Mountain Fritillary (Boloria napaea)
2023 photographs highlighted in green. Click on any photograph to go to an enlarged picture, or simply scroll down the page.
For comments on the taxonomy of the Boloria group please see the page for the Balkan Fritillary (B. graeca). Napaea is very similar to the Shepherd's Fritillary (B. pales) and quite difficult to differentiate, especially as they often fly together at high altitudes. The female napaea is strongly suffused with a greenish sheen and quite different to the female pales. The key differentiating features of the males of these two species appear, from what I have read and observed, to be:
1) black markings: napaea has (allegedly) somewhat finer upperside black markings. However, the Alpine subspecies of pales is palustris, in which the black markings are narrower and the colouring redder. This rather negates the value of the fineness of the markings with regard to differentiating the two.
2) upf marginal markings: Lafranchis says that the upf post-discal and submarginal spots are broadly parallel from s1b to s6 for napaea, whereas for pales they are closer in s4-s6 than they are in s1b-s3. This may sound complicated, but it is the best means of differentiating between the two with any degree of confidence, and it does seem to work. It also seems to me that the napaea submarginal markings on both wings are rather more sagittate than pales.
3) undersides: there are some rather subtle differences in the shape of the underside markings, especially the unh. The white markings of pales seem more pronounced. The unh needs to be checked carefully against the illustrations in T&L. This seems to work quite well, and corroborates other identification clues.
4) wing shape: Lafranchis says the pales forewing is elongated and narrow and pointed at the apex. The napaea forewing is described as very broad.
5) distribution: both are local in the Alpes and Pyrénées, although Lafranchis says pales is widespread and abundant, where napaea is localised but abundant enough in the Alpes and probably restricted to the eastern part of the Pyrénées.
6) altitude range: according to Lafranchis, napaea is found only at high altitudes of 1800m and above, while pales has a normal altitude range of 2000-2500m but can occur as low as 1600m. Lafranchis says that where they fly on the same mountain, pales often flies at higher levels than napaea.
|a male, which I am assuming is napaea on the strength of the delicacy of the markings and the upf post-discal series of spots that are broadly in line. However, the forewings do not seem especially wide and the hindwings seem to lack the angularity I would expect for napaea. The rather reddish colour also suggest pales, but on balance I feel the evidence for napaea is stronger.
a male, the upf post-discal spots are broadly parallel to submarginal marks, although not 100% convincingly. The width of the forewings and the angularity of the hindwing strongly indicate napaea, although these factors tend to contradict the identification of 26958. 22214 is the underside and the identification is based principally on this.
|I believe 30415 to be napaea largely on the grounds of the relative straightness of the upf post-discal marks (identification point 2 above).
|an extraordinarily weakly marked male, with very narrow forewings (and slight deformation of the right wing), and quite extreme in terms of wing angularity (c.f. 26958).
|a typical male, with noticeably angled hindwings.
|a male, clearly an aberration, but of what? It does not fit the normal template for napaea in that the marking are not fine, but then aberrations don't follow the rules. The only other options, at this altitude, were pales or graeca. Neither of these species seemed to be flying at this location, and other napaea were. The reason I believe it to be be napaea rather than graeca is that I have a photograph of the same specimen that shows the hindwing angle and it is clearly not sufficiently sharply angled for graeca.
a female, the greenish suffusion being strongly in evidence. This could not be mistaken for female pales.
|a female with a slight deformity of the forewing tip, but it nicely illustrates the purplish sheen that make female napaea easy to identify in comparison to female pales.
|a male, perhaps slightly less reddish than the norm.
|very similar to 30415 on the basis of markings, but more orange than red. A beautifully delicate colour scheme.
the white markings are not well contrasted with the other unh markings, indicative of napaea. This is the underside of 22216.
|the markings seem spot-on for napaea but whether this is a typical napaea underside is hard to say.
|a very crisply marked male, roosting in inclement conditions. It is quite dark and the colour contrast is quite extreme for napaea.