If you see a small yellow butterfly flitting from flower to flower, odds are at this time of year it is a Clouded Sulphur Butterfly. According to Naturalist John Acorn on a CBC story there are more Clouded Sulphurs than usual and they are on their annual migration. The butterfly can become a nuisance pest because it likes to feed on crops like alfalfa. However, they also can be beneficial because they also have an affinity for many plants that are considered weeds.
According to Wikipedia, because the Clouded Sulphurs does not sequester toxins or other noxious compounds from their food plants, they are a favorite food of many insectivores.
I photographed this little beauty with what most would not consider a macro lens, a 150-600 Sigma out at 600 mm. I was on a little photography road trip west of Milk River with my son Preston.