EEP Crowned pigeon number 4

EEP STUDBOOK CROWNED PIGEONS
Conclusions and discussion
Sometimes it is easy to determine species and subspecies, but because of the continuous
evolution of the earth, there are always mixed forms. Like the definition of mammals and
birds, there still are mammals that produce eggs, it is comparable for species and sub-species.
Without doubt, all forms of crowned pigeons derive from one species and they might have
become separated by environmental and climatic changes. They differ already a lot in
phenotype, and DNA-research proved that their genotype is also quite different. Until now
there is no reference that a hybrid is able to produce (fertile) offspring. In this respect crowned
pigeons match the definition of a species. At the land-bridges, for example, there are lot of
forms which resemble the nominate form very much.
This development did take place not that long ago; therefore it might be possible for some
forms to produce fertile offspring with forms on nearby islands. At this moment it is
preferable to call these forms “sub-species”, and the three forms with large differences
“species”. But like nature itself also these classifications should not be fixed, but always be
susceptible to changes.
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