| 1. | Biodiversity Research and Management Division, NSW National Parks and Wildlife Service, P.O. Box 1967, Hurstville, NSW 2220, Australia; |
| 2. | Australian Museum, 6 College St, Sydney, NSW 2010, Australia; |
| 3. | Insektus, P.O. Box 138, Macarthur Square, NSW 2560, Australia; |
| 4. | Lord Howe Island Board, Lord Howe Island, NSW 2898, Australia; |
| * | Author for correspondence (e-mail: david.priddel@npws.nsw.gov.au; fax: +61-2-9585-6606) |
Biodiversity and Conservation 12: 1391-1403, 2003.
© 2003 Kluwer Academic Publishers. Printed in the Netherlands.
| Page 1391 |
Abstract. The Lord Howe Island Stick-insect (Dryococelus
australis) was formerly abundant on Lord Howe Island, Australia,
but was extirpated by Black Rats (Rattus rattus) in the 1920s.
The species was thought to be extinct, until freshly dead remains were
found by climbers on Balls Pyramid during the 1960s. In February 2001,
a survey of Balls Pyramid led to the discovery of a small population
of D. australis on a precipitous terrace 65 m above sea level.
Two adults and one nymph (all females) were located feeding on an
endemic tea-tree (Melaleuca howeana). An accumulation of plant
debris at the base of the shrub, kept moist by water seepage, provided
the insects with damp hollows suitable for use as daytime refugia.
All evidence indicated that the species was confined to this single
small terrace. A second survey, in March 2002, located a total of 24
D. australis. Twelve individuals were in the same shrub as that
occupied the previous year, and 12 were dispersed among five nearby,
smaller shrubs. Ten individuals were able to be sexed - eight females and
two males. A number of threats to the population of D. australis
on Balls Pyramid are identified and several management actions are
proposed to ensure the conservation of the species.