruger National Park, South Africa. Woody cover (trees and shrubs combined) increased by 12% on granite substrates but decreased by 64% on basalt substrates over the past 58 years. Both these figures are expressed in terms of the initial values, respectively. The density of the large tree component of woody vegetation decreased on both substrates. Woody vegetation cover declined as fire return periods became shorter, but the relationship was weak. The increases in woody plant density and cover on granite are thought to be the result of decreased competition from grasses, which in turn is a result of overgrazing by wild herbivores whose numbers have been kept high through the provision of surface water. These effects were not seen on the relatively nutrient-rich basalts, where grasses can recover rapidly even after heavy grazing. The decline in overall woody cover on basalts is interpreted as a result of regular, short-interval prescribed burning over the past 40 years, while the universal decline in large trees seems to result from an interaction between regular, frequent fires and utilization by elephants. The implications for management are discussed.     

圈养山魈繁殖行为的观察

2001 年1～9 月, 在成都动物园用所有事件取样法对人工饲养状态下7 只(5 ♀♀, 2 ♂♂) 山魈的繁殖行为进行了观察。结果表明, 山魈的繁殖没有明显的季节性, 一年四季均发情繁殖, 月经周期为30.55 ±0.77 d (N = 11) , 行经期2.38 ±0.13 d (N = 16) ; 交配行为均发生在白天, 交配持续时间为14.90 ±0.34 s (N = 246) , 具有明显的交配模式, 其中碟牙、爬跨、插入和抽动4 种行为在每次交配中都出现, 交配姿势仅有背腹式一种; 孕期为171.13 ±4.19 d (N = 8) , 产前不废食; 分娩都在夜间进行, 产程2～3 h ; 育幼期哺乳时间随幼仔长大逐渐减少。     

华南虎圈养种群的统计分析

对《华南虎谱系》307 只登录个体的统计表明, 其圈养的历史有46 年。在人工繁殖的38 年中产122 胎287仔。现存圈养华南虎分散在全国22 家单位, 有57 只个体, 性比M∶F = 1185 , 能成功繁殖后代的个体仅5 只(只占818 %) , 是一个衰退的种群。通过SPARKS 和GENES 软件分析发现: 从1977 年开始, 圈养种群的基因多样性便逐渐下降而近交系数却不断增加。     

Beehive fences as effective deterrents for crop‐raiding elephants: field trials in northern Kenya

Increasing elephant populations in Kenya since 1989 have been widely praised as a conservation success story. However, where elephants and agricultural land overlap, incidents of human–elephant conflict are on the increase. Wildlife managers and farmers are now trying different farm‐based deterrents to keep elephants out of crops. Here, we present data on the effectiveness of a novel beehive fence deployed in a Turkana community of 62 communally run farms in Kenya. Specifically, 1700 m of beehive fences semi‐surrounded the outer boundaries of seventeen farms, and we compared elephant farm invasion events with these and to seventeen neighbouring farms whose boundaries were ‘protected’ only by thorn bush barriers. We present data from 45 farm invasions, or attempted invasions, recorded over 2 years. Thirteen groups of elephants approached the beehive fences and turned away. Of the 32 successful farm invasions, only one bull elephant broke through the beehive fences. These results demonstrate that beehive fences are more effective than thorn bush barriers at deterring elephants and may have a role to play in alleviating farmer–elephant conflict. Additionally, the harvesting of 106 kg of honey during the trial period suggests that beehive fences may also improve crop production and enhance rural livelihoods through honey sales.     

树鼩模型:抑郁症的社会竞争失败与学习和记忆的被捕获条件反射

最近基因组研究表明树鼩属于灵长类或是与灵长类亲缘关系最密切的姐妹种.因此,树鼩可能是应用于建立人类疾病动物模型的最佳动物之一.该文报道一种抑郁症的社会竞争失败病因学树鼩(Tupaia belangerichinensis)模型.一对雄性树鼩被饲养在一个双笼中,用网格把双笼隔开,网格上有一小门.适应1周后,把小门打开,这一对树鼩产生短暂的争斗,每天一次,连续21天.其中争斗失败者被称为服从者.这个过程可导致每天1 h的直接社交冲突和23 h的间接相互影响(比如通过气味、视觉等).与正常对照相比,失败者在第三周也就是社交冲突的最后一周显示了体重、自主活动、躲避行为、尿液皮质醇水平等的变化,并且这种改变可持续至少2周以上.此外,还报道全新的记忆模型,一种被捕获条件反射树鼩模型.在一个封闭的小房间中放置捕获笼,其中挂有一片苹果,小房间中有一只自由活动的树鼩.训练的前4次树鼩进入捕获笼吃苹果并不触发捕获笼关闭,但在第5次时触发捕获笼关闭,并持续一小时才释放树鼩.第1-5次树鼩进入捕获笼的延迟时时间作为适心性指标,其中第5次才是作为被捕获的一次学习训练.24 h后,测试树鼩进入捕获笼的延迟时间作为被捕获记忆能力指标.树鼩经过第5次被捕获训练,能形成很好的被捕获记忆,因为24 h后的延迟时间极人地增加.在训练前腹腔注射已知能阻断记忆形成的NMDA受体拮抗剂MK-801(0.2 mg/kg,腹腔注射),对适应指标没有显著影响,但足极大地缩短了24 h后测试的延迟时间,即阻断了被捕获记忆.这些结果表明了一种抑郁症的慢性社会竞争失败与学习和记忆的一次被捕获条件反射树鼩模型.这两种树趵模型对抑郁症与学习和记忆的机理研究、抗抑郁症新药的临床前药效学评价具有潜在的重要意义.

Abstract：

Recent genome studies indicate that tree shrew is in the order or a closest sister of primates, and thus may be one of the best animals to model human diseases. In this paper, we report on a social defeat model of depression in tree shrew (Tupaia belangeri chinensis). Two male tree shrews were housed in a pair-cage consisting of two independent cages separated by a wire mesh partition with a door connecting the two cages. After one week adaptation, the connecting door was opened and a brief fighting occurs between the two male tree shrews and this social conflict session consisted of 1 h direct conflict (fighting) and 23 h indirect influence (e.g. smell, visual cues) per day for 21 days. The defeated tree shrew was considered the subordinate. Compared with naive animals, subordinate tree shrews at the final week of social conflict session showed alterations in body weight, locomotion, avoidance behavior and urinary cortisol levels.Remarkably, these alterations persisted for over two weeks. We also report on a novel captive conditioning model of learning and memory in tree shrew. An automatic trapping cage was placed in a small closed room with a freely-moving tree shrew. For the first four trials, the tree shrew was not trapped when it entered the cage and ate the bait apple, but it was trapped and kept in the cage for 1 h on the fifth trial. Latency was defined as the time between release of the tree shrew and when it entered the captive cage. Latencies during the five trials indicated adaptation. A test trial 24 h later was used to measure whether the one-trial trapping during the fifth trial could form captive memory. Tree shrews showed much longer trapping latencies in the test trial than the adaptation trials. The N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 (0.2 mg/kg, i.p.), known to prevent the formation of memory, did not affect latencies in the adaptation trails, but did block captive memory as it led to much shorter trapping latencies compared to saline treatment in the test trial. These results demonstrate a chronic social defeat model of depression and a novel one-trial captive conditioning model for learning and memory in tree shrews, which are important for mechanism studies of depression, learning,memory, and preclinical evaluation for new antidepressants.     

Survival and aging in the wild via residual demography

Information about the age distribution and survival of wild populations is of much interest in ecology and biodemography, but is hard to obtain. Established schemes such as capture-recapture often are not feasible. In the proposed residual demography paradigm, individuals are randomly sampled from the wild population at unknown ages and the resulting captive cohort is reared out in the laboratory until death. Under some basic assumptions one obtains a demographic convolution equation that involves the unknown age distribution of the wild population, the observed survival function of the captive cohort, and the observed survival function of a reference cohort that is independently raised in the laboratory from birth. We adopt a statistical penalized least squares method for the deconvolution of this equation, aiming at extracting the age distribution of the wild population under suitable constraints. Under stationarity of the population, the age density is proportional to the survival function of the wild population and can thus be inferred. Several extensions are discussed. Residual demography is demonstrated for data on fruit flies Bactrocera oleae.     

Media framing of the Cayman Turtle Farm: Implications for conservation conflicts

Conflicts over natural resource use and management often arise where groups have different goals or priorities. The media can play an important dual role in these conflicts; article content might offer insights about public opinion, whilst media may shape debates and how issues are perceived by the public and decision-makers. Wildlife farming is a contentious conservation tool attracting the attention of worldwide media, and associated conflicts among different interest groups may undermine its applicability. We investigated the media’s portrayal of the Cayman Turtle Farm (CTF), a facility in the Cayman Islands which breeds green sea turtles (Chelonia mydas) for human consumption, to investigate how the media presents information about wildlife farming (i.e. framing), consider its potential roles influencing conflicts and explore how it can be used for conservation conflict management. Content analysis was used to compare framing, article valence, and stakeholder representation in 634 newspaper articles from the international and local media. These media stories were framed in terms of: tourism, conflict, conservation, culture/community, management, and utilisation. International articles most often described CTF as a tourism facility. However, during a media campaign by an international animal welfare group, CTF was also often depicted as a source of controversy. Trade in turtle products was mostly debated in older articles. Local media mainly had a financial focus. Conflict framing was associated with a negative article valence, and conflict framed articles were significantly more likely to contain no conservation information. Mentions of environmental interest groups were significantly associated with negative articles, whereas academics were significantly more likely to be mentioned in positive articles. Conservationists must consider stakeholder objectives from the outset of interventions and be aware of the multiple roles the media might play. Media analysis and effectively harnessing the potential of media outlets should be considered as tools for managing conservation conflicts.     

Identification of zoonotic Giardia genotypes in marsupials in Australia

A total of 421 fecal samples from a variety of captive and wild marsupial hosts in Western Australia, Victoria and South Australia were screened for the presence of Giardia species/genotypes using PCR and sequence analysis of a fragment of the 18S rRNA gene. Giardia spp. were identified in 13.4% (28/209) of samples from captive marsupials and 13.7% (29/212) of samples from wild marsupials. Sequence analysis at the 18S locus identified the zoonotic Giardia duodenalis Genotypes A and B in both captive and wild marsupials. Eight isolates were typed as genotype B3 and B4 at the gdh locus, although 7/8 were typed as genotype A at the 18S rRNA locus. The possible reasons for this discordance are discussed. This is the first report of genotype B and only the second report of genotype A in marsupials. As some of the genotype B isolates were identical to human-derived Giardia gdh sequences, these results suggest that marsupials in catchments may pose a public health risk and therefore warrant further investigation.