26 de março de 2020

Kororā- Little penguin subspecies identification

This species should not be identified past the species level with these exceptions.
1) White-flippered Penguin for confirmed adults with the notable white flipper
2) Australian LP for those found in Australia
3) Chatham Island LP for those found in the Chathams

iNaturalist uses the Clements list, but this is far behind on kororā taxonomy. No subspecies are supported at present by any modern evidence, except for a notable distinction between E. minor novaehollandiae and the rest of the species. Regardless of the taxonomic validity, the ability to ID to subspecies level is questionable at best.

Visually, no subspecies can be identified, except for E. minor albosignata, so the tendency has been to ID to subspecies level using range. However, these ranges are more clinal than sharp boundaries (Chathams and Australia excepted), and ranges overlap substantially, so range-identification is an unreliable method of identification. This map shows the supposed ranges, but it should be noted the boundaries are not as sharply defined as shown.

For example, Otago is a notable mixing area, including the О̄amaru colony that has been found to be a near even split of those within and without the novaehollandiae taxon.

For these reasons, unless there is very good justification (generally one of the above exceptions), kororā should not be identified to the subspecies level. There is no visual way to confirm either that a kororā of one subspecies is in fact that subspecies visually, or that the bird has not shown up in a place outside of their expected range, with these ranges themselves overlapping.

There still is value in IDing to subspecies level for the exceptions, especially for Australian LP (novaehollandiae) and white-flippered (albosignata), however, as there is debate for the promotion of Australian LP to species rank, and strong conservation value seen in the white-flippered form.

To read more on this,
NZBirdsOnline summarises the topic:
http://nzbirdsonline.org.nz/species/little-penguin

The best and most recent review, with a thorough bibliography:
https://www.birdsnz.org.nz/wp-content/uploads/2019/06/1904-NZ-Penguin-Research-Priorities-Report-Mattern-Wilson.pdf

Publicado em 26 de março de 2020, 02:33 MANHÃ por intyrely_eco intyrely_eco | 0 comments | Deixar um comentário

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