Publications by authors named "Jane L Degabriel"

Environmental DNA (eDNA) analysis has become a popular conservation tool for detecting rare and elusive species. eDNA assays typically target mitochondrial DNA (mtDNA) due to its high copy number per cell and its ability to persist in the environment longer than nuclear DNA. Consequently, the development of eDNA assays has relied on mitochondrial reference sequences available in online databases, or in cases where such data are unavailable, de novo DNA extraction and sequencing of mtDNA.

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Article Synopsis
  • - AusTraits is a comprehensive database that compiles data on 448 traits from 28,640 taxa in Australian flora, integrating information from various sources like field studies and published literature.
  • - The database includes a wide range of traits, from physiological performance measures (like photosynthesis) to morphological features (such as leaf size and plant height), linking these traits to ecological variations.
  • - The latest version, 3.0.2, presents 997,808 trait-by-taxon combinations and aims to facilitate collaboration in archiving and sharing plant trait data, serving as a model for similar initiatives worldwide.
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Grazing-induced changes in plant quality have been suggested to drive the negative delayed density dependence exhibited by many herbivore species, but little field evidence exists to support this hypothesis. We tested a key premise of the hypothesis that reciprocal feedback between vole grazing pressure and the induction of anti-herbivore silicon defenses in grasses drives observed population cycles in a large-scale field experiment in northern England. We repeatedly reduced population densities of field voles () on replicated 1-ha grassland plots at Kielder Forest, northern England, over a period of 1 year.

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Differences in predation risk may exert strong selective pressures on life history strategies of populations. We investigated the potential for predation to shape male mating strategies in an arboreal folivore, the common brushtail possum (Trichosurus vulpecula Kerr). We predicted that possums in a tropical population exposed to high natural levels of predation would grow faster and reproduce earlier compared to those in temperate populations with lower predation.

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Estimating the nutritional value of a herbivore's diet is difficult because it requires knowing what the animal eats, the relative quality of each component and how these components interact in relation to animal physiology. Current methods are cumbersome and rely on many assumptions that are hard to evaluate. We describe a new method for estimating relative diet quality directly from faeces that avoids the problems inherent in other methods.

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Article Synopsis
  • Most plant species have various traits to deter herbivores, but the connections between these defensive traits are poorly understood.
  • Researchers analyzed data from 261 plant species across 80 families globally to explore the relationships between different chemical and physical defenses.
  • The findings reveal that while there are some tradeoffs in defense traits, most species exhibit unique combinations of defenses rather than fitting into coordinated defense syndromes, possibly as a strategy to adapt to competition with coexisting species.
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Plant secondary metabolites (PSMs) strongly influence diet selection by mammalian herbivores. Concentrations of PSMs vary within and among plant species, and across landscapes. Therefore, local adaptations may cause different populations of herbivores to differ in their ability to tolerate PSMs.

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Plants contain a variety of chemical defenses that strongly affect feeding rates in captive mammals, but their effects on the fitness of wild herbivores are largely unknown. This is because the complexity of defensive compounds, and herbivores' counteradaptations to them, make their effects in the wild difficult to measure. We show how tannins interact with protein to produce spatial variation in the nutritional quality of eucalypt foliage, which is related to demography in a wild population of a marsupial folivore, the common brushtail possum (Trichosurus vulpecula Kerr).

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Many regard the concentrations of nitrogen (N), tannins and plant cell wall constituents (fibre) as key indicators of food quality and habitat suitability for browsing herbivores; yet there is no method for measuring their combined effects. We have developed a simple in vitro assay for measuring the effects of tannins and fibre on N availability in browse. We determined the effects of tannins by measuring the polyethylene glycol (PEG)-binding capacity (PEG-BC) of Eucalyptus leaf samples, followed by a two-stage in vitro digestion with pepsin and cellulase to determine the digestibility of dry matter and N.

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