AASAGACITY.NET
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A scoring system to define a species; an evaluation of a taxon/some taxa, using the Sensible Species Definition.  5 points between taxa makes a different species.






Geographic separation/Chance
of cross-breeding
Physical differences Voice
Song/Calls
Habitat preference Behaviour
including
migration
Known
genetic differences

Total Points
sp
or
subsp

Scoring 0-1-2-3 0-1-2-3 0-1-2-3 0-2-3-4 0-1-2-3 0-2-4-5

A SENSIBLE SPECIES DEFINITION (Anderson 1998 and 2012)
Species are populations that are interbreeding and which are reproductively isolated from other such populations by their reproductive isolating mechanisms.
These may include -
geographic separation / chance of cross-breeding;
  morphological and plumage differences;
  voice;
  habitat preference;
  behavioural differences such as nest-building, social grouping or migration;
consistent DNA differences.
Each mechanisms can be weighted according to the strength of difference from a recognised species and given a score between 0 and 5; a total of 5 would give the taxon species status.
0
 
 
 
 
 
1
 
 
 
 
 

2

 
 
  
 
3




4





5




Broad hybrid zone





e.g. Narrow and stable hybrid zone,
or good chance of interbreeding.



e.g A small chance of interbreeding.



No chance of interbreeding.

Feather tracts and/or bare parts a little different,



Feather tracts and/or bare parts noticeably different,



Feather tracts and/or bare
parts very different.

Feather tracts and/or bare
parts completely different.
Not so different voice range and/or song phrases.



Noticeably different voice range and/or song phrases,




Completely different voice range and/or song phrases.
Similar or slightly different habitat preferences.








Noticeably different habitats.







Completely different habitats.
Slightly different behaviour.






Noticeably different behaviour.




Very different behaviour.
Genetic differences are barely measurable.



Genetic differences are measurable.



Genetic differences are larger, e.g. net nucleotide
divergence may be 3%.

Genetic differences are large enough to probably have non-viable offspring.



Genetic differences are so great that viable inter-breeding would be impossible.




Scrubfowl
Comparison of a Universally Accepted Species with Other Taxon such as a Subspecies
Geographic separation/Chance
of cross-breeding
Physical differences Voice

Song/Calls

Habitat preference

Behaviour
differences

Genetic differences

Total Points
sp
or
subsp
Research - from south to north through the Moluccas -
Megapodius f. rienwardt
Orange-footed Scrubfowl
Megapodius f. tenimberensisTanimbar Scrubfowl
Megapodius f. forstenii  Seram/Buru Scrubfowl
Megapodius f. freycinet Dusky Scrubfowl
(Megapodius f. bernsteinii Sula Scrubfowl)
Conclusions -
Megapodius bernsteinii, Sula Scrubfowl, seems to be a species.
Megapodius freycinet, Dusky Scrubfowl, may be a species.
Notes -
BLI: Megapodius forstenii was split, with some justification, from M. reinwardt by Jones et al. (1995), of which it has long been treated as a subspecies. However, Jones et al. (1995) also remark that in structure forstenii is "close to M. freycinet and (especially) M. geelvinkianusbut do not develop the point. However, the case for a close relationship between these forms is supported on mensural and distributional grounds and on the molecular evidence of Birks and Edwards (2002). The BirdLife Taxonomic Working Group therefore does not recognise forstenii as a separate species and consider that it probably best regarded as a subspecies of freycinet."

More research -
Further research into Megapodius reveals much interbreeding between taxa to the point where M. geelvinkianus may become  consumed by M. decollatus New Guinea Scrubfowl, and that M. decollatus interbreeds with M. eremita on Karkar and also possibly with M. rienwardt  on PNG's eastern archipelagos (Handbook of the Birds of the World).
So the following are compared -
Megapodius f. freycinet Dusky Scrubfowl
Megapodius f. geelvinkianus   Biak Scrubfowl
Megapodius f. decollatus  New Guinea Scrubfowl
Megapodius f. eremita  Melanesian Scrubfowl
Megapodius f. rienwardt Orange-footed Scrubfowl

More comparisons -
It seems that only Megapodius f. eremita may be a different species to the original superspecies (up to the 1980s) ofMegapodius freycinet; and that is only on the behaviour difference of a preference for laying in deep holes to take advantage of geothermal heat. Some 53,000 birds were estimated to use this method at one site, Pokilli in New Britain, in 1978 (Handbook of the Birds of the World).
So a further comparison should be made only of those subspecies furthest away from each other -
Megapodius f. eremita Melanesian Scrubfowl
Megapodius f. rienwardt Orange-footed Scrubfowl
Megapodius f. freycinet Dusky Scrubfowl

Conclusions -
There seems little doubt that Megapodius freycinet should again be recognised as the superspecies reverting to the English name of Common Scrubfowl.
And it seems that Megapodius eremita may be the only sub- species that maintains species status in the "new" Megapodius freycinet 'superspecies'. However, there may be evidence already published of other subspecies that lay in burrows although that alone may not be considered sufficient evidence for it to get to species status.
[The largest known breeding site using solar heat is on Haruku, south of Seram, where 4000-5000 pairs of Megapodius freycinet forstenii may lay throughout the year (Handbook of the Birds of the World).]
But in the meantime Megapodius eremita stays as a species.


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sp?
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