@snidge Location plays a part of it, but only in that biogeographical separation can lead to the development of subspecies.
In theory there are visible pattern differences that are stable among the individuals of the population and that differentiate the various subspecies. Usually those differences develop when populations become isolated from one another allowing for a particular feature to become more (or less) prominent.
A lot of the time those differences are only clear when individuals of different populations are compared side-by-side. Where 2 populations meet, the differences often blend and there is no clear way to judge the subspecies.
For example, in ssp. crameri the difference is stated as follows: "Compared to the nominate subspecies the ochreous areas are reduced and are paler in colour (Congdon & Collins, 1998)." (in Williams, 2019)
Now, since (in theory) a lot of care and study is taken in establishing the validity of a subspecies, and since subspecies require some sort of biogeographical separation in order to develop, it's generally safe to ID to the level of subspecies based on location alone.
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Thanks for these they really help.
@snidge My pleasure!
@cabintom I would be interested to find out - is the difference between the below only location?
Common Joker Byblia anvatara ssp. acheloia
Madagascan Joker Byblia anvatara ssp. anvatara
Socotra Joker Byblia anvatara ssp. boydi
Western Joker Byblia anvatara ssp. crameri
@snidge Location plays a part of it, but only in that biogeographical separation can lead to the development of subspecies.
In theory there are visible pattern differences that are stable among the individuals of the population and that differentiate the various subspecies. Usually those differences develop when populations become isolated from one another allowing for a particular feature to become more (or less) prominent.
A lot of the time those differences are only clear when individuals of different populations are compared side-by-side. Where 2 populations meet, the differences often blend and there is no clear way to judge the subspecies.
For example, in ssp. crameri the difference is stated as follows: "Compared to the nominate subspecies the ochreous areas are reduced and are paler in colour (Congdon & Collins, 1998)." (in Williams, 2019)
Now, since (in theory) a lot of care and study is taken in establishing the validity of a subspecies, and since subspecies require some sort of biogeographical separation in order to develop, it's generally safe to ID to the level of subspecies based on location alone.
@cabintom Thank you very much for clearing this up for me. It is a real help.
@cabintom, helpful for me also...
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