Yellow Chat (Capricorn subspecies)

Describes the Yellow Chat, its distribution, habitat, ecology and the reasons for its decline and current threats

Bukkulla vegetation monitoring

The aim of the study undertaken in September 2003 was to enable changes in vegetation structure and species composition at Bukkulla to be assessed. Following acquisition of the property by the Wildlife Land Fund, grazing intensity and possibly fire frequency have been reduced with possible consequences on the vegetation structure of grassy woodlands within the study area. With reduced fire frequency, it is thought that these grassy woodlands may develop a denser midstorey of shrubby woodland and/or vine thicket species. Monitoring is aimed at providing baseline data enabling any changes in woody vegetation density to be assessed over time

Development of ecosystem services within a highly modified creek channel in Port Curtis, Central Queensland : a pilot study

Development of ecosystem services within a highly modified creek channel in Port Curtis, Central Queensland : a pilot stud

Distribution, breeding ecology, population and habitat use of the critically endangered Capricorn Yellow Chat Epthianura crocea macgregori Keast (Aves: Meliphagidae)

"This the first detailed study of the Capricorn Yellow Chat, a critically endangered ground-adapted bird that was considered to be extinct until its rediscovery in 1992. It provides an overview of its distribution, habitat, breeding ecology, population size and the influence of climatic and environmental variables on habitat use and breeding"

Breeding cues in a wetland-dependent Australian passerine of the seasonally wet-dry tropics

The Capricorn yellow chat Epthianura crocea macgregori (Aves: Meliphagidae) occurs in the seasonal wet-dry tropics. This region, although coastal, is typified by highly variable annual rainfall. The Capricorn yellow chat breeds in wetlands, predominantly in the summer-autumn period, but has the capacity to breed in response to out-of-season rainfall events, consistent with an opportunistically breeding species. Most studies of breeding cues in passerines have been on species centred on temperate climates with predictable rainfall season, arid biomes with a highly variable rainfall quantity and season, and the relatively non-seasonal wet tropics. This study was focused on a species that occurs in an intermediate situation with a highly variable but summer dominant rainfall season. It aimed to identify which proximal cues are used by birds in such environments to prepare for breeding. Monthly observations at a breeding ground over a 45-month period were regressed against environmental and climatic variables. There was a significant positive relationship of chat abundance with average minimum monthly air temperature and the extent of inundation. Invertebrate food availability was also sampled. Cross-correlation with prior monthly rainfall showed that abundance of insects (Diptera, Hemiptera and Lepidoptera) and semi-aquatic invertebrates peaked 1-2 months following large rainfall events, coinciding with peaks in presence of dependent young of Capricorn yellow chats. Thus, the Capricorn yellow chat matches the model for arid-adapted birds in which seasonal cues (e.g. increasing day-length or temperature) in spring lead to breeding preparedness, but breeding only occurs in response to proximal factors such as rainfall. However, the Capricorn yellow chat differs in that breeding is delayed until rainfall is sufficient to inundate its wetland habitat and stimulate the production of food resources associated with the low vegetation and muddy margins of the temporarily flooded pools and channels; suggesting that inundation may be the most important breeding cu

Yellow Chat (Gulf subspecies)

Yellow chat (Gulf subspecies, Epthianura crocea crocea Castelnau & Ramsay, 1877

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

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. © 2019 Australian Entomological Societ

Grassfinch decline and local extinction of the Crimson Finch Neochmia phaeton in the Fitzroy River Basin, Queensland

Many granivorous birds of northern Australia, including several species of grassfinches (Estrildidae), have suffered substantial range contractions in the last 50–100 years, apparently as a result of changes in cattle grazing and fire-management regimes. The Crimson Finch Neochmia phaeton was once widespread in woodlands and savannahs of north-eastern Australia, including the extensive Fitzroy River Basin, where it was recorded in all the major subcatchments until the middle of last century. However, surveys in 2006–2008 show that it is now confined to a relatively small area in the north-east of the Basin. A tall river grass, Chionachne Chionachne cyathopoda, is an important component—for food and cover—of its habitat. Complex braiding of river channels, as at the confluence of rivers, is typical of the area where the Finches have persisted, possibly because it increases the availability of water and food, and reduces pressure from cattle grazing during the wet season. A recent local loss of the species was noted in one area where landholders used riparian fencing to maintain greater grazing intensity throughout the year, leading to suppression of Chionachne seeding. Thus, although generally favourable for conservation management, riparian fencing can also be used detrimentally. The loss of one local subpopulation of Finches following changed management practices demonstrates that cattle grazing alone, in the absence of changed fire management, has the capacity to alter habitat suitability for granivorous species

Distinguishing effects of natural disturbances such as droughts on natural vegetation from potential industrial influence in the Port Curtis area using regional reference sites and the differential response of closed and open canopy vegetation

The advent of a shale oil processing industry in Port Curtis region (approximately 15 Ian northwest of Gladstone) in addition to existing industries provided the impetus to establishment of 15 'Sentinel' monitoring sites to assess potential effects of industrially-sourced gaseous outfalls from the Gladstone airshed on natural vegetation. To provide a baseline for widespread regional natural disturbances a further 5 sites ('Reference') were established some 40 - 50 Ian southwest of Gladstone in the Kroombit Tops area. In addition to using passive gas gels to monitor gaseous outfalls of S02, N02, 03, bioindicators monitored included foliar health indices (leaves per I m of branch, average leaf weight and a chlorosis - necrosis score), soil and litter associated invertebrate assemblages and lichen cover. Gaseous outfalls of S02 and N02 at Sentinel sites were 2 to 15 times greater than concentrations at Reference sites but 0 3 was similar. Significant changes in average leaf weight, mostly with a declining trend as typical of effects of gaseous outfalls on vegetation and an increase in variability of invertebrate assemblages in 2001 were found. Significant changes in numbers of leaves per branch (no consistent increasing or decreasing trend) and the chlorosis - necrosis score were also found. The latter bioindicator actually declined and this is the reverse of the predicted response to effects of gaseous outfalls on vegetation and suggests an improvement in vegetation health. There was no clear linkage between these patterns in change in leaf weight and gaseous outfalls within the Sentinel area. Two lines of evidence point to the significant declines in average leaf weight and increases in vertebrate assemblage variability within Sentinel sites being a response to a widespread regional drought in 2001 and 2002. Firstly, similar patterns of declining leaf weight were observed in the regional Reference area relatively remote from Port Curtis where levels of S02 and N02 concentration are substantially lower. Secondly, response of two types of vegetation ('closed', > 70% canopy cover typical of dry rainforest and 'open', 30 - 70% canopy cover typical of sclerophyll woodlands and forests) differed with closed canopy vegetation consistently showing significant declines in average leaf weight irrespective of location whereas most open canopy vegetation sites were non-significant except those associated with ridge-tops in the Sentinel area. Within the Sentinel area only closed vegetation showed an increase in invertebrate assemblage variability in 2001. Dry rainforest vegetation is known to suffer seasonal water stress in the late dry season and a greater vulnerability to drought effects could explain the patterns of change in the bioindicators monitored. The usefulness of dry rainforest vegetation as a way of internally calibrating for drought effects by acting as a sentinel vegetation type for natural disturbance of this kind needs to be more widely tested. If this ability is confirmed for this vegetation type, then it may offer a more cost-effective protocol for testing for natural drought effects compared with regional reference areas, or they may provide an opportunity to have some ability to calibrate for regional effects of droughts where regional reference sites are lacking

Mangrove and seagrass monitoring at the mouth of the Calliope River : report for February 1996 and monitoring program proposals 1996-1997

This report documents a further sampling of mangrove and seagrass communities undertaken by CQU in November/December 1995. It also outlines the strategy and details of a longer term research and monitoring program proposed by CQU for the Targinie landfill area