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  • 1
    Online Resource
    Online Resource
    Aerial survey methodology and the cost of control for feral goats in Western Queensland
    CSIRO Publishing ; 1998
    In:  Wildlife Research Vol. 25, No. 4 ( 1998), p. 393-
    Details
    In: Wildlife Research, CSIRO Publishing, Vol. 25, No. 4 ( 1998), p. 393-
    Abstract: Feral goats (Capra hircus) were shot from a helicopter on four sites in central-western Queensland. These sites centred on Idalia National Park (660 km2) and three nearby properties: Lissoy (360 km2), Mt Calder (260 km2) and Ravensbourne (320 km2), the order reflecting increasing goat density. On Idalia, 134 goats were shot in 8 h of flying time. On Lissoy, 28 goats were shot in 3 h, 1038 goats were shot on Mt Calder in 15 h, while 2307 goats were shot on Ravensbourne in 21 h. The reduction was monitored by aerial surveys using fixed-wing aircraft. No goats were recorded on either Idalia or Lissoy immediately following shooting and substantial reductions in goat numbers were achieved on Mt Calder (75%) and Ravensbourne (49%). Surveys conducted six months after this reduction indicated population increases on all sites following shooting. This was particularly marked on Ravensbourne, where goat numbers had increased by 31% despite further substantial removals by commercial mustering. These population increases were largely the result of immigration. The cooperation of landowners over a large area is therefore essential for effective control of goats. The per capita cost of shooting goats from a helicopter was essentially constant down to a threshold density of 〈 1 goat km-2 , below which the cost increased substantially. The accuracy of fixed-wing aerial surveys was improved by using double-counting and these corrected estimates compared favourably with index–manipulation–index estimates. Estimates of densities 〈 1 goat km-2 were imprecise and at these densities goats were difficult to detect. The extent of vegetation cover did not affect the sightability of goats, whereas group size was positively correlated with the sightability of goats. To estimate true density, correction factors of 1–2 were applied to goat group sizes using survey parameters of 100 m strip width, a survey height of 76 m and a speed of 187 km h-1.
    Type of Medium: Online Resource
    ISSN: 1035-3712
    URL: Article
    DOI: 10.1071/WR97123
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 1998
    SSG: 12
    SSG: 23
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  • 2
    Online Resource
    Online Resource
    An assessment of the accuracy of kangaroo surveys using fixed-wing aircraft
    CSIRO Publishing ; 1998
    In:  Wildlife Research Vol. 25, No. 3 ( 1998), p. 315-
    Details
    In: Wildlife Research, CSIRO Publishing, Vol. 25, No. 3 ( 1998), p. 315-
    Abstract: The use of line-transect methodology, on foot or from a helicopter, is likely to return the most repeatable, least biased estimates of kangaroo density. However, the associated costs make both methods impractical for broad-scale surveys. For these, a fixed-wing aircraft remains the most cost-effective platform. Limitations of the standard fixed-wing method (200-m strip transects) are well known, but it continues to be used because it provides an index of trends, because there are now long runs of data (almost 20 years in some cases) collected in this standard form and an alternative method is lacking. In this study, four variations of fixed-wing surveys of kangaroos were investigated: two line-transect methods (involving different scanning techniques), the standard 200-m strip transect and a 100-m strip transect. Surveys using these methods were compared with helicopter line-transect surveys along the same flight lines in three areas (5000–7500 km2) in western Queensland. Both fixed-wing line-transect methods failed to produce consistently accurate estimates of density for all three species surveyed: red kangaroos (Macropus rufus), eastern grey kangaroos (M. giganteus) and common wallaroos (M. robustus). While generally more accurate than the uncorrected strip-transect counts, they were no less variable. However, the strip-transect counts still need to be corrected for bias for which this study offers revised estimates of correction factors for eastern grey kangaroos (3.7–10.2) and common wallaroos (3.8–4.1), and estimates for red kangaroos (1.7–2.7) that support currently used values. An attractive alternative is to survey in 100-m strip transects, which offer improved visibility (correction factors of 1.0–1.8 for red kangaroos, 2.1–3.6 for eastern grey kangaroos and 1.7–2.1 for common wallaroos) and are therefore likely to be more accurate and repeatable. However, these advantages need to be assessed in relation to continuing long runs of data using the standard 200-m strip transect. Correction factors for wallaroos are conservative as helicopter-based density estimates are known to be underestimates. Further work is needed to assess the generality of correction factors, both spatially and temporally.
    Type of Medium: Online Resource
    ISSN: 1035-3712
    URL: Article
    DOI: 10.1071/WR97077
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 1998
    SSG: 12
    SSG: 23
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  • 3
    Online Resource
    Online Resource
    Trace metal concentrations in livers and kidneys of sea turtles from south-eastern Queensland, Australia
    CSIRO Publishing ; 1998
    In:  Marine and Freshwater Research Vol. 49, No. 5 ( 1998), p. 409-
    Details
    In: Marine and Freshwater Research, CSIRO Publishing, Vol. 49, No. 5 ( 1998), p. 409-
    Abstract: The concentrations of some or all of arsenic (As), cadmium (Cd), mercury (Hg), selenium (Se) and zinc (Zn) were determined in the livers and kidneys of 50 stranded sea turtles (38 Chelonia mydas, eight Caretta caretta, three Eretmochelys imbricata, one Lepidochelys olivacea) from the Moreton Bay region of south-eastern Queensland, Australia. Concentrations of Cd, Se and Zn in the kidney tended to decrease with age, whereas concentrations of Zn in the liver tended to increase. Concentrations of Cd in all sea turtle species (1.7–75.9 µg g-1 wet weight) were amongst the highest recorded for marine vertebrates globally. Although there was no obvious association between metal concentrations and particular diseases in C. mydas, the high concentrations of Cd found in edible turtle tissues may pose a threat to the health of indigenous people whose diet includes C. mydas.
    Type of Medium: Online Resource
    ISSN: 1323-1650
    URL: Article
    DOI: 10.1071/MF97266
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 1998
    detail.hit.zdb_id: 1283028-8
    SSG: 12
    SSG: 21,3
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  • 4
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    A systematic review of ground-based shooting to control overabundant mammal populations
    CSIRO Publishing ; 2020
    In:  Wildlife Research Vol. 47, No. 3 ( 2020), p. 197-
    Details
    In: Wildlife Research, CSIRO Publishing, Vol. 47, No. 3 ( 2020), p. 197-
    Abstract: Abstract Context Ground-based shooting is widely used in management programs aiming to alleviate the impacts of invasive or overabundant wildlife populations. However, evaluations of individual shooting operations have shown variable results, and the effectiveness of ground-shooting as a population-management intervention has not been systematically examined. Aims Our review aimed to (1) assess the efficacy of shooting as a population management tool, and (2) identify commonalities among studies that will help managers identify situations where ground-shooting is most likely to be effective. Methods We systematically reviewed the literature to identify studies involving ground-shooting. From each study, we collated information about operational objectives, target taxa, geographic context, type of shooter used, effort, effectiveness, and use of additional control tools. Key results Most studies had no a priori quantifiable objectives. However, 60% of the 64 case studies produced a detectable reduction in population density and/or damage. The most common type of operation used unpaid or commercial harvest-oriented shooters to reduce herbivore density or damage. Only 30% of the operations that used volunteer shooters or recreational hunters achieved their objectives. Target taxa, geographic area or integration of shooting with other population-control methods had no detectable effect on the effectiveness of shooting operations. Common factors that hindered the effectiveness of shooting operations included immigration of target species from adjacent areas (n=13), decreasing effort from shooters as the target population declined (n=7) and selective harvesting (n=7). Conclusions Ground-based shooting can be an effective management tool for overabundant wildlife populations, but many shooting operations did not achieve a notable decrease in animal abundance or damage. The source of failure could often be attributed to an inability to remove a sufficient proportion of the population to cause a population decline. Implications Managers contemplating using ground-based shooting to reduce the impacts or density of wildlife populations should (1) carefully consider whether this is a suitable management tool to achieve the desired outcomes, (2) establish clear objectives that aim to meet defined outcomes and allow for continuous improvement, and (3) ensure that operations are sufficiently resourced to achieve and maintain those objectives.
    Type of Medium: Online Resource
    ISSN: 1035-3712
    URL: Article
    DOI: 10.1071/WR19129
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 2020
    SSG: 12
    SSG: 23
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  • 5
    Online Resource
    Online Resource
    A physiological assessment of the use of water point closures to control kangaroo numbers
    CSIRO Publishing ; 2007
    In:  Wildlife Research Vol. 34, No. 4 ( 2007), p. 280-
    Details
    In: Wildlife Research, CSIRO Publishing, Vol. 34, No. 4 ( 2007), p. 280-
    Abstract: Controlling kangaroo grazing pressure in national parks without harvesting or culling presents a significant challenge. Fencing off waterpoints is often tried or contemplated as a control measure, but its success obviously depends upon the extent to which kangaroos require access to discrete sources of drinking water. To assess the necessity for red kangaroos to supplement dietary water intake under different conditions by drinking free water, we followed changes in diet and in forage water and energy content as severe drought deepened at Idalia National Park in central Queensland from February to July 2002, the driest of 13 years for which records exist. Animals smaller than 15 kg in February and 25 kg in April did not need free water, but larger individuals needed to drink throughout the period. By July all animals needed to drink. The influence of body size arises because water requirements scale almost proportionally with body mass (M0.92) while energy requirements scale with a lower exponent (M0.74). Because of the sexual dimorphism in red kangaroos, adult females are therefore better able than adult males to survive water shortage. The results help define the constraints that physiological capabilities confer upon the usefulness of fencing off water points to control kangaroos. Smaller (younger) males and females could tolerate dry, cool conditions without drinking, even in this very dry year, but kangaroos of all body sizes needed to drink as the drought became more severe. The effectiveness of water closure will therefore depend on what forage is available, will target larger animals selectively, and will be most effective in semiarid areas like Idalia National Park in very dry years and late in the dry season when temperatures are rising and water requirements increase because of additional requirements for thermoregulation.
    Type of Medium: Online Resource
    ISSN: 1035-3712
    URL: Article
    DOI: 10.1071/WR06041
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 2007
    SSG: 12
    SSG: 23
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  • 6
    Online Resource
    Online Resource
    Origins and population genetics of sambar deer (Cervus unicolor) introduced to Australia and New Zealand
    CSIRO Publishing ; 2023
    In:  Wildlife Research Vol. 50, No. 9 ( 2023-7-20), p. 716-727
    Details
    In: Wildlife Research, CSIRO Publishing, Vol. 50, No. 9 ( 2023-7-20), p. 716-727
    Abstract: Context Some populations of introduced species cause significant undesirable impacts but can also act as reservoirs for genetic diversity. Sambar deer (Cervus unicolor) are ‘Vulnerable’ in their native range and invasive in Australia and New Zealand. Genetic data can be used to determine whether these introduced populations might serve as genetic reservoirs for declining native populations and to identify spatial units for management. Aims We aimed to identify the provenance of sambar deer in Australia and New Zealand, and to characterise their genetic diversity and population structure. Methods We used mitochondrial control region sequences and 18 nuclear microsatellite loci of 24 New Zealand and 63 Australian sambar deer collected across continuous habitat in each location. We estimated genetic diversity and population differentiation by using pairwise FST, AMOVA, and Structure analyses. We compared our data with 27 previously published native and invasive range sequences to identify phylogenetic relationships. Key results Sambar deer in Australia and New Zealand are genetically more similar to those in the west of the native range (South and Central Highlands of India, and Sri Lanka), than to those in the east (eastern India, and throughout Southeast Asia). Nuclear genetic diversity was lower than in the native range; only one mitochondrial haplotype was found in each introduced population. Australian and New Zealand sambar deer were genetically distinct but there was no population structure within either population. Conclusions The genetic differences we identified between these two introduced populations at putatively neutral loci indicate that there also may be underlying diversity at functional loci. The lack of population genetic structure that we found within introduced populations suggests that individuals within these populations do not experience barriers to dispersal across the areas sampled. Implications Although genetic diversity is reduced in the introduced range compared with the native range, sambar deer in Australia and New Zealand harbour unique genetic variants that could be used to strengthen genetic diversity in populations under threat in the native range. The apparent high levels of gene flow across the areas we sampled suggest that localised control is unlikely to be effective in Australia and New Zealand.
    Type of Medium: Online Resource
    ISSN: 1035-3712 , 1448-5494
    URL: Article
    DOI: 10.1071/WR22120
    Language: English
    Publisher: CSIRO Publishing
    Publication Date: 2023
    SSG: 12
    SSG: 23
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