Novel strains of Klebsiella africana and Klebsiella pneumoniae in Australian Fruit Bats (Pteropus poliocephalus)

Over the past decade human associated multidrug resistant (MDR) and hypervirulent Klebsiella pneumoniae lineages have been increasingly detected in wildlife. This study investigated the occurrence of K. pneumoniae species complex (KpSC) in grey-headed flying foxes (GHFF), an Australian fruit bat. Thirty-nine KpSC isolates were cultured from 275 GHFF faecal samples (14.2%), comprising K. pneumoniae (sensu stricto) (n=30), Klebsiella africana (n=8) and Klebsiella variicola subsp. variicola (n=1). The majority (79.5%) of isolates belonged to novel sequence types (ST), including two novel K. africana STs. This is the first report of K. africana outside of Africa and in a non-human host. A minority (15.4%) of GHFF KpSC isolates shared STs with human clinical K. pneumoniae strains, of which, none belonged to MDR clonal lineages that cause frequent nosocomial outbreaks, and no isolates were characterised as hypervirulent. The occurrence of KpSC isolates carrying acquired antimicrobial resistance genes in GHFF was low (1.1%), with three K. pneumoniae isolates harbouring both fluoroquinolone and trimethoprim resistance genes. This study indicates that GHFF are not reservoirs for MDR and hypervirulent KpSC strains, but they do carry novel K. africana lineages. The health risks associated with KpSC carriage by GHFF are deemed low for the public and GHFF.

Spring foraging movements of an urban population of grey-headed flying foxes (Pteropus poliocephalus)

Flying foxes provide ecologically and economically important ecosystem services but extensive clearing and modification of habitat and drought combined with the planting of commercial and non-commercial trees across various landscapes, has meant flying foxes in Australia are increasingly seeking foraging resources in new areas. In 2011, grey-headed flying foxes formed a camp in Adelaide, South Australia, outside their previously recorded range. We used global positioning system telemetry to study the movements and foraging behaviour of this species in Adelaide in spring (September to November) 2015. High-frequency location data were used to determine the foraging range and the most frequently visited foraging sites used by each bat which were ground-truthed to identify forage plants. A total of 7239 valid locations were collected over 170 nights from four collars. Despite being a highly mobile species, the mean core foraging range estimate was only 7.30 km2 (range 3.3–11.2 km2). Maximum foraging distance from the camp in the Botanic Park was 9.5 km but most foraging occurred within a 4-km radius. The most common foraging sites occurred within the residential area of Adelaide and included introduced forage plant species, Lemon-scented gum (Corymbia citriodora) and Port Jackson fig (Ficus rubiginosa). Other observed movement activities included dipping behaviour on inland and marine waters and travel across flight paths around Adelaide airport. Our findings suggest that urban habitats in Adelaide provide sufficient foraging resources for grey-headed flying foxes to use these areas exclusively, at least in spring. This creates substantial opportunities for bats to interact with humans and their infrastructure.

Dietary partitioning in newly sympatric urban flying-foxes (Pteropus poliocephalus and Pteropus alecto)

The black flying-fox (Pteropus alecto) is extending its range southward and is now sympatric with the grey-headed flying-fox (P. poliocephalus) in New South Wales. Competition for food between the two species has been suggested to be a contributor to declines of the vulnerable grey-headed flying-fox. During winter 2016 the diet of both species was investigated over one night at four sites of sympatry, by microscopic analysis of faecal samples. Resource partitioning between the two species was found, with the black flying-fox either preferentially choosing to eat more fruit than the grey-headed flying-fox or being an inferior competitor for pollen and nectar. These results, though limited, do not support the hypothesis that the black flying-fox threatens the grey-headed flying-fox through food competition.

Predation on cicadas by an Australian Flying-fox Pteropus poliocephalus based on DNA evidence

Historically, reports of insectivory in family Pteropodidae have largely been anecdotal and thought to be an incidental corollary of flying-foxes feeding on plant products. More recent direct observations of flying-foxes catching and consuming insects, as well as advances in techniques that increase our ability to detect dietary items, suggest that this behaviour may be deliberate and more common than previously thought. Usually, multiple insects are consumed, but it appears that flying-foxes hunt and eat them one at a time. However, we have collected and photographed oral ejecta pellets under trees with high flying-fox activity, some containing evidence of multiple masticated insects. Further genetic analysis proved that these pellets came from Grey-headed Flying-foxes Pteropus poliocephalus. We propose that flying-foxes use an array of insect feeding strategies, most likely in response to variation in insect abundance and activity, as well as abiotic factors such as light and temperature.

Congregations of a threatened species: mitigating impacts from Grey-headed Flying-fox Pteropus poliocephalus camps on the Batemans Bay community

Flying-fox camps in urban areas are a contentious wildlife management issue. Since 2012, Grey-headed Flying-foxes Pteropus poliocephalus have regularly occupied two camps in Batemans Bay, New South Wales (NSW). At one site, the Water Gardens, impacts on adjacent residents and businesses occur when animals roost near the reserve boundaries. During March–July 2016, a large influx of flying-foxes arrived, causing the camps to spread into neighbouring residential, recreational and industrial areas. Prior to this, impacts had been mitigated through vegetation clearing to create buffer zones and residential subsidies for mitigation equipment and services. The influx warranted additional measures such as a dispersal program and further vegetation removal, which were expedited by the Commonwealth Government granting a National Interest Exemption under section 158 of the Environment Protection and Biodiversity Conservation Act 1999 and the NSW Government committing $2.5 million in funding towards the new measures. These measures moved flying-foxes from key conflict areas but also coincided with flying-fox numbers reducing as local blossom diminished. Ongoing community engagement played an important role in building community resilience to live with this threatened species, which is vital considering that Batemans Bay will likely continue to be an important area for flying-foxes.