Xavier Hoenner
PhD Candidate
 |
|
Contact details Email: xavier.hoenner@cdu.edu.au |
Primary: Dr Clive McMahon
Associate: Assoc Prof Mike Lawes, Dr Scott Whiting, Dr Colin Limpus.
Thesis Title
The nesting ecology and migratory behaviour of hawksbill turtles (Eretmochelys imbricata) in Northern Australia
Due to an intense exploitation of their shells for centuries, hawksbill turtle populations have drastically decreased worldwide and this species is now classified as critically endangered by the IUCN. Within the Indo-Pacific region, Australia supports the largest stocks of breeding hawksbills (Meylan & Donnelly 1999, Limpus 2009). Although hawksbill turtles breed and live along the Northern coast of Australia, hawksbill turtle research has focussed primarily on Queensland populations (Limpus et al. 1983a, Limpus et al. 1983b, Loop et al. 1995, Miller et al. 1998, Dobbs et al. 1999) and information from elsewhere is scarce (Limpus & Miller 2000, Chatto 1998, 2008).
In the Northern Territory, few sea turtle studies have been conducted and no detailed studies have been undertaken on hawksbill turtles. This situation is mainly due to long nesting seasons and limited access to remote areas where hawksbills prefer to nest (Witzell 1983, Chatto & Baker 2008). Nevertheless, multiannual aerial and ground observations have identified important nesting areas along with their broad seasonality (Chatto & Baker 2008). Such studies (Chatto & Baker 2008), even though general in their scope, provide a valuable first step in the conservation of endangered species. But, to adequately inform conservation policy, more accurate insights are required e.g. nesting ecology and biology, accurate knowledge of population size, nightly and annual variation in nesting abundance. Identifying habitat use and describing at-sea behaviour is also paramount since it provides information on the marine phase, which constitutes 94 to 97% of a turtle’s life (Lutcavage & Lutz 1997).
To address the above gaps, my thesis has the following goals:
1. Describe the nesting ecology of hawksbill turtles nesting on Groote Eylandt, Northern Territory by determining key life history parameters including: seasonality of nesting, nesting abundance, internesting interval, beach fidelity within seasons, clutch size, nest locations, nest temperatures, and threats to hawksbill eggs, hatchlings and adults.
2. Determine the biological features of the hawksbill population using measurements such as size and mass of adult females, hatchlings and eggs.
3. Determine the at-sea habitats and diving behaviour for hawksbill turtles using satellite transmitter units. Information on this crucial and main part of the turtles lives allow us to:
- Identify their marine habitats during the inter-nesting periods,
- Identify the migratory pathways they use when returning to their feeding grounds,
- Identify important foraging habitats.
4. Interpret and integrate the above results to deliver management direction at the finer context of local indigenous management and, at the broader context, of regional and global management of hawksbill turtles.
Publications
Conference Presentations
HOENNER X., McMahon C. R., Whiting S., 2010. Migrations, habitats and at-sea behaviour of hawksbill turtles in Northern Australia. 27-29 April. Panaji, Goa, India.
HOENNER X., McMahon C. R., Whiting S., Hindell M. A., 2011. Conservation through satellite telemetry: how accurate are state-space models and other Argos-derived datasets? BIOLOGGING 4, 14-18 March 2011. Hobart, Tasmania, Australia. View poster here
GUERIN F., DIJOUX L., HOENNER X., DENIS V., BRUGGEMANN H., GUILLAUME M., 2008. Genetic diversity of the zooxanthellae symbionts of corals from Reunion Island. Poster presentation for the 11th International Coral Reef Symposium, 7-11 July 2008. Fort Lauderdale, Florida, USA.
GUERIN F., HOENNER X., DENIS V., GUILLAUME M., BRUGGEMANN H., 2007. Preliminary results on the genetic diversity of coral symbionts at Reunion Island. Poster presentation for the 5th WIOMSA Scientific Symposium, 22-26 Oct. 2007. Durban, South Africa.
HOENNER X., 2007. Genetic diversity of the zooxanthellae symbionts of corals from Reunion Island, Western Indian Ocean. Master’s thesis (2nd year). 40 pp.
HOENNER X., 2006. Abundance and characteristics of cyanobacteria of the genus Synechococcus in East China Sea and in the Kuroshio current. Master’s thesis (1st year). 48 pp.
HOENNER X. & BUSCOT M.-J., 2008. Study report on the marine turtle nesting survey on the Tetiaroa atoll (Oct. 07-Mar. 08). Report for the Ministry of Environment of French Polynesia. 221 pp.
HOENNER X. & BUSCOT M.-J., 2008. Bibliographical synthesis on marine turtles: 1) ecological and biological aspects linked to their conservation, 2) Hatchlings rearing and 3) Nest translocation. Report for the Ministry of Environment of French Polynesia. 85 pp.
HOENNER X., Lambert K., Campbell D., 2008. Investigation of sea turtle nesting at North East Island, Groote Eylandt, 3-5 Dec. 2008. Unpublished report for the Anindilyakwa Land Council, 7 p.
HOENNER X., Whiting S., Lambert K., Campbell D., Lalara P., Lalara C., 2008. Investigation of sea turtle nesting at North East Island, Groote Eylandt, 18-20 Nov. 2008. Unpublished report for the Anindilyakwa Land Council, 7 p.
HOENNER X., Lambert K., Campbell D., Lambert D., 2008. Investigation of sea turtle nesting at Dingala Point and North East Isles, Groote Eylandt, 4-9 Nov. 2008. Unpublished report for the Anindilyakwa Land Council, 9 p.
HOENNER X., 2006. A trophic network model: Impact of coral bleaching on the coral reef ecosystem through a symbiosis-based model. Modelling essay. 31 pp.
HOENNER X., 2006. Using the thermosalinometer’s data: Geographic location of the Liguro-provençal current. Report of “Instrumental methods in oceanology”. Masters degree project. 18pp.
From the International Sea Turtle Society for the period 2010: Travel Grant for the 30th Sea Turtle Symposium in Goa, India – US$ 500
From Charles Darwin University, Darwin, AUSTRALIA for the period 2009-2011: International Postgraduate Research Scholarship (IPRS) – AU$ 75 477, University Postgraduate Research Scholarship (UPRS) – AU$ 60 000
From the NT Government, Darwin, AUSTRALIA for the period 2009-2011: Top-up Scholarship – AU$ 45 000
From ANZ Trustees Foundation for the period 2009:, Holsworth Wildlife Research Endowment Grant to support the purchase of more satellite telemetry devices for the PhD project – AU$ 7 500
From University Pierre and Marie Curie, Paris, FRANCE for 2007-2008: Grant for students studying in overseas French territories - € 2 500
From University Pierre and Marie Curie, Paris, FRANCE for 2006-2007: Merit-based Scholarship for the Masters Degree - € 6 100
