So what makes these small mayflies so important to the fly fisher? One reason is that they occur in nearly every type of flowing water habitat. Their worldwide distribution attests to their ability to adapt to many different conditions. They live in streams from sea level to over 10,000 feet high, from alkaline spring creeks to acidic mountain streams, and from hot desert streams to frigid arctic waters. For example, while studying a small desert stream in western Colorado I found Baetis tricaudatus to be one of the most abundant aquatic insects present. At the same time, during study in Alaska, I found Baetis bicaudatus a significant component of the invertebrate community. Water temperatures may be an important factor affecting the distribution of different species. Within the large range of habitats utilized by species of Baetis, the largest populations tend to occur where lush beds of aquatic plants grow in rich spring creeks, or in shallow, fast flowing gravelly riffles of freestone streams and rivers. And wherever Baetis species are abundant they provide a near constant and readily available food supply for many aquatic organisms, including trout.
SwittersB & Exploring 