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Linnets on Madeira (guentheri / nana) (1 Viewer)

Gonçalo Elias

avesdeportugal.info
Portugal
Madeira is home to a local subspecies of Linnet Linaria cannabina.

However, there seems to be some disagreement between IOC and Clements about its name:

  • IOC (version 13.2) calls it L. c. guentheri (Wolters, 1953) and states it occurs in Madeira, Porto Santo and Desertas
  • BOW (which follows Clements) calls it L. c. nana (Tschusi zu Schmidhoffen, 1901) and mentions it occurs in Madeira [I believe it refers to the entire archipelago].

IOC adds the following in the notes: "Includes nana (Tschusi, 1901) as a synonym; permanently invalid (Dickinson & Christidis 2014)."

So it seems that IOC has invalidated a name that Clements is keeping.
 
Madeira is home to a local subspecies of Linnet Linaria cannabina.

However, there seems to be some disagreement between IOC and Clements about its name:

  • IOC (version 13.2) calls it L. c. guentheri (Wolters, 1953) and states it occurs in Madeira, Porto Santo and Desertas
  • BOW (which follows Clements) calls it L. c. nana (Tschusi zu Schmidhoffen, 1901) and mentions it occurs in Madeira [I believe it refers to the entire archipelago].

IOC adds the following in the notes: "Includes nana (Tschusi, 1901) as a synonym; permanently invalid (Dickinson & Christidis 2014)."

So it seems that IOC has invalidated a name that Clements is keeping.
H&M4 (i.e. Dickinson & Christidis 2014) says this of guentheri (Wolters, 1953), for which they give as distribution "Portugal, Madeira":
Includes nana Tschusi, 1901, preoccupied in a broad genus Carduelis by Chrysomitra nana Bonaparte, 1851. Tschusi's name, replaced before 1961, is permanently invalid; contra Howell et al. (1968)
 
Carduelis cannabina guentheri Wolters 1953
...is indeed a replacement name for Cannabina cannabina nana Tschusi 1901, preoccupied by Chrysomitris nana Bonaparte 1850 in a broad Carduelis.

As noted in H&M4, the Code rules that a name replaced due to secondary homonymy before 1961 is in principle permanently invalid (ICZN 59.3) -- i.e., it should not be brought back into use even if the secondary homonyms are no longer regarded as congeneric.
(Which is the case now for the two 'nana' involved here (linnets in Linaria, while Bonaparte's taxon would apparently be a synonym of what is now Spinus psaltria colombianus), and was also the case in the taxonomy adopted by Howell et al 1968 (Peters' check-list, vol. 14; linnets in Acanthis, American goldfinches in Carduelis; v.14 (1968) - Check-list of birds of the world - Biodiversity Heritage Library ), where nana Tschusi was also used unduly.)
 
Thanks both for the replies.

I am not sure I understand what is meant by "secondary homonymy" - does this refer to two subspecies with the same name in two different species of the same genus?

And if that is the case and the name becomes invalid, how come Clements still considers L. c. nana?
 
For species-group names, there are two types of homonymy:
  • primary homonyms are identical species-group names that were originally introduced in the same genus;
  • secondary homonyms are identical species-group names that were originally introduced in different genera, but were subsequently placed in the same genus as a result of taxonomic reappraisal.
The ICZN makes junior primary homonyms permanently invalid -- i.e., they cannot be used as the valid name of a species or subspecies, even if the species or subspecies they would apply to are moved to distinct genera.
As I wrote above, under the current Code, a junior secondary homonym which was replaced before 1961 due to it being a secondary homonym is permanently invalid (at least, unless the replacement name is not in use at all). A junior secondary homonym that was not replaced before 1961 is only invalid as long as it remains congeneric with its senior homonym. I.e., it may become valid again if generic limits are revised in such a way that the two homonyms end up (again) in different genera.
Here, nana Tschusi was replaced with guentheri Wolters in 1953, thus it should in principle remain invalid.

Why Clements departs from this, I cannot tell you.
 

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