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Restricted gene flow in the endangered Capricorn Yellow Chat Epthianura crocea macgregori: consequences for conservation management



The Yellow Chat Epthianura crocea is comprised of three disjunct subspecies. Subspecies E. c. macgregori (Capricorn Yellow Chat) is listed as Critically Endangered under the EPBC Act and has a distribution that also appears to be disjunct, with a limited geographic area of less than 7,000 ha. Some populations are threatened by rapid industrial development, and it is important for conservation of the subspecies to determine the extent to which the putative populations are connected. We used 14 microsatellite markers to measure genetic diversity and to determine the extent of gene flow between two disjunct populations at the northern and southern extremes of the subspecies’ range. No significant differences in genetic diversity (number of alleles and heterozygosity) were observed, but clear population structuring was apparent, with obvious differentiation between the northern and southern populations. The most likely explanation for reduced gene flow between the two populations is either the development of a geographic barrier as a consequence of shrinkage of the marine plains associated with the rise in sea levels following the last glacial maxima, or reduced connectivity across the largely unsuitable pasture and forest habitat that now separates the two populations, exacerbated by declining population size and fewer potential emigrants. Regardless of the mechanism, restricted gene flow between these two populations has important consequences for their ongoing conservation. The relative isolation of the smaller southern groups (the Fitzroy River delta and Curtis Island) from the much larger northern group (both sides of the Broad Sound) makes the southern population more vulnerable to local extinction. Conservation efforts should focus on nature refuge agreements with land owners agreeing to maintain favourable grazing management practices in perpetuity, particularly in the northern area where most chats occur. Supplemental exchanges of individuals from northern and southern populations should be explored as a way of increasing genetic diversity and reducing inbreeding.


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Black, A. B., Duggan, G., Pedler, J. A. and Pedler, L. P. (1983) The Yellow Chat Epthianura crocea at Pandiburra Bore, north-eastern South Australia. South Australian Ornithol. 29: 4245.
Blakers, M., Davies, S. and Reilly, P. (1984) The atlas of Australian birds. Melbourne, Australia: RAOU and Melbourne University Press.
Brooke, B., Bostock, H., Smith, J. and Ryan, D. (2006) Geomorphology and sediments of the Fitzroy River coastal sedimentary system – summary and overview. Brisbane, Australia: Cooperative Research Centre for Coastal Zone, Estuary and Waterway Management. (Technical Report 47).
Campbell, A. J. (1917) The Yellow-breasted Bush-Chat (Epthianura crocea). Emu 17: 61–2.
Ellegren, H. (2004) Microsatellites: Simple sequences with complex evolution. Nature Rev. Genet. 5: 435445.
Excoffier, L. and Lischer, H. (2010) Arlequin ver user manual: an integrated software package for population genetics data analysis. Bern, Switzerland: Computational and Molecular Population Genetics Lab, Institute of Ecology and Evolution, University of Berne.
Ford, J. and Parker, A. (1974) Distribution and taxonomy of some birds from south-western Queensland. Emu 74: 177194.
Frankham, R. (2015) Genetic rescue of small inbred populations: meta-analysis reveals large and consistent benefits of gene flow. Mol. Ecol. 24: 26102618.
Frankham, R. (2016) Genetic rescue benefits persist to at least the F3 generation, based on a meta-analysis. Biol. Conserv. 195: 3336.
Frankham, R., Ballou, J. D., Eldridge, M. D. B., Lacy, R. C., Ralls, K., Dudash, M. R. and Fenster, C. B. (2011) Predicting the probability of outbreeding depression. Conserv. Biol. 25: 465–75.
Frankham, R., Bradshaw, C. J. A. and Brook, B. W. (2014) Genetics in conservation management: Revised recommendations for the 50/500 rules, Red List criteria and population viability analyses. Biol. Conserv. 170: 5663.
Franklin, D. C., Whitehead, P. J., Pardon, G., Matthews, J., McMahon, P. and McIntyre, D. (2005) Geographic patterns and correlates of the decline of granivorous birds in northern Australia. Wildl. Res. 32: 399408.
Hedrick, P. W. and Garcia-Dorado, A. (2016) Understanding inbreeding depression, purging, and genetic rescue. Trends Ecol. Evol. 31: 940952.
Higgins, P. J., Peter, J. M. and Steele, W. K. (2001) Epthianura crocea Yellow Chat. Pp. 12291238 in Higgins, P. J., Peter, J. M. and Steele, W. K., eds. Handbook of Australian, New Zealand and Antarctic birds. Volume 5: Tyrant-flycatchers to Chats. Melbourne, Australia: Oxford University Press.
Houston, W. A. (2010) Distribution, breeding ecology, population and habitat use of the critically endangered Capricorn Yellow Chat Epthianura crocea macgregori Keast (Aves: Meliphagidae). Master of Applied Science Thesis, Central Queensland University, Rockhampton.
Houston, W. A. (2013) Breeding cues in a wetland dependent Australian passerine of the seasonally wet-dry tropics. Austral Ecol. 38: 617–26.
Houston, W. A. and Black, R. L. (2016) Grassfinch decline and local extinction of Crimson Finch (Neochmia phaeton) in north-eastern Australia. Australian Field Ornithol. 33: 133142.
Houston, W. A. and Melzer, A. (2008) Yellow Chat (Capricorn subspecies) Epthianura crocea macgregori Recovery Plan. Brisbane, Australia: Department of the Environment, Water, Heritage and the Arts, Canberra. Queensland Environmental Protection Agency. (
Houston, W. A., Aspden, W., Black, R. L., Elder, R., Carruthers, I., Campbell, L. and Black, L. (2015) Mitochondrial phylogeography of the critically endangered Capricorn Yellow Chat (Epthianura crocea macgregori). Australian J. Zool. 63: 350356.
Houston, W. A., Black, R. and Elder, R. (2013) Distribution and habitat of the critically endangered Capricorn Yellow Chat Epthianura crocea macgregori . Pacific Conserv. Biol. 19: 3954.
Houston, W. A., Elder, R. and Black, R. (2017) Population trend and conservation status of the Capricorn Yellow Chat Epthianura crocea macgregori . Bird Conserv. Internatn. doi:10.1017/S0959270916000526: 116.
Houston, W. A., Jaensch, R., Black, R., Elder, R. and Black, L. (2009) Further discoveries extend the range of Capricorn Yellow Chat in coastal central Queensland Sunbird 39: 2938.
Houston, W. A., Porter, G., O’Neill, P. and Elder, R. (2004) The ecology of the critically endangered Yellow Chat Epthianura crocea macgregori on Curtis Island. Sunbird 34: 1023.
Jakobsson, M. and Rosenberg, N. A. (2007) CLUMPP: A cluster matching and permutation program for dealing with label switching and multimodality in analysis of population structure. Bioinformatics 23: 18011806.
Kearns, A. M., Joseph, L., Toon, A. and Cook, L. G. (2014) Australia’s arid-adapted butcherbirds experienced range expansions during Pleistocene glacial maxima. Nature Communications 5: 111.
Keast, A. (1958) The relationship between seasonal movements and the development of geographic variation in Australian chats (Epthianura Gould and Ashbyia North; Passeres: Muscicapidae, Malurinae). Australian J. Zool. 6: 5368.
King, A. G., Cooke, G. M., Johnson, R. N. and Major, R. E. (2012) Development and multiplex genotyping of eighteen novel microsatellite markers for a threatened saltmarsh bird Epthianura albifrons (Meliphagidae). Conserv. Genet. Resour. 4: 893896.
Mack, G. (1930) The Yellow Chat. Emu 30: 87.
Major, R. E., Johnson, R. N., King, A. G., Cooke, G. M. and Sladek, J. L. T. (2014) Genetic isolation of endangered bird populations inhabiting salt marsh remnants surrounded by intensive urbanization. Anim. Conserv. 17: 419429.
Pritchard, J. K., Stephens, M. and Donnelly, P. (2000) Inference of population structure using multilocus genotype data. Genetics 155: 945959.
Reynolds, I. S., Walter, J. C. and Woodall, P. F. (1982) Observations on Yellow Chats (Epthianura crocea) in western Queensland. Sunbird 12: 2129.
Schodde, R. (1982) Origin, adaptation and evolution of birds in arid Australia. Pp. 191224 in: Barker, W. R. and Greenslade, P. J. M., eds. Evolution of the flora and fauna of arid Australia. Adelaide, Austarlia: Peacock.
Storr, G. M. (1980) Birds of the Kimberley Division, Western Australia. Western Australian Museum Special Publication series No. 11.
Strong, B. W. and Fleming, M. R. (1987) Recent observations of the distribution and habitat of the yellow chat Epthianura crocea in the Northern Territory. South Australian Ornithol. 30: 98102.
Taberlet, P. and Bouvet, J. (1991) a single plucked feather as a source of DNA for bird genetic studies. Auk 108: 959960.
Wang, J. (2013) A simulation module in the computer program colony for sibship and parentage analysis. Mol. Ecol. Resour. 13: 734739.
Weir, J. T. and Schluter, D. (2008) Calibrating the avian molecular clock. Mol. Ecol. 17: 23212328.

Restricted gene flow in the endangered Capricorn Yellow Chat Epthianura crocea macgregori: consequences for conservation management



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