Ecology of feral cats (Felis catus) at a refuse dump in coastal southern Victoria, Australia

The ecology and behaviour of a colony of feral cats was studied at a refuse dump at Anglesea, Victoria. Research found that the cats lived at the dump all year round, congregating on the exposed refuse at night. Here they fed mainly on meat scraps, supplementing their diet with local wildlife. Aggression between individual cats was rare, allowing them to live as a colony, rather than as solitary individuals. Although female cats were fecund, breeding success was low, preventing a steady increase in the population. No justification for controlling these cats could be found at this time.

Aspects of the ecology of the Wedge-tailed Eagle, Aquila audax, in southern Victoria

This study investigated the nest site selection characteristics and diet of the Wedge-tailed Eagle, Aquila audax, in southern Victoria. It was found that sites where local topography afforded some protection from adverse weather and where the nest tree was live were most commonly selected. Rabbits were found to the major prey item of this eagle.

Report on the biology and ecology of Limonium hyblaeum Brullo at Port Fairy, Victoria, with respect to its invasive potential

Limonium hyblaeum Brullo, a perennial, salt tolerant plant native to Sicily forms a large invasion at Griffiths Island and along the strand of nearby Ocean Road, in Port Fairy, Victoria. This is causing concern as it has every appearance of having a high invasive potential but there is little known of its biology and ecology. This study therefore aimed to investigate aspects of its biology and ecology at Griffiths Island and nearby Ocean Road to identify any characteristics that would indicate its invasive nature, quantitatively determine its impact and determine how invasive it was. It was identified as having some key 'weed' attributes, i.e. being apomictic, allelopathic, fast growing in terms of both cover (40% increase in cover between spring and summer or 0.6 m along a transect line) and dry weight, being able to grow in saline and non-saline conditions and of being a transformer. A weed risk assessment demonstrated it was highly invasive and swift management of the species is recommended.

Little penguin Eudyptula minor at Middle Island, Western Victoria : current status

We examined the status of the Little Penguin Eudyptula minor at Middle Island on the west coast of Victoria during the species' 1999/2000 breeding season. The vegetated upper surface of the island had 292 occupied burrows at a density of 0.02/m². Peak dusk arrival occurred in January with 502 penguins coming ashore during a one-hour period. Little Penguins at Middle Island displayed important differences in breeding ecology from penguins in other Australian colonies. Early breeding combined with heavier adult and chick weights resulted in high breeding success. However, as Middle Island is a popular destination for day visitors, during the 1999/2000 Little Penguin breeding season, tourism ·was found to cause detrimental effects, including deaths of some eggs and chicks. There are also concerns for the conservation of the Little Penguin colony as faxes or dogs may readily access the island.

Foraging ecology of ground-feeding woodland birds in temperate woodlands of Southern Australia

Ground-foraging birds of temperate woodlands of southern Australia are prominent among bird species considered to be susceptible to population decline. We examined the foraging ecology, including foraging substrates, actions and heights, of 13 ground-foraging species at four woodland sites in northern Victoria. Nine species are regarded as declining in southern Australia and four are considered common. Ten foraging substrates were identified, of which leaf-litter (54% of observations) and bare ground (17%) were most frequently used. In all woodland sites, litter was used more frequently than expected from its proportional cover. Bare ground was frequently used as a substrate by individual species, and fallen timber and grass were important for some species. Most species were generalists in their use of substrates. Six foraging actions were observed, of which gleaning and pouncing were most frequently recorded. All species foraged close to the ground and four foraged almost entirely at ground level. For pouncing birds, dead branches and fallen timber were the most important launch substrates from which pouncing actions were initiated. Eight of the 13 species differed in some aspect of their foraging ecology between woodland sites, especially in relation to the use of substrates (seven species). Fewer species (four) displayed differences in foraging ecology between seasons, with the greatest seasonal variation being in use of foraging substrates (three species). Overall, no significant differences were evident in the foraging ecologies of common and declining species. Species in both groups encompassed a wide range of foraging behaviours. Owing to this range in foraging ecology, the conservation of diverse assemblages of ground-foraging birds requires the maintenance of heterogeneous ground layers and careful management of disturbance processes.

Miraculous draught of fishes

This print hung in Alfred Deakin's study in 'Llanarth', South Yarra. It is a print of Raphael's original cartoon for the Sistine Chapel tapestries, drawn by him and his workshop in 1515. The original cartoona are in the Victoria and Albert Museum.

Biology curriculum for the senior secondary level in Victoria, Australia

In Victoria, the Victorian Certificate of Education(VCE) is most common among certificates required to apply any tertiary institute in the Victoria State. Thus, the number of students who take the VCE course is larger than other courses in senior secondary schools. VCE Biology is one of the subjects in natural science area. The subject consists of 4 units: Unit 1 is ecology oriented, Unit 2 is cell biology oriented, Unit 3 is physiology and developmental biology oriented, and Unit 4 is systematics, genetics and evolution oriented. One of the distinctive features of the VCE Biology is its assignment. Three or four tasks are prepared in each unit of the subject. In order to complete the assignment, students should carry out some laboratory work, field studies and investigations to collect data and information from a number of sources. They also need to analyze data to write some reports. In Unit 3 and 4, Common Assessment Tasks(CATs), which include writing report and paper test, and prepared. Another distinctive feature of the curriculum is that there are some applied biological aspects in the contents of each unit.

Challenges for native grassland conservation on Victoria's Northern Plains

Discusses some of the challenges faced in attempting to retain and conserve grasslands on Victoria's Northern Plains over the past decade. The development of a strategic vision and directions and opportunities for the future are highlighted.

Conservation ecology and breeding biology of the white-browed treecreeper, Climacteris affinis

The White-browed Treecreeper Climacteris affinis is one of many woodland-dependent birds that are at risk from the encroachment of human-dominated land-uses into natural landscapes. The White-browed Treecreeper inhabits semi-arid woodlands in north-west Victoria, Australia, a vegetation community that has undergone extreme modification in the last century due to the expansion of agriculture in the region. Extant woodlands represent only 10% of the original woodland cover in the region, and are highly fragmented and disturbed in many districts. Thus, the survival of the White-browed Treecreeper may depend on active management. However, current knowledge of the ecology and biology of this species is virtually non-existent, and inadequate for informed and effective conservation actions. The aim of this thesis is to redress this situation and provide the ecological basis for sound conservation management of the species. The thesis consists of two parts: an investigation of habitat use at three spatial scales and a study of the social organization, nesting requirements, breeding behaviour and reproductive success of a population of White-browed Treecreepers. Fifty-six patches of remnant woodland in north-west Victoria were surveyed to determine the factors affecting the occurrence of the White-browed Treecreeper at the regional scale. It was detected in 16 patches, and was largely confined to two core districts - Yarrara and, Wyperfeld (Pine Plains). The floristic composition of the dominant tree species was an important determinant of patch occupancy, with the results providing quantitative support for the previously suspected affinity for Belah Casuarina pauper and Slender Cypress-pine Callitris gracilis — Buloke Allocasuarina luehmannii woodlands. However, the absence of the White-browed Treecreeper from several districts was due to factors other than a lack of appropriate habitat. Demographic isolation - the distance from the focal patch to the nearest population of the White-browed Treecreeper - was the most important variable in explaining variation in patch occupancy. Patches isolated from other treecreeper populations by more than 8.3 km in landscapes of non-preferred native vegetation, and 3 km in agricultural landscapes, were unlikely to support the White-browed Treecreeper. The impact of habitat loss and fragmentation on the capacity of individuals to move through the landscape (i.e. functional connectivity) is considered in relation to disruption to dispersal and migration, and the potential collapse of local metapopulations. Habitat use was then examined in a network of patches and linear strips of Belah woodland embedded in a predominantly cultivated landscape. A minimum area of 18.5 ha of Belah woodland was identified as the most important criterion for patch occupancy at the local scale. This landscape appeared to be permeable to movement by the White-browed Treecreeper, facilitated by the extensive network of linear habitat, and clusters of small to medium fragments. The third scale of habitat use investigated the frequency of use of 1-ha plots within tracts of occupied woodland. It is important to discriminate between habitat traits that operate at the population level, and those that act as proximate cues for habitat selection by individuals. Woodlands that have high tree density, extensive cover of low-stature shrubs, abundant lichen, a complex vertical structure, and relatively low cover of grass and herbs are likely to support larger populations of the White-browed Treecreeper. However, individuals appeared to be using tree dominance (positive) and tall shrub cover (negative) as proximate environmental stimuli for habitat selectivity. A relatively high cover of ground lichen, which probably reflects a ground layer with low disturbance and high structural complexity, was also a reliable indicator of habitat use. Predictive models were developed which could be used to plan vegetation management to enhance habitat for the White-browed Treecreeper. The results of the regional, landscape and patch-scale investigations emphasise that factors operating at multiple spatial scales influence the suitability of remnant vegetation as habitat for the White-browed Treecreeper. The White-browed Treecreeper is typical of many small Australian passerines in that it has high annual survival, small clutches, a long breeding season, multiple broods and relatively low reproductive rates. Reproductive effort is adjusted through the number of clutches laid rather than clutch size. They occupy relatively large, all-purpose territories throughout the year. However, unlike many group territorial birds, territory size was not related to the number of occupants. The White-browed Treecreeper nests in tree hollows. They select hollows with a southerly orientation where possible, and prefer hollows that were higher from the ground. At Yarrara, there was considerable spatial variation in hollow abundance that, in concert with territorial constraints, restricted the actual availability of hollows to less than the absolute abundance of hollows. Thus, the availability of suitable hollows may limit reproductive productivity in some territories, although the magnitude of this constraint on overall population growth is predicted to be small. However, lack of recruitment of hollow-bearing trees would increase the potential for hollow availability to limit population growth. This prospect is particularly relevant in grazed remnants and those outside the reserve system. Facultative cooperative breeding was confirmed, with groups formed through male philopatry. Consequently, natal dispersal is female-biased, although there was no skew in the sex ratio of the fledglings or the general adult population. Helpers were observed performing all activities associated with parenting except copulation and brooding. Cooperatively breeding groups enjoyed higher fledgling productivity than simple pairs, after statistically accounting for territory and parental quality. However, the difference reflected increased productivity in the 1999-breeding season only, when climatic conditions were more favourable than in 1998. Breeding commenced earlier in 1999, and all breeding units were more likely to attempt a second brood. However, only breeders with helpers were successful in fledging second brood young, and it was this difference that accounted for the overall discrepancy in productivity. The key mechanism for increased success in cooperative groups was a reduction hi the interval between first and second broods, facilitated by compensatory reductions in the level of care to the first brood. Thus, females with helpers probably achieved significant energetic savings during this period, which enabled them to re-lay sooner. Furthermore, they were able to recommence nesting when the fledglings from the first brood were younger because there were more adults to feed the dependent juveniles. The current utility, and possible evolutionary pathways, of cooperative breeding is examined from the perspective of both breeders and helpers. Breeders benefit through enhanced fledgling productivity in good breeding conditions and a reduction in the burden of parental care, which may impart significant energetic savings. Further, breeders may facilitate philopatry as a means for ensuring a minimum level of reproductive success. Helpers benefit through an increase in their inclusive fitness in the absence of opportunities for independent breeding (i.e. ecological constraints) and access to breeding vacancies in the natal or adjacent territories (i.e. benefits of philopatry). However, the majority of breeding unit-years comprised unassisted breeders, which suggests that pairs are selectively favoured under certain environmental or demographic conditions.

Flowering ecology of a Box-Ironbark Eucalyptus community

Box-Ironbark forests occur on the inland hills of the Great Dividing Range in Australia, from western Victoria to southern Queensland. These dry, open forests are characteristically dominated by Eucalyptus species such as Red Ironbark E. tricarpa, Mugga Ironbark E. sideroxylon and Grey Box E. microcarpa. Within these forests, several Eucalyptus species are a major source of nectar for the blossom-feeding birds and marsupials that form a distinctive component of the fauna. In Victoria, approximately 83% of the original pre - European forests of the Box-Ironbark region have been cleared, and the remaining fragmented forests have been heavily exploited for gold and timber. This exploitation has lead to a change in the structure of these forests, from one dominated by large 80-100 cm diameter, widely -spaced trees to mostly small (≥40 cm DBH), more densely - spaced trees. This thesis examines the flowering ecology of seven Eucalyptus species within a Box-Ironbark community. These species are characteristic of Victorian Box-Ironbark forests; River Red Gum E. camaldulensis, Yellow Gum E. leucoxylon, Red Stringybark E. macrorhyncha, Yellow Box E. melliodora, Grey Box E. microcarpa, Red Box E. polyanthemos and Red Ironbark E. tricarpa. Specifically, the topics examined in this thesis are: (1) the floral character traits of species, and the extent to which these traits can be associated with syndromes of bird or insect pollination; (2) the timing, frequency, duration, intensity, and synchrony of flowering of populations and individual trees; (3) the factors that may explain variation in flowering patterns of individual trees through examination of the relationships between flowering and tree-specific factors of individually marked trees; (4) the influence of tree size on the flowering patterns of individually marked trees, and (5) the spatial and temporal distribution of the floral resources of a dominant species, E. tricarpa. The results are discussed in relation to the evolutionary processes that may have lead to the flowering patterns, and the likely effects of these flowering patterns on blossom-feeding fauna of the Box-Ironbark region. Flowering observations were made for approximately 100 individually marked trees for each species (a total of 754 trees). The flower cover of each tree was assessed at a mean interval of 22 (+ 0.6) days for three years; 1997, 1998 and 1999. The seven species of eucalypt each had characteristic flowering seasons, the timing of which was similar each year. In particular, the timing of peak flowering intensity was consistent between years. Other spatial and temporal aspects of flowering patterns for each species, including the percentage of trees that flowered, frequency of flowering, intensity of flowering and duration of flowering, displayed significant variation between years, between forest stands (sites) and between individual trees within sites. All seven species displayed similar trends in flowering phenology over the study, such that 1997 was a relatively 'poor' flowering year, 1998 a 'good' year and 1999 an 'average' year in this study area. The floral character traits and flowering seasons of the seven Eucalyptus species suggest that each species has traits that can be broadly associated with particular pollinator types. Differences between species in floral traits were most apparent between 'summer' and 'winter' flowering species. Winter - flowering species displayed pollination syndromes associated with bird pollination and summer -flowering species displayed syndromes more associated with insect pollination. Winter - flowering E. tricarpa and E. leucoxylon flowers, for example, were significantly larger, and contained significantly greater volumes of nectar, than those of the summer flowering species, such as E. camaldulensis and E. melliodom. An examination of environmental and tree-specific factors was undertaken to investigate relationships between flowering patterns of individually marked trees of E. microcarpa and E. tricarpa and a range of measures that may influence the observed patterns. A positive association with tree-size was the most consistent explanatory variable for variation between trees in the frequency and intensity of flowering. Competition from near-neighbours, tree health and the number of shrubs within the canopy area were also explanatory variables. The relationship between tree size and flowering phenology was further examined by using the marked trees of all seven species, selected to represent five size-classes. Larger trees (≥40 cm DBH) flowered more frequently, more intensely, and for a greater duration than smaller trees. Larger trees provide more abundant floral resources than smaller trees because they have more flowers per unit area of canopy, they have larger canopies in which more flowers can be supported, and they provide a greater abundance of floral resources over the duration of the flowering season. Heterogeneity in the distribution of floral resources was further highlighted by the study of flowering patterns of E. tricarpa at several spatial and temporal scales. A total of approximately 5,500 trees of different size classes were sampled for flower cover along transects in major forest blocks at each of five sample dates. The abundance of flowers varied between forest blocks, between transects and among tree size - classes. Nectar volumes in flowers of E. tricarpa were sampled. The volume of nectar varied significantly among flowers, between trees, and between forest stands. Mean nectar volume per flower was similar on each sample date. The study of large numbers of individual trees for each of seven species was useful in obtaining quantitative data on flowering patterns of species' populations and individual trees. The timing of flowering for a species is likely to be a result of evolutionary selective forces tempered by environmental conditions. The seven species' populations showed a similar pattern in the frequency and intensity of flowering between years (e.g. 1998 was a 'good' year for most species) suggesting that there is some underlying environmental influence acting on these aspects of flowering. For individual trees, the timing of flowering may be influenced by tree-specific factors that affect the ability of each tree to access soil moisture and nutrients. In turn, local weather patterns, edaphic and biotic associations are likely to influence the available soil moisture. The relationships between the timing of flowering and environmental conditions are likely to be complex. There was no evidence that competition for pollinators has a strong selective influence on the timing of flowering. However, as there is year-round flowering in this community, particular types of pollinators may be differentiated along a temporal gradient (e.g. insects in summer, birds in winter). This type of differentiation may have resulted in the co-evolution of floral traits and pollinator types, with flowers displaying adaptations that match the morphologies and energy requirements of the most abundant pollinators in any particular season. Spatial variation in flowering patterns was evident at several levels. This is likely to occur because of variation in climate, weather patterns, soil types, degrees of disturbance and biotic associations, which vary across the Box-Ironbark region. There was no consistency among sites between years in flowering patterns suggesting that factors affecting flowering at this level are complex. Blossom-feeding animals are confronted with a highly spatially and temporally patchy resource. This patchiness has been increased with human exploitation of these forests leading to a much greater abundance of small trees and fewer large trees. Blossom-feeding birds are likely to respond to this variation in different ways, depending upon diet-breadth, mobility and morphological and behavioural characteristics. Future conservation of the blossom-feeding fauna of Box-Ironbark forests would benefit from the retention of a greater number of large trees, the protection and enhancement of existing remnants, and revegetation with key species, such as E. leucoxylon, E. microcarpa and E. tricarpa. The selective clearing of summer flowering species, which occur on the more fertile areas, may have negatively affected the year-round abundance and distribution of floral resources. The unpredictability of the spatial distribution of flowering patches within the region means that all remnants are likely to be important foraging areas in some years.

Ecology of epifaunal caridean shrimps in the Hopkins River estuary, and the role of estuaries in the life history of the atyid "Paratya Australiensis" Kemp, 1917 in south-eastern Australia

This study examined the factors affecting the distribution and abundance of epifaunal caridean shrimps in seagrass meadows of the Hopkins River estuary in south-western Victoria, Australia, and investigated the life history patterns of the freshwater Parana australiensis, found for the first time in estuaries. Adult and sub-adult shrimps were surveyed in seagrass meadows along the estuary over two years, and their planktonic larvae were surveyed in adjacent waters. Three species were collected. The marine Palaemon serenus occurred only near the mouth, summer to autumn, in high salinities. The marine/estuarine Macrobrachium intermedium occurred throughout the estuary. Adults were most abundant in late autumn, and least abundant in summer (unlike trends reported in marine meadows). Densities were higher and less variable in downstream meadows. P. australiensis occurred in the upper estuary all year, most abundantly in spring, due to migration from the river after peak discharge. Ovigerous females dominated, while males, showing less migration into the estuary, dominated above estuarine influence. Adults disappeared from the estuary in summer as salinity rose. Breeding period for P. australiensis was briefer in the estuary (September-December) than upstream (July-April). M. intermedium began breeding later in the upper estuary (November/December-March) than in the lower estuary (October-March), probably reflecting a physiological response to lower salinity, rather than an interaction with P. australiensis. No ovigerous P. serenus were found in the estuary. Larvae of P. australiensis and M intermedium occurred abundantly throughout the estuary, but P. serenus larvae did not. P. australiensis was an early coloniser to the plankton after peak discharge (November-December). Larvae concentrated in the deep saline layer at the head of the intruding salt wedge, thus probably maintaining longitudinal position. Diurnal vertical migrations were evident within the salt wedge, and in a deep pool above tidal influence. M. intermedium larvae occurred October-May in the lower estuary and November-April in the upper estuary, peaking in abundance one to two months after P. australiensis. They were associated with low surface flows and surface salinities greater than 10, over an anoxic deeper layer. All three species exhibited extended development of euryhaline larvae in the laboratory. Tolerances and optimal salinities of larvae of the three species reflected their distributions. M. intermedium was the most euryhaline species. P. australiensis larvae were tolerant of higher salinities than juveniles of adults: capable of developing in salinity of at least 15. Most P. australiensis juveniles recruited to the estuary November-December, after which numbers declined dramatically. After settlement, most recruits probably migrated upstream out of the estuary. Two cohorts of M. intermedium recruited to the estuary from larvae in summer (December and February), but some juveniles also migrated from adjacent coastal waters. Post-larval migration was at least as important a determinant of abundance as direct recruitment from estuarine, planktonic larvae in all three species. Distributions among seagrass meadows along the estuary were determined primarily by physico-chemical patterns driven by hydrological changes. Seasonal variations in salinity and temperature were strongly associated with seasonal variations in shrimp abundance. Salinity tolerances of adults of the three species reflected their distribution patterns. Biotic interactions were more important in determining distributions within meadows. P. australiensis, when abundant, were associated with seagrass biomass. M. intermedium were also, but when seagrass was sparsest and least extensive. The two species apparently partitioned the seagrass meadow according to depth in early summer. Laboratory experiments suggested P. australiensis was displaced from deeper water by M. intermedium. Preference for vegetative complexity and competition for position within meadows suggest the underlying importance of predation in regulating shrimp populations. A survey of south-eastern Australian estuaries found P. australiensis larvae abundant in all stable, open, well-developed, salt-wedge estuaries where adults were abundant. Adults were most abundant in low salinities among submerged leafy macrophytes. Reproductive traits of P. australiensis were compared in estuarine and fresh reaches of three rivers. Early in the breeding season, egg size was smaller, and (size-specific) egg number larger in estuaries than upstream. A trade-off between egg size and egg number resulted in no difference in total (size-specific) reproductive investment between locations. Reproductive investment tended to decrease at some locations over the breeding season, and this decrease was a result of decreased egg size in most cases. The decrease in reproductive investment probably reflected reduced food availability for the adult, while the reduced egg size was probably a response to improved conditions for larval development. In the Hopkins River, larger egg size at upstream sites was reflected in larger early stage larvae. Later stage larvae were larger in the estuary, suggesting more favourable conditions for larval development. Allozyme electrophoresis showed the P. australiensis populations in each of the three rivers to be distinct. Allozyme frequencies were not different within the Hopkins River, but upstream and estuarine locations in the Curdies and Gellibrand were different. Although some variation in reproductive traits within catchments may have been due to genotypic differences, trade-offs between egg size and number, and decreases in egg size over summer were probably due to plastic responses to environmental cues. It is proposed P. australiensis inhabits and reproduces in both estuarine and freshwater environments by plastic response to environmental conditions. Recruitment to estuaries is dependent on the presence of suitable adult, littoral habitat, and a stable salt wedge for larval retention. Estuaries are important recruitment sites for P. australiensis, potentially allowing an extra brood each year before riverine recruitment. Estuarine broods could constitute a large part of the total fecundity of P. australiensis females. Euryhaline larvae and estuarine recruitment of P. australiensis suggest marine transport of larvae between estuaries as a possible dispersal mechanism for Paratya species.