South Island stout-legged wren
Xenicus yaldwyni (Millener, 1988)
Other names: South Island stoutlegged wren, South Island stout legged wren
Geographical variation: Sometimes considered conspecific with the North Island stout-legged wren P. jagmi (P. yaldwyni has priority).
The South Island stout-legged wren was the largest of seven species of New Zealand wrens present in New Zealand when early Maori stepped ashore. They are an ancient group of birds, considered to be descended from the earliest branch from the vast songbird tree (Order Passeriformes). They are not at all closely related to the true wrens found in most other parts of the worlds. Three of these New Zealand wrens (including both species of stout-legged wrens) became extinct before European contact, and another two have succumbed since, leaving the rifleman and rock wren as the only survivors of this once diverse group. Stout-legged wrens were originally described in their own genus (Pachyplichas); however, genetic analyses showed them to be more closely related to rock wren (Xenicus gilviventris) than either is to bush wren (X. longipes).
Since they were first recognised, bones of South Island stout-legged wrens have been found fairly commonly in deposition sites throughout the South Island. They have even been recorded from human occupation sites, showing that they survived up to the time people first reached New Zealand but not much longer.
South Island stout-legged wrens share the same physical characteristics as the North Island species but were larger with a weight estimated at 50 g.
Distribution and habitat
South Island stout-legged wrens seem to have been versatile forest dwellers. They have been found throughout the South Island in habitats that were forested ranging from the lowlands up to subalpine scrub and in relatively wet western forests as well as the drier eastern ones, under tree canopies that varied from podocarp and broadleafed hardwoods to New Zealand beeches. Better known birds that show a similar pattern of occurrence in fossil deposits are kokako, robin, saddleback and weka.
Behaviour and ecology
It is not only their morphology that suggests that stout-legged wrens lived on the ground and did not fly, they are commonly found in fossil sites that are essentially pitfall traps. They are also found in laughing owl middens where they were a particularly common prey item suggesting that they were very common forest birds.
Millener, P.R. 1988. Contributions to New Zealand’s late Quaternary avifauna. 1: Pachyplichas, a new genus of wren (Aves: Acanthisittidae), with two new species. Journal of the Royal Society of New Zealand 18: 383-406.
Mitchell, K.J.; Wood, J.R.; Llamas, B.; McLenachan, P.A.; Kardailsky, O.; Scofield, R.P.; Worthy, T.H.; Cooper, A. 2016. Ancient mitochondrial genomes clarify the evolutionary history of New Zealand’s enigmatic acanthisittid wrens. Molecular Phylogenetics and Evolution 102: 295–304.
Tennyson, A.; Martinson, P. 2006. Extinct birds of New Zealand. Te Papa Press, Wellington.
Worthy, T.H.; Holdaway, R.N. 2002. The lost world of the moa. Canterbury University Press, Christchurch.
Southey, I. 2013 [updated 2022]. South Island stout-legged wren. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz
South Island stout-legged wren
- Breeding season
- Egg laying dates