The vegetable ivory industry: Surviving and doing well in Ecuador

Buttons made of vegetable ivory were once in great demand in industrial parts of the world. Vegetable ivory is the hard white seed endosperm from palms of the genusPhytelephas (Arecaceae). After World War II, ivory nuts were largely replaced by plastics. Recently the authors visited a factory on the coast of Ecuador that was founded in 1926 and still produces buttons of vegetable ivory on a large scale. Eighty employees produce about 5000 lb of buttons a month; these are exported to Japan, West Germany, and Italy. The production is described step by step and the future of vegetable ivory is discussed briefly.     

Ivory Ornaments of the Aurignacian in Western Europe: Case studies from France and Germany

Here we present an overview of the personal ornaments of the Swabian Aurignacian and the Early Aurignacian sites of south-western France made from mammoth ivory. The production sequences for the serial manufacture of beads from these sites are quite similar. While the Swabian sites have yielded numerous different types of beads with a focus of the double-perforated bead, the nearly exclusive use of one bead-type, the perle en forme de panier, is striking at the sites of south-western France. Following the presentation of major inventories of ivory ornaments in the two regions concerned, we discuss potential factors underlying both the differences and the similarities we observe in these assemblages.     

Qu’est-ce que l’Ivoire ?

What is ivory? Though the term “ivory” has been generally applied to animal dental materials of commercial value, many specialists reserve the term “true ivory” for the enlarged incisors of elephants and extinct proboscideans. Compared even to the check teeth of the same species, these specialized incisors have chemical and structural properties that are unique, and which have substantial implications for the identification, analysis and interpretation of archaeological artifacts made of true ivory. Below, we present a definition of “true ivory” and an overview of its chemical and structural characteristics and the diagnostic features that can be used in its identification.     

Biodegradation of ivory (natural apatite): possible involvement of fungal activity in biodeterioration of the Lewis Chessmen

Fungal biodeterioration of ivory was investigated with in vitro inoculation of samples obtained from boar and walrus tusks with the fungi Aspergillus niger and Serpula himantioides, species of known geoactive abilities. A combination of light and scanning electron microscopy together with associated analytical techniques was used to characterize fungal interactions with the ivory, including changes in ivory composition, dissolution and tunnelling, and the formation of new biominerals. The research was aimed at providing further understanding of the potential roles of fungi in the colonization and deterioration of ivory in terrestrial environments, but also contributes to our knowledge regarding the possible origins of the surface damage observed on early medieval sculptures made largely from walrus tusks, referred to as ‘the Lewis hoard of gaming pieces’, that were presumably produced for playing chess. The experiments have shown that the possibility of damage to ivory being caused by fungi is realistic. Scanning electron microscopy revealed penetration of fungal hyphae within cracks in the walrus tusk that showed also widespread tunnelling by fungal hyphae as well as ‘fungal footprints’ where the surface was etched as a consequence of mycelial colonization. Similar phenomena were observed with boar tusk ivory, while production of metabolites could lead to complete dissolution of the sample. Colonization of ivory and/or exposure to fungal activity lead to extensive secondary biomineral formation, and this was identified as calcium oxalate, mainly as the monohydrate, whewellite.     

Acquérir l’ivoire vrai et lui donner forme : contraintes pratiques et techniques

Dealing with objects made on osseous materials as mammoth ivory involves questions about the availability of this raw material within the territories occupied by palaeolithic societies. In the case of green ivory procurement, this availability is directly linked with the geographical distribution of mammoth populations. The ways of procurement of this raw material seem to be guided also by some cultural traditions. The authors propose a reflexion about these zooarchaeological issues and the first technical gestures, which come in the initial stages of any exploitation of true ivory.     

Les objets en ivoire du Jura souabe

In the region of the Swabian Jura, four caves, Hohle Fels and Geißenklösterle in the Ach Valley, and Vogelherd and Hohlenstein-Stadel in the Lone Valley, have particularly rich Aurignacian layers. Beside hundreds of ivory tools, they delivered dozens of mobile figurative artworks and several musical instruments made from bone and ivory. They are among the oldest examples of art and music worldwide. In this paper, we present a summarized and updated version of the so far published figurines and recent results concerning art objects and symbolic markings on ivory artefacts from old and recent excavations.     

THE COLLECTION OF FOUND IVORY IN MURCHISON FALLS NATIONAL PARK, UGANDA

The paper concerns the circumstances surrounding the collection of ivory from dead elephants, with particular reference to Murchison Falls National Park. The characteristics of the interval between death and complete disintegration of an elephant are described. These, combined with observations of known age skeletons, comprised the criteria used in classifying skeletons found from the air into three relative age classes. Average annual mortality is estimated for the population north of the Nile (MFPN) at 147 animals yielding 1945 kg of ivory, and for that south of the Nile (MFPS) at 474 animals yielding 7497 kg ivory. Park-found ivory records are analyzed for the 11 y 1959–69. The expected age distribution of deaths is compared with the observed. For MFPN a bias in favour of large (male) tusks is present, explicable by the concentration of ranger search effort in areas of known high male density. For MFPS a bias towards small tusks is thought to be caused by elephants wounded outside the park dying inside it. The National Park recovers an average of 27.6 % of its available ivory per annum, with large annual fluctuations probably correlated with the incidence of wounding outside the park. High losses to poachers are evident. An aerial search for ivory showed a tendency for elephants to die near watercourses. A finding rate of one carcass every 4.3 km of watercourse was obtained. As only 5 % of carcasses still had tusks the aerial searching was prematurely terminated. The results indicated a finding efficiency of 26.4% of the available current year carcasses. Comparative costing suggests that ground searching would be a more efficient method of finding ivory than aerial searching. The high value of the available ivory in Murchison and other areas justifies intensive searching. The low collection rates prevailing in East Africa are largely attributable to the absence of appropriate search efforts.     

Dissecting the Illegal Ivory Trade: An Analysis of Ivory Seizures Data

Reliable evidence of trends in the illegal ivory trade is important for informing decision making for elephants but it is difficult to obtain due to the covert nature of the trade. The Elephant Trade Information System, a global database of reported seizures of illegal ivory, holds the only extensive information on illicit trade available. However inherent biases in seizure data make it difficult to infer trends; countries differ in their ability to make and report seizures and these differences cannot be directly measured. We developed a new modelling framework to provide quantitative evidence on trends in the illegal ivory trade from seizures data. The framework used Bayesian hierarchical latent variable models to reduce bias in seizures data by identifying proxy variables that describe the variability in seizure and reporting rates between countries and over time. Models produced bias-adjusted smoothed estimates of relative trends in illegal ivory activity for raw and worked ivory in three weight classes. Activity is represented by two indicators describing the number of illegal ivory transactions – Transactions Index – and the total weight of illegal ivory transactions – Weights Index – at global, regional or national levels. Globally, activity was found to be rapidly increasing and at its highest level for 16 years, more than doubling from 2007 to 2011 and tripling from 1998 to 2011. Over 70% of the Transactions Index is from shipments of worked ivory weighing less than 10 kg and the rapid increase since 2007 is mainly due to increased consumption in China. Over 70% of the Weights Index is from shipments of raw ivory weighing at least 100 kg mainly moving from Central and East Africa to Southeast and East Asia. The results tie together recent findings on trends in poaching rates, declining populations and consumption and provide detailed evidence to inform international decision making on elephants.     

Isolation of DNA from small amounts of elephant ivory

This protocol describes a method for the extraction of DNA from elephant ivory. These techniques are being used to assign geographic origin to poached ivory by comparing the ivory genotype to a geographic-based gene frequency map, developed separately. The method has three components: ivory pulverization, decalcification and DNA extraction. Pulverization occurs in a freezer mill while the sample is deep frozen in liquid nitrogen, preventing degradation of DNA during the process. Decalcification involves repeated agitation of the sample in 0.5 M ethylenediaminetetraacetic acid over a 4-d period. Extraction follows a modified Qiagen protocol for the extraction of DNA from animal tissue. This method can be used on all forms of ivory. However, DNA recovery is highest when the outermost layer of the tusk, the cementum, is used. When applied to extract DNA from 11 samples, in duplicate, the entire protocol can be completed in 6 d, although much of this time consists of pause points that do not require effort. The protocol provides 0.8 +/- 0.11 ng microl(-1) (mean +/- s.e., n = 48) of DNA per sample.     

An assessment of the maximum sustainable yield of ivory from African elephant populations.

A general, logistic population model is used to explore the dynamics of harvested elephant populations. The model includes two features peculiar to elephant populations and the harvesting of ivory. First, because of the shape of the growth curve of tusks with age, the conversion factor that relates the number of elephants killed to the ivory yield in weight is not constant, but a function of the population size. Second, tusks from animals that die from natural causes can be retrieved and included in the total yield of ivory. The implications of the relationship between tusk size and age of an animal on the maximum sustainable yield in terms of ivory tonnage and in terms of the number of tusks are explored. The nonequilibrium implications of the tusk growth curve on the population dynamics under different harvesting strategies are also investigated. Results indicate that the maximum sustainable yield is achieved at very low harvest rates with population levels close to the pristine equilibrium. When tusks from animals that die of natural causes are included in the harvest, the maximum yield may, depending on the mortality and recruitment parameters, occur when there is no direct harvest.     

High connectivity in a long-lived high-Arctic seabird,the ivory gull <Emphasis Type="Italic">Pagophila eburnea</Emphasis>

Species may cope with rapid habitat changes by distribution shifts or adaptation to new conditions. A common feature of these responses is that they depend on how the process of dispersal connects populations, both demographically and genetically. We analyzed the genetic structure of a near-threatened high-Arctic seabird, the ivory gull (Pagophila eburnea) in order to infer the connectivity among gull colonies. We analyzed 343 individuals sampled from 16 localities across the circumpolar breeding range of ivory gulls, from northern Russia to the Canadian Arctic. To explore the roles of natal and breeding dispersal, we developed a population genetic model to relate dispersal behavior to the observed genetic structure of worldwide ivory gull populations. Our key finding is the striking genetic homogeneity of ivory gulls across their entire distribution range. The lack of population genetic structure found among colonies, in tandem with independent evidence of movement among colonies, suggests that ongoing effective dispersal is occurring across the Arctic Region. Our results contradict the dispersal patterns generally observed in seabirds where species movement capabilities are often not indicative of dispersal patterns. Model predictions show how natal and breeding dispersal may combine to shape the genetic homogeneity among ivory gull colonies separated by up to 2800 km. Although field data will be key to determine the role of dispersal for the demography of local colonies and refine the respective impacts of natal versus breeding dispersal, conservation planning needs to consider ivory gulls as a genetically homogeneous, Arctic-wide metapopulation effectively connected through dispersal.     

Productivity and management of Phytelephas aequatorialis (Arecaceae) in Ecuador

Phytelephas aequatorialis is endemic to western Ecuador. Vegetable ivory (tagua, the hard endosperm) and leaves for thatch (cade) are harvested from the palm and commercialised. Export of vegetable ivory from Ecuador reached a value of 14 million US$ in 2011, making it the second most important product from native palms in the country. Vegetable ivory and leaves are harvested mainly from the wild, although the palm is occasionally cultivated. Most seeds harvested for vegetable ivory are collected from the ground. In times of high demand, however, some harvesters collect immature infructescences; these young seeds are of inferior quality and unsuitable for the fabrication of tagua discs for export. Premature harvest reduces the amount of fully mature, high‐quality seed leading to resource limitation for the processing industry that already is unable to satisfy international demand. Fruit production in lowland agroforestry systems strongly correlates to the level of exposure to light. The development of infructescences takes 3 years in the lowlands (≤93 m a.s.l.) and over 4 years on the Andean slopes at around 1400 m a.s.l. Data from 365 tagged individuals show that male palms produce significantly more leaves than female palms and palms growing in the shade produce fewer, but longer and higher quality leaves for thatch. Leaf harvest has little impact on leaf production, but substantially reduces fruit production. Natural regeneration of Phytelephas populations in pastures is negatively affected, rendering the survival of these populations problematic. Sustainable use and commercialization of the two partially exclusive and locally competing products tagua (vegetable ivory) and cade (leaves for thatch) must be carefully designed. Application of unsustainable practices in the harvest of seeds and leaves, population decline in pastures, and resource limitation in the processing industry represent the main challenges in the sustainable use of this valuable palm species in the future.     

Structure of ivory

Profiles with all orientations have been used to visualize the 3D structure of ivory from tusks of elephant, mammoth, walrus, hippopotamus, pig (bush, boar, and warthog), sperm whale, killer whale, and narwhal. Polished, forming, fractured, aged, and stained surfaces were prepared for microscopy using epi-illumination. Tusks have a minor peripheral component, the cementum, a soft derivative of the enamel layer, and a main core of dentine=ivory. The dentine is composed of a matrix of particles 5-20 microm in diameter in a ground substance containing dentinal tubules about 5 microm in diameter with a center to center spacing of 10-20 microm. Dentinal tubules may be straight (most) or curly (pigs). The main findings relate to the way that dentinal tubules align in sheets to form microlaminae in the length of the tusk. Microlaminae are sheets of laterally aligned dentinal tubules. They are axial but may be radial (most), angled to the forming face (pigs and hippopotamus canines), or radial but helical (narwhals). Within the microlaminae the dentinal tubules may be radial, angled to the axis (whales, walrus, and pigs), or may change their orientation from one microlamina to the next in helicoids (canines of hippopotamuses, incisors of proboscidea). In the nonbanded, featureless ivories from the hippopotamus incisors, the dentinal tubules form radial microlamina from which the arrangements in other ivories can be derived. In the canines of hippopotamuses and incisors of proboscidea, the dentinal tubule orientation changes incrementally from one microlamina to the next in a helicoid, a stack of dentinal tubules that change their orientation by 180 degrees anticlockwise. Dentinal tubules having different orientations are laid down concurrently, not layer by layer as in most examples of helicoidal architecture (e.g., insect cuticle). In proboscidean ivory, the microlaminae are radial, normal to the banding of growth layers marking the plane of deposition. They form radial segments with each 180 degrees turn in the orientation of their constituent dentinal tubules. Below the cementum they are almost complete 180 degrees helicoids, but nearer to the core they become narrower with the loss of radially oriented dentinal tubules. These truncated helicoidal patterns appear in longitudinal profile as VVVV feather patterns rather than intersection intersection intersection intersection, each V or intersection being the side view of a partial or complete helicoid. The Schreger pattern in proboscidean ivory consists of these helicoids divided tangentially into columns in the length of the tusk. Narwhals have the most abundant matrix particles with their radial/helical dentinal tubules having a twist opposite to that in the cementum.     

Muskrat (Ondatra zibethicus) decline after the expansion of American mink (Neovison vison) in Poland

Field survey data in Central Poland revealed that the proportion of sites inhabited by muskrats decreased from 44% to 7% over one decade. This corresponded to the decline in hunting bags of muskrat over the whole of Poland. The largest hunting harvest of muskrat was recorded in 1987/1988 (66,416 individuals), the smallest in 2007/2008 (4,567 individuals). The decline in hunting bags occurred in all regions analysed; however, it was most rapid in the north and north-east. Before the expansion of mink, which started in northern Poland at the beginning of the 1980s, muskrat densities in particular regions depended on the availability of aquatic habitats. A comparison of hunting bags of muskrat and American mink in years 2002–2008 indicated a significant negative correlation between the numbers of these two species harvested in seven regions of Poland. The negative correlation between numbers of muskrat and mink suggests that mink predation is one of the most important factors in the decline of the muskrat population in Poland.     

The Effects of One-Off Ivory Sales on Elephant Mortality

ABSTRACT We revisited the debate about whether the 1999 one-off sale of ivory promoted elephant (Loxodonta africana) poaching in Africa. Complementing earlier work based on ivory seizure data, we considered data on elephant mortality in Zimbabwe and Kenya. Our findings present a mixed picture. At the local level there was some evidence that the one-off sale resulted in extra elephant killing, but this effect was relatively small (and probably short-lived). Although the data were too scanty to draw strong conclusions, decision-making about elephant management and the ivory trade has to continue and will necessarily be based on imperfect information for a long time to come. Our findings suggest that further experimenting with one-off sales may be beneficial from a conservation and development perspective.     

Molecular genetic basis of flower colour variegation in Linaria

To identify transposons that may be of use for mutagenesis we investigated the genetic molecular basis of a case of flower colour variegation in Linaria, a close relative of the model species Antirrhinum majus. We show that this variegation is attributable to an unstable mutant allele of the gene encoding dihydroflavonol-4-reductase, one of the enzymes required for anthocyanin biosynthesis. This allele carries an insertion of a transposon belonging to the CACTA family (Tl1, Transposon Linaria 1) which blocks its expression thus conferring an ivory flower colour phenotype. Tl1 is occasionally excised in dividing epidermal cells to produce clonal patches of red tissue on the ivory background, and in cells giving rise to gametes to generate reversion alleles conferring a fully coloured phenotype. This finding may open the way for targeted transposon-mutagenesis in Linaria, and hence for using this genus in comparative genetic studies.     

Endoscopically assisted reconstruction of male and female poland syndrome

Poland syndrome produces deformities of the breast and chest wall that can be highly disfiguring in both men and women. Incisions from traditional surgical approaches can be unsightly, especially if a muscle harvest is used as part of the reconstruction. Herein is described a case series in which minimally invasive techniques were used to reconstruct defects in male and female patients with Poland syndrome. When evaluating patients with Poland syndrome, one should consider using minimally invasive techniques as an alternative reconstructive option.     

Eriophyoid mites (Acari: Eriophyoidea) on coniferous trees: is the occurrence of one species associated with the other?

Although Eriophyoidea is one of the most important phytophagous mite taxa owing to its negative impact on plants, reports on associations between occurrences of eriophyoid species are scarce. The aim of this paper is to test the hypothesis that the occurrence of one species is correlated with the occurrence of another in some predictive manner. Analyses are carried out for two popular coniferous trees in Poland, i.e., Norway spruce (Picea abies) and Scots pine (Pinus sylvestris). Observations were made in four locations in Poland, from three age groups of trees, namely adult trees (thirty 15-cm shoot samples from each of ten trees), young trees (ten 15-cm shoot samples from each of ten trees) and seedlings (100 whole-seedling samples). The associations were estimated by Yule’s V index. Among four eriophyoid species observed on Scots pine, and the same number of species on Norway spruce, in general no association pattern was observed. It means that their occurrence is independent. The most likely explanation for the absence of co-occurrence is the abundance of microhabitats on coniferous trees for eriophyoid mites, combined with the low mite density on these plant hosts.