Estimating the density of free-ranging wild horses in rugged gorges using a photographic mark - recapture technique

2009 ◽  
Vol 36 (5) ◽  
pp. 361 ◽  
Author(s):  
Karl Vernes ◽  
Melissa Freeman ◽  
Brad Nesbitt
Keyword(s):  
Large Mammals ◽  
Estimation Model ◽  
Density Estimates ◽  
Mark Recapture ◽  
South Wales ◽  
North Eastern ◽  
Line Transects ◽  
Landscape Scales ◽  
Free Ranging ◽  
Study Species

Estimating the density of large, feral species such as wild horses at landscape scales can present a logistical hurdle for wildlife managers attempting to set density-based management targets. We undertook aerial surveys of wild horses by using a helicopter in Guy Fawkes River National Park in north-eastern New South Wales across 3 years to determine whether meaningful density estimates could be obtained efficiently by a mark–recapture technique based on recognition of individual horses. Horse groups photographed from the air on the first of two surveys conducted each year were ‘marked’ on the basis of a unique combination of colours and natural markings, and ‘recaptured’ if they were photographed and identified on the second survey. Population size was estimated with the program MARK using a range of population estimators; however, because horses appeared to be evading detection on the second survey of each year, we chose a final estimation model that accounted for detection shyness in the study species. In 2005, the density estimate was 3.8 horses per km2 (upper and lower 95% CL = 3.5–5.7 horses per km2). Following horse control in these catchments, the estimate in 2007 was 2.3 horses per km2 (upper and lower 95% CL = 2.1–3.4 horses per km2), and this change in density can be accounted for by the known number of horses removed from the survey area between survey periods. Overall, the technique proved useful for estimating densities of wild horses in deeply dissected gorge country where other estimation techniques (such as line transects) are not practical; however, low recapture rates in one of the years of the study shows that the technique may not always be applicable. Our technique should also be suitable for surveying other large mammals with broad ranges in open environments, provided recognition of individuals from unique marks is possible.

Estimating brush-tailed rock-wallaby population size using individual animal recognition

2011 ◽  
Vol 33 (2) ◽  
pp. 228
Author(s):  
Karl Vernes ◽  
Stuart Green ◽  
Piers Thomas
Keyword(s):  
Population Size ◽  
National Park ◽  
New South ◽  
Morphological Characters ◽  
Population Estimates ◽  
Individual Animal ◽  
Mark Recapture ◽  
South Wales ◽  
North Eastern ◽  
Estimate Population Size

We undertook surveys of brush-tailed rock-wallabies (Petrogale penicillata) at four colonies in Oxley Wild Rivers National Park, north-eastern New South Wales, with the aim of developing a technique based upon individual animal recognition that could be used to obtain robust population estimates for rock-wallaby colonies. We identified individuals on the basis of distinct morphological characters in each colony using visual observations, and used the data within a ‘mark–recapture’ (or sight–resight) framework to estimate population size. More than 37 h of observations were made over 10 sampling days between 18 May and 9 June 2010. We could identify 91.7% of all rock-wallabies that were independently sighted (143 of 156 sightings of 35 animals). A small percentage of animals could not be identified during a visit because they were seen only fleetingly, were in dense cover, or were partly obscured by rock. The number of new animals sighted and photographed declined sharply at the midpoint of the survey, and there was a corresponding increase in resighting of known individuals. Population estimates using the mark–recapture methodology were nearly identical to estimates of total animals seen, suggesting that this method was successful in obtaining a complete census of rock-wallabies in each colony.

scholarly journals Role of free-ranging mammals in the deposition of Escherichia coli into a Texas floodplain

2013 ◽  
Vol 40 (7) ◽  
pp. 570 ◽  
Author(s):  
Israel D. Parker ◽  
Roel R. Lopez ◽  
Reema Padia ◽  
Meghan Gallagher ◽  
Raghupathy Karthikeyan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Population Density ◽  
Didelphis Virginiana ◽  
Large Mammals ◽  
Density Estimates ◽  
Cedar Creek ◽  
E Coli ◽  
Free Ranging

Context The role of wildlife in faecal pollution of water bodies (deposition of Escherichia coli (E. coli)) is not well understood. Current water-quality and land-use planning research largely relies on unreliable wildlife data (e.g. poor sourcing of abundance estimates, population density estimates applied to multiple fundamentally different areas, suspect or insufficiently described data collection techniques) Aims Our goal for the present research was to investigate deposition of E. coli into a floodplain by free-ranging mammals. Objectives of the research were to determine the density of important free-ranging meso- and large mammals in the study area, determine faecal E. coli loads for each species, and evaluate spatial data on species-specific faecal deposition. Methods We conducted our research in south-eastern Texas, USA, on two cattle ranches bisected by Cedar Creek (44-km long). Cedar Creek has elevated E. coli concentrations. We conducted mark–recapture and mark–resight population density estimates (2008/09) for meso- and large mammals in the study areas. We collected faecal samples from all captured wildlife. We also conducted transects through the study area to determine faecal-deposition patterns. Key results We found that raccoons (Procyon lotor), wild pigs (Sus scrofa), Virginia opossums (Didelphis virginiana) and white-tailed deer (Odocoileus virginianus) all had substantial faecal E. coli loads and population densities, thus implying an important role in E. coli deposition into the study floodplain. All species were widely distributed through the floodplain. Conclusions Free-ranging mammals contribute E. coli to floodplains and potentially affect water quality. We determined that four species commonly found in floodplains throughout North America all contributed E. coli to the study floodplain, thus implying mammal E. coli contributions in many locations and this is potentially important for E. coli management. Implications Improved locally specific mammal population estimates and estimates of locally derived E. coli concentration will improve floodplain and water-quality models that often depend on data of various quality. Additionally, our analyses demonstrated the need for continued research into the role of wildlife in E. coli deposition.

Scat contents of the spotted-tailed quoll Dasyurus maculatus in the New England gorges, north-eastern New South Wales

2007 ◽  
Vol 55 (1) ◽  
pp. 63 ◽  
Author(s):  
Peter J. Jarman ◽  
Lee R. Allen ◽  
Dennis J. Boschma ◽  
Stuart W. Green
Keyword(s):  
New England ◽  
Small Mammals ◽  
New South ◽  
New South Wales ◽  
Large Mammals ◽  
Terrestrial Mammal ◽  
South Wales ◽  
Arboreal Marsupials ◽  
North Eastern ◽  
Fly Larvae

In 1313 scats of the spotted-tailed quoll Dasyurus maculatus, collected over 5 years from the gorge country of north-eastern New South Wales, the most frequent and abundant items were derived from mammals and a restricted set of insect orders. These quolls also ate river-associated items: waterbirds, eels, crayfish, aquatic molluscs and even frogs. Macropods contributed most of the mammal items, with possums, gliders and rodents also being common. Some food, particularly from macropods and lagomorphs, had been scavenged (as shown by fly larvae). The most frequent invertebrates were three orders of generally large insects Coleoptera, Hemiptera and Orthoptera, which were most frequent in summer and almost absent in winter scats. Monthly mean numbers of rodent and small dasyurid items per scat were inversely related to these large insects in scats. The numbers of reptile items were inversely related to the numbers of mammal (especially arboreal and small terrestrial mammal) items per scat, thus types of items interacted in their occurrences in monthly scat samples. Frequencies of most vertebrate items showed no seasonal, but much year-to-year, variation. This quoll population ate four main types of items, each requiring different skills to obtain: they hunted arboreal marsupials (possibly up trees), terrestrial small mammals and reptiles (on the ground), and seasonally available large insects (on trees or the ground), and scavenged carcases, mostly of large mammals but also birds and fishes (wherever they could find them).

scholarly journals Urinary suPAR: a non-invasive biomarker of infection and tissue inflammation for use in studies of large free-ranging mammals

2020 ◽  
Vol 7 (2) ◽  
pp. 191825 ◽  
Author(s):  
James P. Higham ◽  
Christiane Stahl-Hennig ◽  
Michael Heistermann
Keyword(s):  
Immune Activation ◽  
Rhesus Macaques ◽  
Soluble Form ◽  
Surgical Trauma ◽  
Large Mammals ◽  
Urokinase Plasminogen Activator Receptor ◽  
Different Temperatures ◽  
Processing And Storage ◽  
Cellular Immune ◽  
Free Ranging

Studies of large free-ranging mammals incorporating physiological measurements typically require the collection of urine or faecal samples, due to ethical and practical concerns over trapping or darting animals. However, there is a dearth of validated biomarkers of immune activation and inflammation that can be measured non-invasively. We here evaluate the utility of urinary measurements of the soluble form of the urokinase plasminogen activator receptor (suPAR), for use as a health marker in studies of wild large mammals. We investigate how urinary suPAR concentrations change in response to viral infection and surgical trauma (inflammation), comparing it to the measurement of a marker of cellular immune activation, urinary neopterin (uNEO), in captive rhesus macaques. We then test the field utility of urinary suPAR, assessing the effects of soil and faecal contamination, sunlight, storage at different temperatures, freeze–thaw cycles, and lyophilization. We find that suPAR concentrations rise markedly in response to both infection and surgery-associated inflammation, unlike uNEO concentrations, which only rise in response to the former. Our field validation demonstrates that urinary suPAR is reasonably robust to many of the issues associated with field collection, sample processing, and storage, as long as samples can be stored in a freezer. Urinary suPAR is thus a promising biomarker applicable for monitoring various aspects of health in wild primates and potentially also other large mammals.

Effectiveness of protected areas in north-eastern New South Wales: recent trends in six measures

2002 ◽  
Vol 106 (1) ◽  
pp. 57-69 ◽  
Author(s):  
R.L Pressey ◽  
G.L Whish ◽  
T.W Barrett ◽  
M.E Watts
Keyword(s):  
Protected Areas ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
North Eastern ◽  
Recent Trends

Outflow ignimbrite sheets from Late Carboniferous calderas, Currabubula Formation, New South Wales, Australia

1983 ◽  
Vol 120 (5) ◽  
pp. 487-503 ◽  
Author(s):  
J. McPhie
Keyword(s):  
New South ◽  
Sedimentary Facies ◽  
Late Carboniferous ◽  
The West ◽  
Pyroclastic Deposits ◽  
Flow Units ◽  
South Wales ◽  
Accretionary Lapilli ◽  
North Eastern ◽  
Thickness Variations

SummaryRegionally mappable, silicic, outflow ignimbrite sheets are interbedded with fluvial volcanogenic conglomerates and sandstones of the Late Carboniferous Currabubula Formation of north-eastern N.S.W. Four of the most widespread of these ignimbrites are described and defined as members. The oldest member is comprised of many thin, originally non-welded flow units. Interbedded accretionary lapilli horizons may indicate phreatomagmatic activity at vent during the eruption in addition to local rain-flushing of co-ignimbrite ash clouds. Of the three other members, two are multiple flow-unit sheets, 160–180 m in aggregate thickness. Substantial portions of these sheets were originally welded. The remaining member is a simple welded ignimbrite characterized by abundant spherulites and lithophysae. Irregular pre-eruption topography and contemporaneous erosion were responsible for thickness variations of the ignimbrite sheets. Some palaeovalleys, now delineated by the ignimbrites, persisted in spite of repeated pyroclastic influxes. Relic pumice, shards and crystal fragments are ubiquitous components of the sedimentary facies of the Currabubula Formation, and were probably derived from originally poorly consolidated pyroclastic deposits such as airfall ash layers and non-welded ignimbrites. No surface trace of the sources of these ignimbrites exists. However, internal facies, thickness variations and volumes of the ignimbrites indicate that they periodically emanated from a multiple-caldera terrain which was continuously active during the Late Carboniferous, and located several kilometres to the west of present exposures.

scholarly journals Modeling Methane Emission from Wetlands in North-Eastern New South Wales, Australia Using Landsat ETM+

2010 ◽  
Vol 2 (5) ◽  
pp. 1378-1399 ◽  
Author(s):  
Clement E. Akumu ◽  
Sumith Pathirana ◽  
Serwan Baban ◽  
Daniel Bucher
Keyword(s):  
Methane Emission ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
North Eastern

On-site domestic wastewater treatment by reed bed in the moist subtropics

2001 ◽  
Vol 44 (11-12) ◽  
pp. 353-360 ◽  
Author(s):  
L. Davison ◽  
T. Headley ◽  
M. Edmonds
Keyword(s):  
New South ◽  
Domestic Wastewater ◽  
Moisture Loss ◽  
Reed Beds ◽  
Treatment Performance ◽  
South Wales ◽  
Domestic Wastewater Treatment ◽  
Australian State ◽  
North Eastern ◽  
Reed Bed

This paper summarises the results of studies on four subsurface flow wetlands (reed beds) located in the moist sub-tropical north eastern corner of the Australian state of New South Wales. The reed beds, which are subjected to a variety of effluent types, all have a gravel substrate planted with Phragmites australis. All four units were found to maintain satisfactory treatment performance year round. Mean removal efficiencies ranged from 56% to 90% (SS), 70% to 93% (BOD), 38% to 66% (TN), 87% to 99.8% (Faecal coliforms), and 42% to 70% (TP - with one seasonal result of 0% for the eight year old unit) for the four reed beds. After eight years in operation the oldest reed bed was showing signs of phosphorus saturation with outlet TP concentrations exceeding inlet concentrations on some occasions. The youngest reed bed studied appeared to be operating efficiently after five months. A summer water balance on one of the reed beds revealed an average crop factor of 1.6 and a moisture loss to atmosphere of 40% of influent flow. Treatment performance (particularly for TN and SS) was found to be negatively correlated with rainfall during one study. The paper discusses the implications of the above results for on-site system designers and regulators and identifies areas for further investigation.

Models of the distribution and abundance of ground-dwelling mammals in the eucalypt forests of north-eastern New South Wales in relation to environmental variables

2002 ◽  
Vol 29 (3) ◽  
pp. 313 ◽  
Author(s):  
P. C. Catling ◽  
R. J. Burt ◽  
R. I. Forrester
Keyword(s):  
Environmental Variables ◽  
New South ◽  
New South Wales ◽  
Slope Position ◽  
Slope Aspect ◽  
Significant Variable ◽  
South Wales ◽  
North Eastern ◽  
Eucalypt Forests ◽  
A Site

Statistical models are presented of the distribution and abundance of ground-dwelling mammals in eucalypt forests in relation to environmental variables within an area of approximately 24 000 km2 in north-eastern New South Wales. Environmental variables are defined as climatic or topographic variables that may be useful to map the distribution of fauna. The environmental variables examined were season, temperature, rainfall, elevation, lithology, steepness of slope, position on slope, aspect and landform profile. The probability of recording some species was higher in spring than autumn and many species were in highest abundance in areas of low temperature (high elevation). Although aspect was a significant variable in a number of models, no species was absent from any aspect category. Mid-slopes down to and including creeks and drainage lines were particularly important for many species, as were areas with flatter terrain. Although we have modelled environmental variables only there will no doubt be longer-term interactions between habitat and environmental variables. Fundamentally, environmental variables will determine the type of habitat present at a site, and the distribution of canopy communities, at least, can be predicted from environmental variables. However, other studies have shown for ground-dwelling mammals that environmental variables contribute little and it is the state of the habitat locally, and particularly the understorey, that determines their presence and abundance at a site. The results are discussed in relation to similar models using habitat variables and in relation to the use of such models in the management of ground-dwelling fauna in forests.

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