04/14/10
Insects and other foods the trout may be eating:
1.   Blue-winged Olives
2.   Little Black Winter Stoneflies
3.   Quill Gordon Mayflies
4.   Blue Quill Mayflies
5.   Little Brown Stoneflies
6.   Little Black Caddis (American Grannoms)
7.   Hendricksons and Red Quills
8.   Little Short Horned Sedges
9.   Sculpin, baitfish and small crayfish (Imitate with streamers)
10  Midges

American March Browns - More General Information:
The American March Browns are now classified as a Maccaffertium vicarium. As
mentioned yesterday, the Gray Fox is just another common name for the American
March Brown. There was a prime reason for the Gray Fox name. The American
March Browns hatch over such a long period of time they are available at one
time or another in various sizes depending on the particular time they hatched.
What anglers call the Gray Fox is just a smaller size and a slightly different color of
the American March Brown. In other words, in terms of what is important to anglers -
size, there is a difference. There is nothing wrong with varying the size of the March
Brown imitations to match the ones on the stream at any given time.

Why is the name "American" added to the name March Brown? It is because there
are two March Browns - a Western March Brown and the American March Brown.
The two mayflies are not very similar as you may expect. They don't even belong to
the same genus. By the way, this can be a factor when you are buying flies. You
may purchase Western March Brown imitations for American March Brown mayflies
if you are not careful.

The hatch is usually not concentrated into a short period of time. About the only
heavy concentration of March Browns that you are likely to see is during the spinner
fall which occurs just before dark. In the last part of the long hatch period, they may
not fall until it is completely dark. The spinner fall occurs in a short time period and
this congregates the mayflies that have hatched previously.  

By the way, it is not a bi-brooded mayfly. It is a single hatch with a very long
duration. The "multiple" hatches (other mayflies that hatch during the same time
period) that normally occur at the same time lessen the importance of the American
March Brown.

The American March Brown nymphs are clinger nymphs. Most of their life the flat
like nymphs are doing what their name implies - clinging to the undersides of rocks
and are not readily available to trout. These nymphs are strong. They can move
around on the streambed very fast compared to other nymphs. When they want to,
they are able to cling to the rocks to the point you would have to pry them loose if
you tried to remove one. They remind me of a crawfish. They run backwards if you
approach them from the front. They have a mean look to them although they cannot
hurt you.

You will find American March Brown duns on the streams in the park for the next two
months. When you see a dun or two, it doesn't necessarily mean they haven't
started to hatch. They may be hatching about as well as they are going to in that
particular section. Also, you may find one that just hatched at 10:00 AM or at 5:00
PM on the same day. Most of them hatch mid to late afternoon, but there's nothing
specific about the time they will hatch.

Another thing many anglers fail to recognize is that when they hatch, they don't
actually hatch in the fast water riffles and runs. They hatch in the current seams to
the edges of the fast water. They usually get caught up in the fast water fairly
quickly but they actually emerge in the seams. That is where you would want to
place an emerging nymph imitation or an emerging dun imitation. The dun imitation
can be fished directly in the riffles and runs. The trout will take them in the fast water.

Tomorrow I will get into the specifics of fishing the hatch, starting with the nymph.