Treacherous objects : a Jacobite compass in Australia?

What does a Jacobite compass in Australia tell us about 'treacherous objects', nationalism, material culture, and diaspora today?

The origin of unknown source DNA from touched objects

The presence of DNA in a criminal investigation often requires scrutiny in relation to how it came to be where it was found. There is a paucity of data with respect to the extent to which one can assume that the last person handling an object, which has previously been touched by others, will contribute to the DNA profile generated from it. There are limited data in detailing the extent to which any foreign DNA is picked-up from a previously touched object and transferred to subsequently touched objects. This study focuses on DNA transfer and persistence on a knife handle after multiple handlings with the knife by different individuals soon after each other, as well as handprints left on flat DNA-free surfaces immediately after touching a knife handle with a known history of prior handling. The profiles of later handlers of a knife are more prominent than earlier handlers; however, the last handler is not always the major contributor to the profile. Proportional contributions to the profiles retrieved from knife handles vary depending on the individuals touching the knife handle. They can also vary when knife handles have been handled in the same manner by the same individuals in the same sequence on different occasions. Hands readily pickup DNA left on objects by others and transfer it to subsequently touched objects. The quantity of foreign DNA picked up by a hand and deposited on subsequently touched objects diminishes as more DNA-free objects are handled soon after each other. Caution is advised when considering how DNA from different individuals may have been transferred to the object from which it was collected.

Critically low levels of genetic diversity in fragmented populations of the endangered Glenelg spiny freshwater crayfish Euastacus bispinosus

The Glenelg spiny freshwater crayfish Euastacus bispinosus is a large endangered freshwater invertebrate of southeastern Australia that has suffered major population declines over the last century. Disjunct populations in the state of South Australia are in a particularly critical condition, restricted to a few isolated rising-spring habitats and in an ongoing state of decline. We assessed genetic diversity and gene flow within E. bispinosus across its current range using allele frequencies from 11 nuclear microsatellite loci and DNA sequence data from a single mitochon -drial locus (cytochrome oxidase subunit I). Populations were characterized by low levels of genetic diversity and found to be highly structured, with gene flow restricted both within and across catchments, highlighting the species' vulnerability to further habitat fragmentation and the importance of managing environmental threats on local scales across its current natural range. South Australian populations were characterized by critically low levels of genetic diversity generally, highlighting their potential vulnerability to localized extinction. Holistic conservation efforts are necessary to conserve populations, including local habitat management and, potentially, translocations to increase genetic diversity and evolutionary potential, and reduce possible inbreeding effects and the threat of extinction.

Conceptual domain of the matrix in fragmented landscapes

In extensively modified landscapes, how the matrix is managed determines many conservation outcomes. Recent publications revise popular conceptions of a homogeneous and static matrix, yet we still lack an adequate conceptual model of the matrix. Here, we identify three core effects that influence patch-dependent species, through impacts associated with movement and dispersal, resource availability, and the abiotic environment. These core effects are modified by five 'dimensions': spatial and temporal variation in matrix quality; spatial scale; temporal scale of matrix variation; and adaptation. The conceptual domain of the matrix, defined as three core effects and their interaction with these five dimensions, provides a much-needed framework to underpin management of fragmented landscapes and highlights new research priorities.

Roadside connectivity does not increase reptile abundance or richness in a fragmented mallee landscape

The effect of isolation and the importance of dispersal in establishing and maintaining populations in fragments of remnant habitat remain poorly understood. Nevertheless, environmental connectivity is likely to be important for ensuring the long-term preservation of biodiversity in extensively cleared landscapes. In this study, we compared reptile communities in large conservation parks with those in small woodland remnants 6.5-12km from the parks, on the Eyre Peninsula, South Australia, Australia. We assessed the impact of fragmentation on the abundance, richness and habitat preferences of reptiles, and examined whether connection to linear roadside vegetation altered reptile communities in small woodland remnants. Of the 31 reptile species, 12 were restricted to conservation parks and six to habitat fragments in farmland. There was a substantial reduction in reptile species richness and abundance in farmland fragments. Direct connection of remnant vegetation to roadside corridors did not affect abundance of common species in the farmland fragments, although species richness was lower in isolated remnants in one of our two study regions. The habitat preference of the scincid lizard Menetia greyii differed between farmland fragments, where they were regularly found on dunes and roadsides, and conservation parks, where they were rare and not detected on dunes. We suggest that habitat fragmentation may have altered interspecific interactions, enabling an expansion of habitat use in the farming landscape. Significantly lower abundance of four common species in farmland settings compared with reserves indicated that existing corridors and small fragments provide inadequate connectivity over larger distances. To counter this effect, large reserves may need to be less than 10km apart.

Spatial dynamics of the knob-tailed gecko Nephrurus stellatus in a fragmented agricultural landscape

In fragmented landscapes, a species' dispersal ability and response to habitat condition are key determinants of persistence. To understand the relative importance of dispersal and condition for survival of Nephrurus stellatus (Gekkonidae) in southern Australia, we surveyed 92 woodland remnants three times. This gecko favours early post-fire succession conditions so may be at risk of extinction in the long-unburnt agricultural landscape. Using N-mixture models, we compared the influence of four measures of isolation, patch area and two habitat variables on the abundance and occurrence of N. stellatus, while taking into account detection probability. Patch occupancy was high, despite the long-term absence of fire from most remnants. Distance to the nearest occupied site was the most informative measure of patch isolation, exhibiting a negative relationship with occupancy. Distance to a nearby conservation park had little influence, suggesting that mainland-island metapopulation dynamics are not important. Abundance and occurrence were positively related to %-cover of spinifex (Triodia), indicating that niche-related factors may also contribute to spatial dynamics. Patterns of patch occupancy imply that N. stellatus has a sequence of spatial dynamics across an isolation gradient, with patchy populations and source-sink dynamics when patches are within 300 m, metapopulations at intermediate isolation, and declining populations when patches are separated by >1-2 km. Considering the conservation needs of the community, habitat condition and connectivity may need to be improved before fire can be reintroduced to the landscape. We speculate that fire may interact with habitat degradation and isolation, increasing the risk of local extinctions.