Population trend and conservation status of the Capricorn Yellow Chat <i>Epthianura crocea macgregori</i>

Houston, Wayne; Elder, R. J.; Black, Robert L.

doi:10.1017/s0959270916000526

Cited by 7 publications

(18 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Capricorn yellow chat is another subspecies of the yellow chat (Keast, 1958), with a localized distribution in the Fitzroy River Delta near Rockhampton, central Queensland, and several sites adjacent to Broad Sound, 150 km to the north, where it inhabits seasonally inundated marine plain wetlands (Houston & Melzer, 2008). It is categorized as Endangered under the IUCN criteria (Garnett et al, 2011), and Critically Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (Department of the Environment, 1999).…”

Section: Methodsmentioning

confidence: 99%

“…It is categorized as Endangered under the IUCN criteria (Garnett et al, 2011), and Critically Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (Department of the Environment, 1999). The Capricorn yellow chat is potentially threatened by habitat degradation caused by grazing, trampling and digging by mammalian herbivores, invasion by exotic pasture grasses, alteration of natural water flows, expansion of industrial operations, and wildfire (Houston & Melzer, 2008). There was a loose collection of mainly non-government actors who had a common interest in the subspecies and its habitat and who undertook population monitoring, surveys and research.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Strengths and vulnerabilities of Australian networks for conservation of threatened birds

Holmes

Head

Possingham

et al. 2016

Oryx

View full text Add to dashboard Cite

We analysed the supportive social networks associated with the conservation of six threatened Australian bird taxa, in one of the first network analyses of threatened species conservation programmes. Each example showed contrasting vulnerabilities. The Alligator Rivers yellow chat Epthianura crocea tunneyi had the smallest social network and no real action was supported. For the Capricorn yellow chat Epthianura crocea macgregori the network was centred on one knowledgeable and committed actor. The orange-bellied parrot Neophema chrysogaster had a strongly connected recovery team but gaps in the overall network could limit communication. The recovery teams for the swift parrot Lathamus discolor and Baudin's black-cockatoo Calyptorhynchus baudinii had strong links among most stakeholders but had weak ties to the timber industry and orchardists, respectively, limiting their capacity to manage threatening processes. Carnaby's black cockatoo Calyptorhynchus latirostris seemed to have the most effective social network of any of the taxa studied but may be vulnerable to skill shortages. In each case the network analysis pointed to gaps that could be filled to enhance the conservation effort, and highlighted the importance of recovery teams. The research suggests that formal network analysis could assist in the design of more effective support mechanisms for the conservation of threatened species.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Strengths and vulnerabilities of Australian networks for conservation of threatened birds

Holmes

Head

Possingham

et al. 2016

Oryx

View full text Add to dashboard Cite

show abstract

“…In 2008, Harrisia cactus was developing into dense thickets in one of the key dry season habitats occupied by the critically endangered Capricorn Yellow Chat Epthianura crocea macgregori Keast (Aves: Meliphagidae) (Houston et al . , ). Chemical control at this site had caused mortality of the original saltmarsh vegetation, particularly the samphire Tecticornia pergranulata (J.M.…”

Section: Introductionmentioning

confidence: 99%

Biocontrol of Harrisia cactus Harrisia martinii by the mealybug Hypogeococcus festerianus (Hemiptera: Pseudococcidae) in salt‐influenced habitats in Australia

Houston

Elder

2019

Austral Entomology

Self Cite

View full text Add to dashboard Cite

This study provides new information on the efficacy of Harrisia mealybug Hypogeococcus festerianus Lizer y Trelles control of Harrisia cactus Harrisia martinii, a major weed of grazing lands, after the last reported field assessments in 1985. In particular, the effectiveness of H. festerianus in a salt-influenced environment, on the marine plains of tropical Australia, was evaluated, under both high-density and low-density Harrisia cactus cover conditions. Effectiveness of the biocontrol agent was evaluated by assessing mealybug occurrence levels and groundcover estimates of Harrisia cactus over time. Similar to studies from the 1970s, mealybugs reduced dense stands of Harrisia cactus to low levels within 4 years, although plants were only killed after being heavily infected for a few years. New plants were also infected with mealybugs and did not reach more than one or two small unhealthy stems in size. For the first time, successful inoculation of relatively sparse infestations of Harrisia cactus infestations was demonstrated. The mealybug established in~70% of treated clumps and, as in dense infestations, substantial mortality and reduction in area of cactus cover was apparent 4 years post-inoculation. The Harrisia mealybug also dispersed to adjacent uninfested areas at two locations, indicating that sustainable long-term biocontrol may be possible even in low-density infestations. This study confirmed the efficacy of H. festerianus as a control agent in these physically extreme marine plain environments in both dense and scattered populations. The relatively low effort (a few ad hoc releases) to achieve establishment and natural dispersal to low-density situations as compared with annual herbicide control efforts augurs well for real-world situations where grazers are time constrained.

show abstract

“…Although the Inland subspecies is regarded as nomadic and dispersive by some authors (Ford and Parker 1974, Storr 1980, Black et al 1983, Blakers et al 1984, there is no evidence to suggest that the Capricorn Yellow Chat is similarly dispersive. Capricorn Yellow Chats have been observed to undertake small-scale seasonal movements of up to 10 km between breeding and non-breeding (dry season) habitats (Houston 2010, Houston et al 2017 but the extent of dispersal following breeding is unknown. Of the 15 Capricorn Yellow Chat sites, only five are known to support them throughout the year, the others being seasonally or opportunistically used for breeding (Houston et al 2013(Houston et al , 2017.…”

Section: Introductionmentioning

confidence: 99%

“…Capricorn Yellow Chats have been observed to undertake small-scale seasonal movements of up to 10 km between breeding and non-breeding (dry season) habitats (Houston 2010, Houston et al 2017 but the extent of dispersal following breeding is unknown. Of the 15 Capricorn Yellow Chat sites, only five are known to support them throughout the year, the others being seasonally or opportunistically used for breeding (Houston et al 2013(Houston et al , 2017. Identified threats to this endangered species include the loss of water flows into breeding habitat and habitat loss due to industrial expansion, leading to further depletion in numbers and consequent further diminishment of genetic fitness (Houston 2013).…”

Section: Introductionmentioning

confidence: 99%

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

Houston

Aspden

Elder

et al. 2017

Bird Conservation International

Self Cite

View full text Add to dashboard Cite

SummaryThe 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.

show abstract

Population trend and conservation status of the Capricorn Yellow Chat Epthianura crocea macgregori

Cited by 7 publications

References 30 publications

Strengths and vulnerabilities of Australian networks for conservation of threatened birds

Strengths and vulnerabilities of Australian networks for conservation of threatened birds

Biocontrol of Harrisia cactus Harrisia martinii by the mealybug Hypogeococcus festerianus (Hemiptera: Pseudococcidae) in salt‐influenced habitats in Australia

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

Contact Info

Product

Resources

About