The Black Grass-dart Butterfly Ocybadistes knightorum has a highly restricted distribution along the New South Wales north coast and is listed as an Endangered species in the State. Recent surveys have dramatically increased the known distribution of the species, warranting a reassessment of its conservation status. Fine-scale mapping of the entire known habitat of the species enabled a detailed assessment to be conducted that was commensurate with the small size of the butterfly and the fine-grained environmental data available. We evaluate the status of O. knightorum against IUCN Criteria B (Geographic Range). The butterfly was found to have an extent of occurrence of 312 km2 and an area of occupancy of 76 km2, at three locations. A detailed digital elevation model was used to demonstrate the likelihood of continued decline due largely to sea-level rise induced by climate change. An estimated 85% of the current habitat of O. knightorum will become unsuitably saline by 2100 according to the best currently available sea-level rise prediction. Weed invasion and anthropogenic disturbance are also serious threats, contributing to continued decline in some areas. Adopting a precautionary approach, we assess the species as Endangered under IUCN criteria.

Andren, M. and Cameron, M. A. 2012. The distribution of the Black Grass-dart Butterfly, Ocybadistes knightorum (Lepidoptera: Hesperiidae). Australian Zoologist 36(2): 159-68. http://dx.doi.org/10.7882/AZ.2012.012
Braby, M. F. 2000.The Butterflies of Australia: their Identification, Biology and Distribution. CSIRO Publishing, Collingwood, Victoria.
The Butterflies of Australia: their Identification, Biology and Distribution
Braby, M. F. and Nielson, J. 2011. Review of the conservation status of the Atlas Moth, Attacus wardi Rothschild, 1910 (Lepidoptera: Saturniidae) from Australia. Journal of Insect Conservation 15: 603-8. http://dx.doi.org/10.1007/s10841-011-9402-y
CHCC 2007.Coffs Harbour City Council Metadata Documentation for the LiDAR Terrain Model. Coffs Harbour City Council, Coffs Harbour, NSW.
Church, J. A., Gregory, J. M., White, N. J., Platten, S. M. and Mitrovica, J. X. 2011. Understanding and projecting sea level change. Oceanography 24(2): 130-43. http://dx.doi.org/10.5670/oceanog.2011.33
DECCW 2009.Derivation of the NSW Government's Sea Level Rise Planning Benchmarks. New South Wales Department of Environment, Climate Change and Water, Sydney, NSW.
DECCW 2010.NSW Climate Impact Profile: the Impacts of Climate Change on the Biophysical Environment of New South Wales. New South Wales Department of Environment, Climate Change and Water, Sydney, NSW.
Dennis, R. L. H., Shreeve, T. G. and Van Dyck, H. 2006. Habitats and resources: the need for a resource-based definition to conserve butterflies. Biodiversity and Conservation 15: 1943-66. http://dx.doi.org/10.1007/s10531-005-4314-3
Dover, J. and Settele, J. 2009. The influences of landscape structure on butterfly distribution and movement: a review. Journal of Insect Conservation 13: 3-27. http://dx.doi.org/10.1007/s10841-008-9135-8
Eastwood, R., Braby, M. F., Schmidt, D. J. and Hughes, J. M. 2008. Taxonomy, ecology, genetics and conservation status of the pale imperial hairstreak (Jalmenus eubulus) (Lepidoptera: Lycaenidae): a threatened butterfly from the Brigalow Belt, Australia. Invertebrate Systematics 22: 407-23. http://dx.doi.org/10.1071/IS06028
Groom, C. 2010. Justification for continued conservation efforts following the delisting of a threatened species: a case study of the woylie, Bettongia penicillata ogilbyi (Marsupialia: Potoroidae). Wildlife Research 37: 183-93. http://dx.doi.org/10.1071/WR09129
Harris, J. M. and Goldingay, R. L. 2005. Distribution, habitat and conservation status of the Eastern Pygmypossum Cercartetus nanus in Victoria. Australian Mammalogy 27: 185-210.
Distribution, habitat and conservation status of the Eastern Pygmypossum Cercartetus nanus in Victoria
Australian Mammalogy
, vol. 
27
 (pg. 
185
-
210
)
IUCN 2011.Guidelines for Using the IUCN Red List Categories and Criteria. Version 9.0 International Union for Conservation of Nature Species Survival Commission, Gland, Switzerland and Cambridge, United Kingdom.
Karlsson, B. and Wiklund, C. 2005. Butterfly life history and temperature adaptations: dry open habitats select for increased fecundity and longevity. Journal of Animal Ecology 74: 99-104.
Butterfly life history and temperature adaptations: dry open habitats select for increased fecundity and longevity
Journal of Animal Ecology
, vol. 
74
 (pg. 
99
-
104
)
Lewis, O. T. and Senior, M. J. M. 2011. Assessing conservation status and trends for the world's butterflies: the sampled red list approach. Journal of Insect Conservation 15: 121-8. http://dx.doi.org/10.1007/s10841-010-9329-8
Miller, R. M., Rodriguez, J. P., Aniskowicz-Fowler, T., Bambaradeniya, C., Boles, R., Eaton, M. A., Gardenfors, U., Keller, V., Molur, S., Walker, S. and Pollock, C. 2007. National threatened species listing based on IUCN criteria and regional guidelines: current status and future perspectives. Conservation Biology 21: 684-96. http://dx.doi.org/10.1111/j.1523-1739.2007.00656.x
Moseby, K.E., Brandle, R. and Adams, M. 1999. Distribution, habitat and conservation status of the rare dusky hopping-mouse Notomys fuscus (Rodentia: Muridae). Wildlife Research 26: 479-94. http://dx.doi.org/10.1071/WR97061
Morris, K. D. 2000. The status and conservation of native rodents in Western Australia. Wildlife Research 27: 405-19. http://dx.doi.org/10.1071/WR97054
New, T. 2008. Conserving narrow range endemic insects in the face of climate change: options for some Australian butterflies. Journal of Insect Conservation 12: 585-9. http://dx.doi.org/10.1007/s10841-008-9145-6
New, T. 2011. Butterfly conservation in south-eastern Australia: progress and prospects. Springer, Netherlands. http://dx.doi.org/10.1007%2F978-90-481-9926-6
New, T. R. and Sands, D. P. A. 2003. The listing and de-listing of invertebrate species for conservation in Australia. Journal of Insect Conservation 7: 199-205. http://dx.doi.org/10.1023/B:JICO.0000020955.94081.84
NSW Chief Scientist and Engineer 2012. Assessment of the Science behind the NSW Government's Sea Level Rise Planning Benchmarks. Report to the New South Wales Government, Sydney, NSW.
NSW Scientific Committee 2002.Black Grass-dart Butterfly – Endangered Species Listing Final Determination. New South Wales Scientific Committee, Sydney, NSW.
Sands, D.P.A. 1997. Alexfloydia repens Simon: a food plant for Ocybadistes knightorum Lambkin & Donaldson (Lepidoptera: Hesperiidae) and their conservation significance. Australian Entomologist 24(3): 117-8.
Alexfloydia repens Simon: a food plant for Ocybadistes knightorum Lambkin & Donaldson (Lepidoptera: Hesperiidae) and their conservation significance
Australian Entomologist
, vol. 
24
 (pg. 
117
-
8
)
Sands, D. P. A. and New, T. R. 2002. The Action Plan for Australian Butterflies. Environment Australia, Canberra, ACT.
The Action Plan for Australian Butterflies
Thomas, J. A., Bourn, N. A. D., Clarke, R. T., Stewart, K. E., Simcox, D. J., Pearman, G. S., Curtis, R. and Goodger, B. 2001. The quality and isolation of habitat patches both determine where butterflies persist in fragmented landscapes. Proceedings of the Royal Society of London B 268:1791-6. http://dx.doi.org/10.1098/rspb.2001.1693
Vierling, K. T., Vierling, L. A., Gould, W. A., Martinuzzi, S. and Clawges, R. M. 2008. LiDAR: shedding new light on habitat characterisation and modeling. Frontiers in Ecology and Environment 6(2): 90-8. http://dx.doi.org/10.1890/070001
WallisDeVries, M. F. 2004. A quantitative conservation approach for the endangered butterfly Maculinea alcon. Conservation Biology 18(2): 489-99.
A quantitative conservation approach for the endangered butterfly
Maculinea alcon. Conservation Biology
, vol. 
18
 (pg. 
489
-
99
)
Ward, M. J., Ruykys, L., Van Weenan, J., De Little, S., Dent, A, Clarke, A. and Partridge, T. 2011. Status of warru (Petrogale lateralis MacDonnell Ranges race) in the Anangu Pitjantjatjara Yankunytjatjara lands of South Australia. 2. Population dynamics. Australian Mammalogy 33: 142-51. http://dx.doi.org/10.1071/AM10055
Wilson, R. J. and Maclean, M. D. 2011. Recent evidence for the climate change threat to Lepidoptera and other insects. Journal of Insect Conservation 15: 259-68. http://dx.doi.org/10.1007/s10841-010-9342-y
Wood, B. C. and Pullin, A. S. 2002. Persistence of species in a fragmented urban landscape: the importance of dispersal ability and habitat availability for grassland butterflies. Biodiversity and Conservation 11: 1451-68. http://dx.doi.org/10.1023/A:1016223907962
This content is only available as a PDF.