Measured reductions in the density of camels under the Australian Feral Camel Management Project

2016 ◽  
Vol 38 (2) ◽  
pp. 173 ◽  
Author(s):  
Mark Lethbridge ◽  
Keith W. Saalfeld ◽  
Glenn P. Edwards
Keyword(s):  
Population Decline ◽  
South Australia ◽  
Density Estimates ◽  
Management Intervention ◽  
Mobile Species ◽  
Aerial Surveys ◽  
Project Monitoring ◽  
Management Project ◽  
Territory Border ◽  
Simpson Desert

In this paper we provide a coarse comparison between camel density estimates derived from aerial surveys conducted during the early and latter stages of the Australian Feral Camel Management Project, considering the number of camels removed between the surveys as a result of management intervention across three large and distinct geographic zones. Overall, despite the assumptions made during our analyses and possible errors associated with these, the post-aerial surveys in all three zones show a significant population decline compared with the corresponding pre-aerial surveys. The observed population decline in two zones (the Pilbara and that centred on the South Australia-Western Australia-Northern Territory border junction) were broadly consistent with the number of camels removed in each zone between aerial surveys. The population decline detected in the third zone (the Simpson Desert) was much greater than the known removals and there appeared to be another factor involved, possibly drought-induced natural mortality. We raise a number of concerns about making this type of comparison, including the limitations of working with a highly mobile species distributed across a broad landscape and the low number of aerial surveys available for this type of comparison due to a limited project monitoring budget.

Testing the potential for supplementary water to support the recovery and reintroduction of the black-footed rock-wallaby

2017 ◽  
Vol 44 (3) ◽  
pp. 269 ◽  
Author(s):  
Rebecca West ◽  
Matthew J. Ward ◽  
Wendy K. Foster ◽  
David A. Taggart
Keyword(s):  
Population Growth ◽  
Threatened Species ◽  
Population Decline ◽  
South Australia ◽  
Camera Traps ◽  
Limiting Factor ◽  
Population Growth Rates ◽  
Introduced Predators ◽  
Predation Effects

Context Supplementary resource provision is increasingly used by conservation managers to manipulate habitat conditions that limit population growth of threatened species. These methods are popular in reintroduction programs because they can assist released individuals to adapt to novel environments. In situ management and reintroductions are being used to recover warru (black-footed rock-wallaby, Petrogale lateralis MacDonnell Ranges race) on the arid Anangu Pitjantjatjara Yankunytjatjara (APY) Lands of South Australia. Direct predation by introduced predators is thought to be the main cause of population decline, but indirect predation effects reducing access to water resources has also been proposed as a limiting factor. Aims To determine whether warru would use supplementary water and so provide a tool to alleviate resource pressure for in situ (wild) and reintroduced warru populations. Methods We provided supplementary water to a wild and reintroduced warru population across 12 months. Drinking rates were calculated by monitoring water points with camera traps and modelled against plant moisture content and total rainfall. We also examined whether number of visits to water points by warru predators and competitors was significantly different to control points (no water present). Key results Wild and reintroduced warru used water points within 0–10 days of installation. No significant increase in visits by predators or competitors was observed at water points. Drinking rates were significantly higher during dry winter months (March–October) for both wild and re-introduced populations. Conclusions Supplementary water is readily utilised by warru. Water could be provided in this manner to warru populations where predators are present, particularly during drier months (generally March–October on the APY Lands), periods of drought or after fire, when food resources will have a lower water content and/or be less abundant. This may increase breeding rates and recruitment of young, and improve the probability of persistence for populations of this threatened species, and should be further investigated. Implications Supplementary water provision may be a useful tool to increase population growth rates for threatened mammalian herbivores in arid habitats. Experimental trials of the uptake of supplementary water and effects on population dynamics will provide important data for implementing adaptive management frameworks for conservation.

Effectiveness of the Felixer grooming trap for the control of feral cats: a field trial in arid South Australia

2020 ◽  
Vol 47 (8) ◽  
pp. 599
Author(s):  
K. E. Moseby ◽  
H. McGregor ◽  
J. L. Read
Keyword(s):  
Field Trial ◽  
South Australia ◽  
Camera Traps ◽  
Specific Method ◽  
Density Estimates ◽  
Live Prey ◽  
Feral Cats ◽  
Before And After ◽  
Remote Camera ◽  
Track Counts

Abstract ContextFeral cats pose a significant threat to wildlife in Australia and internationally. Controlling feral cats can be problematic because of their tendency to hunt live prey rather than be attracted to food-based lures. The Felixer grooming trap was developed as a targeted and automated poisoning device that sprays poison onto the fur of a passing cat, relying on compulsive grooming for ingestion. AimsWe conducted a field trial to test the effectiveness of Felixers in the control of feral cats in northern South Australia where feral cats were present within a 2600-ha predator-proof fenced paddock. MethodsTwenty Felixers were set to fire across vehicle tracks and dune crossings for 6 weeks. Cat activity was recorded using track counts and grids of remote camera traps set within the Felixer Paddock and an adjacent 3700-ha Control Paddock where feral cats were not controlled. Radio-collars were placed on six cats and spatial mark–resight models were used to estimate population density before and after Felixer deployment. Key resultsNone of the 1024 non-target objects (bettongs, bilbies, birds, lizards, humans, vehicles) that passed a Felixer during the trial was fired on, confirming high target specificity. Thirty-three Felixer firings were recorded over the 6-week trial, all being triggered by feral cats. The only two radio-collared cats that triggered Felixers during the trial, died. Two other radio-collared cats appeared to avoid Felixer traps possibly as a reaction to previous catching and handling rendering them neophobic. None of the 22 individually distinguishable cats targeted by Felixers was subsequently observed on cameras, suggesting death after firing. Felixer data, activity and density estimates consistently indicated that nearly two-thirds of the cat population was killed by the Felixers during the 6-week trial. ConclusionsResults suggest that Felixers are an effective, target-specific method of controlling feral cats, at least in areas in which immigration is prevented. The firing rate of Felixers did not decline significantly over time, suggesting that a longer trial would have resulted in a higher number of kills. ImplicationsFuture studies should aim to determine the trade-off between Felixer density and the efficacy relative to reinvasion.

On bias, precision and accuracy in wildlife aerial surveys

2008 ◽  
Vol 35 (4) ◽  
pp. 253 ◽  
Author(s):  
Jim Hone
Keyword(s):  
Survey Data ◽  
Wildlife Management ◽  
Aerial Survey ◽  
Review Of The Literature ◽  
Density Estimates ◽  
True Value ◽  
Wildlife Population ◽  
Aerial Surveys ◽  
Precision And Accuracy ◽  
Definition Of

Bias, precision and accuracy have been studied extensively in wildlife population estimation including aerial surveys. A review of the literature shows that the concepts of bias and precision are used broadly consistently. Aerial survey data from known populations of feral pig carcases and white-tailed deer show that few density estimates are unbiased and precise. Research is needed, however, to clarify how much bias and how much precision are enough for the various types of wildlife management activities. Accuracy is used in two closely related but different ways. One set of definitions of accuracy relates to deviations from the true value (bias) and the second set relates to squared deviations from the true value (bias and precision). The implications are that authors are encouraged to clearly state which definition of accuracy they use, or focus solely on bias and precision.

Engaging the Pastoral Industry in the Australian Feral Camel Management Project (AFCMP)

2016 ◽  
Vol 38 (2) ◽  
pp. 135 ◽  
Author(s):  
Donna Digby ◽  
Liz Bird ◽  
Lyndee Severin ◽  
Paul O'Leary ◽  
Mac Jensen ◽  
...  
Keyword(s):  
Western Australia ◽  
South Australia ◽  
Northern Territory ◽  
Operational Planning ◽  
Management Approach ◽  
Stakeholder Groups ◽  
Project Governance ◽  
Management Project ◽  
Planning Implementation ◽  
Flexible Management

Feral camels occur over almost 3.3 million km2 of the Australian rangelands, including parts of the Northern Territory, Queensland, South Australia and Western Australia. Within this range, pastoral land encompasses an area of 1.39 million km2 (1189 properties). The pastoral industry was identified as one of the key stakeholder groups to work with under the Australian Feral Camel Management Project. The impacts of feral camels fall into three main categories: economic, environmental and social/cultural. It should be noted that not all pastoralists were impacted by feral camels. Under the Australian Feral Camel Management Project, multiple approaches were used to engage the pastoral industry through their involvement in developing partnerships, operational planning, implementation and communication. Critical to the success of the project was the commitment to effectively consult with landholders, build partnerships, respect landholder values, establish effective project governance and adopt a flexible management approach.

Talking camels: a consultation strategy for consent to conduct feral camel management on Aboriginal-owned land in Australia

2016 ◽  
Vol 38 (2) ◽  
pp. 125 ◽  
Author(s):  
Ben Kaethner ◽  
Peter See ◽  
Adam Pennington
Keyword(s):  
Informed Consent ◽  
South Australia ◽  
Landscape Scale ◽  
Northern Territory ◽  
Aboriginal Communities ◽  
Communication Techniques ◽  
Management Project ◽  
Landscape Types ◽  
Vast Area ◽  
Broad Scale

Thorough consultation and informed consent are required for any work on Aboriginal-owned land in Australia. Consultations for feral camel (Camelus dromedarius) management under the Australian Feral Camel Management Project across the Northern Territory, Western Australia and South Australia were conducted across a vast area, spanning a diversity of cultures and landscape types. Aboriginal organisations from these jurisdictions developed consultative processes that supported Aboriginal communities in making informed decisions on any removal of camels from their country. This article describes the communication techniques used to depict the feral camel issues and opportunities to Aboriginal communities at the local and landscape scale. The decisions that communities arrived at were varied, but consistently focussed on feral camel removal. Their decisions have led to broad-scale feral camel removal under the Australian Feral Camel Management Project, and beyond.

scholarly journals Long term population decline and the impacts of COVID-19 in South Australia’s regions

2021 ◽  
Vol 5 (2) ◽  
pp. 73-85
Author(s):  
Jacob Irving ◽  
Sandy Horne ◽  
Andrew Beer
Keyword(s):  
Age Structure ◽  
Economic Activity ◽  
Census Data ◽  
Population Change ◽  
Economic Impacts ◽  
Population Decline ◽  
South Australia ◽  
Population Data ◽  
Resident Population

Background   South Australian regions have been given little attention in discussions on population decline. Aims   This paper aims to examine the nature and incidence of population decline in South Australia as well as evaluate the potential impacts of COVID-19. Data and methods   Estimated Resident Population data from 2001 to 2020, and Census data from 2006 and 2016, were used to investigate demographic and economic change. Measures of population change, age structure, employment and components of population change were used. Results   Population decline has been a feature of South Australia’s regions for decades and continues to be so as more of the population concentrates in its capital and regional centres where greater opportunities of employment and greater provisions of amenities are available. COVID-19 has the potential to accelerate this change if South Australia’s vulnerable regions are not able to absorb the economic impacts the pandemic poses. Conclusions   A strong driver of population decline in the regions is employment loss in core industries. Strategies that support these industries or otherwise aim to stimulate economic activity in these communities are required to moderate further decline in South Australia’s regions especially as the economy recovers from the impacts of COVID-19.

scholarly journals Historical trend in harbour seal (Phoca vitulina) abundance in Iceland back to the year 1912

2010 ◽  
Vol 8 ◽  
pp. 147 ◽  
Author(s):  
Erlingur Hauksson ◽  
Sólmundur T Einarsson
Keyword(s):  
Population Decline ◽  
Phoca Vitulina ◽  
Harbour Seal ◽  
Early 20Th Century ◽  
Fishing Gear ◽  
Early 19Th Century ◽  
Harvest Rate ◽  
Aerial Surveys ◽  
Seal Population ◽  
By Catch

The harbour seal (Phoca vitulina) is Iceland’s most abundant seal and has likely been exploited since the settlement of the country. Detailed information on skin exports is available as far back as 1912, and suggests that the catch, consisting mainly of pups, was far higher in the early 20th century than now. Assuming that skin exports were proportional to catches, these data were used to back-calculate the size of the Icelandic harbour seal population to the year 1912. The results indicate that the harbour seal population was considerably larger in the early 19th century than at present, about 60,000 (90% CI:40-100) animals. Aerial surveys conducted since 1980 indicate that the population has declined from 33,000 (90% CI:26,000-44,000) animals in 1980 to about 12,000 (90% CI:9,000-16,000) animals in 2006. The population time series suggests thatthe stock began to decline rapidly around 1960 and continued to decrease until 2003. In the period 1980 - 2003, the population declined even though reported catches were relatively low. Harvest rate had probably been about 10% before 1960. Between 1960 and 1980 the reported harvest rate increased to about 13%, but unknown numbers of adult seals were also taken as by-catch and shot in defence of salmon rivers. Since 2003, total removals have decreased and the population decline appears to have ceased. Entanglements in fishing gear and other incidental unreported hunting could increase again in the future. Therefore, the population must be monitored on a regular basis, and better information on by-catch and other unreported harvest is needed.

scholarly journals Trends in numbers and changes in the distribution of feral goats (capra hircus) in the South Australia pastoral zone

1996 ◽  
Vol 23 (6) ◽  
pp. 687 ◽  
Author(s):  
AR Pople ◽  
GC Grigg ◽  
SC Cairns ◽  
P Alexander ◽  
LA Beard ◽  
...  
Keyword(s):  
Random Distribution ◽  
South Australia ◽  
Capra Hircus ◽  
The South ◽  
Sample Unit ◽  
Flinders Ranges ◽  
Aerial Surveys

Trends in numbers and changes in the distribution of feral goats in the South Australian pastoral zone (217300 km*2) during 1978-94 were determined by winter aerial surveys. Only the presence or absence of goats on sample units was scored between 1978 and 1988. On the assumption of a random distribution of goat groups, these indices were transformed to densities of goat groups. Between 1989 and 1994 actual goat numbers were recorded on each sample unit, allowing goat density to be estimated. Goats were consistently at their highest densities in the south-east of the pastoral zone, a region dominated by open mallee scrub and chenopod shrubland. Densities of goat groups fluctuated from a low in 1984, following a drought, to a peak in 1990, following above-average rainfalls, when there were an estimated 193700 +/- 29600 goats in the pastoral zone. This estimate is conservative because it is uncorrected for the visibility bias associated with sighting groups and undercounting their sizes. The estimate also excludes the Flinders Ranges for which a similar number of goats has been estimated.

Automated Vertical Photography for Detecting Pelagic Species in Multitaxon Aerial Surveys

2014 ◽  
Vol 48 (1) ◽  
pp. 36-48 ◽  
Author(s):  
Jessica K.D. Taylor ◽  
Robert D. Kenney ◽  
Donald J. LeRoi ◽  
Scott D. Kraus
Keyword(s):  
Sampling Method ◽  
Photographic Method ◽  
Proof Of Concept ◽  
Future Directions ◽  
Density Estimates ◽  
Leatherback Turtles ◽  
Aerial Surveys ◽  
Manual Processing ◽  
Digital Documentation ◽  
The Cost

AbstractMarine aerial surveys are designed to maximize the potential for detecting target species. Collecting data on different taxa from the same platform is economically advantageous but normally comes at the cost of compromising optimal taxon-specific scanning patterns and survey parameters, in particular altitude. Here, we describe simultaneous visual and photographic sampling methods as a proof of concept for detecting large whales and turtles from a single aircraft, despite very different sighting cues. Data were collected for fishing gear, fish, sharks, turtles, seals, dolphins, and whales using two observers and automated vertical photography. The photographic method documented an area directly beneath the aircraft that would otherwise have been obscured from observers. Preliminary density estimates were calculated for five species for which there were sufficient sample sizes from both methods after an initial year of data collection. The photographic method yielded significantly higher mean density estimates for loggerhead turtles, ocean sunfish, and blue sharks (p < 0.01), despite sampling a substantially smaller area than visual scanning (less than 11%). Density estimates from these two methods were not significantly different for leatherback turtles or basking sharks (p > 0.05), two of the largest species included in the analysis, which are relatively easy to detect by both methods. Although postflight manual processing of photographic data was extensive, this sampling method comes at no additional in-flight effort and obtains high-quality digital documentation of sightings on the trackline. Future directions for this project include automating photographic sighting detections, expanding the area covered by photography, and performing morphometric measurement assessments.

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