The equipment needed for this type of study is minimal. A small field guide to the local butterflies is useful until the common species are learned. Most common butterflies can be identified without having the specimen in hand, and those species which require close inspection with microscope or hand lens are not well suited for population studies by the amateur. Some method of keeping track of the number of individuals seen is essential. A notebook and pen is the simplest, but requires stopping to tally the sightings, which may not appeal to the jogger or walker who is trying to maintain a steady pace.
Small hand held counters are ideal.
They can be carried easily and operated without ever breaking stride. Some have several buttons so more than one species can be counted at the same time. With no more than this equipment, some very detailed and valuable studies can be carried out. It is best to begin with the large species if one is not very familiar with butterflies. The Monarch and the Tiger Swallowtail are probably the easiest for the beginner to recognize with the Spicebush Swallowtail close behind.