AASAGACITY.NET
  Knowledge is Empowering
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

Assuming a rate of divergence in mtDNA of 1.6–2.0% per million years. (Fleischer et al.1998; also see Lovette 2004; Ho 2007; Weir and Schluter 2008).

From mtDNA analysis, species take from between 0.2 to 5.5m yrs.  ("The Speciation & Biogeography of Birds", Ian Newton, 2003.

Total points
sp
or
subsp

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

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, or successful breeding is not known to occur where there is breeding overlap.


Physical characteristics little different



Physical characteristics noticeably different.



Physical characteristics very different.


Physical characteristics 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 definitely measurable.



Genetic differences are larger.


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


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




Australasian Riflebirds
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
Known
genetic differences

Total Points
sp
or
subsp
Research -
Ptilorus magnificus Magnificent Riflebird, PNG
Ptilorus m. alberti Magnificent Riflebird, Australia
Ptilorus m. intercedens Magnificent Riflebird, Eastern PNG
Conclusions -
P. magnificus is clearly the species, m. intercedens differs only on voice and that is a growl on the same pitch as the whistle that m. magnificus gives. Furthermore, birds from the Lake Kutubu area have calls intermediary to m. magnificus and m. intercedens which is common among world species which occupy linear contiguous habitats, i.e. a vocal cline is evident.
P. m. magnificus and m. alberti also have similar whistles although the double whistle of m. alberti has almost the reverse of the pitch that m. magnificus has, like a reverse dog-whistle. 
Research -
Ptilorus paradiseus Paradise Riflebird, East Australia
Ptilorus p. victoriae Victoria's Riflebird,  NE Queensland
Conclusions -
Probably the only way victoriae can be recognised as a species is if the genetic divergence indicates a separation of 0.5 million years or more.    



0
3
0











0
3

0
0
0











0
1

0
0-1
1











0
0

0
0
0











0
0

0
0
0











0
0

0
0
0











0
0

0
3-4
1











0
4

sp
subsp
subsp











sp
subsp