Trish Fleming

Under ‘Western Shield’, the Western Australian Department of Environment and Conservation have aerially deployed 1080 meat baits seasonally over the last 15 years, covering almost 3.5 million hectares. Supplementary hand baiting is also carried out at high conservation significance sites (e.g. swamps harbouring threatened quokka populations). Previous bait uptake studies have predominantly focussed on unbaited areas, with foxes taking large percentages of baits. Few studies have investigated bait uptake under established baiting programs. We monitored 1080 bait uptake at 7 monthly hand-baited sites (baited over 14 years to protect known quokka populations). Our study shows that very few baits are taken by target pest species (i.e. <10% of baits were taken by foxes, cats or feral pigs), with non-target species, including quokkas (~45% of baits monitored), western grey kangaroos, bandicoots, brush tail possums, and mardo, frequently consuming baits. Baits were out for an average of 4 days after deployment; the longest duration monitored was 30 days. This study indicates that only a small proportion of baits are being taken by target feral species. The large uptake by non-target species, particularly native species that are already of conservation importance, suggests that greater focus needs to be placed on bait delivery mechanisms.

Worldwide Phytophthora diseases have significant direct and indirect impact on flora and fauna. In south-west Western Australia approximately 41% of the 5710 described plant species across a large number of plant families are susceptible to P. cinnamomi a pathogen listed as ‘a key threatening process’ to Australia’s biodiversity by the Commonwealth Government. P. cinnamomi in Western Australia is considered a ‘Biologial Bulldozer’ because of its ability to permanently change the structure and function of plant communities and the species they support. Through anthroprogenic activities this introduced exotic pathogen and related species are now widely distributed and many unique plant community types are now infested or threatened. Concerted effort is now spent on mapping its occurrence, identifying areas that are pathogen-free, considered protectable in the medium to long-term and have high conservation value. This presentation will discuss the biology of Phytophthora as a genus and what makes them such devastating plant pathogens, the methods used to diagnose and map their occurrence and the procedures used to select ‘protectable’ communities of high value. Case studies will be used to discuss the impact of the pathogen on plant communities in terms of floristics and habitat change and how this in turn impacts on native fauna and ecosystem function. Control strategies including communication, hygiene implementation measures, the aerial application of phosphite and the use of eradication techniques for spot infestations will be also be discussed with regards to their benefits and possible detrimental effects to native plant communities.

Conducting population studies on elusive species can be challenging. Despite intensive sampling effort, individuals can vary markedly in their trappability. These differences in detection probabilities are problematic for population estimates, where models incorporate assumptions that, if they are present within an area, all animals have an equal probability of being trapped. This study investigates the use of remote cameras to estimate detectability of a medium-sized macropod. We conducted intensive monitoring of quokkas (Setonix brachyurus) at four riparian sites in southwest Western Australia. Quokkas were trapped (seasonally over 18 months) and marked. Camera traps were placed out for 12 months in the vicinity of the trapping area. Camera trap events were reviewed and animals were classified as marked or not-marked. Animals were identified from photos as adult or juvenile and sexed (presence of pouch young, head size) where possible. Cameras indicated the presence of trap-shy animals which had not been marked during the course of the 18 months trapping, and allowed the estimation of detection probabilities for different cohorts. We conclude that camera trapping can enhance the robustness of population estimates of these elusive animals.

The quokka is a medium sized macropod endemic to southwest WA and two islands: Rottnest and Bald. Quokkas were once ‘commonly observed’ in swamps, although few surveys were conducted to establish historical presence. Quokkas suffered a major decline in the 1930s; by the 1950s, the quokka was thought to be extinct on the mainland. Fox predation was highlighted as an ongoing threat and fox baiting began in the mid-1990s targeting protection of this species (and other native fauna). Post-fox control monitoring at eight sites in the northern jarrah forest (1998-2000; Hayward and colleagues) identified small, fragmented populations, but no detectable response to fox baiting. The aim of our research was to establish the current status of quokka populations at these sites (7 of the 8 sites were suitable). Seasonal trapping during 2010-2011 indicated that these populations have increased over the last decade: trap success of the present study (9.4 new individuals/100 trap nights; 85 individuals over 900 trap nights) was substantially higher than previously (0.3 new individuals/100 trap nights; 71 individuals over 21,287 trap nights). Viable quokka populations were found in six of the seven sites surveyed, including two where quokkas had been pronounced ‘locally extinct’. Unlike a number of other native mammal species, and contrary to predictions of further decline, northern jarrah forest quokka populations have increased over the past decade. The quokka may be one ‘good news story’ for native species recovery in WA.

Large portions of the world’s forest are currently impacted by declines in tree health, however the impacts of these declines on woodland birds is largely unknown. Since 2002, small patches of Eucalyptus wandoo woodlands in the wheatbelt of southwest Western Australia have demonstrated decline in condition. Retraction or loss of canopy foliage can result in reduction in foraging resources such as nectar and pollen; insects, lerps and manna, and can also reduce habitat quality and nest sites for woodland birds. To investigate the influence of tree decline on bird foraging, we conducted observations of five bird species (rufous treecreeper, wattle bird spp., yellow plumed honeyeater, weebill and striated pardalote) on trees in various states of health in Dryandra State Forest and Wandoo Conservation Park. We observed birds by following flocks or using the sit-and-wait approach. Responses measured include the health of trees utilised, time spent within trees and the activity of each bird. Birds used both healthy and declining trees for their foraging activities; however, each individual species of bird demonstrated dissimilar preferences for healthy and declining trees. Striated pardalotes were never seen foraging on focal trees categorised as declining and weebills similarly displayed a preference for trees with low amounts of dieback in the canopy. In contrast, wattlebird spp. did not show a preference for the health of trees. Although the decline of E. wandoo may have temporarily affected resource availability for canopy foraging species (e.g. striated pardalotes), the patchy nature of the decline is likely to have had minimal influence on the food resources for the overall woodland birdlife.