Southern emu-wren Stipiturus malachurus
The southern emu-wren is a small passerine from the Maluridae family, which gets its name from its long filamentous tail resembling that of an emu. Our research into the emu-wren involved studying the breeding biology and demography of the species over three breeding seasons. We found that the nesting behaviour is typical of the Maluridae family, with 2-3 eggs that are incubated for around 19 days and hatch after 14 days. The main cause of nest failure was due to predation by snakes.
Interestingly, we observed some male offspring delaying breeding attempts to help raise younger siblings – the first time cooperative behaviour has been observed in this species. We found those juveniles that did disperse, moved over 1km away and were capable of breeding in their first year. We also found that individual mortality was high and pair duration was short (<6 months). As part of this general investigation into the breeding behaviour of southern emu-wrens, we isolated and characterised eight microsatellite loci that we could then use to determine levels of genetic diversity within and between populations of the species.
Many close relatives of the southern emu-wren display high levels of extra-pair paternity (e.g. superb fairy-wren) and we were keen to investigate whether a similar pattern occurs in this species. By assessing the paternity for a large number of offspring, we were able to determine that extra-pair paternity is comparatively low in this species (only 12% of tested offspring were a result of extra-pair matings). We suggest that these low levels of extra-pair matings may be because the female is reliant on her partner to provide offspring care, compared to more promiscuous species which typically have “helpers” to assist.
This research was part of a PhD carried out by Dr. Grainne Maguire, entitled “Behavioural ecology of the southern emu-wren (Stipiturus Malachurus)”. Grainne now works as a Project Manger with Birds Australia.
More information about this research can be found in these publications:
Maguire, GS & Mulder, RA (2008). Low levels of extra-pair paternity in southern emu-wrens (Aves: Maluridae). Australian Journal of Zoology 56: 79-84. Full text
Maguire, SG, Guay, P-J & Mulder, RA (2006). Isolation and characterization of microsatellite markers in the southern emu-wren (Stipiturus malachurus: Aves). Molecular Ecology Notes 6: 422-424. Full text
Maguire, SG & Mulder, RA (2004). Breeding biology and demography of the southern emu-wren (Stipiturus malachurus). Australian Journal of Zoology 52: 583-604. Full text
Photo: Chris Tzaros