| 1. |
- Dudaniec, Rachael, et al.
(författare)
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Genetic and morphological divergence in island and mainland birds: Informing conservation priorities
- 2011
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Ingår i: Biological Conservation. - : Elsevier BV. - 1873-2917 .- 0006-3207. ; 144:12, s. 2902-2912
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Tidskriftsartikel (refereegranskat)abstract
- Evolutionary processes can complicate conservation efforts for species with uncertain taxonomic classifications and discrete geographic populations. Discordant morphological and genetic patterns across the geographic range of species further calls for the identification of evolutionary significant units for conservation. Using island and mainland populations of a small Australian passerine (the superb fairy-wren, Malurus cyaneus), we examine the relationship between morphological and genetic divergence among two subspecies, M. c. ashbyi (Kangaroo Island, South Australia) and M. c. leggei (South Australia, mainland), using eight microsatellite markers. Island birds showed clear evidence for morphological divergence, with a larger body size and thinner bill compared to mainland birds. Two genetic clusters were found using Bayesian methods, comprising mainland and island regions. Estimates of recent migration rates between all sites were very low (<2%). Morphological and genetic differentiation between island and mainland sites correlated significantly, but not when controlling for isolation by distance. Genetic and morphological substructure was evident with three distinct genetic clusters in each region. Males, the highly sedentary sex, appeared to drive correlations between morphological and genetic differentiation. Our study provides evidence that the subspecies classification of M. cyaneus in island and mainland regions encapsulates two independently diverging populations that can be recognised in conservation planning.
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| 2. |
- Kleindorfer, Sonia, et al.
(författare)
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Changes in Philornis infestation behavior threaten Darwin's finch survival
- 2014
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Ingår i: Current Zoology. - 1674-5507. ; 60:4, s. 542-550
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Tidskriftsartikel (refereegranskat)abstract
- The conservation behavior framework is useful to identify key linkages between behavior and conservation practice. We apply this framework to a novel host-parasite system on the Galapagos Islands and ask if there have been changes in parasite oviposition behavior and host mortality patterns across the first decade (2004-2013) of its known association. The Dipteran parasite Philornis downsi was first discovered in Darwin's finch nests in 1997 and is the biggest threat to the survival of Galapagos land birds. Host mortality has increased over the past decade. In Dipterans, pupation and pupae size are determined by access to host resources. Here, we test the hypothesis that P. downsi flies are laying eggs in finch nests earlier in the nestling phase to maximize larval feeding time and therefore chance of pupation success before host death. The results show fewer 1st instar larvae later in the host nesting cycle in support of earlier egg laying behavior by female flies. Between 2004 and 2013, parasite intensity increased from similar to 28 to similar to 48 parasites per nest, host mortality increased from similar to 50% to similar to 90%, and host age at death decreased from similar to 11 to similar to 5 days. The earlier age at host death was correlated with fewer pupae (from similar to 50% to similar to 20%) and smaller pupae size (similar to 10% decrease). Changes in parasite behavior reveal new fitness costs to both the parasite and Darwin's finches. These findings underscore the need for urgent conservation action to save Darwin's finches from extinction due to a novel, lethal and introduced parasite
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| 3. |
- Kleindorfer, Sonia, et al.
(författare)
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Species Collapse via Hybridization in Darwin's Tree Finches
- 2014
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Ingår i: American Naturalist. - : University of Chicago Press. - 0003-0147 .- 1537-5323. ; 183:3, s. 325-341
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Tidskriftsartikel (refereegranskat)abstract
- Species hybridization can lead to fitness costs, species collapse, and novel evolutionary trajectories in changing environments. Hybridization is predicted to be more common when environmental conditions change rapidly. Here, we test patterns of hybridization in three sympatric tree finch species (small tree finch Camarhynchus parvulus, medium tree finch Camarhynchus pauper, and large tree finch: Camarhynchus psittacula) that are currently recognized on Floreana Island, Galaapagos Archipelago. Genetic analysis of microsatellite data from contemporary samples showed two genetic populations and one hybrid cluster in both 2005 and 2010; hybrid individuals were derived from genetic population 1 (small morph) and genetic population 2 (large morph). Females of the large and rare species were more likely to pair with males of the small common species. Finch populations differed in morphology in 1852--1906 compared with 2005/2010. An unsupervised clustering method showed (a) support for three morphological clusters in the historical tree finch sample (1852--1906), which is consistent with current species recognition; (b) support for two or three morphological clusters in 2005 with some (19%) hybridization; and (c) support for just two morphological clusters in 2010 with frequent (41%) hybridization. We discuss these findings in relation to species demarcations of Camarhynchus tree finches on Floreana Island.
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| 4. |
- Malekian, M., et al.
(författare)
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Development of a multiplex panel of microsatellite markers for two species of gliding marsupials, Petaurus breviceps and Petaurus norfolcensis
- 2013
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Ingår i: Australian Journal of Zoology. - 0004-959X. ; 61:6, s. 475-478
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Tidskriftsartikel (refereegranskat)abstract
- Here, we describe the development of seven new microsatellite loci from Petaurus breviceps. Together with eight loci from previous studies of gliders, we tested their utility for amplification, multiplexing and polymorphism in two glider species, P. breviceps and P. norfolcensis. Of the 15 loci tested, all were polymorphic in P. breviceps and 12 were polymorphic in P. norfolcensis. Overall, 260 sugar gliders from 13 sites in south-eastern South Australia and 106 squirrel gliders collected throughout south-east Queensland were used in analyses. Numbers of alleles per locus ranged from 4 to 27 in P. breviceps and from 2 to 44 in P. norfolcensis. Observed heterozygosity ranged between 0.438 and 0.904 in P. breviceps and between 0.189 and 0.981 in P. norfolcensis. Within the populations analysed, one of the 15 loci for P. breviceps and two of the 12 loci for P. norfolcensis deviated from Hardy-Weinberg equilibrium. The microsatellite loci will provide valuable tools for further study of social organisation, mating systems and population biology of these gliding marsupials.
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