Aerial survey methodology and the cost of control for feral goats in Western Queensland

1998 ◽  
Vol 25 (4) ◽  
pp. 393 ◽  
Author(s):  
A. R. Pople ◽  
T. F. Clancy ◽  
J. A. Thompson ◽  
S. Boyd-Law
Keyword(s):  
National Park ◽  
Survey Methodology ◽  
Aerial Survey ◽  
Capra Hircus ◽  
Effective Control ◽  
Correction Factors ◽  
Large Area ◽  
Aerial Surveys ◽  
The Cost ◽  
Capita Cost

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.

Correcting for Incomplete Sighting in Aerial Surveys of Kangaroos

1986 ◽  
Vol 13 (3) ◽  
pp. 339 ◽  
Author(s):  
A Barnes ◽  
GJE Hill ◽  
GR Wilson
Keyword(s):  
Species Differences ◽  
Aerial Survey ◽  
Time Of Day ◽  
Correction Factors ◽  
Density Estimates ◽  
Mathematical Properties ◽  
Aerial Surveys ◽  
Alternative Method ◽  
Management Procedures ◽  
Continued Use

Kangaroo density estimates derived from aerial survey depend on the method of deriving sightability correction factors developed by Caughley. The method depends on five assumptions, some concerned with the mathematical properties of a model for sightability probabilities and others with deriving correction factors from this model. All these assumptions can be criticized. In addition, evidence on the performance of the method does not suggest that it is accurate. Published density estimates are less precise than indicated, and may include biases due to factors not considered in the correction factors used, e.g. seasonal conditions, time of day, and species differences. At present, no satisfactory alternative method of correction exists but, because inaccuracies may be large, continued use of the method requires much greater caution than has previously been shown. This is particularly relevant where density estimates are used to determine management procedures.

scholarly journals The potential for unmanned aerial vehicles (UAVs) to conduct marine fauna surveys in place of manned aircraft

2017 ◽  
Vol 75 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Andrew P Colefax ◽  
Paul A Butcher ◽  
Brendan P Kelaher
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Aerial Survey ◽  
Civil Aviation ◽  
Human Observer ◽  
Large Area ◽  
Marine Fauna ◽  
Survey Tool ◽  
Observer Error ◽  
Aerial Vehicles ◽  
Aerial Surveys

Abstract Unmanned aerial vehicles (UAVs) are increasingly used in marine wildlife research. As technological developments rapidly advance the versatility and functionality of affordable UAVs, their potential as a marine aerial survey tool is quickly gaining attention. Currently, there is significant interest in whether cost-effective UAVs can outperform manned aircraft in aerial surveys of marine fauna at sea, although few empirical studies have compared relative sampling efficiency, accuracy and precision. Civil aviation restrictions, and subsequent available civilian technologies, make it unlikely that UAVs will currently be more effective than manned aircraft for large area marine surveys. UAVs do, however, have the capacity to fill a niche for intensive smaller spatial scale sampling and for undertaking aerial surveys in isolated locations. Improvements in UAV sensor resolutions and alternative sensor types, such as multispectral cameras, may increase area coverage, reduce perception error, and increase water penetration for sightability. Additionally, the further development of auto-detection software will rapidly improve image processing and further reduce human observer error inherent in manned aerial surveys. As UAV technologies and associated methodology is further developed and becomes more affordable, these aircraft will be increasingly adopted as a marine aerial survey tool in place of traditional methods using manned aircraft.

scholarly journals Performance of manned and unmanned aerial surveys to collect visual data and imagery for estimating arctic cetacean density and associated uncertainty

2018 ◽  
Vol 6 (3) ◽  
pp. 128-154 ◽  
Author(s):  
M.C. Ferguson ◽  
R.P. Angliss ◽  
A. Kennedy ◽  
B. Lynch ◽  
A. Willoughby ◽  
...  
Keyword(s):  
Marine Mammal ◽  
Aerial Survey ◽  
Small Sample ◽  
Unmanned Aircraft ◽  
Bowhead Whale ◽  
Line Transect ◽  
Camera System ◽  
Density Estimates ◽  
Aerial Surveys ◽  
The Cost

Manned aerial surveys have been used successfully for decades to collect data to infer cetacean distribution, density (number of whales/km2), and abundance. Unmanned aircraft systems (UAS) have potential to augment or replace some manned aerial surveys for cetaceans. We conducted a three-way comparison among visual observations made by marine mammal observers aboard a Turbo Commander aircraft; imagery autonomously collected by a Nikon D810 camera system mounted to a belly port on the Turbo Commander; and imagery collected by a similar camera system on a remotely controlled ScanEagle® UAS operated by the US Navy. Bowhead whale density estimates derived from the marine mammal observer data were higher than those from the Turbo Commander imagery; comparisons to the UAS imagery depended on survey sector and analytical method. Beluga density estimates derived from either dataset collected aboard the Turbo Commander were higher than estimates derived from the UAS imagery. Uncertainties in density estimates derived from the marine mammal observer data were lower than estimates derived from either imagery dataset due to the small sample sizes in the imagery. The visual line-transect aerial survey conducted by marine mammal observers aboard the Turbo Commander was 68.5% of the cost of the photo strip-transect survey aboard the same aircraft and 9.4% of the cost of the UAS survey.

scholarly journals The Swiss National Park

Oryx ◽  
1955 ◽  
Vol 3 (2) ◽  
pp. 64-70
Author(s):  
G. N. Zimmerli
Keyword(s):  
National Park ◽  
Swiss Society ◽  
Large Area ◽  
Nature Protection ◽  
Swiss National Park ◽  
Plant Life ◽  
Eastern Border ◽  
Set Up ◽  
The One ◽  
Protection Commission

The idea of a Swiss national park originated with the Swiss Society for Nature Research and this Society played the leading part in its realization. In 1906 the Society set up as part of its own organization a Swiss Nature Protection Commission and charged it to search for an area in Switzerland suitable for establishment as a reserve, in which all the animal and plant life could be protected against interference by man and so could be left entirely to the play of natural forces. It was not easy to find in Switzerland a suitably large area which still retained its original characteristics, was virtually free from human settlement, and contained some wealth of fauna and flora. After a careful survey of the whole country it became clear that the most suitable region was the Lower Engadine, with its isolated valleys on the eastern border of the country. The district in which, at the beginning of the century, bears had still lived was the one in which primitive nature could be found in its truest state.

Preliminary Estimates of Costs of Foodborne Disease in the United States

1989 ◽  
Vol 52 (8) ◽  
pp. 595-601 ◽  
Author(s):  
EWEN C. D. TODD
Keyword(s):  
United States ◽  
Food Industry ◽  
The United States ◽  
Control Measures ◽  
Effective Control ◽  
Foodborne Diseases ◽  
Hemorrhagic Colitis ◽  
E Coli ◽  
The Cost ◽  
Total Impact

Although the full economic impact of foodborne diseases has yet to be measured, preliminary studies show that the cost of illness, death, and business lost is high indeed. This impact is probably greatest in developing countries, but few facts are known. For the United States, preliminary estimates are 12.6 million cases costing $8.4 billion. These may seem excessive but other authors have postulated even higher case and dollar figures. Microbiological diseases (bacterial and viral) represent 84% of the United States' costs, with salmonellosis and staphylococcal intoxication being the most economically important diseases (annually $4.0 billion and $1.5 billion, respectively). Other costly types of illnesses are toxoplasmosis ($445 million), listeriosis ($313 million), campylobacteriosis ($156 million), trichinosis ($144 million), Clostridium perfringens enteritis ($123 million), and E. coli infections including hemorrhagic colitis ($223 million). Botulism has a high cost per case ($322,200), but its total impact is only $87 million because relatively few cases occur (270). This is because the food industry has been able to introduce effective control measures. Salmonellosis, however, is much more widespread (2.9 million cases) and affects all sectors of the food industry.

scholarly journals Changes in number and distribution of hippoptamus (Hippopotamus amphibius) in the Sabie River, Kruger National Park, during the 1992 drought

Koedoe ◽  
1995 ◽  
Vol 38 (2) ◽  
Author(s):  
P.C. Viljoen
Keyword(s):  
Southern Africa ◽  
National Park ◽  
Dry Season ◽  
Kruger National Park ◽  
Population Densities ◽  
Drought Period ◽  
Aerial Surveys ◽  
Hippopotamus Amphibius ◽  
Reduced Flow

The 1991/92 drought in Southern Africa and the effect of the resultant reduced flow of the Sabie River on hippopotami was investigated. Hippopotami are counted annually in the Kruger National Park's (KNP) major rivers as part of the park's monitoring pro- gramme. Two additional aerial surveys were conducted to document changes in hippopotamus population densities in the Sabie River during the drought period. The hippopotamus population decreased during the drought by 12.6 to 672 animals between July 1991 and October 1992. The highest and lowest hippopotamus densities recorded were 11.6 and 2.2 animals/km river length respectively in different river sections. Only 12 hippopotamus mortalities were recorded at the end of the 1992 dry season (October).

scholarly journals Elephant population growth in Kruger National Park, South Africa, under a landscape management approach

Koedoe ◽  
2017 ◽  
Vol 59 (1) ◽  
Author(s):  
Sam M. Ferreira ◽  
Cathy Greaver ◽  
Chenay Simms
Keyword(s):  
Population Growth ◽  
National Parks ◽  
National Park ◽  
Landscape Management ◽  
Aerial Survey ◽  
Kruger National Park ◽  
Management Approach ◽  
Intensive Management ◽  
Ecological Processes ◽  
Management Interventions

South African National Parks (SANParks) manage landscapes rather than numbers of elephants (Loxodonta africana) to mitigate the effects that elephants may have on biodiversity, tourism and stakeholder conservation values associated with protected areas. This management philosophy imposes spatial variability of critical resources on elephants. Restoration of such ecological processes through less intensive management predicts a reduction in population growth rates from the eras of intensive management. We collated aerial survey data since 1995 and conducted an aerial total count using a helicopter observation platform during 2015. A minimum of 17 086 elephants were resident in the Kruger National Park (KNP) in 2015, growing at 4.2% per annum over the last generation of elephants (i.e. 12 years), compared to 6.5% annual population growth noted during the intensive management era ending in 1994. This may come from responses of elephants to density and environmental factors manifested through reduced birth rates and increased mortality rates. Authorities should continue to evaluate the demographic responses of elephants to landscape scale interventions directed at restoring the limitation of spatial variance in resource distribution on elephant spatiotemporal dynamics and the consequences that may have for other conservation values.Conservation implications: Conservation managers should continue with surveying elephants in a way that allows the extraction of key variables. Such variables should focus on measures that reflect on how theory predicts elephants should respond to management interventions.

scholarly journals Caribou distribution during calving in the northeast National Petroleum Reserve-Alaska, June 1998 to 2000

Rangifer ◽  
2003 ◽  
Vol 23 (5) ◽  
pp. 283 ◽  
Author(s):  
Lynn E. Noel ◽  
John C. George
Keyword(s):  
Survey Methodology ◽  
Aerial Survey ◽  
Small Sample ◽  
Telemetry Data ◽  
Minimum Convex Polygon ◽  
Survey Period ◽  
Private Industry ◽  
Coverage Area ◽  
Cow Calf ◽  
Strip Transect

Barren ground caribou (Rangifer tarandus granti) of the Teshekpuk Caribou Herd (TCH) inhabit the western portion of Alaska's Arctic Coastal Plain within the National Petroleum Reserve&mdash;Alaska (NPR-A). Alaska's North Slope communities, management agencies, and private industry are interested in this herd because of its importance as a subsistence resource and location relative to potential petroleum development. From 1998 through 2000, we monitored caribou distribution during the calving period within the Northeast Planning Area of the NPR-A using systematic strip-transect aerial surveys, as well as VHF and satellite telemetry for cow caribou. Aerial survey and telemetry data indicated cows with calves were distributed around Teshekpuk Lake, with a concentration south of the lake in 1999 and 2000. Inconsistencies in weather conditions, survey timing (both strip-transect and VHF surveys), 100% coverage survey areas, and small sample sizes confound interpretations of our results. However, several patterns were apparent. Later transect survey timing (7&mdash;12 June versus 4&mdash;7 and 5&mdash;8 June) resulted in more cow/calf pairs recorded. Our 18% coverage area, originally based on VHF telemetry data for the extent of TCH calving, covered a consistently high proportion (95% to 100%) of the annual calving ranges (95% kernel utilization distributions), but accounted for only 24% to 46% of the adult cows in the TCH based on the current Alaska Department of Fish and Game population estimate (1999) and average 1998&not;2000 herd composition. It appears that either our transect survey methodology significantly underestimated the true number of caribou cows in the study area, many cows calved outside the area or moved into the area and calved after our surveys, or we have over estimated the number of reproductive cows in the herd. Our 100% coverage transect areas covering oil and gas lease areas, contained 38% of the calving range with 23% of TCH cows in 1999; and 18% of the calv&not;ing range with 8% of TCH cows in 2000. Based on 95% minimum convex polygon ranges, satellite collared cow/calf pairs were not stationary during either our survey period (14.7 &plusmn; 6.56 km2; mean &plusmn; standard error of the mean; 4&mdash;12 June) or during the calving period (86.9 &plusmn; 72.30 km2; 1&mdash;20 June) during 1998&mdash;2000. Site specific pre-development data on caribou distribution during calving in NPR-A will be useful for assessing the importance of specific areas to caribou during calving and for designing oilfields that minimize impacts should oil development occur.

Pressure Sensing Fabric

2006 ◽  
Vol 920 ◽  
Author(s):  
Zhang Hui ◽  
Tao Xiao Ming ◽  
Yu Tong Xi ◽  
Li Xin Sheng
Keyword(s):  
Pressure Sensor ◽  
Fabrication Process ◽  
Sensing Element ◽  
Large Area ◽  
Pressure Sensing ◽  
Conductive Yarns ◽  
Flexible Pressure Sensor ◽  
Fabric Surface ◽  
The Cost ◽  
Resistive Grids

AbstractThis paper presents an approach for decoding the pressure information exerted over a piece of fabric by means of resistive sensing. The proposed sensor includes a distributed resistive grids constructed by two systems of orthogonally contacted electrical conductive yarns, with no external sensing element to be attached on the fabric. Since the conductive yarns serve as the sensing and wiring elements simultaneously, this design simplifies the fabrication process, reduces the cost and makes the production of large area flexible pressure sensor possible. The location of the pressure applied on the fabric can be identified by detecting the position where the change of the resistances occurs between two embroidered yarns. Meanwhile, the magnitude of the pressure can be acquired by measuring the variations of the resistance. In order to eliminate the “crosstalk” effect between adjoining fibers, the yarns were separately wired on the fabric surface.

scholarly journals Beyond grayscale lithography: inherently three-dimensional patterning by Talbot effect

2019 ◽  
Vol 8 (3-4) ◽  
pp. 233-240
Author(s):  
Roberto Fallica
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Talbot Effect ◽  
Large Area ◽  
Projection Lithography ◽  
Main Technique ◽  
Direct Laser ◽  
The Cost ◽  
Diffraction Effects

Abstract There are a growing number of applications where three-dimensional patterning is needed for the fabrication of micro- and nanostructures. Thus far, grayscale lithography is the main technique for obtaining a thickness gradient in a resist material that is exploited for pattern transfer by anisotropic etch. However, truly three-dimensional structures can only be produced by unconventional lithography methods such as direct laser writing, focused ion beam electrodeposition, colloidal sphere lithography, and tilted multiple-pass projection lithography, but at the cost of remarkable complexity and lengthiness. In this work, the three-dimensional shape of light, which is formed by Talbot effect diffraction, was exploited to produce inherently three-dimensional patterns in a photosensitive polymer. Using light in the soft X-ray wavelength, periodic three-dimensional structures of lateral period 600 nm were obtained. The position at which the sample has to be located to be in the Fresnel regime was simulated using an analytical implementation of the Fresnel integrals approach. Exploiting the light shape forming in diffraction effects thus enables the patterning of high-resolution three-dimensional nanostructures over a large area and with a single exposure pass – which would be otherwise impossible with conventional lithographic methods.

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