New records for prehistoric introduction of Neotropical mammals to the West Indies: evidence from Carriacou,Lesser Antilles

Aim This paper investigates the prehistoric introduction of five mammalian taxa to Carriacou (Lesser Antilles) and refines the known anthropogenic ranges for these fauna in the pre‐Columbian West Indies. The importance of such records for understanding the region’s historical biogeography and ecology is considered. Location Carriacou Island, Grenada (12°28′ N, 61°26′ W). Methods Zooarchaeological assemblages from Carriacou’s earliest documented prehistoric sites, Grand Bay and Sabazan, were analysed, and exotic taxa were identified and quantified. The timing of introductions was established based on multiple radiocarbon assays, including three new accelerator mass spectrometry (AMS) direct dates obtained on the bone of exotic taxa. Source species and location(s) are considered and compared with known prehistoric records for the Caribbean to synthesize anthropogenic distributions for the pre‐Columbian period. The contexts of the zooarchaeological remains are evaluated to better understand the nature and purpose of introductions. Results Zooarchaeological investigation on Carriacou reveals the occurrence of multiple mammal introductions from South American between c. ad 700 and ad 1400. This paper presents the first records for guinea pig (Cavia sp.), armadillo (Dasypus sp.), peccary (Tayassu/Pecari sp.), opossum (Didelphis sp.) and agouti (Dasyprocta sp.) from the island. Human‐mediated transport of these taxa is indicated by their absence from the record prior to human settlement of Carriacou. Several translocated species are either rare or entirely unknown for the region, and overall West Indian distributions are temporally and spatially discontinuous. Archaeological contexts indicate that mammalian introductions arose from human subsistence needs, but other social factors may have shaped the dispersal of these fauna. Main conclusions The taxonomic combination and richness of Carriacou’s introduced fauna are unusual within the region. Importantly, the new records significantly improve the known pre‐Columbian geographic range for peccary, guinea pig and armadillo. Integrated with regional records, these data augment our understanding of the Caribbean’s historical biogeography, and have the potential to improve our understanding of human mobility and anthropogenic environmental impacts in the West Indies prior to the arrival of Europeans.     

Disentangling invasion processes in a dynamic shipping-boating network

The relative importance of multiple vectors to the initial establishment, spread and population dynamics of invasive species remains poorly understood. This study used molecular methods to clarify the roles of commercial shipping and recreational boating in the invasion by the cosmopolitan tunicate, Botryllus schlosseri. We evaluated (i) single vs. multiple introduction scenarios, (ii) the relative importance of shipping and boating to primary introductions, (iii) the interaction between these vectors for spread (i.e. the presence of a shipping-boating network) and (iv) the role of boating in determining population similarity. Tunicates were sampled from 26 populations along the Nova Scotia, Canada, coast that were exposed to either shipping (i.e. ports) or boating (i.e. marinas) activities. A total of 874 individuals (c. 30 per population) from five ports and 21 marinas was collected and analysed using both mitochondrial cytochrome c oxidase subunit I gene (COI) and 10 nuclear microsatellite markers. The geographical location of multiple hotspot populations indicates that multiple invasions have occurred in Nova Scotia. A loss of genetic diversity from port to marina populations suggests a stronger influence of ships than recreational boats on primary coastal introductions. Population genetic similarity analysis reveals a dependence of marina populations on those that had been previously established in ports. Empirical data on marina connectivity because of boating better explains patterns in population similarities than does natural spread. We conclude that frequent primary introductions arise by ships and that secondary spread occurs gradually thereafter around individual ports, facilitated by recreational boating.     

论植物园的活植物收集

对植物园活植物收集评价、引种中的取样方法和迁地保护种群大小等问题进行了论述.对活植物收集的评价包括科学性和代表性,最具有科学意义的是经过调查从野外收集的有完整记录的材料,其次是从植物园等机构 引种的有记录的材料,再次是从各地引种的基本上无记录的材料.根据收集物的代表性可分为具有保护意义的收集和保护性收集.取样技术主要针对保护性收集而言,要求收集样本能涵盖该物种95%以上、频率大于5%的等位基因.活植物收集种群的大小应从科学性和现实性二方面来考虑,对植物园里大量的具有保护意义的收集,其种群大小为乔木10～20株,灌木40～50株,草本100～200株;对于保护性收集则至少为乔木50～100株,灌木200株或更多,草本300～500株以上.另外,对当前植物园活植物收集圃建设的一些重要问题也进行了探讨.     

西南桦速生单株选择

采用方差分析、遗传参数分析和聚类分析方法,在福建省华安县引种实验林进行西南桦(Betula alnoides Buch.-Ham.ex D. Don)速生单株选择,从25个种源中筛选出8个优良种源,树高平均遗传增益为10.4%.对8个种源中69个家系进行聚类分析,选择出13个速生家系,树高的平均遗传增益为29.4%.运用K快速聚类法从95个单株中筛选出14株速生单株,其遗传增益为118.01%,增产效果显著,在闽南一带可用作无性繁殖材料,以加速西南桦引种造林良种化进程.     

In situ hatching of invertebrate diapausing eggs from ships' ballast sediment

Ships that enter the Great Lakes laden with cargo carry only residual ballast water and sediment in ballast tanks. These ships are designated ‘no ballast on board’ (NOBOB) and constitute > 90% of inbound traffic. We conducted in situ experiments using emergence traps to assess the viability and the introduction potential of invertebrate diapausing stages present in ships’ ballast sediment. All trials commenced while vessels operated on the lower lakes (Erie, Ontario) and were completed 6–11 days later at ports on the upper lakes (Michigan, Lake Superior). Eight trials were conducted on four ships using five different ballast sediments. Hatching was observed on every ship, although not from all sediments on all ships. Overall hatch rates were very low (0.5 individuals per 500 g sediment), typically involving activation of < 0.05% of total eggs present. Five species of rotifers and copepod nauplii were hatched from ballast sediments, although only one or two species typically hatched from any one sediment. Results of this study indicate that hatching of diapausing eggs contained in ballast sediment of NOBOB ships poses a relatively low risk of invasion to the Great Lakes. However, as reproduction may occur in tanks, and non‐indigenous species may be involved in numerous introduction events, the risk posed by this vector is small but potentially important. While dormancy is a characteristic enabling enhanced survival during transportation in ballast tanks, it becomes a hindrance for introduction.     

ILLEGAL TRANSLOCATION AND GENETIC STRUCTURE OF FERAL PIGS IN WESTERN AUSTRALIA

Abstract: Unlike many regions in the world where wild pigs (Sus scrofa) are threatened, in Australia they are a significant invasive species. As such, the molecular ecology of feral pigs was investigated to understand their social and population genetic structure. Samples from 269 adult animals were collected over their distribution in southwestern Australia. Using 14 highly polymorphic microsatellite markers, we identified 7 inferred feral pig populations that had moderate heterozygosity (mean = 0.580) and displayed a high level of differentiation (mean R_ST = 0.180). In revealing the genetic structure of feral pigs, we detected anomalies in the putative origin of some individuals. Samples from these animals were collected from 2 main areas: recently colonized regions that were previously uninfested, and established feral pig populations, where animals from geographically isolated areas had been introduced. In the latter, these corresponded to areas that were in close proximity to public road access and towns. Given the large distances immigrants were found from their population of origin (from 50 to >400 km), the generally low levels of dispersal of southwest feral pigs, and the grouping and sex of these pigs, we suggest that these individuals have been deliberately and illegally translocated to supplement recreational hunting stocks. Additionally, we could not detect any genetic contribution in these feral pigs from domestic pig herds, suggesting that the deliberate release of domestic pigs to restock feral populations is relatively uncommon. Our molecular data allowed some inferences regarding the success or lack thereof of current management practices, and offered considerable insights into the dynamics of the feral pig populations and identification of “new” approaches that may allow for better control of this highly destructive species.     

珙桐的引种繁殖研究

珙桐是我国特有的珍稀植物,为保护、发展这一树种,对珙桐进行了引种实验和一系列的繁殖研究。     

The genetic rescue of the Florida panther

We examine the consequences of panthers introduced from Texas into south Florida, an area housing a small, isolated, inbred and distinct subspecies ( Puma concolor coryi ). Once part of a continuous, widespread population, panthers became isolated in south Florida more than a century ago. Numbers declined and the occurrence of genetic defects increased. Hoping to reverse the genetic damage, managers introduced eight female panthers from Texas into south Florida in the mid-1990s. This action was highly controversial and we explain the arguments for and against the intervention. We synthesized data systematically collected on the Florida panthers from before, during and after this management intervention. These data include information on movements, breeding, mortality, survivorship and range. There is no evidence that purebred Florida females produce fewer kittens at a later age or less often than do hybrid cats (i.e. those with a Texas ancestor). Hybrid kittens have about a three times higher chance of becoming adults as do purebred ones. Hybrid adult females survive better than purebred females; there is no obvious difference between the males. Males die younger than females, are more often killed by other males and are more likely to disperse longer distances into habitats that are dangerous to them. Hybrids are expanding the known range of habitats panthers occupy and use.     

Comparison of historical bottleneck effects and genetic consequences of re‐introduction in a critically endangered island passerine

Re‐introduction is an important tool for recovering endangered species; however, the magnitude of genetic consequences for re‐introduced populations remains largely unknown, in particular the relative impacts of historical population bottlenecks compared to those induced by conservation management. We characterize 14 microsatellite loci developed for the Seychelles paradise flycatcher and use them to quantify temporal and spatial measures of genetic variation across a 134‐year time frame encompassing a historical bottleneck that reduced the species to ~28 individuals in the 1960s, through the initial stages of recovery and across a second contemporary conservation‐introduction‐induced bottleneck. We then evaluate the relative impacts of the two bottlenecks, and finally apply our findings to inform broader re‐introduction strategy. We find a temporal trend of significant decrease in standard measures of genetic diversity across the historical bottleneck, but only a nonsignificant downward trend in number of alleles across the contemporary bottleneck. However, accounting for the different timescales of the two bottlenecks (~40 historical generations versus <1 contemporary generation), the loss of genetic diversity per generation is greater across the contemporary bottleneck. Historically, the flycatcher population was genetically structured; however, extinction on four of five islands has resulted in a homogeneous contemporary population. We conclude that severe historical bottlenecks can leave a large footprint in terms of sheer quantity of genetic diversity lost. However, severely depleted genetic diversity does not render a species immune to further genetic erosion upon re‐introduction. In some cases, the loss of genetic diversity per generation can, initially at least, be greater across re‐introduction‐induced bottlenecks.