Black Flying-fox - removal of vulnerable species listing

NSW Scientific Committee - final determination

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to remove the Black Flying-fox Pteropus alecto Temminck 1837 from the Schedules of the Act by omitting reference to this species from Part 1 of Schedule 2 (Vulnerable species). The omission of species from the Schedules is provided for by Part 2 of the Act.

 

The Scientific Committee has found that:

 

1. There is clear evidence that the distribution and abundance of Black Flying-foxes Pteropus alecto has increased in New South Wales since their listing on the Threatened Species Conservation Act 1995. The species first entered NSW during the mid-1900s as it expanded its range south from Maryborough after 1930 (Ratcliffe 1932, Tidemann 1999), reaching Murwillumbah by 1960 (Nelson 1965) and the Richmond River by 1990 (Eby and Palmer 1991). The southern limit of their range has since extended approximately 600 km (c. 500%) from 1990 to 2006. This range extension has been accompanied by greater local abundance of breeding individuals. Estimates of the state-wide abundance of Black Flying-foxes based on counts at camps (roost sites) were less than 1000 in 1960 (Nelson 1965). At each of six camps monitored in 1988–91, Black Flying-foxes numbered less than 2000 (Eby and Palmer 1991). Although they also occupied other camps, these data indicate a relatively low state-wide population size at this time. Estimates from 10 surveys between 1998–2004 range from 26 000 to 142 000, with large annual fluctuations owing to migration of flying foxes across the New South Wales/Queensland border (Eby 2004). The distributional shift to the south may be the result of regionally severe drought conditions over the last two decades in Queensland, possibly coupled with a long-term climatic shift (Tidemann 1999; Hughes 2003; Hennessy et al. 2004; CSIRO 2007).

 

2. In 1990, the southern-most camp of Black Flying-foxes was at the mouth of the Richmond River. In 1998, surveys revealed that Black Flying-foxes co-occupied camps of Grey-headed Flying-foxes Pteropus poliocephalus along the Clarence River, about 100 km south of the Richmond River. This range extension included two camps that had been thoroughly searched in 1988–91 without observing any Black Flying-foxes. By 2004, Black Flying-foxes were found in camps on the Manning River. In 2006, more than 50 breeding females and young were observed in Newcastle and approximately 75 breeding females and young were seen in the Royal Botanic Gardens, Sydney (Eby 2007). These data on range extensions of Black Flying-foxes do not include sightings of less than 50 individuals, nor sightings of greater than 50 individuals that did not remain sedentary for greater than 4 weeks, and so exclude any records of vagrants. The Black Flying-fox population within NSW may comprise younger cohorts of a much broader, interconnected metapopulation occupying eastern Australia (K. Parry-Jones pers. comm. April 2008). Thus, any future decline in populations of the Black-flying Fox in Queensland may affect the viability of the species in NSW.

 

3. Counts of flying-foxes at six camps in New South Wales made in the periods 1988–91 and 1998–2004 all show a substantial increase in numbers of Black Flying-foxes. For example, at a long-used camp in Currie Park, Lismore, estimates of Black Flying-foxes always numbered less than 2000 in the period of 1988–91, whereas during the period of 1998–2004 the majority of estimates ranged between 20 000 and 40 000 (Eby and Palmer 1991; Eby 2004).

 

4. Black-flying Foxes face a number of threats in New South Wales including legal and illegal culling by fruit-orchard growers, disturbance at camps and loss of foraging habitat (Duncan et al. 1999; Eby et al. 1999; Hall and Richards 2000). As flying-foxes are dietary specialists and congregate at specific locations, they are especially susceptible to habitat alteration and disturbance. In addition, anthropogenic climate change is expected to increase the frequency of extremely high temperatures in coastal areas of NSW occupied by Black-flying Foxes, causing mass die-off events due to hyperthermia (Welbergen et al. 2007). To date, these threats have not prevented expansion of the population in NSW. However, the extent of these threatening processes strongly suggests that continued yearly monitoring is needed to detect any future change in the species’ abundance in NSW.

 

5. The current status of the Black Flying-fox in NSW no longer meets the criteria for listing under the Threatened Species Conservation Act. The increases in both abundance and geographic distribution since the 1990s indicate that there has not been a moderately large reduction in the population. The current range from Tweed River to Sydney indicates that the geographic distribution of the species is not moderately restricted. Recent estimates of the population size in NSW ranging from 26 000 to 142 000 indicate that the total number of mature individuals of the species is not low.

 

6. In view of the above the Scientific Committee is of the opinion that the Black Flying-fox Pteropus alecto Temminck 1837 is no longer eligible to be listed as a Vulnerable species in Part 1 of Schedule 2 of the Threatened Species Conservation Act 1995.

 

Professor Lesley Hughes

Chairperson

Scientific Committee

References:

CSIRO (2007) ‘Climate change in Australia – Technical report 2007’. CSIRO, Canberra. This report can be accessed on the web at www.climatechangeinaustralia.org.au/resources.php

Duncan A, Baker GB, Montgomery N (1999) ‘The action plan for Australian bats’ Environment Australia, Canberra.

Eby P (2004) ‘National count of grey-headed flying foxes April 3 & 4, 2004.’ A report to the Department of Environment and Heritage, Canberra.

Eby P, Palmer C (1991) Flying foxes in rainforest remnants in northern New South Wales. In ‘Rainforest remnants’. (Ed. S. Phillips) pp. 48-56. (NSW National Parks and Wildlife Service: Lismore)

Eby P, Richards G, Collins L, Parry-Jones (1999) The distribution, abundance and vulnerability to population reduction of a nomadic nectarivore, the Grey-headed Flying Fox Pteropus poliocephalus in New South Wales, during a period of resource concentration. Australian Zoologist 31, 240-253.

Eby P (2007) ‘Evidence of changes to the extent and abundance of Black Flying Foxes in New South Wales 1990-2007.’ A report to the NSW Scientific Committee, Sydney.

Hall LS, Richards G (2000) ‘Flying foxes: fruit and blossom bats of Australia.’ (University of New South Wales Press: Sydney)

Hennessy K, Page C, McInness K, Jones R, Bathols J Collins D, Jones D (2004a) ‘Climate change in New South Wales. Part 1: Past climate variability and projected changes in average climate.’ CSIRO: Melbourne.

Hennessy K, McInness K, Abbs D, Jones R, Bathols J, Suppiah R, Ricketts J, Rafter T, Collins D, Jones D (2004b) ‘Climate change in New South Wales. Part 2: Projected change in climate extremes.’ (CSIRO: Melbourne).

Hughes, L (2003) Climate change and Australia: trends, projections and research directions. Austral Ecology 28, 423-443.

Nelson JE (1965) Movements of Australian flying-foxes (Pteropidae: Megachiroptera). Australian Journal of Zoology 13, 53-73.

Ratcliffe F (1932) Notes on the Fruit Bats (Pteropus spp.) of Australia. Journal of Animal Ecology 1, 32-57.

Tidemann CR (1999) Biology and management of the grey-headed flying fox, Pteropus poliocephalus. Acta Chiropterologica 1, 151–64.

Welbergen JA, Klose SM, Markus N and Eby P (2007) Climate change and the effects of temperature extremes on Australian flying-foxes. Proceedings of the Royal Society B Published online doi:10.1098/rspb.2007.1385

 

 

Page last updated: 28 February 2011