Dave O'Connor

Dave

Position: PhD student
Year: 1999 - 2003
Email: daveotravel@gmail.com
Phone: N/A
Fax: N/A
Location: N/A


Current Research

The Evolution of Sociality in Reptiles

Egernia saxatilis

Reptiles provide an ideal system to formulate and test hypotheses about the evolution of social groupings as they lack a number of the confounding factors found in other social systems, in particular parental care. By studying reptilian species we can formulate and test hypotheses about the evolution of social systems in these species and in species, in particular within the Australian skink genus Egernia, are commonly found in what appears to be family groups, i.e. one or two adults with a number of juvenile and sexually immature animals. Such groupings are commonly observed in the black rock skink, Egernia saxatilis.

If, as is sometimes assumed, animals in a "family" group are related, a number of questions are raised with regard to the social structure and parental care within these groups. Long term pair bonds are formed in a related species, Tiliqua rugosa, and it is not unreasonable to expect similar bonding in other species including E. saxatilis. If indeed pair bonding does occur within Egernia, are the groups observed in the wild that of "nuclear" families, and if so, what are the fitness benefits associated with being a member of such a family? Furthermore, do "parents" aid offspring in the selection of suitable shelter, predator avoidance, protection from predators or from other adults?

snake

If pair bonding occurs, do parents, and in particular males, recognise offspring that are not their own? The project has three main components, a field study, behavioural experiments and a genetic analysis of relatedness. The overall aim of the project is to combine the results from these three components in order to formulate and test hypotheses about the evolution of sociality in reptiles and gain a more complex understanding of the ecology and life history characteristics of Egernia saxatilis. My field site is situated in Kanangra-Boyd National Park in the Blue Mountains, 3 hours west of Sydney. On initial capture individuals are measured, a genetic sample taken and individually marked. Subsequent visits to the site involve surveying for the animals and recording habitat use and social interactions.

The field study has two main aims: 1. Describe the basic ecology and life history of Egernia saxatilis and 2. Document social groupings and collect data on interactions within and between groups. Behavioural observations from the field site form the basis for formulating hypotheses about the evolution and maintenance of social behaviour in the black rock skink. These hypotheses are then tested (as far as is possible without a time machine) and expanded on in a laboratory environment. The current behavioural experiments are focussed on investigating aggressive interactions between individuals and groups and determining the degree of individual recognition of offspring and group members. The third component of the study is assessing the degree of relatedness of individuals using microsatellites. This will not only allow me to determine if the observed groups are in fact family groups, but can also be integrated with a large amount of the previously collected data to provide information on extra-pair paternity, fitness, mate choice and migration between outcrops.

PhD project supervised by Prof. Rick Shine

Rainforest Speciation

rainforest speciation

Investigating the interaction between genetic isolation and morphological evolution in the rainforest skinks, Saproscincus rosei and Eulamprus murrayi. The role of refugia in rainforest speciation has been debated since the idea was first proposed in 1969. Whilst there is increasing evidence that historical rainforest fragmentation results in reduced population size and gene flow between isolated populations of rainforest endemic animals, it is still to be conclusively demonstrated that this isolation also results in significant phenotypic divergence or speciation. Most speciation theories incorporate genetic isolation acting in accord with founder effects, inbreeding, genetic drift and selection to create morphological changes. The expansion and contraction of rainforest isolates creates conditions suitable for a large degree of population expansion and contraction. If populations contract to small effective sizes, genetic drift and founder effects are predicted to have a significant effect on phenotypic characters under these conditions, resulting, among other changes, in differences in morphology between isolated populations.

rainforest speciation

Previous comparisons of molecular versus morphological variation in rainforest faunas have focussed on the wet tropics of north Queensland, where historical isolation has been overlain by expansion and secondary contact. If a correlation between molecular and morphological variation does exist it is expected that this would be stronger in a system where populations are confined to rainforest remnants that are currently as well as historically isolated. Accordingly we are currently examining molecular and morphological variation in two species of skink confined to naturally disjunct rainforest areas in south-east Australia. Under the current vicariant hypothesis, historical barriers to gene flow should create conditions under which morphological differences between populations are, in part, driven by genetic drift. If the phylogeographies of Saproscincus rosei and Eulamprus murrayi show a pattern of genetic isolation then individual populations are expected to show random shifts in morphological traits. It is also expected that there will be some degree of correlation between the genetic distance between populations and the degree of morphological change. We are currently investigating the degree of correlation between genetic distance, geographical distance, climatic factors and morphological differences between populations.

Collaborators: Adnan Moussalli 1, Ross Sadlier 2 and Craig Moritz 1,3

  1. Cooperative Research Centre for Tropical Rainforest Ecology and Management, Department of Zoology and Entomology, University of Queensland,
  2. Australian Museum.
  3. Museum of Vertebrate Zoology, Berkeley Reptile Systematics Molecular

Systematics of the genus Eulamprus

The phylogenetic relationships of species in the skink genus Eulamprus are poorly known, with similarities in morphology preventing current resolution of a phylogeny below the level of the three species clades (the E. quoyii, E. murrayi and E. tenuis clades). In the current study, mitochondrial DNA sequencing of the ND4 region is being used to test the current hypothesised species groups and provide resolution below the level of the species groupings. Based on mitochondrial data it is highly likely that Eulamprus is a paraphyletic genus.

In collaboration with Craig Moritz, Museum of Vertebrate Zoology, Berkeley

Publications

Some papers are available as pdfs. To request a copy please contact .

16.
Langkilde T.,D. O‚Connorand R. Shine. 2007. The benefits of parental care: do juvenile lizards obtain better-quality habitat by remaining with their parents?Austral Ecology 32:950-954.
15.
Whiting, M.J., D. Stuart-Fox,D. O‚Connor, D. Firth, N. G. Bennet and S. Blomberg. 2006. Ultraviolet signals ultra-aggression in a lizard.Animal Behaviour 72:353-363.
14.
O'Connor, D.and R. Shine. 2006. Kin discrimination in the social lizardEgernia saxatilis(Scincidae).Behavioral Ecology 17:206-211.
13.
O'Connor, D. 2004.  Foraging success by the Laughing Kookaburra (Dacelo novaeguineae) in a suburban habitat.Corella 29:9-10.
12.
O'Connor, D. 2004. Psuedocordylus subtesselatus: range extension. African Journal of Herpetology.
11.
O'Connor, D.2004. Austrelaps superbus(Australian Copperhead) andEgernia saxatilis(Black Rock Skink). Predation.Herpetological Review 35:174-175.
10.
O'Connor, D.and R. Shine. 2004. Parental care protects against infanticide in the lizardEgernia saxatilis(Scincidae).Animal Behaviour 68:1361-1369.
9.
O'Connor, D.2003.  Predation by the laughing kookaburra on eastern blue-tongued lizards.Herpetofauna 33:103-104.
8.
O'Connor, D.and R. Shine. 2003. Lizards in "nuclear families": a novel reptilian social system inEgernia saxatilis(Scincidae).Molecular Ecology 12:743-752.
7.
O'Connor, D.2003. Vocalisation and aggression in the Prickly Forest SkinkGnypetoscincus queenslandiae.Australian Zoologist 32:265-266.
6.
Langkilde, T.,D. O'Connorand R. Shine. 2003. Shelter-site use by five species of montane scincid lizards in south-eastern Australia.Australian Journal of Zoology 51:1-12.
5.
O'Connor, D.and C. Moritz. 2003. A molecular perspective on relationships and evolution within the skink generaEulamprus,GnypetoscincusandNangura.Australian Journal of Zoology 51:317-330.
4.
Shine, R.,D. O'Connor, M. P. LeMaster and R. T. Mason. 2001. Pick on someone your own size: ontogenetic shifts in mate choice by male garter snakes result in size-assortative mating.Animal Behaviour 61:1133-1141.
3.
Shine, R.,D. O'Connorand R. T. Mason. 2000. Female mimicry in garter snakes: behavioural tactics of "she-males" and the males that court them.Canadian Journal of Zoology 78:1391-1396.
2.
Shine, R.,D. O'Connorand R. T. Mason. 2000. The problem with courting a cylindrical object: how does an amorous male snake determine which end is which?Behaviour 137:727-739.
1.
Shine, R.,D. O'Connorand R. T. Mason. 2000. Sexual conflict in the snake den.Behavioural Ecology and Sociobiology 48:392-401.

Grants

2002
University of Sydney Overseas Research Grant $1,400.00
2002
University of Sydney Overseas Research Grant $1,400.00
2002
University of Witswatersrand Invited Seminar $400.00
2002
University of Stellenbosch Invited Seminar $250.00
2002
Joyce W. Vickery Scientific Research Fund $300.00
2001
University of Sydney Conference Travel Grant $1,200.00
2001
Ethel Mary Read Research Grant $600.00
1999
Peter Rankin Trust Fund for Herpetology $400.00
1999
University of Sydney Conference Travel Grant $140.00
1999
University of Queensland Conference Travel Grant $400.00

Conferences and Presentations

2003
WEA Seminar, Sydney
2002
Witswatersrand University, South Africa, Departmental Seminar
2002
Stellenbosch University, South Africa, Departmental Seminar
2002
Australian Society of Herpetologists, Canberra
2002
Australian Herpetological Society, Sydney
2001
Fourth World Congress of Herpetology, Sri Lanka (2 oral presentations)
2001
Ecological Society of Australia, Wollongong
2001
Australian Society of Herpetologists, Tasmania
2000
University of Queensland, Zoology Department
2000
Institute of Wildlife Research, Sydney (Poster)
2000
Flinders University, Zoology Department
2000
Evolution and Ecology Society, Canberra
1999
Genetics Society of Australia, Brisbane (Poster)
1998
Australian Society of Herpetologists, Yungaburra

Awards Received

2002
Best Postgraduate Oral Presentation, Australian Society of Herpetologists 2002
2002
Finalist, School of Biological Sciences Award for Postgraduate Excellence
1996
Science Faculty Commendation For High Achievement, University of Queensland
1995-96
Dean's List, Faculty of Science, University of Queensland
1995-96
Dean's List, Faculty of Arts, University of Queensland
1995
F. A. Perkins Prize in Entomology, University of Queensland

Shemale