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.

Physical characteristics a 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 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.




Northern Wren Troglodyte troglodyte
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 -
Troglodyte t. troglodyte
Northern Wren
Troglodyte t. hiemalis Winter Wren
Troglodyte t. pacificus Pacific Wren
or
Troglodyte t. hiemalis Winter Wren
Troglodyte t. pacificus Pacific Wren
Troglodyte t. troglodyte Northern Wren
Conclusions -
Clearly, hiemalis & pacificus are of the same species in spite of some voice, mtDNA, and size differences (size in those Bering Sea races of pacificus). There are also slight voice differences between the 14 sub-species found in North America but probably not enough differences to count for much.
However, there are enough differences between North American Winter Wren and Eurasian Wren to keep these taxa under constant review.
(There are 44 subspecies of Northern Wren around the Holarctic - Birds of the World, A Checklist, 5th ed. James.F.Clements).

0
2
2

0
1
2


0
0
0

0
0-1
0-1

0
0-1
0-1

0
0-1
0-1



0
0
0

0
0
0







0
0
0

0
0
0







0
1
1

0
1
1






0
3-4
3-4

0
2-4
3-5








sp
subsp
subsp

sp
subsp
subsp