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| Two males photographed in situ. One typical N.n.helvetica and one possible helvetica/persa hybrid? | 
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| Typical British form (N.n.helvetica) | 
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| Persa phenotype. | 
![]()  | 
| Two males photographed in situ. One typical N.n.helvetica and one possible helvetica/persa hybrid? | 
![]()  | 
| Typical British form (N.n.helvetica) | 
![]()  | 
| Persa phenotype. |