Genetic diversity and morphological variation in African boxthorn (Lycium ferocissimum)–characterising the target weed for biological control
- Authors: McCulloch, Graham A , Mauda, Evans V , Chari, Lenin D , Martin, Grant D , Gurdasani, Komal , Morin, L , Walter, Grenville H , Raghu, S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423474 , vital:72064 , xlink:href="https://doi.org/10.1016/j.biocontrol.2020.104206"
- Description: Lycium ferocissimum (African boxthorn) is a Weed of National Significance in Australia. Biological control may have potential to manage this weed, but taxonomic uncertainty needs to be addressed first to facilitate searches for potential agents. We sampled putative L. ferocissimum (i.e. tentatively identified morphologically in the field) across its native range in South Africa and introduced range in Australia. Morphometric and genetic analyses were conducted to confirm the species identity of these samples, and to assess morphological and genetic variation across both ranges. All samples collected in Australia were confirmed as L. ferocissimum, with no evidence of hybridisation with any other Lycium species. Nuclear and chloroplast genetic diversity within L. ferocissimum across both South Africa and Australia was low, with no evidence of genetic structure. One of the two common chloroplast haplotypes found across Australia was found at only two sites in South Africa, both near Cape Town, suggesting that the Australian lineage may have originated from this region. Ten samples from South Africa putatively identified in the field as L. ferocissimum were genetically characterised as different (unidentified) Lycium species. Our morphometric analyses across different Lycium species in South Africa did not identify any leaf or floral characteristics unique to L. ferocissimum, and thus morphological identification of the latter species in its native range may remain problematic. To ensure the correct Lycium species is surveyed for candidate biological control agents we suggest that individuals should be permanently tagged and putative morphological determinations supplemented with genetic analyses to confirm species identity.
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- Date Issued: 2020
Group displays in pale-winged starlings
- Authors: Hulley, Patrick E , Craig, Adrian J F K , Walter, Grenville H
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465380 , vital:76599 , https://doi.org/10.1080/15627020.2002.11657161
- Description: Cliff-nesting pale-winged starlings (Onychognathus nabouroup) gather on the cliff tops to perform Group Displays which include both aggressive and courtship elements: Hopping, Wing Stretching, Wing Drooping, Wing Flicking, Staring, Head Forward Threat and Butterfly Fluttering. These displays occur throughout the year, most frequently in the late afternoon. We suggest that this behaviour may be important in pair formation, and in establishing dominance relationships between birds breeding at the same site.
- Full Text:
- Date Issued: 2002
The Behaviour Of Palewinged Starlings And A Comparison With Other Onychognathvs Species
- Authors: Craig, Adrian J F K , Hulley, Patrick E , Walter, Grenville H
- Date: 1991
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447868 , vital:74680 , https://doi.org/10.1080/00306525.1991.9639648
- Description: Pairs of Palewinged Starlings associate throughout the year and roost at the nest sites. Flock sizes are generally small, even during the non-breeding season. Allofeeding and allopreening have not been recorded. Wing displays emphasize the white region of the primaries. The territory appears to be restricted to the nest site. Interspecific aggression occurred between Redwinged and Palewinged Starlings, and was also directed at other Ed species frequenting the cliff. A form of ceremonial gathering occurs re in Palewinged Starlings. A review of the literature suggests that on behavioural grounds the Palewinged Starling shows no close affinity to the Redwinged Starfng or to any other member of the genus.
- Full Text:
- Date Issued: 1991
Nesting of sympatric redwinged and pale winged starlings
- Authors: Craig, Adrian J F K , Hulley, Patrick E , Walter, Grenville H
- Date: 1989
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447827 , vital:74677 , https://doi.org/10.1080/00306525.1989.9634513
- Description: Observations were made over four breeding seasons at Cradock, South Africa, where Redwinged Starlings Onychognathus morio and Palewinged Starlings O. nabouroup nest on the same cliffs. Nests were not accessible, and the stage of breeding was determined by the behaviour of the birds. Both species reuse the same nest sites, and only the females incubate, but both sexes feed the young. The timing of breedingMaybe more variable in the Palewinged Starling. A review of the available data on nest site selection and nest construction shows apparent species-specific differences: Redwinged Starlings usually nest on ledges, often on buildings, and use mud in the nest base; Palewinged Starlings favour vertical crevices, and do not use mud.
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- Date Issued: 1989
Speciation, adaptation and interspecific competition
- Authors: Walter, Grenville H , Hulley, Patrick E , Craig, Adrian J F K
- Date: 1984
- Subjects: To be catalogued
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/10962/465486 , vital:76613 , https://doi.org/10.2307/3544775
- Description: The species concept and current ideas on speciation are relevant to the debate on the significance of competition theory in community ecology. The speciation event and the subsequent post-speciation history of a species must be distinguished when applying competition theory. For post-speciation events we draw the important distinction between local and species-wide adaptations attributed to the action of competition. These ideas have the following consequences for community ecology. (1) Competition may have a limited evolutionary role at speciation. It is one of the possible factors that influence adaptation in the small isolated populations that are the major, or only, source of new species. This would occur where competition is sustained because of a consistent limiting resource such as space for sessile animals. (2) Once a new species comes under stabilising selection and expands, competition can produce only local and relatively minor adaptations. The acquisition of species-wide characteristics because of competition requires an improbable set of conditions. (3) The concept of an "organised" community, particularly if it carries evolutionary connotations, is unrealistic.
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- Date Issued: 1984