bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Helicopter Line Transects with Walked Line Transects for Estimating Densities of Kangaroos
Authors: Clancy T. F. , Pople A. R. , Gibson L. A.
Published: August 2004

The performance of helicopter surveys for estimating population densities of
red kangaroos (Macropus rufus), eastern grey kangaroos
(Macropus giganteus) and common wallaroos
(Macropus robustus) was investigated by comparing
line-transect density estimates obtained from helicopter surveys with those
from ground (walked) surveys. Comparisons were made at four sites in central
western Queensland (areas with high densities of red kangaroos and common
wallaroos) that were surveyed during winter and summer from December 1991
until February 1995, and one site in south-eastern Queensland (an area of high
eastern grey kangaroo density) surveyed annually during autumn from March 1991
until March 1994. Helicopter surveys generally recorded lower sample sizes
than did ground surveys (means ± s.e = 34 ± 6%, 33
± 9% and 76 ± 2% lower for red kangaroos, eastern
grey kangaroos and wallaroos, respectively). Density estimates obtained from
the helicopter surveys were not significantly different from those obtained
from ground surveys for both red and eastern grey kangaroos as assessed by
repeated-measures ANOVA and regression analysis. However, helicopter surveys
of common wallaroos consistently returned density estimates about half those
of ground surveys. The relationships between the two methods did not differ
between winter and summer for any species. The conventional aerial survey
method for kangaroos of strip transects from fixed-wing aircraft has limited
ability to adjust for varying sightability conditions. Therefore, helicopter
surveys with line-transect sampling are an attractive alternative.
The ‘Judas’ Pig Technique: a Method that Could Enhance Control Programmes against Feral Pigs, Sus scrofa
Authors: McIlroy J. C. , Gifford E. J.
Published: August 2004

The successful ‘Judas’ goat technique has been adapted for use
with feral pigs. The ‘Judas’ goat technique involves releasing
radio-collared goats into a control area and, after a sufficient period to
allow them to join other goats, tracking them down and culling the other
individuals associated with them.
Trials with the technique on feral pigs in Namadgi National Park, ACT,
indicated that it worked best with sows captured in the same area. Each of
these sows established contact with 1–8 other pigs in the area within
1–7 days of release and was located with at least one other pig on
67–100% of occasions. In contrast, sows and boars from outside
the study area took longer to come into contact with ‘local’ pigs
and associated with them much less frequently.
A subsequent control exercise in Namadgi, using ‘Judas’ pigs to
indicate where to lay warfarin baits from a helicopter, resulted in a
75% reduction in the low-density population still present after a
larger control exercise two years earlier. Since then, the technique has been
used to eradicate a small colony of feral pigs in central Australia and is
proving successful for control of feral pigs and other ungulates in other
parts of Australia and New Zealand.
Estimating body condition in the mountain brushtail possum, Trichosurus caninus
Authors: Viggers K. L. , Lindenmayer D. B. , Cunningham R. B. , Donnelly C. F.
Published: August 2004

Two methods of assessing body condition were examined for the mountain
brushtail possum, Trichosurus caninus (Ogilby) at a
single study site in central Victoria, south-eastern Australia. Condition
indices were derived from measures of skeletal size and body mass, and body
water composition was determined using isotopic dilution of tritiated water to
give an estimate of total body water space. There were significant negative
relationships between body water composition and the condition indices for
body length, total length and pes length. Body water composition of
T. caninus was significantly higher in spring than in
winter, and those animals with higher body water composition had lower
absolute neutrophil counts and higher urea values. The relative usefulness of
the two methods used for estimating body condition in
T. caninus is discussed.
Powerline Easements: Do They Promote Edge Effects in Eucalypt Forest for Small Mammals?
Authors: Goldingay Ross L. , Whelan Robert J.
Published: August 2004

The distribution and abundance of small terrestrial mammals were assessed in
forest adjacent to powerline easements at three different sites in New South
Wales. At each site, four transects of 300 m length extended into the forest
from the edge of the easement. The abundances of two native species
(Antechinus stuartii,
Rattus fuscipes) did not differ significantly with
distance from the easement but abundances differed markedly among sites.
Mammals were captured in only one easement where dense vegetation was present.
Feral carnivores, which may mediate edge effects on small mammals, were
surveyed by using hair-sampling tubes. Cats and dogs were detected only
50–200 m inside the forest. Foxes were not detected by hair-tubes but
were observed on two easements. These results suggest that powerline easements
may not create edge effects in eucalypt forest for some native mammal species,
although further studies are needed to determine the generality of this
conclusion. We recommend that easement management should be more benign to
native mammals, given the ubiquity of this form of habitat fragmentation.
Promotion of dense vegetative cover and habitat linkages within easements
could achieve this.
Reliability of morphometric measures for determining the sex of adult and fledgling shy albatrosses, Diomedea cauta cauta, in Australia
Authors: Hedd April , Gales Rosemary , Brothers Nigel
Published: August 2004

Dissection and measurement of the carcasses of shy albatrosses,
Diomedea cauta cauta, provided morphometric data from
known-sex birds from fledgling age to adulthood. These data were used to
determine the efficacy of external measures for reliably identifying the sex
of birds in the field. As fledglings were smaller than adults and subadults in
all measures, separate age-specific equations were developed for assigning
their sex. Sexual dimorphism was evident in all head, beak and leg
measurements for the adult and subadult birds, with males being significantly
larger than females, while there were no sex differences in measures of the
wings and tail. Beak and head measurements, along with the weight of
fledglings, were taken, and sex differences were evident for all parameters. A
stepwise discriminant function analysis of the seven head and beak measures
(head length, head width, basal bill width, culmen length, basal bill depth,
minimum bill depth and upper bill depth) indicated that 98% of adult
and subadult birds could be correctly sexed by measuring the upper bill depth
and head width, whilst the sex of 89% of fledglings could be discerned
by measuring head length and width and the minimum bill depth. Discriminant
scores overlapped less for adults–subadults than for fledglings,
indicating that external measurements may be used more reliably to sex this
age-class. Data from three experienced observers indicated significant
differences in the morphometric measures taken from the same individual
albatrosses. The extent of these differences, however, varied greatly
depending on the measure taken (i.e. beak v. wing
measures), with head and beak measures showing the least inter-observer
differences. Such differences resulted in a decrease in the success rate of
the adult–subadult discriminant function analysis from 98 to 90%.
When working with breeding birds, sex-allocation errors can be reduced by
measuring both members of a pair and allowing the relative size of the
discriminant score to identify the individuals concerned.
The effectiveness of aerial baiting for control of feral pigs (Sus scrofa) in North Queensland
Authors: Mitchell J.
Published: August 2004

This study assessed the proportion of a feral pig population that consumed
aerially distributed baits incorporating a non-toxic biomarker (iophenoxic
acid). Baits were distributed at a rate of 18 baits km-2
over 70 km2 of a seasonally inaccessible habitat. A
total of 102 feral pigs were then captured by trapping and ground-shooting.
Blood samples from 63 adult feral pigs were analysed for the presence of the
biomarker; 40 (63%) were considered to have consumed at least one bait.
Ground-shooting and trapping over 6 days resulted in 18% and 16%
population reduction respectively.
Evaluation of Techniques for Indirect Measurement of Body Composition in a Free-ranging Large Herbivore, the Southern Hairy-nosed Wombat
Authors: Woolnough Andrew P. , Foley William J. , Johnson Christopher N. , Evans Murray
Published: August 2004

Several indirect methods for measuring body composition in a large herbivore,
the southern hairy-nosed wombat (Lasiorhinus latifrons),
were evaluated. Body composition was determined by whole-body chemical
analysis of 15 wild-caught wombats, and compared with several indices of body
fat: total body water measured by isotope dilution, bioelectrical impedance
analysis (BIA), body-mass index, and a body- condition score. Total body water
and total body fat (by soxhlet analysis) were highly correlated
(r2 = 0.97, intercept s.e.
= 1.00). Total body water measured by desiccation was highly correlated
with isotope dilution space (r2
= 0.97, intercept s.e. = 0.43 for deuterium;
r2 = 0.95, intercept s.e.
= 0.44 for H218O).
Percentage body fat by soxhlet analysis was highly correlated with total body
water measured as deuterium dilution space
(r2 = 0.83, intercept s.e.
= 2.46). Multiple linear regression models using BIA plethysmograph
measurements (resistance and impedance) and total body mass, were successful
in predicting body fat (r2
= 0.90, s.e. = 1.99) and total body water
(r2 = 0.90, s.e. =
1.64). Isotope-dilution techniques are the most accurate means of indirectly
measuring total body water and total body fat, but at considerable expense of
time and money. BIA offers reduced accuracy but at less cost and may be useful
for measuring changes in body composition in populations of herbivores.
Body-condition indices and scores correlate poorly with body fat, suggesting
that their application as a means to predict body fat is limited.
The development of a carbon monoxide producing cartridge for rabbit control
Authors: Ross J. , Page R. J. C. , Nadian A. K. , Langton S. D.
Published: August 2004

A new method of rabbit control has been developed using carbon monoxide
generated by ignition of a cartridge containing sodium nitrate, charcoal and
zinc oxide. Ignition of cartridges inside the entrances of an unoccupied
artificial rabbit warren showed that carbon monoxide dispersed poorly through
the warren and diffused out of the warren within 3–4 hours. Wind speed
and direction markedly affected the distribution and persistence of carbon
monoxide. Nevertheless, concentrations of carbon monoxide within most of the
warren were sufficiently high to render rabbits rapidly insensible, but in
some deeper parts of the warren, they remained at low levels, unlikely to have
any effect on rabbits. Field trials showed that treatment of rabbit warrens
with carbon monoxide cartridges (79 ± 10.8% kill) was as
effective as treatment with cyanide powder (78 ± 11.9% kill),
and suggested that rabbits were quickly rendered insensible. Therefore the
technique shows considerable promise as an effective, safe and relatively
humane method of rabbit control.
Assessment of reproductive state in the turtle Mauremys leprosa: a comparison between inguinal palpation and radiography
Authors: Keller Claudia
Published: August 2004

Inguinal palpation and radiography were carried out simultaneously on a sample
of 387 adult female Mediterranean turtles,
Mauremys leprosa, to assess the presence of calcified
oviductal eggs. A significantly higher frequency of pregnant females was
obtained through radiography. Egg-bearing females (as shown on radiographs)
with positive palpation tended to have significantly larger clutches than did
females with negative palpation. Clutches in the earlier calcification stages
were less likely to be detected by palpation than were more calcified eggs.
The frequency of positive palpations of egg-bearing females varied
significantly throughout the nesting season, as a function of variations in
both clutch size and average calcification level.
The effects of forest clearing and regeneration on the fauna of Wivenhoe Park, south-east Queensland
Authors: Green Ronda J. , Catterall Carla P.
Published: August 2004

The effects on terrestrial fauna of clearing, fragmentation and regeneration
of eucalypt forest and woodland were investigated in a former cattle-grazing
area of south-east Queensland. The abundance of species and higher taxa was
compared among four major habitat types: interior of relatively mature forest,
interior of earlier stages of regenerating forest, cleared pasture, and abrupt
edges between the forest and cleared land. The regenerating sites were several
decades old and consisted mainly of Eucalyptus saplings
3–6 m high, with a grassy understorey.
Numbers of pitfall-trapped invertebrate orders were significantly higher in
forest interior and forest edge than in cleared or regenerating sites; numbers
of coleopterans were significantly higher in forest interior sites than in
cleared or regenerating sites; and numbers of isopterans were significantly
higher in both forest interior and forest edge sites than in cleared sites.
Total abundance of native non-flying mammals was significantly higher in
forest interior than elsewhere. Other vertebrates apart from birds were
detected in numbers too low for analysis. Cleared sites supported
significantly lower numbers of avian species and Orders, and of total birds,
than any other habitat in winter, with a similar but non-significant trend in
summer. Forest interior sites showed a significantly higher abundance of
several avian species than any other habitat, but noisy miners and Torresian
crows were significantly more abundant in edge sites than in forest interior
sites. Sites of low regeneration were chiefly utilised by birds characteristic
of forest edge. Many decades of regeneration would appear to be necessary
before many forest-dependant species are adequately supported in these areas.
Implications of prefeeding for the development of bait aversions in brushtail possums (Trichosurus vulpecula)
Authors: Moss Zane N. , O'Connor Cheryl E. , Hickling Graham J.
Published: August 2004

Development of aversions, or learned ‘bait-shyness’, in frequently
poisoned possum (Trichosurus vulpecula) populations is
becoming increasingly detrimental to the efficacy of pest-control operations
in New Zealand. This experiment aimed to identify the effects of prefeeding, a
common management procedure, on the subsequent development of aversions in
possums. Wild possums (n = 96) were captured and
acclimatised, then allocated to one of three treatments groups that for seven
days received either (i) no prefeed, (ii) plain RS5 cereal baits, or (iii)
green-dyed and cinnamon-lured RS5 cereal baits. The possums were then offered
a standard green-dyed and cinnamon-lured RS5 bait that contained a sublethal
dose (0.4 mg kg-1) of the toxin sodium monofluoroacetate
(1080). The possums were tested for development of an aversion towards a toxic
RS5 1080 bait, a prefeed bait, and a prefeed bait containing an alternative
toxin, brodifacoum.
Most (96%) of the non-prefed possums became averse to the 1080 bait
after two exposures, compared with only 55% and 9% of the two
prefed groups. Similarly, 90% and 92% of the non-prefed possums
were averse to prefeed and brodifacoum baits, respectively, compared with
8% and 14% of the prefed possums. This suggests that pest
managers can reduce the risk of ‘bait shyness’ by prefeeding. A
further advantage of prefeeding is that if poison shyness develops, use of an
alternative toxin such as brodifacoum in the original bait base may still be
successful.
An analysis of bait-take and non-target impacts during a fox-control exercise
Authors: Dexter Nick , Meek Paul
Published: August 2004

The effectiveness of a fox-control exercise at the Beecroft Peninsula, New
South Wales, was evaluated by examining the change in proportion of baits
taken during free-feeding and after lethal baiting in four different habitats
(heath, forest, coastal scrub, beach), and the change in number of
radio-collared foxes alive during the course of the baiting exercise. The
change in proportion of baits taken by non-target species was also examined
over the course of the study. Bait take declined by 97% from the
initiation of poison baiting to the final day of poison baiting eight days
later with significantly more baits being taken in heath than in any other
habitat. Four out of six radio-collared foxes died on the first day of poison
baiting while the other two foxes died within ten days of the start of the
poison-baiting session. Black rats, currawongs and ravens took a small number
of baits throughout the baiting exercise.
The impact of bush-rock removal on an endangered snake species, Hoplocephalus bungaroides (Serpentes : Elapidae)
Authors: Shine Richard , Webb Jonathan K. , Fitzgerald Mark , Sumner Joanna
Published: August 2004

We examined the impact of habitat degradation (removal of surface rocks) on an
endangered snake species (Hoplocephalus bungaroides,
Elapidae) at 23 sites in south-eastern Australia, by quantifying the impact of
rock removal on (i) the availability of suitable shelter-sites for the snakes
and their major prey species (the velvet gecko,
Oedura lesueurii), and (ii) the numbers of snakes and
geckos. Our survey showed that both the snakes and the geckos prefer rocks
lying on other rocks, rather than on soil, and select rocks of particular
sizes. The rocks removed by bush-rock collectors overlap considerably in size
(diameter and thickness) and substrate (rock on rock) with those used by
broad-headed snakes and velvet geckos. Multivariate path analysis suggests
that population densities of broad-headed snakes (as measured by capture
rates) may be determined primarily by gecko numbers, which in turn depend upon
availability of suitable rocks. In some sites, rock numbers were substantially
reduced by anthropogenic disturbance. Thus, our survey data suggest that
bush-rock removal has contributed to the endangerment of
H. bungaroides.
Predation by house cats, Felis catus (L.), in Canberra, Australia. II. Factors affecting the amount of prey caught and estimates of the impact on wildlife
Authors: Barratt D. G.
Published: August 2004

Information on the amount of vertebrate prey caught by house cats in Canberra
was collected by recording prey deposited at cat owners’ residences over
12 months. The amount of prey taken was not significantly influenced by cat
gender, age when neutered, or cat breed. Nor did belling or the number of
meals provided per day have a significant influence on the amount of prey
caught. The age of the cat and the proportion of nights spent outside
explained approximately 11% of the variation in the amount of prey
caught by individual cats. In all, 43% of variation in predation on
introduced species (predominantly rodents) was explained by distance from
potential prey source areas (i.e. rural/grassland habitat) and cat
density. The mean number of prey reported per cat over 12 months (10.2) was
significantly lower than mean predation per cat per year based on estimates
made by cat owners before the prey survey began (23.3). Counts of the amount
of prey caught by house cats were highly positively skewed. In all, 70%
of cats were observed to catch less than 10 prey over 12 months, but for
6% of cats, more than 50 prey were recorded. Estimates of predation by
house cats, particularly extrapolated estimates, should be treated with
caution. The total number of prey caught by house cats in Canberra estimated
using the sample median was approximately half the estimate based on the
sample mean. Predation estimates alone do not prove that prey populations are
detrimentally affected, especially in highly disturbed and modified
environments such as suburbs. Impacts on native fauna are likely to be most
significant in undisturbed habitat adjacent to new residential developments.
The spatial and temporal distribution of koala faecal pellets
Authors: Ellis W. A. H. , Sullivan B. J. , Lisle A. T. , Carrick F. N.
Published: August 2004

Faecal pellets were collected under trees used by free-ranging koalas in
south-western, central and south-eastern Queensland to determine the spatial
and temporal distribution of pellets with respect to the activity of koalas.
Deposition of faecal pellets by koalas was analysed according to the time of
day at which the tree was occupied. For free-ranging koalas, 47% of
daily faecal pellet output was recovered using a collection mat of 8 ×
8 m placed under a day-roost tree. The best predictor of pellet production was
the presence of a koala in a tree between 1800 hours and midnight. For other
periods, there was no relationship between period of tree occupancy and faecal
pellet recovery. There was a significant relationship between the average
length of tree occupancy and the time of day that a koala entered a tree.
The effect of manipulating population density on the probability of den-sharing among common brushtail possums, and the implications for transmission of bovine tuberculosis
Authors: Caley P. , Spencer N. J. , Cole R. A. , Efford M. G.
Published: August 2004

Common brushtail possums (Trichosurus vulpecula) act as
a reservoir of bovine tuberculosis (Mycobacterium bovis)
in New Zealand and the simultaneous sharing of dens may result in the
transmission of Tb between possums. The effect of manipulating population
density on the per capita probability of simultaneous
den-sharing among possums was investigated at a site near Dunedin, New
Zealand. Den characteristics that could affect the probability of simultaneous
sharing were also investigated, though none were found to be significant. The
daily probability of a possum sharing a den was estimated to be 0.07 for
possums denning within uncontrolled areas of the study area. Den-sharing was
most common between female pairs, though sharing was also recorded between
male–female and male–male pairs. The highest number of possums
recorded sharing a single den was four. Reducing population density
significantly lowered the probability of possums simultaneously sharing dens
within the study area, with greater than 60% reductions estimated to
eliminate simultaneous den-sharing altogether. The relationship between the
contact rate arising from den-sharing and population density was convex-down,
rather than convex-up, as often hypothesised for animal–animal disease
contact processes. The implications of simultaneous den-sharing for the
transmission and control of bovine tuberculosis in brushtail possum
populations are discussed.
The art and science of wildlife management
Authors: Walker Brian
Published: August 2004

Too much of wildlife management is today still more of an art than a science.
Turning the art into a much- needed predictive science requires including
research in the management process. The key to the process is developing an
appropriate model of how the wildlife system responds to management actions,
applying the actions, monitoring the outcomes, and using this to improve the
management model. Extrapolating management outcomes to different wildlife
areas requires the development of theory, as illustrated by a range of
examples.
Feeding behaviour of the squirrel glider at Bungawalbin Nature Reserve, north-eastern New South Wales
Authors: Sharpe D. J. , Goldingay R. L.
Published: August 2004

The diet of the squirrel glider (Petaurus norfolcensis)
was described by qualitative observations of feeding behaviour at a
floristically rich site on the north coast of New South Wales. Twelve gliders
from six groups were examined over a 10-month period. Flowering and
bark-shedding data were also collected. Nectar and pollen were the most
important food resources and accounted for 59% of all observations.
Banksia integrifolia was the most important source of
these foods, but eucalypts were used heavily when in flower and several other
genera were also visited. Feeding on arthropods constituted 26% of all
feeding observations. Arthropods were harvested in all months of the study
from a variety of substrates. Feeding on arthropods was relatively unimportant
in May and June when pollen ingestion was presumed to be high. Honeydew was
used but was absent from the diet during winter.
Acacia gum was obtained from two species in autumn and
one, Acacia irrorata, was incised to promote gum
production. Corymbia intermedia and
Angophora woodsiana were incised for sap in autumn and
winter. Sap flows resulting from insect (borer) damage on other species were
also used. Fruit, Acacia seeds and arils, and lichens
were consumed on a few occasions. The squirrel glider displayed seasonal
trends in feeding behaviour that, in part, accorded with observed phenological
patterns. The foods used by the squirrel glider during this study were similar
to those previously reported for the genus. However, few studies have
documented such a diversity of dietary items at one site. Management of the
squirrel glider appears to require the maintenance of floristic diversity, and
particularly the persistence of midstorey species.
Spotlight counts, site fidelity and migration of European rabbits (Oryctolagus cuniculus)
Authors: Twigg Laurie E. , Lowe Tim J. , Gray Garry S. , Martin Gary R. , Wheeler Amanda G. , Barker William
Published: August 2004

Regardless of their sex and age, the persistence of 76 rabbits
(Oryctolagus cuniculus) translocated onto 5 different
sites with relatively low rabbit densities was identical to that of resident
rabbits. Emigration and exploratory movements by rabbits from 12 discrete
populations were positively correlated with rabbit density and mainly
undertaken by adult rabbits. Adult males moved significantly more often and
further than adult females. Two peaks in immigration were observed; a large
peak (usually in January) immediately following the breeding season, and a
second but smaller peak in March which preceded the start of the next breeding
season. Again, significantly more adult males than females immigrated. The
proportion of rabbits seen in spotlight counts was positively correlated with
rabbit density, which suggests that biases in population estimates could
result in some situations. No clear patterns on the effects of a variety of
weather variables on spotlight counts could be established, but increasing
rainfall, wind speed and moonlight may have reduced rabbit activity.
The ecology of the European rabbit (Oryctolagus cuniculus) in coastal southern Western Australia
Authors: Twigg Laurie E. , Lowe Tim J. , Martin Gary R. , Wheeler Amanda G. , Gray Garry S. , Griffin Sandra L. , O'Reilly Catherine M. , Butler Tania L. , Robinson David J. , Hubach Peter H.
Published: August 2004

Demographic changes in three free-ranging rabbit
(Oryctolagus cuniculus) populations were monitored over
4 years in southern Western Australia. Peak densities followed periods of high
rainfall and pasture biomass. The breeding season was prolonged, often
extending from at least April to November, with some pregnancies occurring
outside this period. Fecundity, determined by the autopsy of pregnant offsite
rabbits and the known length of each breeding season, appeared to be
relatively high, with the potential for 34–39 kittens
doe-1 year-1; however, because not
all females are pregnant in all months, the overall productivity of these
populations was estimated at 25–30 kittens adult
female-1 year-1. Exponential rates
of increase varied from 0.13 to 0.30 during the breeding periods and
–0.05 to –0.14 during the nonbreeding season. Kitten survival was
generally low whereas some adults lived for more than 5 years. Two patterns of
myxomatosis were observed: annual epizootics of the disease (3 of 4 years) and
an epidemic that slowly spread over many months. European rabbit fleas were
most abundant during winter–spring and attained highest densities on
adult female rabbits.
Secondary poisoning of stoats (Mustela erminea) at low mouse (Mus musculus) abundance in a New Zealand Nothofagus forest
Authors: Brown K. P. , Alterio N. , Moller H.
Published: August 2004

Two different brodifacoum (Talon 20 P™) poisoning regimes effectively
killed 100% of resident radio-tagged stoats
(Mustela erminea) by secondary poisoning in a New
Zealand Nothofagus forest when mice
(Mus musculus) were scarce. Resident possums
(Trichosurus vulpecula) and ship rats
(Rattus rattus) were also killed. The relative
importance of different prey species as sources of poison for stoats has not
been clearly identified but availability of poisoned prey will determine the
efficacy of secondary poisoning in years of low prey abundance. Tracking
tunnels did not accurately measure the decline in the stoat population and
were probably influenced by immigrant stoats that were kill-trapped and
contained high levels of poison. This study corroborates the findings of
several other similar studies that secondary poisoning using brodifacoum
effectively kills stoats.
Shelter selection and home range of echidnas, Tachyglossus aculeatus, in the highlands of south-east Queensland
Authors: Wilkinson Darren A. , Grigg Gordon C. , Beard Lyn A.
Published: August 2004

We recorded physical attributes of sites used for daily shelter or as
hibernacula by nine echidnas, Tachyglossus aculeatus,
living on a sheep-grazing property in south-eastern Queensland. Home ranges
were also determined. For daily shelter sites, echidnas most often used hollow
logs and depressions under the roots of fallen trees. Daily shelters were
found more often on north-facing slopes and usually provided >90%
cover. Hibernation sites always provided 100% cover but, in contrast to
daily sites, were distributed randomly in relation to the slope of the
terrain. Rabbit burrows, which offer much better thermal buffering than hollow
logs, were used most commonly as hibernacula. There were differences between
individuals in the type of shelter they used and, moreover, echidnas did not
use shelter sites in proportion to what was available, indicating that choice
was being exercised. Re-use of sites occurred non-randomly, implying that
echidnas can recognise previously used shelters and probably have a learned
familiarity with their living area. Home ranges varied between 20.6 ha and
93.3 ha (mean = 49.8, s.d. = 25.4), overlapped with those of
other echidnas and correlated positively with body weight.
Variance estimate for the Allen activity index
Authors: Engeman Richard M. , Allen Lee , Zerbe Gary O.
Published: August 2004

The Allen activity index, originally developed for monitoring dingo
populations, is statistically described as a mixed linear model, from which a
variance formula for the index is derived. The resulting formula requires
input of variance component estimates, the estimation of which is accomplished
using restricted maximum-likelihood estimation. An example is used to
demonstrate the calculation of the variance components and their use in the
variance formula. Application of the variance formula substantially enhances
the quantitative practicality of this useful index of wildlife populations.
Use of nest trees by the mountain brushtail possum (Trichosurus caninus) (Phalangeridae : Marsupialia). IV. Transitions between den trees
Authors: Welsh A. H. , Lindenmayer D. B. , Donnelly C. F. , Ruckstuhl A.
Published: August 2004

Statistical models of the patterns of den-tree choice by the mountain
brushtail possum (Trichosurus caninus) at Cambarville in
the mountain ash (Eucalyptus regnans) forests of the
central highlands of Victoria, south-eastern Australia are presented. These
models enable us to predict, for a particular possum, the choice of den tree
on the basis of patterns of recent den-tree usage and are required for
individual-based simulation studies. The models show that the pattern of
den-tree use is more complicated than might have been expected, in the sense
that it is animal-specific, and that old animals exhibit more complicated
patterns of den-tree choice than young ones.
The use of nest trees by the mountain brushtail possum (Trichosurus caninus) (Phalangeridae : Marsupialia). V. Synthesis of studies
Authors: Lindenmayer D. B. , Welsh A. , Donnelly C. F.
Published: August 2004

A general synthesis is presented of the key results of a series of studies of
den tree use by the mountain brushtail possum
(Trichosurus caninus) at Cambarville in the mountain ash
(Eucalyptus regnans) forests of the central highlands of
Victoria, south-eastern Australia. The project produced a range of unexpected
results including (1) the number of den trees used, (2) the extent of den
sharing, especially among adult males, (3) the overlap in denning ranges of
animals, and (4) the predictability of transitions between den trees. Possible
reasons for these findings are outlined. We also discuss the limitations of
our study, how it could be improved if it were to be repeated, and some of the
important implications of the findings for the management of forests where
T. caninus occurs.
Food preferences of house mice (Mus domesticus) and their implications for control strategies
Authors: Robards G. E. , Saunders Glen
Published: August 2004

A series of pen evaluations of food preferences of the house mouse
(Mus domesticus) were conducted to determine whether the
acceptability of poison baits could be enhanced with variations to grain type
and the incorporation of flavour enhancers. Results showed that soft wheat,
canary seed and rice were the most preferred foods, particularly when fish
meal was added. Apart from some differences due to the addition of fishmeal,
none of the additives, flavours or dyes had a statistically significant effect
on food consumption. Management implications of the results are discussed.
The influence of pasture distribution and temperature on habitat selection by feral pigs in a semi-arid environment
Authors: Dexter Nick
Published: August 2004

The two parameters believed to influence habitat utilisation by feral pigs and
wild boar (Sus scrofa) are protection from high
temperatures and distribution of food. However, whether there is an
interaction between these parameters is unknown. To examine the influence of
high temperature on habitat utilisation, the use of four rangeland habitats
(shrubland, woodland, riverine woodland, and ephemeral swamps) by feral pigs
in north-west New South Wales, Australia, was measured by radio-telemetry
during and after a drought. In each habitat, protection from high temperature
was indexed once by vegetation cover, at three strata, while over the course
of the study, food distribution was indexed by estimating pasture biomass in
each habitat. Riverine woodland provided the most shelter from high
temperature, followed by woodland, shrubland and ephemeral swamps. On average,
ephemeral swamps had the highest pasture biomass, followed by riverine
woodland, shrubland and woodland. The amount of pasture in each habitat
increased after the drought but changed at different rates. During autumn,
spring and summer feral pigs preferred riverine woodland but in winter
shrubland was preferred. Multivariate regression indicated that habitat
utilisation was significantly influenced by pasture biomass in shrubland and
mean maximum temperature in the study area. The results suggest that feral
pigs are restricted by high temperatures to more shady habitats during hot
weather but when the constraint of high temperature is relaxed they distribute
themselves more according to the availability of food.
The grouping dynamics of the black-striped wallaby
Authors: Hoolihan D. W. , Goldizen A. W.
Published: August 2004

The grouping dynamics of the black-striped wallaby
(Macropus dorsalis) were investigated using
mark–resight techniques at Taunton National Park, in Central Queensland.
Individually marked black-striped wallabies were observed in groups of varying
size and composition. Marked wallabies were never observed together twice,
despite some individuals being seen up to 15 times. Black-striped wallabies on
Taunton National Park appeared to form the open-membership grouping structure
common to most gregarious macropods. However, black-striped wallabies in the
present study were found to be less gregarious than social macropods in
previous studies.
Reproduction of the whiptail wallaby, Macropus parryi Bennett (Marsupialia : Macropodidae), in captivity with age estimation of the pouch-young
Authors: Johnson P. M.
Published: August 2004

Reproduction of the whiptail wallaby, Macropus parryi,
was studied in captivity. The mean length of the oestrous cycle was 41.8 days
while the mean length of the gestation period was 38.0 days.
M. parryi bred throughout the year and post-partum
oestrus was not recorded although mating did occur during the pouch life when
the pouch-young was 118–168 days of age. The length of the pouch-life
was 256–267 days and weaning occurred 104–215 days after emergence
from the pouch. Sexual maturity for females occurred at 509–647 days of
age. An age-determination table was produced and found useful for predicting
age of pouch-young using body measurements.
Ecology of the western barred bandicoot (Perameles bougainville) (Marsupialia: Peramelidae) on Dorre and Bernier Islands, Western Australia
Authors: Short Jeff , Richards J. D. , Turner Bruce
Published: August 2004

Population structure, reproduction, condition, movements and habitat
preference were assessed for western barred bandicoots
(Perameles bougainville) on Dorre and Bernier Islands
over seven trapping sessions between 1988 and 1995. Data comes from 372
captures of bandicoots in 2535 trap-nights (an average of 14·7 captures
per 100 trap-nights). Trap success was 5.7–25.8% on Dorre and
5.7–7.6% on Bernier. Recaptures within a trip made up 29%
of bandicoot captures. The overall sex ratio (excluding recaptures) was skewed
heavily towards males at 1.7: 1 for trapped animals, but varied between male
and female dominance at any time according to reproductive status of females.
Sex ratio of pouch young was 1.2: 1. Production of young was concentrated in
the wetter winter months. The smallest western barred bandicoot with pouch
young weighed 175 g. Bandicoots showed a pattern of increasing litter size
with size of mother. Females with young had an average litter size of 1.8,
with young reaching independence at about 100 g body weight. Large testes size
relative to body size in males suggested a promiscuous mating system. Body
condition could be predicted by sex (females were typically in better
condition than males) and by rainfall over the previous 2 months. Some sexual
dimorphism was evident, with females having longer heads and typically being
heavier than males. There was no detected dimorphism between island
populations. Movements of bandicoots appeared limited, with the median
distance moved by animals captured more than once within a 9–11-day
trapping session being 154 m. There was no significant difference in movements
between the sexes, with males moving a median distance of 160 m and females
138 m within trapping sessions. The greatest movement by a male was 1020 m
while the greatest distance moved by a female was 490 m. Only 13% of
recorded movements were greater than 400 m. Home ranges overlapped, with
51% of traps catching more than one individual and as many as five
males being caught at the same trap site. Bandicoots were widely dispersed
through all habitats surveyed. Bandicoots appeared to suffer a substantial
reduction in numbers on Dorre Island in a prolonged drought extending from
October 1986 to April 1989, reducing overall trap success to less than
6% in the 1988 survey.
Using the presence and condition of eggshells to determine nest success in the magpie goose, Anseranas semipalmata
Authors: Whitehead Peter J. , Turner Stephen
Published: August 2004

In a sample of 104 closely monitored magpie goose nests, all of 66 successful
nests contained substantial numbers of eggshell fragments
(52–1000+), many embedded deeply in the nest matrix. Detached shell
membranes were also found in all successful nests. All but one of 38
unsuccessful nests contained no shell fragments. The exception contained about
60% of the shell from one egg, but fragments were clearly
distinguishable from shells of hatched eggs because they were contaminated
with egg yolk. Weight of eggshell in individual nests could be related to the
number of hatchlings (excluding failed nests:
r2 = 0.67,
P < 0.0001, n = 39), but
the time required to retrieve and process shell fragments is perhaps too long
to justify routine use to estimate hatchling production for individual nests.
Rather, we suggest that the presence of substantial quantities of eggshell
fragments (>12 g or the equivalent of more than 1 egg) embedded in the nest
matrix be regarded as diagnostic of hatching success. We interpret the clear
discrimination between successful and failed nests as a direct result of
consistent features of magpie goose biology and the breeding environment. The
most important of these are: (i) the prolonged hatching and on-nest brooding
period, during which eggshells from hatched eggs are crushed and their
movement into the nest matrix promoted; (ii) the continuous addition of
vegetation to the nest, often covering shells; (iii) the removal of shells
from damaged (but not hatched) eggs by attending adults; and (iv) the dominant
egg predator being a large snake (the water python, Liasis fuscus) which
consumes eggs whole and hence leaves no shells at the nest site. We suggest
that post-hatch surveys of nest structures should be used to improve
understanding of spatial variation in nest success within colonies, and to
compare success between colonies of different size.
Predation of artificial nests in a fragmented landscape on the New England Tablelands of New South Wales
Authors: Taylor Lee N. H. , Ford Hugh A.
Published: August 2004

Artificial, cup-shaped nests containing one quail egg and one plasticine egg
were placed in small (20 ha), medium-sized (90 ha) and large (350 ha) remnants
of eucalypt woodland. Nests were placed near edges and centres of the two
larger sites; the small site was considered all edge. Overall, 69%
(659/960) of nests were preyed upon within 4 days, reflecting a high
predation pressure. More nests were preyed upon in the medium-sized than in
the larger or smaller sites. Loss of nests was no higher at the edge than in
the centre overall, though it was significantly higher at the edge than the
centre of the largest site. The main predators were identified (from beak
marks on plasticine eggs) as large and medium-sized birds. Our results provide
only weak support for the hypothesis that habitat fragmentation has increased
predation on open nests. It is possible that nest predators and their impact
have increased regionally, rather than locally. Habitat degradation may also
lead to higher predation of nests, due to loss of understorey and an increase
in nest predators.
The gizzard morphology of an avian herbivore: the domestic goose, Anser anser
Authors: Moore S. J.
Published: August 2004

The gizzard of the herbivorous domestic goose,
Anser anser, was investigated in order to understand how
it can break down food such as grass. The gizzard consists of two thick
opposing muscles that are joined on its dorsal and ventral surface by large
tendons. The long axis of the fibre bundles of these muscles are aligned with
the rigid lumen of the gizzard. Thus, the distance between the two tendons
cannot decrease during contraction. Instead, contractions reduce the curvature
of the muscle fibre bundles. This reduction in curvature and associated
swelling of the muscle bundles generates forces in the lumen of the gizzard.
However, as the thick muscles are asymmetrical, these forces generate
translational rather than simple compressive movements. Such movement is also
suggested by the wear on the lining of the gizzard lumen. A band of thin
muscle runs perpendicular to the thick muscles and positions the food in the
lumen in readiness to allow for food breakdown by the thick muscles.
The comparative functional gizzard morphology of several species of birds
Authors: Moore Suzanne J.
Published: August 2004

The gizzards of eight species of birds were studied to investigate the
relationship between diet, gizzard lumen volume and gizzard muscle movement
and contractile force. The similar asymmetry of the gizzard muscles within and
among species suggested that there is an ideal gizzard morphology, which
generates a translational movement, for breaking down plant food. The
narrowness of the gizzard lumen, even in gizzards with relatively large
volumes, suggests the importance of this movement (which is most efficient
when the lumen is narrow) to breaking down plant material. Heavier gizzards
did not necessarily result in greater forces being applied to individual food
items within the gizzard. However, they were capable of processing greater
volumes of food. Discriminant analysis revealed that the greatest forces for
breaking down food were to be found in grass-eating birds. It is suggested
that breakdown of fibrous foods such as grass involves a trade-off, as a
concession to weight reduction, between gizzard muscle mass, and hence the
pressure generated within the gizzard, and the amount of food that can be
processed at any one time.
A Biogeographical Analysis of the Tasmanian Endemic Ptunarra Brown Butterfly, Oreixenica ptunarra Couchman (Lepidoptera : Nymphalidae : Satyrinae)
Authors: McQuillan P. B. , Ek C. J.
Published: August 2004

Considerable geographic variation occurs in the Tasmanian endemic butterfly,
Oreixenica ptunarra, and there is a high correlation
between clusters of morphological characters and ecological factors,
especially climate and elevation. Evidence is presented for the existence of a
longitudinal cline in phenotypic characters of wing pattern and size, which is
unrelated to the modest amount of variation in the male genitalia (a possible
surrogate for genetic variability). Butterflies from warmer, less cloudy
eastern Tasmania are larger and less dark in colour than those from the west,
culminating in the small dark populations of the north-west. This suggests
selection for efficiency in thermoregulation as climatic conditions become
more marginal for adult activity from east to west. The prevailing subspecies
classification does not fully reflect the range of variation in this species.
Conservation strategies that aim to guarantee the survival of the collective
phenotype of O. ptunarra based on this taxonomy are
therefore misinformed. The north-west populations are disjunct geographically
and in features of phenotype, but are not especially discrete in the
morphology of the male genitalia. We propose that the subspecies
angeli Couchman and roonina
Couchman be reduced to synonymy with nominotypical
ptunarra Couchman, and a new subspecies should be
recognised to incorporate populations from the montane grasslands of
north-western Tasmania.