We document changes in the avifauna of Longueville, a residential suburb of Sydney, between 1971–73 and 1977–79 based on daily bird lists, and make comparisons with the present avifauna based on surveys in 2013–14. Of the 31 most common native terrestrial bird species, 17 were ‘decreasers’, present in 1971–73 but not recorded in 2013–14 (although 16 of them were recorded in a large bushland remnant 5 km away), and 14 were ‘increasers’, seven of which were absent or very rare in 1971–73. Eleven species decreased during the 1970s, and six species afterwards. Eight species increased during the 1970s and six species afterwards. The decreasers were predominantly small insectivores and nectarivores. The increasers were of three main types: medium to large carnivores, large frugivores or granivores, and medium-sized nectarivores. Two of the nectarivores, the noisy miner (Manorina melanocephala) and rainbow lorikeet (Trichoglossus haematodus), now dominate the urban bird community of Longueville and are by far the most numerous birds. The increase of both species dates from the late 1970s. The noisy miner is highly aggressive towards other birds and its dramatic increase (it was absent in 1971–73) appears to be the chief cause of the decline of small native birds in Longueville.

The bumphead parrotfish, Bolbometopon muricatum, is an iconic and ecologically significant species that is vulnerable to extinction. Although the Great Barrier Reef provides extensive habitat for this species, the scarcity of juvenile fish in this region may suggest that these populations rely on colonisation by adults from further north, rather than local larval recruitment. Consequently, B. muricatum populations exhibit the strongest latitudinal gradient of any parrotfish on the Great Barrier Reef. Here, we review all records of B. muricatum from the southern Great Barrier Reef and report a new observation of a juvenile at Heron Reef. This is the southernmost report of a juvenile for this species. Given its size (standard length, 25–30 cm), this individual is likely to have settled as a larval recruit in the relative vicinity of Heron Reef, rather than migrating from a more northern site on the Great Barrier Reef or beyond.

The morphology of the skin of living dipnoans can be compared with the arrangements present in the dermis and epidermis of the snout and mandible of fossil dipnoans, but the structures that may have been present in the fossils are significantly reduced in living lungfish. One advantage of assessing the living species is that soft tissues are intact. Fossil dipnoans have cosmine in the epidermis of the snout and mandible, and the dermis is supported by several layers of structured extracellular matrix. Cosmine includes dentine elements as well as pore canals. Among the pore canals are gaps in the cosmine layer that would have housed electroreceptors in the living fish. Below the cosmine is a layer of cancellous bone, separated from the dermal tissues within by a thin, almost continuous, ossified layer. Deep to this layer is a region that lacks any ossified structure, and below this the tubules that pass through the dermis terminate in irregular bulbs. Thin branches with an ossified coat arise from the tubules in the terminal layer and enter the cancellous bone below the cosmine and the pore canals, although they are not numerous. Living dipnoans have no ossified structures in the skin, and lymphatic vessels in the snout are reduced to the plexus below the epidermis, and the lymphatic loops that emerge from the plexus and enter the epidermis. These are numerous and occur in regular layers. In the living species, the lymphatic loops are close to electroreceptors. This may have been the case in fossil lungfish as well. Parallels in fossil and living dipnoans are present.

Rises in abundance of a population in response to increased resources is often followed by a rise in predator abundance. The non-threatened eastern barn owl (Tyto alba delicatula) and the threatened eastern grass owl (Tyto longimembris) are predators that may have occupancy patterns linked with prey abundance. It is important to identify the resources that cause increases in primary prey items to further understanding of the ecology of these species. Here I test the hypothesis that grass seeds cause increased abundances of wetland-dwelling house mice (Mus musculus) in austral summer, and identify a wetland monocot that provides a food recourse to achieve this effect, as well as report eastern grass owl and barn owl observations. A 2.6 ha wetland area (on Kooragang Island, New South Wales) was surveyed almost weekly to quantify abundance of prey items from September to April for three years (2016–2019). Typha sp. (a monocot) had flowering periods that coincided with increases in house mouse observations (n = 90 in flowering, n = 2 in non-flowering), where 22% were detected feeding on Typha flowers/seeds or fleeing from flower stalks. Eastern grass owls were only observed during a Typha flowering period (n = 3). These observations confirmed the original hypothesis and led to the formulation of another hypothesis: wetland occupancy by eastern grass owls is influenced by Typha flowering. Future studies should aim to test this hypothesis and identify other wetland plants that provide an important food source for wetland-dwelling rodents.

The abundance of feral pigs in Australia has been estimated previously and been a topic of some debate. This study aims to update a previous estimate of abundance (13.5 million, 95% CI: 3.5 million to 23.5 million) of feral pigs in Australia. Abundance estimates for the 1970s, 1980s, 1990s, 2000s and 2010s were collated from published literature. Mean abundances in the middle decades were estimated using the ratio method. The average abundance of feral pigs varied from 4.4 million (95% CI: 2.4 million to 6.3 million) in the 1980s, to 3.0 million (95% CI: 2.3 million to 3.7 million) in the 1990s, to 3.2 million (95% CI: 2.4 million to 4.0 million) in the 2000s. Mean density across all 142 studies was 1.03 pigs km^–2. The average abundance of feral pigs in Australia during the 1980s to 2000s was much lower and more precise than estimated previously, so scientists and managers should update their use of abundance estimates. Density estimates are above, and below, estimates of threshold host densities for infectious exotic disease establishment.

The two iconic Tasmanian species, the Tasmanian devil (Sarcophilus harrisii) and the thylacine (Thylacinus cynocephalus), are of great interest to the general public and the media. The most likely extinct Tasmanian wolf or tiger, the thylacine, symbolises human responsibility for nature and species conservation and inspired the ‘National Threatened Species Day’, which commemorates the death of the last thylacine at Beaumaris Zoo in Hobart on 7 September 1936 to raise awareness of endangered plants and animals. Since the spread of the Devil Facial Tumour Disease critically endangered the survival of the largest remaining native carnivore (S. harrisii) today, this has generated both scientific interest and the interest of the general public. Google Trends has already been used as a tool for documenting and investigating the information needs and concerns of the population, as has been shown using the example of diseases. In this study, Google Trends data were used to examine the seasonality of the search term ‘thylacine sightings’ and the development of the frequency of different search terms in the period between 2004 and 2020. As a result, relative search intensities for ‘thylacine cloning’ and ‘cloning extinct species’ have shown a decrease over time. While Google Trends cannot clearly determine search motivation, search terms can be selected for the examinations that document more hope or a rational need for information or concern.

Using single nucleotide polymorphisms and mitochondrial DNA sequences we find some evidence of genetic structure within a widespread and naturally fragmented species, the purple-gaped honeyeater (Lichenostomus cratitius), of southern Australian mallee shrublands. The very earliest stages of differentiation either side of the Nullarbor Barrier may already have been arrested by gene flow, some of which may have been anthropogenically induced.

In the last several decades, habitat loss, overexploitation, invasive organisms, disease, pollution and, more recently, climate change have led to catastrophic declines in amphibian biodiversity. Montane amphibian species, particularly those with narrow distributions and specific habitat requirements are likely to be at particular risk under future climate change scenarios. Despite this, fundamental ecological data are lacking for most of these species. Philoria kundagungan is a poorly known representative of a range-restricted genus of montane amphibians from eastern Australia. Using an occupancy framework, we conducted repeated call playback surveys at 32 sites across the mountainous regions of south-east Queensland and north-eastern New South Wales, Australia, to investigate: (1) the current extent of this species’ geographic range, and (2) environmental predictors of this species’ presence. We found that P. kundagungan has a highly restricted and fragmented distribution, being limited to ∼11 km² of potentially suitable habitat, and that its presence is strongly associated with high elevation (>800 m). Our survey protocol resulted in a high probability of detection (>70%) at occupied sites from relatively few visits. From these baseline data, future studies will have the ability to determine changes in this species’ geographic range and occupancy rate in response to the ever-increasing threats faced by P. kundagungan, thereby supporting more effective conservation strategies and policy decisions.