The dynamics of social networks among female Asian elephants

Background

South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrone's Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF) biome using herbarium data of habitat specialist species.

Results

Current biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1) poor spatial resolution, and (2) poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM) approach where georeferenced herbarium data is used in conjunction with bioclimatic data.

Conclusions

Georeferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in biome mapping, and could be particularly useful for mapping poorly known, fragmented, or degraded vegetation. We wish to highlight that biome delimitation is not an exact science, and that transparency is needed on how biomes are used as study units in macroevolutionary and ecological research.     

Outbreak of sarcoptic mange in alpacas (Vicugna pacos) and control with repeated subcutaneous ivermectin injections

An outbreak of sarcoptic mange was investigated in an alpaca herd. Clinical disease occurred 2 months after the introduction of four alpacas with dry seborrhoeic skin lesions, the cause of which was not investigated. Initially a group of females was affected, despite repeated topical treatment with ivermectin at a dose of 0.5 mg/kg bodyweight. One female died and post-mortem examination indicated sarcoptic mange as the cause of death. Infection with Sarcoptes scabiei was also demonstrated on microscopic examination of skin scrapes taken from clinically affected cohorts. Later in the outbreak, a separate group of male alpacas was also affected. Treatment using subcutaneous ivermectin injections at a dose of 0.2 mg/kg, administered at 14-day intervals, was evaluated. During this course of treatment, another female died. A successful response in the other alpacas was eventually reached following 12 treatments of the female group and 8 treatments of the male group.     

Nutrient changes in potting mix and <Emphasis Type="Italic">Eucalyptus nitens</Emphasis> leaf tissue under macadamia biochar amendments

The effect of macadamia nut shell biochar on nitrogen, potassium, phosphorus, magnesium, calcium and sodium concentrations in potting mix used to grow Eucalyptus nitens seedlings was investigated in a glasshouse experiment. The treatments combined two fertiliser rates (50 and 100% rate of the commercial mix commonly used in forestry nurseries) with eight biochar rates (0, 2, 5, 10, 20, 50, 80 and 100 t ha^?1) arranged in a randomised complete block with three replicates of four sample plants. Nutrients were quantified in the potting mix and seedling leaves at four destructive harvests 135, 177, 219 and 269 days after planting. Biochar significantly increased nitrate-N, Colwell P, Colwell K and exchangeable Na and reduced ammonium-N, Mg and Ca concentrations in the potting mix. Seedling leaf concentrations of P, K and Na were increased by biochar application, while N remained dependent on fertiliser rate only. Mg and Ca leaf concentrations decreased in response to increasing biochar rates. Elevated nitrate-N and decreased ammonium-N concentrations suggest that biochar might have increased nitrification in the potting mix. We presumed that biochar mediated processes that reduced uptake of P and K when high doses of biochar were combined with full fertilisation. Changes in potting mix K, Na, Mg and Ca were consistent with selective adsorption of ions to biochar surfaces.     

Modeling Spatial Variability of Soil Chemical Parameters for Site-Specific Farming Using Stochastic Methods

Spatial variability of soil properties affects nutrient transport in the field. The purpose of this study was to examine the extent of spatial variability in the soil chemical parameters, and to develop stochastic models to represent these variations. The parameters selected include concentration levels of Ca, Mg, Mn, NO3-N, P, K and Zn, and OM and pH of soil. Data were collected from 55 grids of 20 × 20 m size from a field within the Coastal Plains of Virginia. Analyses were performed based on the deterministic and stochastic components of the chemical parameters. All the parameters had different degrees of variability in the spatial domain. NO3-N, P, K and Zn exhibited greater degrees of variability compared to other parameters. Among the nine parameters, NO3-N and Zn had the greatest spatial variation with coefficient of variation (CV) of 40 and 49%, respectively, while pH had the lowest variation with a CV of only 4%. The spatial variations of each parameter were not random, but were mutually correlated with their values at the adjoining grids. The analysis showed that the deterministic component of these parameters could be represented by a Fourier series containing sine and cosine functions, while different types of models were required to describe their stochastic component. A second-order autoregressive model, AR(2), for Ca, Mg, Mn and OM; a first-order autoregressive model, AR(1), for pH; and a mixed autoregressive-moving average, ARMA(2,1), for NO3-N, P, K and Zn parameters were found suitable. These models were capable of describing the spatial structure of chemical parameters, and hence can be used to determine their values at any unsampled locations to develop site-specific nutrient management plans for the study site.     

Spirometra erinacei / S. erinaceieuropaei in a feral cat in Manawatu with chronic intermittent diarrhoea

CASE HISTORY: A feral cat captured in the Manawatu region of New Zealand was treated for worms and fleas, and kept confined in a metabolic cage. It showed good appetite and weight gain but had intermittent watery, yellow diarrhoea.

CLINICAL FINDINGS: Clinical examination under sedation was unremarkable and routine blood tests showed no significant abnormalities. The cat was negative for feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Different canned cat foods did not alter the course of the diarrhoea, and the cat was euthanised 6 months after capture. At necropsy, two sections of adult Spirometra tapeworms were found in the jejunum and typical Spirometra eggs were found in colonic contents. Molecular identification of the parasite was undertaken, using the cytochrome- c oxidase subunit-1 gene (cox1) sequence.

DIAGNOSIS: Chronic intermittent diarrhoea associated with Spirometra erinacei / S. erinaceieuropaei infection.

CLINICAL RELEVANCE: Spirometra has not been reported in New Zealand before but has been associated with gastrointestinal disease in cats in other parts of the world. It requires speciestargeted treatment to be eliminated effectively, and is zoonotic. Diagnosis could be diffi cult for clinicians who are not familiar with the parasite and its life cycle.     

Immunisation against ovine caseous lymphadenitis: comparison of Corynebacterium pseudotuberculosis vaccines with and without bacterial cells

Sheep were immunised with Corynebacterium pseudotuberculosis vaccines prepared from cell-free toxoid or from toxoid with formalin-killed cells of C pseudotuberculosis added. Resistance of sheep to infection was tested 6 months after immunisation by inoculation with caseous lymphadenitis pus. The outcome was assessed 3 months later by slaughter and inspection of the sheep for lesions of caseous lymphadenitis. immunised sheep were adequately protected against infection as shown by a significant reduction in the number of sheep exhibiting lesions compared with control sheep, and by fewer abscesses in affected vaccinated sheep than in affected control sheep. The protective potency of the vaccines was not improved by the inclusion of cells of C pseudotuberculosis.     

Galloping exercise induces regional changes in bone density within the third and radial carpal bones of Thoroughbred horses

This study was performed to test the hypothesis that a localised bone hypertrophy could occur within the subchondral cancellous architecture of the third and radial carpal bones. Using 2 levels of controlled and defined exercise, it was observed that a high intensity treadmill exercise protocol resulted in functional adaptation of the carpal bones. The increase in trabecular thickening and density was seen to be localised to those regions underlying common sites of cartilage degradation, the interface of the thickened trabeculae with the normal architecture in the third carpal bone was coincident with a common site of clinical fractures. The bone changes were determined both qualitatively on examination of slab radiographs and quantified by dual energy x-ray absorptiometry. The findings from this study are relevant to mechanical factors involved in the pathophysiology of joint degeneration. The potential clinical implications of this study are in relation to changes in the type and duration of exercise regimens used in training of equine athletes. The rapid response of bone to mechanical stimulation has implications in the longer term for localised cartilage degradation. Imaging techniques could be developed to monitor these early bone changes in the specific areas identified in this study and thus allow appropriate changes in training intensity to minimise subsequent damage to the articular surface.