Wednesday, August 3, 2011

Pyranees Butterfly Sampler

Hiking took Wendi, Leona, Alan and me into various nooks of the upper Hecho Valley, a splendid region of the Pyrenees, and one replete with butterflies and flowers. These public trails wind through sectors of the Parque Natural Valles Occidentales, or Western Valleys Natural Park. 

In three days, we barely sampled the miles of trails that you could walk. All were in excellent condition. One, straight up the road from Hotel Uson and past Boca de Infierno, passes dolmens and other artifacts of prehistoric humanity.

The butterflies were exceptional! Here are a few:

Old World Swallowtail (Papilio machaon) in the upper Hecho Valley
(Photos by Narca)

The Old World Swallowtail is the type species of the genus Papilio––the first one to be described by Linnaeus, who devised the system of classiflying organisms into related groups. Despite the common name, this swallowtail occurs at higher latitudes across the entire Northern Hemisphere, including North America, so it has a classic Holarctic range. Most of its populations are in good shape, although it is a protected species in some countries like Austria, the UK, and India.

Its cousin, the Apollo, is a tail-less swallowtail, closely related to the parnassians of montane North America. They swoop rapidly across the mountain slopes, and I felt lucky when this one deigned to pause briefly on a composite.

Apollo (Parnassius apollo)

The highly prized Apollo is considered threatened by the IUCN. Finland is among the countries declaring it endangered. Its decline is likely due to a combination of factors, including habitat change and––in some areas––over-collecting. Locally, automobiles are a factor, notably in South Tyrol, Italy. Because the few Apollos remaining in Finland and Sweden are restricted to limestone soils, it is thought that acid rain may also have contributed to their decline. Where limestone moderates the effects of acid rain, this beautiful butterfly continues to soar across the mountain meadows.

Heath Fritillary (Melitaea athalia)

Any real butterfly experts out there, help me out! I think that this is a Heath Fritillary, but frits are subtle beasts, and my field guide is none too clear. If so, it is a species doing well in several parts of Europe, but not in the UK, where it is one of the rarest British butterflies. (After 30 years of conservation efforts, British stewards have seen rebounds at Blean Woods National Nature Reserve.) Its host plants include plantains, speedwells, Common Cow-wheat, foxglove, and toadflax. (Note that in North America we would call these smaller fritillaries checkerspots or crescents, but in Europe they are all called fritillaries.)

A female Large Skipper (Ochlodes sylvanus, a.k.a. O. venatus)

Sunning on a rock is another Palearctic species, which ranges from Europe across Asia to Japan. The Large Skipper is the sole European member of a genus that is more diverse in North America. One of the grass skippers, it is shown here with a leaf of its larval food plant, grass. Like other typical skippers, its caterpillar constructs a leafy shelter by curling a leaf, then stitching it with silk. The young caterpillar hides inside its leaf and feeds.

Skippers are part of a lepidopteran lineage separate from other butterflies. They differ in having hooked antennae clubs and larger eyes. They have a very sturdy look, with strong wing muscles which support wings that are usually smaller in proportion to the rest of their bodies. Within the skipper family, a basic division is between the grass skippers, like the Large Skipper above, and the spread-winged skippers, like the intriguing Marbled Skipper, pictured below.

Marbled Skipper (Carcharodus lavatherae)

Attractive Marbled Skippers are reminiscent of North American powdered skippers. Their host plants are mints, including Stiff Hedgenettle or Yellow Woundwort (Stachys recta) and Mountain Tea (Sideritis scordioides). Both plants are thought to have medicinal value: they contain antioxidants and also counter inflammation and microbes. Sideritis is used in Greek cuisine. These two plant genera are very closely related, and genetic studies may eventually show that they belong in the same genus. 

Many mysteries in the relations between organisms remain to be unraveled! Taxonomists should have job security for a very long time––for as long as the public values a deep understanding of nature.

Wikipedia gives a list of butterflies of the Iberian Peninsula, including some photos and range maps.

Coming next: those challenging satyrs!

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