Two’s company,three’s a crowd: Exploring how host–parasite–microbiota interactions may influence disease susceptibility and conservation of wildlife

A large body of research has demonstrated that host‐associated microbiota—the archaeal, bacterial, fungal and viral communities residing on and inside organisms—are critical to host health (Cho & Blaser, 2012). Although the vast majority of these studies focus on humans or model organisms in laboratory settings (Pascoe, Hauffe, Marchesi, & Perkins, 2017), they nevertheless provide important conceptual evidence that the disruption of host‐associated microbial communities (termed “dysbiosis”) among wild animals may reduce host fitness and survival under natural environmental conditions. Among the myriad of environmental factors capable of inducing dysbiosis among wild animals (Trevelline, Fontaine, Hartup, & Kohl, 2019), parasitic infections represent a potentially potent, yet poorly understood, factor influencing microbial community dynamics and animal health. The study by DeCandia et al. in this issue of Molecular Ecology is a rare example of a host–parasite–microbiota interaction that impacts the health, survival and conservation of a threatened wild animal in its natural habitat. Using culture‐independent techniques, DeCandia et al. found that the presence of an ectoparasitic mite (Otodectes cynotis) in the ear canal of the Santa Catalina Island fox (Urocyon littoralis catalinae) was associated with significantly reduced ear canal microbial diversity, with the opportunistic pathogen Staphylococcus pseudintermedius dominating the community. These findings suggest that parasite‐induced inflammation may contribute to the formation of ceruminous gland tumours in this subspecies of Channel Island fox. As a rare example of a host–parasite–microbiota interaction that may mediate a lethal disease in a population of threatened animals, their study provides an excellent example of how aspects of disease ecology can be integrated into studies of host‐associated microbiota to advance conservation science and practice.     

Speciation and phylogeography of Hawaiian terrestrial arthropods

The Hawaiian archipelago is arguably the world's finest natural laboratory for the study of evolution and patterns of speciation. Arthropods comprise over 75% of the endemic biota of the Hawaiian Islands and a large proportion belongs to species radiations. We classify patterns of speciation within Hawaiian arthropod lineages into three categories: (i) single representatives of a lineage throughout the islands; (ii) species radiations with either (a) single endemic species on different volcanoes or islands, or (b) multiple species on each volcano or island; and (iii) single widespread species within a radiation of species that exhibits local endemism. A common pattern of phylogeography is that of repeated colonization of new island groups, such that lineages progress down the island chain, with the most ancestral groups (populations or species) on the oldest islands. While great dispersal ability and its subsequent loss are features of many of these taxa, there are a number of mechanisms that underlie diversification. These mechanisms may be genetic, including repeated founder events, hybridization, and sexual selection, or ecological, including shifts in habitat and/or host affiliation. The majority of studies reviewed suggest that natural selection is a primary force of change during the initial diversification of taxa.     

Bridging the Gap: How Can Information Access and Exchange Between Conservation Biologists and Field Practitioners be Improved for Better Conservation Outcomes?

It is widely accepted that there is a considerable gap between the science of conservation biology and the design and execution of biodiversity conservation projects in the field and science is failing to inform the practice of conservation. There are many reasons why this implementation gap exists. A high proportion of papers published in scientific journals by conservation biologists are seldom read outside of the academic world and there are few incentives for academics to convert their science into practice. In turn, field practitioners rarely document their field experiences and experiments in a manner that can meaningfully inform conservation scientists. Issues related to access to scientific literature, scientific relevance in multidisciplinary environments, donor expectations and a lack of critical analysis at all levels of conservation theory and practice are factors that exacerbate the divide. The contexts in which conservation biologists and field practitioners operate are also often highly dissimilar, and each has differing professional responsibilities and expectations that compromise the ability to learn from each other's expertise. Building on recent debate in the literature, and using case studies to illustrate the issues that characterize the divide, this paper draws on the authors' experiences of project management as well as academic research. We identify five key issues related to information exchange: access to scientific literature, levels of scientific literacy, lack of interdisciplinarity, questions of relevance and lack of sharing of conservation-related experiences and suggest new ways of working that could assist in bridging the gap between conservation scientists and field practitioners.     

试论生物多样性保护理论与实践面临的困难及现实出路

保护生物学作为一门新兴的交叉科学,已经在最近的一二十年中迅速发展成为一门独立的学科,然而,人们似乎过分沉湎于保护生物学的理论研究之中,却对这样一个事实置若罔闻;保护生物多样性的实践并未能取得预期的成效,生物多样性的危机不仅远未消除,反而越来越严峻,本文从保护生物多样性的伦理妯,保护生物学的理论,保护生物多样性的实践等多个层面上,分析了生物多样性保护面临的重重困难,着重指出,来自社会人文方面的种种不利因素,尤其是经济方面的驱动力,才是制约生物多样性保护的根源所在,并提出通过人文学科的社会经济,政策,法律等方面与自然学科的技术和理论的密切合作研究,综合地探求解决生物多样性危机的有效途径,应该成为保护生物学研究一个新的重点领域。     

Introduced animals and their parasites: The cane toad,Bufo marinus,in Australia

Abstract The impact of introducing animals into an established ecosystem can be directly observed through predator-prey and competition interactions. The impact of animals via more obscure relationships, such as the host-parasite relationship, are generally not considered. The cane toad Bufo marinus (Linnaeus) was introduced to Australia in 1935. Despite intensive research into many aspects of the biology of the toad, there has been no systematic survey of the parasite fauna of B. marinus in Australia. It is unknown exactly what parasites the toad may have introduced to Australia and also the range of parasites that may have adapted to the toad from native fauna since its introduction. The provisional conclusion from this review is that all the helminth parasites so far recorded from B. marmus in Australia have been acquired from local hosts. The interaction of toads and nativa fauna via their parasites remains unknown.     

Pollination of endangered Cuban cycad Microcycas calocoma (Miq.) A.DC.

Observations indicate that natural regeneration in the field of the cycad Microcycas calocoma (Miq.) A.DC. is extremely low, and has been so since early this century. It appears that populations of its insect pollinator are practically extinct, but some pollinator activity appears to be present in the largest population of Microcycas. Recommendations for identification and captive breeding of die pollinator are suggested as a complementary conservation strategy to a Microcycas propagation programme already established at the Cuban National Botanical Garden.     

影响水稻纹枯病流行、危害的因子分析

以连作早稻为研究对象,对影响水稻纹枯病发生、危害有关的因子,即品种、施氮肥量、气象因素、为害损失、发病时间、病情程度及药剂等作了系统的定量研究.结果表明,品种间存在抗病性和危害损失程度上的差异;施氮肥量与发病程度关系密切;气象因素中以日均温和雨日频率与病害流行速率关系密切;发病时间与为害损失率相关性不明显,药剂防治效果与控病时间、病情基数有关.     

Mitochondrial DNA variation, population structure, and evolution of mountain sheep in the south-western United States and Mexico

In the south-western United States and Mexico, mountain sheep were found to have low levels of mtDNA sequence divergence among haplotypes and low overall nucleotide diversity. Potential causes for this low diversity are discussed. Significant differences in mtDNA haplotype distributions over short distances and high values of N_ST on a local scale appear to be a result of the tendency of female mountain sheep to disperse less frequently and over shorter distances than males. A lack of concordance between mtDNA haplotype distributions and assumed subspecies boundaries suggest that some taxonomic labels need to be revised.     

The impact of armed conflict on protected-area efficacy in Central Africa

What determines the vulnerability of protected areas, a fundamental component of biodiversity conservation, to political instability and warfare? We investigated the efficacy of park protection at Garamba National Park (Democratic Republic of Congo) before, during and after a period of armed conflict. Previous analysis has shown that bushmeat hunting in the park increased fivefold during the conflict, but then declined, in conjunction with changes in the sociopolitical structures (social institutions) that controlled the local bushmeat trade. We used park patrol records to investigate whether these changes were facilitated by a disruption to anti-poaching patrols. Contrary to expectation, anti-poaching patrols remained frequent during the conflict (as bushmeat offtake increased) and decreased afterwards (when bushmeat hunting also declined). These results indicate that bushmeat extraction was determined primarily by the social institutions. Although we found a demonstrable effect of anti-poaching patrols on hunting pressure, even a fourfold increase in patrol frequency would have been insufficient to cope with wartime poaching levels. Thus, anti-poaching patrols alone may not always be the most cost-effective means of managing protected areas, and protected-area efficacy might be enhanced by also working with those institutions that already play a role in regulating local natural-resource use.     

Simple method for calculating confidence limits around inbreeding rate and effective population size estimates from pedigrees

An important concept in population genetics is effective population size (N_e), which describes the expected rate of loss of genetic variability from a population. One way to estimate N_e is using a pedigree. However, there are no methods for comparing the N_e estimated from a pedigree with that expected from life-history models. In the paper we show how N_e can be estimated from the change in inbreeding rate (f) estimated from a pedigree. The mean individual inbreeding rate in a population at a given time must be calculated from averaged values for males and females, where each age class is weighted by its reproductive value. We show an exact method for placing confidence intervals around f and N_e using a binomial distribution, and present a method for approximating this interval for large N_es using a Poisson distribution. These confidence intervals can be used to compare f and N_e from a pedigree to expected values from demographic models, and to compare N_es of two populations.     

中国石松类和蕨类植物的多样性与地理分布

物种编目及其科属系统排列是了解生物多样性的基础, 本文采用Flora of China使用的分类系统, 结合最新分子分类学研究成果以及近几年发表的新资料, 对中国石松类和蕨类植物多样性和地理分布数据进行了统计和分析。结果表明中国共有石松类和蕨类植物40科178属2,147种5个亚种118个变种, 其中特有种839个, 占总种数的39.08%。种数最多的5个科依次为鳞毛蕨科(505种, 含种下单位, 下同)、蹄盖蕨科(323种)、水龙骨科(280种)、凤尾蕨科(266种)和金星蕨科(209种); 种数最多的5个属依次为耳蕨属(Polystichum, 209种)、鳞毛蕨属(Dryopteris, 176种)、蹄盖蕨属(Athyrium, 137种)、双盖蕨属(Diplazium, 98种)和凤尾蕨属(Pteris, 97种)。在地理分布上, 种数排名前5的省份为云南(1,365种)、四川(875种)、贵州(838种)、广西(785种)和台湾(779种)。含中国特有石松类和蕨类植物的科属中, 排前3位的科分别为鳞毛蕨科(257种)、蹄盖蕨科(169种)和凤尾蕨科(113种); 排前3位的属为耳蕨属(140种)、蹄盖蕨属(82种)和鳞毛蕨属(61种)。     

Stability of the gorilla microbiome despite simian immunodeficiency virus infection

Simian immunodeficiency viruses (SIVs) have been discovered in over 45 primate species; however, the pathogenic potential of most SIV strains remains unknown due to difficulties inherent in observing wild populations. Because those SIV infections that are pathogenic have been shown to induce changes in the host's gut microbiome, monitoring the microbiota present in faecal samples can provide a noninvasive means for studying the effects of SIV infection on the health of wild‐living primates. Here, we examine the effects of SIVgor, a close relative of SIVcpz of chimpanzees and HIV‐1 of humans, on the gut bacterial communities residing within wild gorillas, revealing that gorilla gut microbiomes are exceptionally robust to SIV infection. In contrast to the microbiomes of HIV‐1‐infected humans and SIVcpz‐infected chimpanzees, SIVgor‐infected gorilla microbiomes exhibit neither rises in the frequencies of opportunistic pathogens nor elevated rates of microbial turnover within individual hosts. Regardless of SIV infection status, gorilla microbiomes assort into enterotypes, one of which is compositionally analogous to those identified in humans and chimpanzees. The other gorilla enterotype appears specialized for a leaf‐based diet and is enriched in environmentally derived bacterial genera. We hypothesize that the acquisition of this gorilla‐specific enterotype was enabled by lowered immune system control over the composition of the microbiome. Our results indicate differences between the pathology of SIVgor and SIVcpz/HIV‐1 infections, demonstrating the utility of investigating host microbial ecology as a means for studying disease in wild primates of high conservation priority.     

High‐throughput SNPs for all: genotyping‐in‐thousands

Understanding the genetic structure of species is essential for conservation. It is only with this information that managers, academics, user groups and land‐use planners can understand the spatial scale of migration and local adaptation, source‐sink dynamics and effective population size. Such information is essential for a multitude of applications including delineating management units, balancing management priorities, discovering cryptic species and implementing captive breeding programmes. Species can range from locally adapted by hundreds of metres (Pavey et al. 2010 ) to complete species panmixia (Côté et al. 2013 ). Even more remarkable is that this essential information can be obtained without fully sequenced or annotated genomes, but from mere (putatively) nonfunctional variants. First with allozymes, then microsatellites and now SNPs, this neutral genetic variation carries a wealth of information about migration and drift. For many of us, it may be somewhat difficult to remember our understanding of species conservation before the widespread usage of these useful tools. However most species on earth have yet to give us that ‘peek under the curtain’. With the current diversity on earth estimated to be nearly 9 million species (Mora et al. 2011 ), we have a long way to go for a comprehensive meta‐phylogeographic understanding. A method presented in this issue by Campbell and colleagues (Campbell et al. 2015 ) is a tool that will accelerate the pace in this area. Genotyping‐in‐thousands (GT‐seq) leverages recent advancements in sequencing technology to save many hours and dollars over previous methods to generate this important neutral genetic information.     

马蹄香的保护生物学研究

马蹄香是我国特有的单种属植物,也是一个受威胁的物种,被列为国家级重点保护植物。作者调查了马蹄香在陕西秦巴山区的分布、生境及其现状,论述了它的保护价值,重点分析了致濒原因,提出了以就地保护与迁地保护相结合,以就地保护为主,积极进行分株繁殖,以实现在其原产地恢复和发展种群为最终目的的保护措施。