Genetic differentiation of Euterpe edulis Mart. populations estimated by AFLP analysis

Heart-of-palm (Euterpe edulis Mart.) is a wild palm with a wide distribution throughout the Atlantic Rainforest. Populations of E. edulis represent important renewable natural resources but are currently under threat from predatory exploitation. Furthermore, because the species is indigenous to the Atlantic Rainforest, which is located in the most economically developed and populated region of Brazil, social and economic pressures have devastated heart-of-palm forests. In order to estimate the partitioning of genetic variation of endangered E. edulis populations, 429 AFLP markers were used to analyse 150 plants representing 11 populations of the species distribution range. Analysis of the genetic structure of populations carried out using analysis of molecular variance (AMOVA) revealed moderate genetic variation within populations (57.4%). Genetic differentiation between populations (F-ST = 0.426) was positively correlated with geographical distance. These results could be explained by the historical fragmentation of the Atlantic coastal region, together with the life cycle and mating system The data obtained in this work should have important implications for conservation and future breeding programmes of E. edulis.

Patterns of variation at a mitochondrial sequence-tagged-site locus provides new insights into the postglacial history of European Pinus sylvestris populations

Due to their maternal mode of inheritance, mitochondrial markers can be regarded as almost 'ideal' tools in evolutionary studies of conifer populations. In the present study, polymorphism was analysed at one mitochondrial intron (nad 1, exon B/C) in 23 native European Pinus sylvestris populations. In a preliminary screening for variation using a polymerase chain reaction-restriction fragment length polymorphism approach, two length variants were identified. By fully sequencing the 2.5 kb region, the observed length polymorphism was found to result from the insertion of a 31 bp sequence, with no other mutations observed within the intron. A set of primers was designed flanking the observed mutation, which identified a novel sequence-tagged-site mitochondrial marker for P. sylvestris. Analysis of 747 trees from the 23 populations using these primers revealed the occurrence of two distinct haplotypes in Europe. Within the Iberian Peninsula, the two haplotypes exhibited extensive population differentiation (Phi(ST) = 0.59; P less than or equal to 0.001) and a marked geographical structuring. In the populations of central and northern Europe, one haplotype largely predominated, with the second being found in only one individual of one population.

Is naturalisation of the brown hare in Ireland a threat to the endemic Irish hare?

On islands, one of the greatest risks to native wildlife is the establishment of alien species. In Ireland, the Irish hare (Lepus timidus hibernicus), the only native lagomorph, may be at risk from competitive exclusion and hybridisation with naturalised brown hares (L. europaeus) that were introduced during the late nineteenth century. Pre- and post-breeding spotlight surveys during 2005 in the north of Ireland determined that brown hare populations are established in mid-Ulster and west Tyrone. In mid-Ulster, brown hares comprised 53%-62% of the hare population, with an estimated abundance of 700-2000 individuals between pre- and post-breeding periods. Comparison of habitat niches suggest that Irish and brown hares have comparable niche breadths that at times completely overlap, suggesting the potential for strong competition between the species. Anecdotal evidence suggests that both species may hybridise. Further research is urgently required to assess the degree of risk that naturalised brown hares pose to the Irish hare population and what action, if any, is needed to ensure the future ecological security and genetic integrity of the native species.

Factors associated with hare mortality during coursing

Hare coursing is a widespread but controversial activity. In an attempt to reduce hare mortality and mitigate the activity's impact on hare welfare, the Irish Coursing Club introduced measures including the compulsory muzzling of dogs in 1993. However, the efficacy of these measures remained the subject of heated debate. Official records, corroborated by independent video evidence, were used to assess the fate of individual Irish hares (Lepus timiclus hibernicus) during coursing events from 1988-2004. Muzzling dogs significantly reduced levels of hare mortality. In courses using unmuzzled dogs from 1988189-1992193 mean hare mortality was 15.8%, compared to 4.1% in courses using muzzled dogs from 1993194-2003104. Further reductions in mortality could not be accounted for by muzzling dogs, supporting the efficacy of other factors such as improved hare husbandry. The duration of the head start given to the hare prior to the release of the dogs significantly affected the outcome of the course. Hares that were killed had head starts of greater duration than those that were chased but survived, suggesting the former may have been slower. The selection of hares by assessment of their running ability may provide means to reduce hare mortality during courses further. Our findings support the efficacy of measures taken to mitigate the impact of coursing on individual hares. However, it is necessary to evaluate the impact of removing hares from the source population and of returning coursed hares to the wild before the wider impact of coursing on wild hare populations can be determined.

Influence of access to grass silage on the welfare of sows introduced to a large dynamic group

This experiment investigated the effects of providing access to grass silage on the welfare of sows introduced to a large dynamic group. Two treatments were applied: (1) access to racks containing grass silage (offering an average of 1.9 kg silage/sow/day), and (2) control treatment with no grass silage racks. Treatments 1 and 2 were applied to two separate dynamic groups, each containing 37 (2) sows. Approximately 9 sows were replaced in both groups at 3-week intervals, and each of these replacements constituted a replicate of the study. The study was replicated six times using a total of 108 sows. In a time-based cross-over design, treatments were swapped between the two dynamic groups after three replicates. Highest levels of rack usage were shown between 08:00 and 14:00 h. During peak periods, 9.8% of sows were observed at the racks at a given time. On average, 78.5% of sows observed at the racks were newly-introduced animals. Overall levels of aggression to which newly-introduced sows were exposed on the day of introduction to the group were low, and did not differ significantly between treatments (P > 0.05). In addition, injury levels measured 1-week post-introduction to the group did not differ significantly between treatments (P > 0.05). Sham chewing behaviour was more prevalent in the post-rather than the pre-feeding yard (P

European hare (Lepus europaeus) invasion ecology: Implication for the conservation of the endemic Irish hare (Lepus timidus hibernicus)

European hare Lepus europaeus populations have undergone recent declines but the species has successfully naturalised in many countries outside its native range. It was introduced to Ireland during the mid-late nineteenth century for field sport and is now well established in Northern Ireland. The native Irish hare Lepus timidus hibernicus is an endemic subspecies of mountain hare L. timidus and has attracted major conservation concern following a long-term population decline during the twentieth century and is one of the highest priority species for conservation action in Ireland. Little is known about the European hare in Ireland or whether it poses a significant threat to the native mountain hare subspecies by compromising its ecological security or genetic integrity. We review the invasion ecology of the European hare and examine evidence for interspecific competition with the mountain hare for habitat space and food resources, interspecific hybridisation, disease and parasite transmission and possible impacts of climate change. We also examine the impact that introduced hares can have on native non-lagomorph species. We conclude that the European hare is an emerging and significant threat to the conservation status of the native Irish hare. Invasive mammal species have been successfully eradicated from Ireland before and immediate action is often the only opportunity for cost-effective eradication. An urgent call is issued for further research whilst the need for a European hare invasive Species Action Plan (iSAP) and Eradication strategy are discussed.

Influence of replacement rate on the welfare of sows introduced to a large dynamic group

This experiment investigated the effects of replacing 10, 20, 30 or 40% of a dynamic group of forty sows on the welfare of newly-introduced animals. The experiment was replicated five times, using a total of 200 multiparous sows. Replacements took place at 3 week intervals, and 3 days prior to sows being added to the group the same number of animals were removed from the group. Sows were added to the dynamic group as pre-formed groups of four animals which had resided together for a period of 5 weeks beginning directly after their piglets were weaned. Replacement rate did not appear to influence overall levels of aggression to which newly-introduced animals were exposed on the day of mixing, however aggression among newly-introduced animals increased significantly as replacement rate increased between 20 and 40% (P

Resolving genetic functions within microbial populations: In situ analyses using rRNA and mRNA stable isotope probing coupled with single-cell raman-fluorescence in situ hybridization

Prokaryotes represent one-half of the living biomass on Earth, with the vast majority remaining elusive to culture and study within the laboratory. As a result, we lack a basic understanding of the functions that many species perform in the natural world. To address this issue, we developed complementary population and single-cell stable isotope (C-13)-linked analyses to determine microbial identity and function in situ. We demonstrated that the use of rRNA/mRNA stable isotope probing (SIP) recovered the key phylogenetic and functional RNAs. This was followed by single-cell physiological analyses of these populations to determine and quantify in situ functions within an aerobic naphthalene-degrading groundwater microbial community. Using these culture-independent approaches, we identified three prokaryote species capable of naphthalene biodegradation within the groundwater system: two taxa were isolated in the laboratory (Pseudomonas fluorescens and Pseudomonas putida), whereas the third eluded culture (an Acidovorax sp.). Using parallel population and single-cell stable isotope technologies, we were able to identify an unculturable Acidovorax sp. which played the key role in naphthalene biodegradation in situ, rather than the culturable naphthalene-biodegrading Pseudomonas sp. isolated from the same groundwater. The Pseudomonas isolates actively degraded naphthalene only at naphthalene concentrations higher than 30 mu M. This study demonstrated that unculturable microorganisms could play important roles in biodegradation in the ecosystem. It also showed that the combined RNA SIP-Raman-fluorescence in situ hybridization approach may be a significant tool in resolving ecology, functionality, and niche specialization within the unculturable fraction of organisms residing in the natural environment.

Osmoregulatory traits of broad-toothed field mouse (Apodemus mystacinus) populations from different habitats

One mechanism for physiological adjustment of small mammals to different habitats and different seasons is by seasonal acclimatization of their osmoregulatory system. We examined the abilities of broad-toothed field mice (Apodemus mystacinus) from different ecosystems ('sub-alpine' and 'Mediterranean') to cope with salinity stress under short day (SD) and long day (W) photoperiod regimes. We compared urine volume, osmolarity, urea and electrolyte (sodium, potassium and chloride) concentrations. Significant differences were noted in the abilities of mice from the two ecosystems to deal with salinity load; in particular sub-alpine mice produced less concentrated urine than Mediterranean mice with SD- sub-alpine mice seeming to produce particularly dilute urine. Urea concentration generally decreased with increasing salinity, whereas sodium and potassium levels increased, however SD- sub-alpine mice behaved differently and appeared not to be able to excrete electrolytes as effectively as the other groups of mice. Differences observed provide an insight into the kinds of variability that are present within populations inhabiting different ecosystems, thus how populations may be able to respond to potential changes in their environment. Physiological data pertaining to adaptation to increased xeric conditions, as modelled by A. mystacinus, provides valuable information as to how other species may cope with potential climatic challenges.