|Many butterflies are restricted to particular habitats, and this is a key not only to finding them but to identifying them. Seasons are important as well. Even in warm climates, only a few species are on the wing year-round; in most species, adults are present only in certain seasons.
The distribution of butterflies is dynamic and ever-changing, even without the influence of man's effects on the biosphere. Each species has a unique distribution that changes from year to year, as some populations contract or die out while others expand or are formed anew by colonists and migrants.
The distribution of butterflies that are found in weedy habitats changes at the greatest rate, while that of species found in forests and other relatively stable, predictable habitats changes most slowly.