Weka; two subspecies

[Neil Fitzgerald]

In the NZ Herald a few days ago is an article about DNA work by Steve Trewick and others on weka, stating they should be just two subspecies; North Island (Gallirallus australis greyi) and South Island (G.a. australis). There must be a paper out there somewhere, but I haven't come across it yet.

[Davidthomas]

Its a rather interesting piece of research really. I work with Steve Pilkington one of the co-authors (who did all the research/analysis) and he said that the southern ones only differ by a single base-pair between all of the traditional sub-species, while there was a 15 base pair difference between NI and SI birds, hence the lumping to two sub-species.

Although i hope they maintain control over the chatham birds as they certainly represent a unique phenotype even if theyre not that genotypically distinct.

[Ian Southey]

Interesting - a consistent difference of one base pair is still a difference and would be sufficient to justify some sort of taxonomic status I would think. I'm sure the differences are recent, probably post glacial as the plumage differences might be climate driven but as far as I know Pied and Variable Oystercatchers are not distinguished by any base pairs at all - do they get lumped?

Ian

[Michael Szabo]

Here's the link: http://www.nzherald.co.nz/nz/news/artic ... d=11934273

[David Riddell]

Interesting - a consistent difference of one base pair is still a difference and would be sufficient to justify some sort of taxonomic status I would think. I'm sure the differences are recent, probably post glacial as the plumage differences might be climate driven but as far as I know Pied and Variable Oystercatchers are not distinguished by any base pairs at all - do they get lumped?

According to the paper abstract (https://www.ncbi.nlm.nih.gov/pubmed/28805283), the study analysed "DNA sequences of mitochondrial genes and nuclear β-fibrinogen and five microsatellite loci" - in other words a tiny proportion of the entire weka genome. It's a virtual certainty that if the genomes of all the various weka populations are ever sequenced it will be found that they differ from one another by much more than a single base pair. There are clear differences between some of the South Island weka populations, and if this study of a strictly limited DNA subset has been unable to detect them it doesn't mean they're any less real.