Peoples Bay Research Articles

Phytophthora cinnamomi: extent and impact in Two Peoples Bay Nature Reserve, Western Australia (1983–2024)

Context Phytophthora cinnamomi has been present in Two Peoples Bay Nature Reserve in Western Australia for decades, with impacts observed in susceptible plant communities. Aims This study aimed to examine the past and present impact of P. cinnamomi on ecosystems. Methods The distribution of P. cinnamomi was mapped 1983–1995 and reassessed in 2024. The long-term spread of the pathogen was measured. Plant densities were assessed, dry-weight biomass measured, and visits by avifauna quantified in infested and healthy vegetation. The persistence of chlamydospores was assessed. Key results Mapping confirmed the widespread distribution of P. cinnamomi in the Reserve, with some areas mapped as disease-free up to 1995 now infested. Phytophthora dieback has spread in Banksia shrubland at an average of 1.5 m/year over a 33-year period. The density of species from the Proteaceae, Fabaceae, Ericaceae, and Hibbertia was significantly reduced; and the biomass of non-sedge species and visits by avifauna lower in infested compared with healthy Banksia shrubland. However, pockets of healthy habitat persist in infested areas and two highly susceptible Ericaceae (Leucopogon glabellus, Styphelia flavescens) were observed in high numbers in infested vegetation. Recovery of chlamydospores confirmed the persistence of the pathogen behind the dieback front. Conclusions The impact of P. cinnamomi is long term and irreversible, however, some susceptible species may have mechanisms to ensure their persistence through prolific seed production. Implications Protection of areas of healthy susceptible habitat from the introduction and spread of P. cinnamomi, the implementation of existing control measures and research into alternative measures continue to be a priority.

A new vegetation classification for Western Australia’s Two Peoples Bay Nature Reserve and its significance for fire management

A new vegetation classification for Western Australia’s Two Peoples Bay Nature Reserve and its significance for fire management

Plant diversity on the edge: floristics, phytogeography, fire responses, and plant conservation of Two Peoples Bay Nature Reserve in the context of OCBIL theory

Context There have been few long-term studies of the flora, phenology, and ecology of specific reserves in the species-rich flora of the Southwest Australian Floristic Region. Aims This project, extending over five decades, aimed to develop an authoritative flora list and acquire data on phenology, threatened species, endemism, old and young landscapes, phytogeography, old lineages, and fire responses at Two Peoples Bay Nature Reserve. Methods The study used botanical collection on repeat surveys, herbarium studies, granite outcrop surveys and comparative phytogeographic analyses from maps on the Western Australian Herbarium’s Florabase. Key results Floristic survey recovered 853 taxa, 26% of those known in the Albany local government area. Possibly as many as 950–1000 taxa will be found in the future. The herbarium collections are the second largest of any conservation reserve in the Albany area. Flowering was most evident in spring and least in autumn. Three declared rare species and 20 conservation priority species were identified, as were short-range endemics, old clades, and natural hybrids. Conclusions The flora is dominated by species predominantly from wetter forest regions. Consequently, Two Peoples Bay Nature Reserve is correctly placed within the Bibbulmun Botanical Province. Several hypotheses of OCBIL theory (which addresses old, climatically-buffered, infertile landscapes) were supported, with increased local endemism, ancient clades, and reduced rates of natural hybridisation identified for the granite inselberg OCBIL Maardjitup Gurlin/Mt Gardner. Implications Long term studies are invaluable for plant inventory. Continuing the minimal use of prescribed burning is advocated from plant data, in support of approaches to help conserve threatened animals.

Introduction to the special issue of The Natural History of Two Peoples Bay Nature Reserve, Western Australia

Context This paper introduces the special issue of Pacific Conservation Biology devoted to the natural history of Two Peoples Bay Nature Reserve on the south coast of Western Australia. Methods This paper provides the background to the special issue. Key results Two Peoples Bay Nature Reserve was gazetted in 1967 for the conservation of the native biota, including two species; the Djimaalap/noisy scrub-bird (Atrichornis clamosus) and Ngilgaitch/Gilbert’s potoroo (Potorous gilbertii), both believed extinct for over 100 years before being rediscovered on the Reserve. The Reserve is 4774.7 ha in area, with wetlands, heathlands, granite outcrops, sand dunes, beaches, cliffs, and islands. Since it was established, mean annual rainfall has decreased by 16.8%, mean annual maximum temperature has increased by 0.2°C, and mean annual minimum temperature has increased by 0.7°C. Conclusions The paper poses the question: what do the changes of drier winters, hotter summers, and more extreme weather events mean for managers of conservation areas such as Two Peoples Bay? Implications Changing climate will pose problems for the managers of Two Peoples Bay Nature Reserve in ensuring the conservation of the Djimaalap/noisy scrub-bird and Ngilgaitch/Gilbert’s potoroo.

A Merningar Bardok family’s Noongar oral history of Two Peoples Bay Nature Reserve and surrounds

Warning Aboriginal and Torres Strait Islander readers should be aware that this document may contain sensitive information, images or names of people who have since passed away. Context Two Peoples Bay Nature Reserve on Western Australia’s south coast is world renowned for its biodiversity, particularly its threatened fauna. Future co-management of the Reserve with Aboriginal peoples is likely, although very little information on the Noongar cultural heritage of the Reserve has been published and thus available for stewardship guidance. Methods This study used oral history interviews on Country based on open-ended questioning and respect for intellectual property. Comprehensive surveys for Noongar cultural heritage were conducted on foot on the Reserve. Key results A rich trove of women’s and men’s stories from the Knapp family about Two Peoples Bay is recalled and recorded. The Reserve features prominently in Wiernyert/Dreaming stories with classical human moral dilemmas, and transformations for wrong-doing are featured. Threatened animals and important plants are named as borongur/totems. Trading of gidj/spears of Taxandria juniperina is prominent. Use of fire traditionally was circumspect, and is confined to small areas and pathways in lowlands. Granite rocks are replete with lizard traps, standing stones, and stone arrangements. Conclusions The Reserve has a long and layered oral history for Merningar Bardok Noongars, exemplified here by the Knapp family, members of which have enjoyed continuous oral history for countless generations. Granite rocks, wetlands, flora, and fauna are vitally important vessels of such knowledge. Implications Cultural suppression has inhibited free cross-cultural exchange of kaatidjin/knowledge until recently. As respect for culture and Elders becomes paramount, positive co-stewardship of the Reserve will become a reality. Vibrant cultural interpretation and active management by Noongar guides and rangers is recommended.

Bryophytes of Two Peoples Bay Nature Reserve, Western Australia

Context Although the vascular flora of Western Australia is renowned for high species diversity and endemism, very little is known about the state’s moss and liverwort flora. Aims In 1984 we conducted surveys of bryophytes in Two Peoples Bay Nature Reserve. Methods We searched comprehensively for bryophytes at seven major habitats on the Reserve, collecting voucher specimens subsequently identified with modern literature and with the help of Australian bryophyte experts. We updated the text to reflect modern taxonomy and considering modern literature on phytogeography and hypotheses associated with OCBIL (Old, Climatically Buffered, Infertile Landscapes) theory. Key results A total of 38 species of mosses representing 25 genera from 13 families were identified along with 10 species of liverworts representing nine genera and six families. Two moss species (Distichium inclinatum and Tortella dakinii) were previously unknown from Western Australia. Another represented a new species (Pleurophascum occidentale) in a heretofore monotypic genus, family, and order. The Pottiaceae, with 11 species, was the most diverse family of mosses. The Lepidoziaceae, with three species, was the most diverse family of liverworts. Conclusions Lower levels of endemism in bryophytes versus vascular plants may reflect the bryophytes’ capacity for wide and long-distance dispersal of spores and fragments. Bryophyte diversity and endemism may be less than on extensive OCBILs because much of the Reserve emerged from the ocean as recently as the mid-Pleistocene. Implications This, the first listing published of bryophytes on a Reserve in WA, indicates the potential rewards for further survey of mosses and liverworts.

History and establishment of Two Peoples Bay Nature Reserve

Context This paper sets out the events leading to the establishment of Two Peoples Bay Nature Reserve. Methods This paper is based on research into literature relating to the Albany region, government files and oral accounts relating to the area. Key results Long known to the Noongar peoples, Two Peoples Bay was first mapped by Europeans in 1791 by Captain George Vancouver. The area was rapidly established as a base for the over-exploitation of natural resources. As the region became more developed and human population increased, recreational pressure on the area was such that the Western Australian Government surveyed Two Peoples Bay to establish a townsite. Just before the final surveys for the townsite were completed, the supposedly-extinct noisy scrub-bird (Atrichornis clamosus), was rediscovered there. National and international pressure on the WA Government from the conservation movement resulted in the reversal of the decision to develop a town in the area and led to the establishment of Two Peoples Bay Nature Reserve in 1967. Conclusions The establishment of Two Peoples Bay Nature Reserve in the face of pressure for the development of a town on the bay, provides an interesting example of the needs of nature conservation over-riding real estate development. Implications Although nature conservation values rarely stop real estate development, the Two Peoples Bay example demonstrates that nature conservation may prevail over real estate development, in this case involving the rediscovery of a species believed extinct.

Hyporthodus griseofasciatus (Perciformes: Epinephelidae), a new species of deep-water grouper from the west coast of Australia.

A new species of deep-water epinephelid fish is described from the west coast of Australia based on 14 specimens, 99-595 mm standard length. Hyporthodus griseofasciatus sp. nov. is endemic to Western Australia from Barrow Island to Two Peoples Bay in depths of 76-470 m. It has a series of eight grey bands alternating with eight brown bands along the body and the soft dorsal, soft anal and caudal fin margins are pale cream to white. It is distinguished from its nearest congener, H. ergastularius, by the presence of a star-like pattern of radiating lines on the head versus an overall brownish colour in the latter as well as significant differences in the quantitative analyses of 25 morphological characters. The two species have allopatric distributions on either side of the Australian continent. H. griseofasciatus is distinguished from H. octofasciatus by several grey bands being distinctly narrower than other grey bands (vs. all grey bands subequal in the latter) and the presence of broad white margins on the dorsal, caudal and anal fins (vs. narrow or absent in the latter). Some scale counts appear to also differ. Analyses of mitochondrial cytochrome oxidase subunit 1 sequences revealed reciprocally monophyletic clades with fixed differences and genetic distances typical of recently diverged species of fishes.

Analysis of rDNA reveals a high genetic diversity of Halophila major in the Wallacea region.

The genus Halophila shows the highest species diversity within the seagrass genera. Southeast Asian countries where several boundary lines exist were considered as the origin of seagrasses. We hypothesize that the boundary lines, such as Wallace's and Lydekker's Lines, may act as marine geographic barriers to the population structure of Halophila major. Seagrass samples were collected at three islands in Vietnamese waters and analyzed by the molecular maker ITS. These sequences were compared with published ITS sequences from seagrasses collected in the whole region of interest. In this study, we reveal the haplotype and nucleotide diversity, linking population genetics, phylogeography, phylogenetics and estimation of relative divergence times of H. major and other members of the Halophila genus. The morphological characters show variation. The results of the ITS marker analysis reveal smaller groups of H. major from Myanmar, Shoalwater Bay (Australia) and Okinawa (Japan) with high supporting values. The remaining groups including Sri Lanka, Viet Nam, the Philippines, Thailand, Malaysia, Indonesia, Two Peoples Bay (Australia) and Tokushima (Japan) showed low supporting values. The Wallacea region shows the highest haplotype and also nucleotide diversity. Non-significant differences were found among regions, but significant differences were presented among populations. The relative divergence times between some members of section Halophila were estimated 2.15-6.64 Mya.

Molecular characterization of native Australian trypanosomes in quokka (Setonix brachyurus) populations from Western Australia

The quokka, Setonix brachyurus, is a vulnerable, small marsupial endemic to Western Australia. Blood samples were collected from quokkas from three different geographical locations; Two Peoples Bay, Bald Island and Rottnest Island. The overall prevalence of trypanosomes by nested PCR at the 18S ribosomal RNA gene was 57.3% (63/110) with prevalences of 91.4%, 85.3% and 4.9% respectively for Two Peoples Bay, Bald Island and Rottnest Island. Phylogenetic analysis conducted on 47 18S PCR positives identified two Trypanosoma copemani genotypes, with T. copemani genotype B, the most prevalent genotype infecting quokka populations from the three locations with an overall prevalence of 51.8% (24/47) compared to 34% for T. copemani genotype A (16/47). The overall prevalence of mixed T. copemani genotype A and B infections was 14.9% (7/47). Phylogenetic analysis of 26 quokka isolates at the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) locus, largely supported the 18S analysis but identified a mixed infection in one quokka isolate (Q4112-4117 from Two Peoples Bay). T. copemani genotype B has previously only been isolated from quokkas and the Gilbert's potoroo whereas T. copemani genotype A has a wide host range and may be pathogenic. Further work is required to determine the clinical impact of T. copemani on marsupial populations.

Further characterisation of two Eimeria species (Eimeria quokka and Eimeria setonicis) in quokkas (Setonix brachyurus)

The identification and characterisation of novel Eimeria species has largely been based on sporulated oocyst and sporocyst morphology, the host species and the geographical range. Variation in the size and shape of Eimeria oocysts across their host range however, make the identification and characterisation of novel species using traditional methodologies alone problematic. The use of molecular markers and phylogenetic analysis has greatly advanced our ability to characterise Eimeria species and has recently been applied to understand evolutionary relationships among Eimeria species from Australian marsupials.In the present study, Eimeria species isolated from quokkas (Setonix brachyurus) captured from Two Peoples Bay, Bald Island and Rottnest Island, Western Australia, were morphologically identified as Eimeria quokka and Eimeria setonicis. Both Eimeria species were identified as being polymorphic in nature with regards to sporulated oocyst and sporocyst morphometrics. Phylogenetic analysis using 18S rRNA and COI (cytochrome c oxidase subunit 1) genes, grouped E. quokka and E. setonicis within the Eimeria marsupial clade together with Eimeria trichosuri from brushtail possums, Eimeria macropodis from tammar wallabies (Macropus eugenii) and several unidentified macropod Eimeria species from western grey kangaroos (Macropus fuliginosus). This study is the first to characterise E. quokka and E. setonicis by molecular analysis, enabling more extensive resolution of evolutionary relationships among marsupial-derived Eimeria species.

Habitat preference of the Australian water rat (Hydromys chrysogaster) in a coastal wetland and stream, Two Peoples Bay, south-western Australia

This study provides a preliminary investigation of the home range and habitat selection of the Australian water rat (Hydromys chrysogaster) in Two Peoples Bay Nature Reserve near Albany, Western Australia. Six individuals were captured (trap success 1.9%) from 810 trap-nights. This low number suggests that the water rat population in Two Peoples Bay Nature Reserve is much smaller than anecdotal evidence would suggest. Home-range size (neighbour-linkage method) averaged 18.9 ha (±11.6). Individuals preferentially utilised wetland habitats characterised by dense, low-lying vegetation (0–30 cm from ground), low-density canopy cover and shallow, narrow water bodies.

Vector of Trypanosoma copemani identified as Ixodes sp.

A total of 41 ticks were collected from 15 quokkas on Bald Island and 2 ticks from a Gilbert's potoroo from Two Peoples Bay. Three species of Ixodid ticks Ixodes australiensis, Ixodes hirsti and Ixodes myrmecobii were identified on the quokkas known to have a high prevalence of Trypanosoma copemani. Tick faeces from ticks isolated from 8 individual quokkas and a Gilbert's potoroo were examined with one identified as positive for trypanosomes. Faecal examination revealed trypanosomes similar to in vitro life-cycle stages of T. copemani. In total 12 ticks were dissected and trypanosomes found in sections of their midgut and haemolymph, 49 and 117 days after collection. Tick faeces, salivary glands and midguts from I. australiensis were screened using an 18S rRNA PCR with amplification seen only from the midguts. Sequencing showed 100% homology to T. copemani (genotype A) and 99.9% homology to the wombat (AII) isolate of T. copemani. Trypanosomes were only detected in I. australiensis as neither I. hirsti nor I. myrmecobii survived the initial 30-day storage conditions. We therefore identify a vector for T. copemani as I. australiensis and, given the detection of trypanosomes in the faeces, suggest that transmission is via the faecal-oral route.

Monitoring reproduction in the critically endangered marsupial, Gilbert’s potoroo ( Potorous gilbertii): Preliminary analysis of faecal oestradiol-17β, cortisol and progestagens

Gilbert’s potoroo ( Potorous gilbertii) was rediscovered in 1994 after having been presumed extinct for 120 years. Estimates indicate fewer than 40 individuals remain at Two Peoples Bay Nature Reserve on the south coast of Western Australia although a translocated population of approximately 20 animals has recently been established on nearby Bald Island. A captive breeding facility has been established adjacent to the mainland population but few young have been produced (8 since 1995). Faecal levels of oestradiol-17β (E 2) were monitored over a 2-year period in an effort to determine cyclic reproductive activity, and faecal cortisol levels were also monitored to gauge whether chronic stress may be a factor limiting breeding in captivity. Faecal steroids were monitored in six captive females, and four captive male potoroos, and four wild females. The only captive births recorded after 1998 were one in August 1999 and one in February 2001, both to the same female. Peaks in E 2 concentration, up to 10 ng g −1 of dried faecal mass were measured and results to date suggest the main breeding period to be November–December based on elevated E 2 levels at this time. Clear patterns of reproductive activity in the captive females, however, were not evident. Analysis of epithelial cell counts from urinogenital swabs and faecal E 2 and progestagen (PM) levels from a single female kept at the Perth Zoo, suggest that Gilbert’s potoroo has an oestrous cycle of approximately 39 days. Faecal cortisol levels in captive females were significantly lower than those in wild-caught individuals and thus there is no indication that elevated cortisol levels per se inhibited reproduction in captive females.

Theileria gilberti n. sp. (Apicomplexa: Theileriidae) in the Gilbert's Potoroo (Potorous gilbertii)

The morphology and genetic characterisation of a new species of piroplasm identified in the blood of the Gilbert's potoroo (Potorous gilbertii) from the Two Peoples Bay Nature Reserve near Albany, Western Australia, is described from blood and tissue samples from 16 Gilbert's potoroos. Microscopy of blood showed these parasites are highly pleomorphic with a mean length of 1.8 mum and mean width of 0.85 mum. Phylogenetic analysis of 18S rRNA sequence data identified the piroplasm as a new species of Theileria that is closely related to other Australian marsupial piroplasm species. Based on biological and molecular data, it is proposed that the parasite from Gilbert's potoroo be given the name Theileria gilberti n. sp.

Fungi consumed by translocated Gilbert's potoroos (Potorous gilbertii) at two sites with contrasting vegetation, south coastal Western Australia

Gilbert’s potoroo (Potorous gilbertii) was previously widespread in south-west Australia but is now restricted to one location – a granitic area of shrubby heath at Two Peoples Bay Nature Reserve on the south coast of Western Australia. To alleviate the threat of extinction a program is under way to establish potoroos in other locations. At Two Peoples Bay Gilbert’s potoroos feed almost exclusively on truffle fungi. However, it was not known whether potoroos translocated to any new areas would be able to rapidly access and consume fungi after translocation, or whether truffles could be a sustainable food supporting breeding populations of potoroos in translocation sites. Furthermore, it was not known whether translocation of potoroos would be successful only in areas with vegetation similar to their refuge at Two Peoples Bay. The current study addressed these questions by analysing the diet of potoroos translocated into two contrasting areas – one on Bald Island with similar topography and vegetation to that of Two Peoples Bay, and the other a 14-ha enclosure on the mainland dominated by Eucalyptus–Allocasuarina woodland. The diet of potoroos was characterised by microscopic examination of scats from individuals trapped after their translocation to these areas. At Bald Island a diverse range of fungi was consumed immediately after translocation. Four potoroos released onto the island only 4–8 days previously consumed 23 species of fungi. Consumption was sustained over time. Three potoroos released onto Bald Island 1–2 years previously and one island-born individual consumed 27 species of fungi during a two-day sampling period. Nine of the 27 fungi species were the same as those that had been consumed by the potoroos within days after their release onto the island. This indicates that production of fungi and their consumption by potoroos on the island was sustained at least 1–2 years after translocation. Potoroos bred on Bald Island during this period. During the same period, two potoroos that were moved from captivity to the mainland site (Ryedene) were consuming six species of truffles within 29 days after release, and 14 species within three months. Such data indicate that a wider selection of vegetation types and areas than just those similar to where potoroos occur at Two Peoples Bay may be able to sustain potoroos and should be investigated for future translocations.

Posidonia australis seed predation in seagrass habitats of Two Peoples Bay, Western Australia

Posidonia australis seed predation experiments conducted in three seagrass habitats ( P. australis, Posidonia sinuosa, Halophila ovalis) and bare sand in Two Peoples Bay, Western Australia, showed higher predation rates in seagrass than bare sand, supporting general conclusions from two previous predation studies in Western Australia. However, much higher rates were noted in H. ovalis, compared to previous observations of very low rates in H. ovalis on Rottnest Island, Western Australia. We attribute these differences to gammaridean amphipods (family Lysianassidae) that were present in a detrital layer within the H. ovalis in Two Peoples Bay. Our data from Two Peoples Bay continues to add to the growing body of information showing high seed predation rates in most seagrass habitats by a diverse group of crustacean species.

A quantitative dietary study of the ?Critically Endangered? Gilbert?s potoroo Potorous gilbertii.

Faecal analysis from the only known population of Gilbert?s potoroo (Potorous gilbertii) near Albany, Western Australia revealed that it, like other rat-kangaroo species is primarily mycophagous. Diet was determined by faecal collections from live-captured animals within Two Peoples Bay Nature Reserve. Microscopic examination of samples collected from June - September 2000 and additional samples from storage, found fungi to comprise over 90% of faecal matter. A total of 44 fungal spore types were identified with many believed to be of hypogeous origin. Fungal spores belonging to the genera Mesophellia, Elaphomyces, Hysterangium and an unknown spore type (Unknown 1) were frequently recorded in samples. Non-fungal material including plants (stems, roots and seeds) and invertebrates represented the remainder. This investigation found that P. gilbertii fed almost exclusively on fungi and could be considered a specialised mycophagist.

The singing behavior of the Noisy Scrub-bird, Atrichornis clamosus: congeneric comparisons and the feasibility of using individual variation in song as a census tool

The Noisy Scrub-bird, Atrichornis clamosus, is a small, elusive, threatened passerine endemic to southwestern Australia. Its elusive nature limits the usefulness of conventional individual marking methods, hampering efforts to study the biology of this species. The territorial songs of 12 territory-holding male A. clamosus were recorded at Two Peoples Bay Nature Reserve in order to compare the singing behaviour of this species with that of the Rufous Scrub-bird, A. rufescens, and to investigate the feasibility of using this vocalisation as a method of identifying individual male A. clamosus in the field. In contrast to that of A. rufescens, the territorial song of A. clamosus is structurally complex and highly variable. Each territory-holding male A. clamosus has a repertoire of 4–7 song types, which is sung with a pattern of immediate variety rather than eventual variety, as in A. rufescens. The song types comprising the repertoire of an individual A. clamosus are not necessarily unique to that individual and may be shared with one or more other males. In some cases the repertoires of several birds may consist of the same song types. Such extensive song sharing precludes unambiguous individual identification. Therefore, the territorial song of A. clamosus is an unsuitable method of individual identification.

Detecting a genetic bottleneck in Gilbert's Potoroo (Potorous gilbertii) (Marsupialia: Potoroidae), inferred from microsatellite and mitochondrial DNA sequence data

Gilbert's Potoroo isAustralia's most critically endangeredmarsupial, known from a single population inthe Two Peoples Bay National Park in WesternAustralia. We present results from a study ofgenetic variation in microsatellite andmitochondrial DNA. Mean heterozygosity at fivemicrosatellite loci was 49.3%, and the amountof mtDNA variation was extremely low (π =0.0004). There was evidence for a bottleneckin both sets of markers, and this wasconsistent with a demographic decline. Effective population size was estimated usingtwo different models of mutation formicrosatellites (Ne = 243 and 362). The results from this study highlight theconcern for the long-term survival of thisspecies.