Dr John G Ewen

Curriculum Vitae:

• 2004-present: Research Fellow, Institute of Zoology.
• 2002-2004: Postdoctoral Research Fellow, Université Pierre et Marie Currie, Paris.
• 1998-2002: PhD Zoology, La Trobe University, Australia.
• 1995-1998: MSc Ecology, Massey University, New Zealand.
  .

Research Interests:

Hihi / Stitchbird Conservation

Behavioural ecology and conservation in the hihi (stitchbird).

I am a behavioural ecologist and have always tried to utilise this discipline to enhance the management of threatened species. My research focuses on the conservation of hihi, an endemic and endangered New Zealand passerine. My current project is titled ‘Sexual selection and the hihi: an investigation of population limitation in an endangered bird’ and is conducted in collaboration with Anders Møller from the Université Pierre et Marie Curie and Doug Armstrong from Massey University.
Hihi are a sexually dimorphic species with extreme mating behaviours (including forced face-to-face copulations!) resulting in intense competition to reproduce. The aim of my project is to understand the possible trade-off between investing carotenoids (dietary biochemical’s) in self maintenance (carotenoids act as antioxidants and are important in the immune system) versus investment in both display (male plumage pigments) and reproduction (female investment in egg yolk).

Phylogenetic affinities of hihi and kokako.

New Zealand’s birds are special, not least because they are characterised by high levels of endemism. This is important given the majority of these endemics are threatened with extinction and priorities must be set for management. Phylogenetic uniqueness is a major factor to consider. Recently the placement of hihi within the Meliphagidae (honeyeaters) has been questioned and I am currently working with Per Ericson from the Swedish Museum of Natural History to identify their systematic affinities. We are also interested in the endemic family Callaeidae (wattlebirds) and particularly in identifying the affinity of previously un-sequenced kokako.
.

Main Collaborations

Blood-borne parasites in the New Zealand avifauna.

Biological invasions are renowned for their negative impacts on native fauna. Along with Camille Bonneaud from the Center for Tropical Research (UCLA) and Javier Perez-Tris from Lund University, I am investigating this issue with a focus on malarial parasites. Our first aim is to determine the extent to which avian malaria is present in the native avifauna and whether the parasites are native or the result of introduction from exotic species. We are also investigating patterns of parasitism across species to understand the variable threats to New Zealand’s birds.

Carotenoids and signalling in birds.

This collaborative research, led by Phillip Cassey from the University of Birmingham, investigates patterns of carotenoid use across passerine species introduced to New Zealand. Continuing work focuses on the signalling function of biliverdin pigments in egg shell related to maternal quality and investment of carotenoids in egg yolk.
.

Publications:

Cassey, P., Ewen, J.G., Boulton, R., Blackburn, T., Møller, A.P., Biard, C., Olson, V., and Karadas, F. (2005). Egg carotenoids in passerine birds introduced to New Zealand: relations to ecological factors, integument coloration, and phylogeny. Journal of Functional Ecology. In press.

Cassey, P., Ewen, J.G., Blackburn, T.M., Hauber, M.E., Vorobyev, M. and Marshall, N.J. (2008) Eggshell colour does not predict measures of maternal investment in eggs of Turdus thrushes. Naturwissenschaften 95: 713-721. DOI: 10.1007/s00114-008-0376-x

Armstrong, D.P., Richard, Y., Ewen, J.G. and Dimond, W.J. (2008) Avoiding hasty conclusions about effects of habitat fragmentation. Avian Conservation and Ecology 3(1): 8.

Ewen, J.G., Ciborowski, K.L., Clarke, R.H., Boulton, R.L. and Clarke, M.F. (2008) Evidence of extra-pair paternity in two socially monogamous Australian passerines: the Crescent Honeyeater and the Yellow-faced Honeyeater. Emu 108: 133-137. DOI: 10.1071/MU07040

Ewen, J.G., Thorogood, R., Karadas, F. and Cassey, P. (2008) Condition dependence of nestling mouth colour and the eVect of supplementing carotenoids on parental behaviour in the hihi (Notiomystis cincta). Oecologia. DOI: 10.1007/s00442-008-1073-3

Ewen, J.G. and Armstrong, D.P. (2007) Strategic monitoring of reintroductions in ecological restoration programmes. Ecoscience 14(4): 401-409.

Cassey, P., Ewen, J.G., Boulton, R.L., Karadas, F., Moller, A.P. and Blackburn, T.M. (2007) A nondestructive method for extracting maternally derived egg yolk carotenoids. Journal of Field Ornithology 78(3): 314-321. DOI: 10.1111/j.1557-9263.2007.00111.x

Ewen, J.G., Thorogood, R., Nicol, C., Armstrong, D.P. and Alley, M. (2007) Salmonella typhimurium in hihi, New Zealand. Emerging Infectious Diseases 13(5): 788-790.

Cassey, P., Ewen, J.G., Karadas, F. and Hauber, M.E. (2006) Repeatability of laboratory measurements for maternally derived yolk carotenoid concentrations in bird eggs. Australian Journal of Zoology 54(6): 381-384.

Ewen, J.G., Flux, I. and Ericson, P.G.P. (2006) Systematic affinities of two enigmatic New Zealand passerines of high conservation priority, the hihi or stitchbird Notiomystis cincta and the kokako Callaeas cinerea. Molecular Phylogenetics and Evolution 40(1): 281-284.

Ewen, J.G., Surai, P., Stradi, R., Moller, A.P., Vittorio, B., Griffiths, R. and Armstrong, D.P. (2006) Carotenoids, colour and conservation in an endangered passerine, the hihi or stitchbird (Notiomystis cincta). Animal Conservation 9: 229-235.

Ewen, J.G., Thorogood, R., Karadas, F., Pappas, A.C. and Surai, P.F. (2006) Influences of carotenoid supplementation on the integrated antioxidant system of a free living endangered passerine, the hihi (Notiomystis cincta). Comparative Biochemistry and Physiology 143: 149-154.

Ewen, J.G., Cassey, P. and Møller, A.P. (2004). Facultative primary sex ratio variation: a lack of evidence in birds? Proceedings of the Royal Society London B 271: 1277-1282.

Ewen, J.G., Armstrong, D.P., Ebert, B. and Hansen, L.H. (2004). Extra-pair copulation and paternity defense in the hihi (or stitchbird) Notiomystis cincta. New Zealand Journal of Ecology 28: 233-240.

Cassey, P., Ewen, J.G., Blackburn, T.M. and Moller, A.P. (2004). A survey of publication bias within evolutionary ecology. Proceedings of the Royal Society London Biology Letters 271: 451-454.

Ewen, J.G., Crozier, R.H., Cassey, P., Ward-Smith; T., Painter, J.N., Robertson, R.J., Jones, D.A., and Clarke, M. F. (2003). Facultative control of offspring sex in the cooperatively breeding bell miner, Manorina melanophrys. Behavioral Ecology 14: 157-164.

Ewen, J.G., Cassey, P., and King, R. (2003). An assessment of the randomization test for sex ratio biases. Auk 120: 62-68.

Clarke, M. F., Schipper, C., Boulton, R. and Ewen, J.G. (2003). The social organisation and breeding behaviour of the yellow-faced honeyeater Lichenostomus chrysops - a migratory passerine from the southern hemisphere. Ibis 145: 611-623.

Ewen, J.G., and Armstrong, D.P. (2002). Unusual sexual behaviour in the stitchbird (or hihi) Notiomystis cincta. Ibis 144: 530-531.

Armstrong, D.P. and Ewen, J.G. (2002). Dynamics and viability of a New Zealand robin population reintroduced to regenerating fragmented habitat. Conservation Biology 16: 1-13.

Armstrong, D.P., Davidson, R.S., Dimond, W.J., Perrott, J.K., Castro, I., Ewen, J.G., Griffiths, R. and Taylor, J. (2002). Population dynamics of reintroduced forest birds on New Zealand islands. Journal of Biogeography 29: 1-13.

Armstrong, D.P., Raeburn, E.H., Powlesland, R.G., Howard, M., Christenson, B., and Ewen, J.G. (2002). Obtaining meaningful comparisons of nest success: data from New Zealand robin (Petroica australis) populations. New Zealand Journal of Ecology 26: 1-13.

Clarke, R.H., Boulton, R.L., Ewen, J.G., Moysey, E. and Clarke, M.F. (2002). Methods for aging and sexing the Black-eared Miner Manorina melanotis and Yellow-throated Miner M. flavigula. Emu 102: 339-344.

Clarke, M.F., Jones, D.A., Ewen, J.G., Robertson, R.J., Griffiths, R., Painter, J., Boag, P.T. and Crozier, R. (2002). Male-biased sex ratios in broods of the cooperatively breeding bell miner, Manorina melanophrys. Journal of Avian Biology 33: 71-76.

Ewen, J.G., Clarke, R.H., Moysey, E., Boulton, R., Crozier, R.H., and Clarke, M.F. (2001). Primary sex ratio bias in an endangered cooperatively breeding bird, the black-eared miner, and its implications for conservation. Biological Conservation 101: 137-145.

Armstrong, D.P. and Ewen, J.G. (2001). Testing food limitation in reintroduced hihi populations:contrasting results for two islands. Pacific Conservation Biology 7: 87-92.

Armstrong, D.P. and Ewen, J.G. (2001). Assessing the value of follow-up translocations: a case study using New Zealand robins. Biological Conservation 101: 239-247.

Armstrong, D.P. and Ewen, J.G. (2001). Estimating impacts of poison operations using mark-recapture analysis and population viability analysis: an example with New Zealand robins (Petroica australis). New Zealand Journal of Ecology 25: 29-38.

Goodisman, M.A.D., Evans, T.A., Ewen, J.G. and Crozier, R.H. (2001). Microsatellite markers in the primitive termite Mastotermes darwiniensis. Molecular Ecology Notes 1: 250-251.

Ewen, J.G., and Armstrong, D.P. (2000). Male provisioning is negatively correlated with attempted extra-pair copulation in the stitchbird (or hihi). Animal Behaviour 60: 429-433.

Armstrong, D.P., Ewen, J.G., Diamond, W.J., Lovegrove, T.G., Bergstrom, A., and Walter, B. (2000). Breeding biology of North Island robins (Petroica australis longipes) on Tiritiri Matangi Island, Hauraki Gulf, New Zealand. Notornis 47: 106-118.

Ewen, J.G., Armstrong, D.P., and Lambert, D.M. (1999). Floater males gain reproductive success through extra-pair fertilisations in the stitchbird. Animal Behaviour 58: 321-327.