Review of the ecology of Australian urban fauna: A focus on spatially explicit processes

Cities have a major impact on Australian landscapes, especially in coastal regions, to the detriment of native biodiversity. Areas suitable for urban development often coincide with those areas that support high levels of species diversity and endemism. However, there is a paucity of reliable information available to guide urban conservation planning and management, especially regarding the trade-off between investing in protecting and restoring habitat at the landscape level, and investing in programmes to maintain the condition of remnant vegetation at the local (site) level. We review the literature on Australian urban ecology, focusing on urban terrestrial and aquatic vertebrate and invertebrate fauna. We identify four main factors limiting our knowledge of urban fauna: (i) a lack of studies focusing at multiple ecological levels; (ii) a lack of multispecies studies; (iii) an almost total absence of long-term (temporal) studies; and (iv) a need for stronger integration of research outcomes into urban conservation planning and management. We present a set of key principles for the development of a spatially explicit, long-term approach to urban fauna research. This requires an understanding of the importance of local-level habitat quality and condition relative to the composition, configuration and connectivity of habitats within the larger urban landscape. These principles will ultimately strengthen urban fauna management and conservation planning by enabling us to prioritize and allocate limited financial resources to maximize the conservation return.

Epizootic activity of Murray Valley encephalitis and Kunjin viruses in an aboriginal community in the Southeast Kimberley region of Western Australia: Results of mosquito fauna and virus isolation studies

We undertook annual surveys of flavivirus virus activity in the community of Billiluna of Western Australia in the southeast Kimberley region between 1989 and 2001. Culex annulirostris was the dominant mosquito species, particularly in years of above average rains and flooding. Murray Valley encephalitis (MVE) virus was isolated in 8 of the 13 years of the study from seven mosquito species, but more than 90% of the isolates were from Cx. annulirostris. The results suggest that MVE virus is epizootic in the region, with activity only apparent in years with average or above average rainfall and increased numbers of Cx. annulirostris. High levels of MVE virus activity and associated human cases were detected only once (in 1993) during the survey period. Activity of MVE virus could only be partially correlated with wet season rainfall and flooding, suggesting that a number of other factors must also be considered to accurately predict MVE virus activity at such communities.

A modern soft-bottom, shallow-water crinoid fauna (Echinodermata) from the Great Barrier Reef, Australia

A recent preliminary survey revealed that 12 species of unstalked crinoids occur on a gentle sandy slope (12-18 m depth) at Lizard Island, Great Barrier Reef, Australia; five of which are also found on coral reefs. The other seven appear to constitute a unique assemblage restricted to unconsolidated substrates, where most cling to algae or hide beneath rubble or sponges. Members of this assemblage exhibit all of the basic feeding postures found among reef-dwelling species. However, Comatula rotalaria, which lacks anchoring cirri and bears uniquely differentiated short and long arms, exhibits a posture different from other living crinoids. Quantitative transects reveal apparent depth-related differences in species composition: C. rotalaria dominated the 12 transects in 12-13 m (84% of 82 specimens), while Comatella nigra, Comatula cf. purpurea, Amphimetra cf. tessellata and Zygometra microdiscus accounted for 96% of 54 specimens observed along 12 transects in 16-17 m.

In situ measures of spawning synchrony and fertilization success in an intertidal, free-spawning invertebrate

The rocky intertidal zone has the potential to be one of the harshest environments for free-spawning organisms, but empirical data on fertilization success are scarce. Here, I report on an intertidal, solitary ascidian, Pyura stolonifera, which was observed to spawn at low tide. At a scale likely to be most important to gametes (metres, duration of tide), approximately 30% of individuals in the population were spawning synchronously. Spawned gametes remained in a viscous matrix and this appeared to minimise their dilution. Fertilization success varied greatly among individuals (0 to 92%) and was related to the distance to the nearest neighbouring spawner. Occasional wave wash facilitated the movement of sperm between spawners. Fertilization success in some individuals was limited by the scarcity of sperm whilst the experimental addition of sperm did not increase success in others.

Macro-botanical evidence for plant use at Neolithic Catalhoyuk, south-central Anatolia, Turkey

Analysis of charred plant macro-remains, including wood charcoals, cereals, seeds, tubers and fruits from the Neolithic site of Catalhoyuk has indicated complex patterns of plant resource use and exploitation in the Konya plain during the early Holocene. Evidence presented in this paper shows that settlement location was not dictated by proximity to high quality arable land and direct access to arboreal resources (firewood, timber, fruit producing species). A summary of the patterns observed in sample composition and species representation is outlined here together with preliminary interpretations of these results within their broader regional context.

Variation in the dispersal potential of non-feeding invertebrate larvae: the desperate larva hypothesis and larval size

For many species of marine invertebrates, variability in larval settlement behaviour appears to be the rule rather than the exception. This variability has the potential to affect larval dispersal, because settlement behaviour will influence the length of time larvae are in the plankton. Despite the ubiquity and importance of this variability, relatively few sources of variation in larval settlement behaviour have been identified. One important factor that can affect larval settlement behaviour is the nutritional state of larvae. Non-feeding larvae often become less discriminating in their 'choice' of settlement substrate, i.e. more desperate to settle, when energetic reserves run low. We tested whether variation in larval size (and presumably in nutritional reserves) also affects the settlement behaviour of 3 species of colonial marine invertebrate larvae, the bryozoans Bugula neritina and Watersipora subtorquata and the ascidian Diplosoma listerianum. For all 3 species, larger larvae delayed settlement for longer in the absence of settlement cues, and settlement of Bugula neritina larvae was accelerated by the presence of settlement cues, independently of larval size. In the field, larger W subtorquata larvae also took longer to settle than smaller larvae and were more discriminating towards settlement surfaces. These differences in settlement time are likely to result in differences in the distance that larvae disperse in the field. We suggest that species that produce non-feeding larvae can affect the dispersal potential of their offspring by manipulating larval size and thus larval desperation.

Offspring size affects the post-metamorphic performance of a colonial marine invertebrate

The positive relationship between offspring size and offspring fitness is a fundamental assumption of life-history theory, but it has received relatively little attention in the marine environment. This is surprising given that substantial intraspecific variation in offspring size is common in marine organisms and there are clear links between larval experience and adult performance. The metamorphosis of most marine invertebrates does not represent a newbeginning, and larval experiences can have effects that carry over to juvenile survival and growth. We show that larval size can have equally important carryover effects in a colonial marine invertebrate. In the bryozoan Bugula neritina, the size of the non-feeding larvae has a prolonged effect on colony performance after metamorphosis. Colonies that came from larger larvae survived better, grew faster, and reproduced sooner or produced more embryos than colonies that came from smaller larvae. These effects crossed generations, with colonies from larger larvae themselves producing larger larvae. These effects were found in two populations (in Australia and in the United States) in contrasting habitats.

ANNA: A new prediction method for bioassessment programs

1. Cluster analysis of reference sites with similar biota is the initial step in creating River Invertebrate Prediction and Classification System (RIVPACS) and similar river bioassessment models such as Australian River Assessment System (AUSRIVAS). This paper describes and tests an alternative prediction method, Assessment by Nearest Neighbour Analysis (ANNA), based on the same philosophy as RIVPACS and AUSRIVAS but without the grouping step that some people view as artificial. 2. The steps in creating ANNA models are: (i) weighting the predictor variables using a multivariate approach analogous to principal axis correlations, (ii) calculating the weighted Euclidian distance from a test site to the reference sites based on the environmental predictors, (iii) predicting the faunal composition based on the nearest reference sites and (iv) calculating an observed/expected (O/E) analogous to RIVPACS/AUSRIVAS. 3. The paper compares AUSRIVAS and ANNA models on 17 datasets representing a variety of habitats and seasons. First, it examines each model's regressions for Observed versus Expected number of taxa, including the r(2), intercept and slope. Second, the two models' assessments of 79 test sites in New Zealand are compared. Third, the models are compared on test and presumed reference sites along a known trace metal gradient. Fourth, ANNA models are evaluated for western Australia, a geographically distinct region of Australia. The comparisons demonstrate that ANNA and AUSRIVAS are generally equivalent in performance, although ANNA turns out to be potentially more robust for the O versus E regressions and is potentially more accurate on the trace metal gradient sites. 4. The ANNA method is recommended for use in bioassessment of rivers, at least for corroborating the results of the well established AUSRIVAS- and RIVPACS-type models, if not to replace them.

Offspring size effects in the marine environment: A field test for a colonial invertebrate

A central tenet of life-history theory is the presence of a trade-off between the size and number of offspring that a female can produce for a given clutch. A crucial assumption of this trade-off is that larger offspring perform better than smaller offspring. Despite the importance of this assumption empirical, field-based tests are rare, especially for marine organisms. We tested this assumption for the marine invertebrate, Diplosoma listerianum, a colonial ascidian that commonly occurs in temperate marine communities. Colonies that came from larger larvae had larger feeding structures than colonies that came from smaller larvae. Colonies that came from larger larvae also had higher survival and growth after 2 weeks in the field than colonies that came from smaller larvae. However, after 3 weeks in the field the colonies began to fragment and we could not detect an effect of larval size. We suggest that offspring size can have strong effects on the initial recruitment of D. listerianum but because of the tendency of this species to fragment, offspring size effects are less persistent in this species than in others.

Larval hosts of Australian Drosophilidae (Diptera): A field survey in subtropical and tropical Australia

The drosophilid fauna in Australia offers an important study system for evolutionary studies. Larval hosts are unknown for most species, however, and this imposes serious limits to understanding their ecological context. The present paper reports the first systematic, large-scale field survey of potential larval hosts to be conducted, in order to obtain an overview of the host utilisation patterns of Australian drosophilids. Potential hosts (mostly fruit and fungi) were collected from different vegetation types in northern and eastern Australia. Host data were obtained for 81 drosophilid species from 17 genera (or 28% of the known Fauna). Most genera were restricted to either fruit or fungi, although Scaptodrosophila spp. and Drosophila spp. were recorded from fruit, fungi, flowers and compost, and Drosophila spp. also emerged from the parasitic plant Balanophora fungosa. There was no evidence that use of either fruit or fungi was correlated to host phylogeny. Drosophilids emerged from hosts collected from all sampled vegetation types (rainforest, open forest, heath and domestic environments). Vegetation type influenced drosophilid diversity, both by affecting host availability and because some drosophilid species apparently restricted their search for hosts to particular vegetation types.

Endemism and cryptogenesis in 'segmented' mites: A review of Australian Alicorhagiidae, Terpnacaridae, Oehserchestidae and Grandjeanicidae (Acari : sarcoptiformes)

Endeostigmata are early derivative acariform mites, fossils of which are known from the Devonian. Extant species bear numerous plesiomorphies, the most striking being remnant opisthosomal segmentation. Also, many are all-female parthenogens with broad geographical distributions. Many of the species reported in the present study may represent clones of ancient Gondwana species. Before the present study only a handful of endeostigmatans had been reported from Australia. A key to the families of Endeostigmata is provided in the present paper, along with a review of the Australian fauna of the families Alicorhagiidae (new record), Grandjeanicidae (new record), Oehserchestidae (new record), and Terpnacaridae. Terpnacarus gibbosus (Womersley) is redescribed. A report of the first records of the cosmopolitan parthenogens Alicorhagia usitata Theron et al., Alycosmesis palmata (Oudemans), Stigmalychus veretrum Theron et al., Terpnacarus carolinaensis Theron, and Oehserchestes arboriger (Theron) in Australia is provided, along with a description of the new species Grandjeanicus theroni (Grandjeanicidae). Terpnacarus variolus Shiba and T. glebulentus Theron are junior synonyms of T. gibbosus.