Tactics and Vectors 98/99 |
How To Identify Common Species of Migratory Butterflies Many species of migratory butterflies have distinctive patterns and are easy to
identify. Others are not particularly distinctive and can be confused with similar
migratory or non-migratory species. Easily identified species include buckeyes, mourning
cloaks, and red admirals. Problem migratory species, with many look-a-likes, include cloudless
sulphurs, pipevine swallowtails, most of the angle wings, and fritillaries. Ironically,
the single best know and most studied species, the monarch butterfly is also a problem
species with two look-a-likes, the queen butterfly (migratory), and the viceroy butterfly
(non-migratory). Because viceroy butterflies do not migrate and are not particularly
abundant when monarch butterflies are making their spring and fall migrations, viceroys
are unlikely to be picked up by our sampling techniques. Fortunately, monarch butterflies
are usually much more abundant than queen butterflies during the migration period,
minimizing the risk of errors due to mistaken identification. In any case, it is essential
for researchers in this project to get a good field guide, a pair of binoculars, and a
butterfly net (which can double as a wind sock), and practice identification in the field.
Some species with highly distinctive markings can be identified by viewing them through
binoculars. However, most species will have to netted and examined at close range. As
noted above, monarchs fall into the second category. Over the years I have netted
'monarchs' flying among vegetation that turned out upon closer examination to be viceroys,
queens, and on one occasion, a large gulf fritillary. |