Some human, aircraft and animal factors affecting aerial surveys: how to enumerate animals from the air

2008 ◽  
Vol 35 (4) ◽  
pp. 258 ◽  
Author(s):  
Peter J. S. Fleming ◽  
John P. Tracey
Keyword(s):  
Visual Acuity ◽  
New South ◽  
Human Memory ◽  
Aerial Survey ◽  
Factors Affecting ◽  
Counting Error ◽  
Aerial Surveys ◽  
South Wales ◽  
Survey Estimates ◽  
Aerial Platforms

Aerial surveys of wildlife involve a noisy platform carrying one or more observers moving over animals in order to quantify their abundance. This simple-sounding system encapsulates limits to human visual acuity and human concentration, visual attention, salience of target objects within the viewed scene, characteristics of survey platforms and facets of animal behaviours that affect the detection of animals by the airborne observers. These facets are too often ignored in aerial surveys, yet are inherent sources of counting error. Here we briefly review factors limiting the ability of observers to detect animals from aerial platforms in a range of sites, including characteristics of the aircraft, observers and target animals. Some of the previously uninvestigated limitations identified in the review were studied in central and western New South Wales, showing that inaccuracies of human memory and enumeration processes are sources of bias in aerial survey estimates. Standard protocols that minimise or account for the reviewed factors in aerial surveys of wildlife are recommended.

Factors affecting post-fire seedling establishment of selected mallee understorey species

2000 ◽  
Vol 48 (1) ◽  
pp. 59 ◽  
Author(s):  
J. S. Cohn ◽  
R. A. Bradstock
Keyword(s):  
Large Scale ◽  
Prescribed Burning ◽  
New South ◽  
Eucalyptus Species ◽  
Factors Affecting ◽  
Acacia Species ◽  
Introduced Herbivores ◽  
South Wales ◽  
Rabbit Grazing ◽  
Seedling Germination

Factors affecting the survival of post-fire germinants in mallee communities, in central western New South Wales, were examined. Experiments compared the relative effects of native and introduced herbivores (kangaroos, goats, rabbits), after small- and large-scale fires (20–50 and > 10 000 ha, respectively), with particular emphasis on edge effects, seedling clustering, topography and eucalypt canopy presence. The experiments (1985–1997) focused on common understorey species Acacia rigens Cunn. ex Don, A. wilhelmiana F.Muell. and Triodia scariosa N.T.Burb. subsp. scariosa, in mallee dominated by Eucalyptus species. Following a large fire (1985), high spring rainfall and rabbit grazing on A. rigens only, survival of Acacia species and T. scariosa remained relatively high 4 years later (60–70%). After small burns (1987, 1988), low spring rainfall and grazing by rabbits and kangaroos, survival of Acacia species declined to between 0 and 30% of the germinants by the second summer. In most cases, local extinction had occurred within 8 years. After small burns (1988, 1989) and low spring rainfall, the survival of T. scariosa declined to between 0 and 35% of germinants by the second summer (effect of grazing unknown). No consistent effect of edge, topography and eucalypt canopy was found. Survival of clustered Acacia seedlings was between 10 and 20% lower than unclustered seedlings. Given the high frequency of low rainfall and its interaction with grazing, prescribed burning of mallee for wildfire control and nature conservation may require the local elimination of rabbits and a reduction in kangaroo numbers, especially in the first spring and summer following seedling germination.

An Aerial Survey of 3 Game Species of Waterfowl (Family Anatidae) Populations in Eastern Australia

1986 ◽  
Vol 13 (2) ◽  
pp. 213 ◽  
Author(s):  
LW Braithwaite ◽  
M Maher ◽  
SV Briggs ◽  
BS Parker
Keyword(s):  
Surface Waters ◽  
New South ◽  
New South Wales ◽  
Aerial Survey ◽  
Game Species ◽  
South Wales ◽  
Black Duck ◽  
The Pacific ◽  
Eastern Australia ◽  
Central Eastern

Populations of waterfowl of three game species, the Pacific black duck Anus superciliosa, grey teal A. gibberifrons, and maned duck Chenonetta jubata, were assessed by aerial survey in October 1983 within a survey region of 2 697 000 km2 of eastern Australia. The numbers of each species were assessed on all surface waters of over 1 ha, and on a sample of smaller surface waters within 10 survey bands each 30 km wide and spaced at intervals of 2� latitude from 20�30' to 38�30'S. The area within the survey bands was 324 120 km2, which gave a sampling intensity of 12.0% of the land surface area. The area of features shown as wetlands or water impoundments within the survey bands on 1 : 2 500 000 topographic maps was 19 200 km2 or 11.2% of the total area of these features in the survey region. The area of surface waters surveyed was assessed at 465 300 ha. Assessments of populations of each species were tallied for wetlands by grid cells of 6 min of 1� longitude along the survey bands (258-309 km2 depending on latitude). Distributions were then mapped, with log*10 indices of populations in each cell. Distributions of the black duck and grey teal showed a pattern of intense aggregation in limited numbers of cells, that of the maned duck was more evenly distributed. The major concentrations of the Pacific black duck were recorded in northern New South Wales and the south-eastern, western, central eastern and central coastal regions of Queensland; those of the grey teal were in south-western, western and northern New South Wales and central-eastern Queensland; the maned duck was broadly distributed over inland New South Wales with the exception of the far west, inland southern Queensland, and central northern Victoria.

Factors affecting the germination of Giant Parramatta grass

1997 ◽  
Vol 37 (4) ◽  
pp. 439 ◽  
Author(s):  
T. S. Andrews ◽  
C. E. Jones ◽  
R. D. B. Whalley
Keyword(s):  
Leaf Extract ◽  
New South ◽  
New South Wales ◽  
North Coast ◽  
Factors Affecting ◽  
The North ◽  
South Wales ◽  
Seed Fall ◽  
Allelopathic Interactions ◽  
And Control

Summary. Four experiments were conducted to determine the effects of temperature, light and leaf extract solutions on the germination of Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] collected from a population on the North Coast of New South Wales. In the first experiment, seeds were subjected to one of a range of temperature combinations immediately after collection and again after 8 and 27 weeks. Germination was restricted to a narrow range of alternating temperatures with a peak at 35°C day/15°C night when seeds were tested immediately after collection. More seeds germinated when the samples had been stored, although germination remained depressed at constant temperatures. These data indicate that freshly collected GPG seeds are subject to primary dormancy and that few would germinate in the field immediately after seed fall. In a second experiment, seeds were buried beneath leaf litter in a pasture immediately after collection. After 7 months, the seeds were exhumed and subjected to either constant (20°C) or alternating (35/15°C) temperatures in either full light, reduced red:far-red (R : FR) light or dark treatments. Over 95% of GPG seeds germinated when subjected to alternating temperatures, regardless of light treatment. At constant temperatures, 97% of seeds germinated under full light, 59% at reduced R : FR light and <1% in dark treatments. A germination response to alternating temperatures and/or light treatments has been reported in pasture weeds and may be an adaptation to detecting gaps in the pasture canopy. Consequently, the germination of GPG in a pasture may be manipulated to some extent by altering the amount of pasture cover using grazing management, mowing and fertiliser applications. In experiment 3, leaves from a range of coastal grasses were mixed with water and the solutions were used to germinate GPG seeds. Solutions extracted from setaria (Setaria sphacelata) leaves completely inhibited GPG germination while 27% of GPG seeds germinated when imbibed with kikuyu leaf extract solution. Solution extracted from carpet grass (Axonopus affinis) leaves had the least effect on GPG germination. In experiment 4, the effects of solutions that had been leached from the leaves of either setaria or carpet grass on seed germination, and root and shoot lengths of GPG seedlings were compared. Germination was less inhibited by leachate solutions compared with the extract solutions used in experiment 3. Seedlings in setaria leachates had significantly shorter roots and shoots than both those germinated in carpet grass leachates and control seedlings. This may explain, at least in part, why carpet-grass-based pastures are readily infested with GPG while setaria-based pastures are relatively resistant to infestation. The potential for allelopathic interactions between GPG and setaria to be fully utilised to reduce the abundance of GPG in coastal New South Wales pastures is discussed.

Habitat Utilization by Sympatric Red Kangaroos Macropus-Rufus, and Western Grey Kangaroos Macropus-Fuliginosus, in Western New-South-Wales

1988 ◽  
Vol 15 (4) ◽  
pp. 413 ◽  
Author(s):  
D Priddel
Keyword(s):  
Temporal Change ◽  
New South ◽  
New South Wales ◽  
Aerial Survey ◽  
Habitat Utilization ◽  
South Wales ◽  
Macropus Rufus

Habitat utilisation by sympatric red kangaroos, Macropus rufus, and western grey kangaroos, M. fuliginosus, was monitored by aerial survey. Red kangaroos used floodplain and sandplain with equal intensity. Western grey kangaroos favoured floodplain and utilised woodland on both landforms relatively more than did red kangaroos. Movements of kangaroos between sandplain and floodplain paralleled changes in pasture condition. Red kangaroos responded to pasture growth, moving to sandplain immediately after rain. Western greys followed up to 3 months later, the increase in use of sandplain being weakly correlated (r = 0.70) to an increase in pasture biomass. There was no evidence of any temporal change in use of either woodland or open plain by either species.

A Study of the Biology of the Wild Rabbit in Climatically Different Regions in Eastern Australia V*. The Use of Aerial Surveys to Map the Distribution of Rabbit Warrens over Large Areas of Semiarid North-western New South Wales

1974 ◽  
Vol 1 (1) ◽  
pp. 17 ◽  
Author(s):  
BS Parker ◽  
K Myers
Keyword(s):  
New South ◽  
Wild Rabbit ◽  
Good Picture ◽  
Fine Grained ◽  
Aerial Surveys ◽  
South Wales ◽  
Eastern Australia ◽  
Recent Sediments ◽  
North Western ◽  
Arid And Semiarid

Aerial surveys can be used to measure the distribution of rabbit warrens over large areas of arid and semiarid Australia. Clumped patterns of distribution of rabbit warrens found by ground surveys are also detected in aerial surveys, which further show that the highest density of warrens occurs in habitats containing shales or other fine-grained rocks overlain by recent sediments, or those closely related to drainage systems. A good picture of rabbit distribution is obtained when about 25% of the area has been overed by the aircraft. * Part IV, Aust. J. Zool., 1971, 19, 355–70.

FACTORS AFFECTING RADIOTHERAPY UTILIZATION IN GERIATRIC ONCOLOGY PATIENTS IN NEW SOUTH WALES, AUSTRALIA

2019 ◽  
Vol 10 (6) ◽  
pp. S13-S14
Author(s):  
P.L. Mackenzie ◽  
G.S. Gabriel ◽  
M.B. Barton
Keyword(s):  
New South ◽  
New South Wales ◽  
Geriatric Oncology ◽  
Oncology Patients ◽  
Factors Affecting ◽  
South Wales

Some factors affecting the extraction of soil 'available' phosphate

Soil Research ◽  
1978 ◽  
Vol 16 (3) ◽  
pp. 355
Author(s):  
GD Batten
Keyword(s):  
Soil Solution ◽  
New South ◽  
New South Wales ◽  
Large Vessel ◽  
Soil Tests ◽  
Factors Affecting ◽  
Laboratory Error ◽  
South Wales ◽  
Available Phosphate

Twenty soils from southern New South Wales were analysed for acid extractable phosphate in 1971, and again in 1977 when it was found that an increase had occurred. These same samples were also analysed using reciprocating shakers with different distances of travel. More phosphate was extracted when a shaker with a greater distance of travel was used and when more soil, but at the same soil : solution ratio, was placed in a large vessel. It is suggested that such variations in technique contribute to inter-laboratory error in soil tests for phosphate.

Patterns of waterbird use in wetlands of the Paroo, A river system of inland Australia.

1992 ◽  
Vol 14 (2) ◽  
pp. 128 ◽  
Author(s):  
MT Maher ◽  
LW Braithwaite
Keyword(s):  
New South ◽  
New South Wales ◽  
River System ◽  
Aerial Survey ◽  
Flood Event ◽  
Flood Events ◽  
Inland Wetlands ◽  
South Wales ◽  
Waterbird Species ◽  
North Western

The significance of inland wetlands to Australian waterbirds has been overlooked until recently. One important area identified from regular aerial survey centres on the Paroo River in north-western New South Wales. Between April 1983 and December 1985, a period covering a major flood, waterbird populations were estimated on five wetland systems associated with the Paroo during 14 trips. Fifty- three waterbird species were recorded with the anatids, Anas gibberifrons and Malacorhynchus membranaceus, accounting for 75 per cent of total estimated populations. Most breeding events were observed in those wetlands dominated by Muehlenbeckia florulenta (lignum). Breeding accounted for shifts in waterbird populations between wetland systems. A model of waterbird usage of the five wetland systems in relation to a complete flood event is described. The importance for waterbird conservation of wetlands used for breeding and maintenance of populations between flood events, and threats to the integrity of these wetlands are discussed.

Factors affecting pre-weaning growth and weaning conformation of Angus cattle

1978 ◽  
Vol 29 (2) ◽  
pp. 359
Author(s):  
R Barlow ◽  
EB Dettmann ◽  
LG Williams
Keyword(s):  
Least Squares ◽  
New South ◽  
Average Daily Gain ◽  
Factors Affecting ◽  
Angus Cattle ◽  
South Wales ◽  
Weaning Age ◽  
Males And Females ◽  
Main Effects ◽  
Daily Gain

Weaning weight (ww) and conformation score (cs) records from Angus calves in five New South Wales herds were analysed by least-squares procedures to assess the nature and magnitude of variation. Herd, year, age of dam and sex were considered as main effects. Covariates included in the models were weaning age (WA) for ww and average daily gain (ADG), and both WA and ww for cs. Male calves (steers and bulls) were 16.6 kg heavier at weaning than female calves. Dams that were 5-8 years of age weaned calves that were 30.1 kg, 15.4 kg and 6.7 kg heavier than 2-, 3- and 4-year-old dams respectively. When ww was not included as a covariate in the model, age of dam effects on cs reflected those on ww, and there was little difference in cs between males and females. When adjusted for differences in ww, males had poorer cs than females, and calves from 3-year-old dams, and from dams over 8 years old, had poorer cs than those from dams of all other ages. Partial regressions of ww and ADG on WA, and of cs on ww, varied considerably between herd/year/sex subgroups.

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