Natural Sightings #518 - Western Tiger Swallowtail.jpg

A Western Tiger Swallowtail nectar-feeds on a Butterfly Bush.

Marsha Morris took this photograph in West Golden Hills of a Western Tiger Swallowtail (Papilio rutulus) as it was nectar-feeding on a Butterfly Bush (Buddleia sp.).

Western Tiger Swallowtails are the most common large butterfly encountered in the Tehachapi Mountains. For their food plants — the ones on which the female butterflies will lay their eggs to produce caterpillars — Western Tiger Swallowtails will commonly use cottonwoods, willows, quaking aspens and others. They are not as species-specific as Monarchs, which generally use milkweed plants exclusively as their larval host plant.

Though it seems like a funny choice of camouflage, Western Tiger Swallowtail caterpillars initially resemble bird droppings, complete with a white blotch. This helps protect the little caterpillars from predators. A large portion of a bird dropping is white because unlike mammals, birds don't urinate and they must excrete nitrogenous wastes in the form of uric acid, which appears as a white paste. Uric acid doesn't readily dissolve in water, which is why "bird whitewash" on your car windshield or patio furniture can be frustratingly stubborn to remove.

Tiger Swallowtail caterpillars eventually turn a beautiful green color with yellow eyespots marked with blue dots. When fully grown, they spin a chrysalis that looks like a twig. To make the concealment even more effective, the caterpillars attach it to a stem so that the chrysalis leans out at a 45-degree angle, looking as though it was the stub of a dead twig growing out of a branch. From this weathered wood-looking chrysalis, a beautiful Western Tiger Swallowtail will emerge.

The Nuwä (Kawaiisu or Paiute) word for butterfly is ayaataniizi, pronounced aye-yah-tah-NEE-zee.

NATURAL SIGHTINGS is a regular feature of the Tehachapi News edited by Jon Hammond which showcases photos of the natural beauty that enhances the quality of life in Tehachapi. If you have a good quality image of plants, animals, insects, trees, birds, weather phenomena, etc., taken in the Tehachapi area, you may submit it to the Tehachapi News for possible publication. Submissions can be dropped by the News office in the form of a print or CD, or sent by email to: