|scientific name Nymphalis californica |
common name California Tortoiseshell
Open montane woods south of the Crowsnest, rare migrant elsewhere.
One brood per year, appearing in early spring (April to May) and again in August to October.
Most similar to the Compton Tortoiseshell (Roddia l-album = N. vaualbum), but californica has a black dorsal hindwing margin, not heavily marked with orange-brown as in l-album.
There are no described subspecies; the name herri mentioned by Bird et al. is a cool-weather induced phenotype according to Guppy & Shepard (2001). There appears to be little geographic variation in this species, possibly due to the fact that it is able to migrate long distances, resulting in mixing of populations.
The cylindrical, yellow-green eggs have vertical ridges. The mature larva is velvety black with two diffuse, yellow dorsal lines and orange-brown, branched spines (Guppy & Shepard 2001). Like the Compton Tortoiseshell, this species is very rare or absent in some years; it is unclear if all Aberta records represent migrants (spring) or offspring of migrants (fall). It is possible that californica is able to overwinter in the greater Waterton area wher the larval food plant occurs, although Guppy & Shepard (2001) suggest southern interior BC populations must be maintained over the long term by migrants from the south. Alberta records outside of the Waterton region certainly represent migrants, since the larval food plant does not occur elsewhere in the province.
Not of concern.
The larvae feed on species of tea bush (Ceanothus spp.) in the western US and BC (Guppy & Shepard 2001).
According to Opler (1999), this species is permanently established only from southern BC south to California, and southern Wyoming to northern New Mexico. Migrants occur as far north as the southern portion of the western provinces.
Joe Belicek (2014-03-04)
Breeding resident colony discovered in Alberta: Norbert Kondla (pers. comm.) wrote: "These critters are tough to find in Alberta because the larval food plant is rare/local even in the extreme SW corner of the province where it is present. There have been historical cases of population blooms. It was not until 2006 that I had solid evidence of them actually breeding in Alberta by finding cats munching on Ceanothus velutinus in Waterton Lakes National Park during a butterfly consulting project. Have collected the Crowsnest Pass many times but only ever turned up one californica there, in 2008 on the BC side of the pass."
In 2008, I (JB) collected a single specimen feeding on planted flowers in front of the Lake Louise Hotel at Lake Louise, in Banff National Park. The parking lot for the hotel was full of campers (Winebagos) with California licence plates. Evidently, the collected voucher specimen was transported to Alberta, probably trapped-in one of those vehicles.
Other Alberta records: I have in my collection one specimen collected in Edmonton. Presumably, also this specimen was also transported here from its native breeding areal by tourism or commerce.
Joe Belicek (2014-03-17)
The taxon N. californica herri Field, 1936 was described as a northern race (i.e. subspecies) of N. californica Boisduval, 1852. ?TL: Buckhorn Mtn. in the NE or NW corner of Washington state. Named for Clarence Wilson Herr (1864-1938), who collected the first specimens? (Kondla, pers. comm). Warren (2005) claims that comparisons of series of herri with californica from the Pacific Northwest and Sierra Mtns. (Nevada, California), no consistent morphological differences seem to exist between them. However, even if most people think that californica and herri are the same species, in my opinion, the taxonomic status of the taxon herri needs to be re-examined in detail. There are numerous examples of visually very similar sibling taxa from all butterfly families (e.g. Roddia j-album /R. l-album).
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