Impacts of urbanisation on the native avifauna of Perth, Western Australia

Urban development either eliminates, or severely fragments, native vegetation, and therefore alters the distribution and abundance of species that depend on it for habitat. We assessed the impact of urban development on bird communities at 121 sites in and around Perth, Western Australia. Based on data from community surveys, at least 83 % of 65 landbirds were found to be dependent, in some way, on the presence of native vegetation. For three groups of species defined by specific patterns of habitat use (bushland birds), there were sufficient data to show that species occurrences declined as the landscape changed from variegated to fragmented to relictual, according to the percentage of vegetation cover remaining. For three other groups (urban birds) species occurrences were either unrelated to the amount of vegetation cover, or increased as vegetation cover declined. In order to maximise the chances of retaining avian diversity when planning for broad-scale changes in land-use (i.e. clearing native vegetation for housing or industrial development), land planners should aim for a mosaic of variegated urban landscapes (\u3e60 % vegetation retention) set amongst the fragmented and relictual urban landscapes (% vegetation retention) that are characteristic of most cities and their suburbs. Management actions for conserving remnant biota within fragmented urban landscapes should concentrate on maintaining the integrity and quality of remnant native vegetation, and aim at building awareness among the general public of the conservation value of remnant native vegetation

A late Quaternary vertebrate deposit in Kudjal Yolgah Cave, south-western Australia: refining regional late Pleistocene extinctions

We describe the stratigraphy and chronology of Kudjal Yolgah Cave in south-western Australia, a late Quaternary deposit pre- and post-dating regional human arrival and preserving fossils of extinct and extant fauna. Single-grain optically stimulated luminescence (OSL) dating shows that seven superposed units were deposited over the past 80 ka. Remains of 16 mammal species have been found at the site, all of them represented in Unit 7, for which seven OSL ages indicate accumulation between 80 and 41 ka. Single-grain OSL equivalent dose distribution patterns show no evidence of reworking of older or younger sediments into Unit 7, but late Holocene charcoal has been washed into the top of it from adjacent Unit 2, deposited 1.2 ka ago. Six species that failed to survive the Pleistocene are recorded in Unit 7, but only the south-western wombat Vombatus hacketti is recorded in younger units. Two species, the large extinct kangaroos Protemnodon sp. cf. P. roechus and Procoptodon browneorum, are represented by articulated specimens near the top of Unit 7, immediately adjacent to an OSL sediment sample dated to 41 ± 2 ka. These are the youngest reliably dated records of these genera from mainland Australia, and among the youngest megafaunal remains from the continent. All species currently known from the middle Pleistocene of the south-west persisted into the late Pleistocene, which removes a key pillar supporting the argument against a driving role for human impacts in the extinctions

Was The Archean Biosphere Upside Down

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62929/1/329710a0.pd

Visual acuity testability and comparability in Australian preschool children: The Sydney paediatric eye disease study

Purpose: To establish standardised protocols for vision screening, testability and comparability of three different vision tests were examined in a population-based, cross-sectional sample of preschool children (Sydney Paediatric Eye Disease Study). Methods: Measurement of presenting monocular distance visual acuity (VA) using the Amblyopia Treatment Study (ATS) HOTV protocol, was attempted by all (1774) children aged≥24 months. In addition, in children aged≥60 months (576), VA was also tested using the logMAR retro-illuminated HOTV or Early Treatment Diabetic Retinopathy Study (ETDRS) linear charts (CSV 1000). Children able to have both eyes tested monocularly were considered. Results: Testability significantly increased with age for all VA tests. The ATS HOTV with an overall testability of 80% (females: 82%, males: 78%) was the most testable of the VA tests (