When trout begin rising all around you and yet ignore all your offerings, trout madness can easily occur. Multiple hatches can be a prime reason for such frustrations.
It had been a slow day of fishing, but the day wasn’t over yet. In fact, on a bright warm day like today I figured the best fishing was going to be the last hour or two of daylight. Even better I had one of my favorite runs all to myself and was in a perfect spot just as the sun dropped below the canyon walls. The air began to feel cooler almost immediately and the few caddis adults I’d been seeing turned into many more. Perfect. I checked my leader, knotted on an elk hair caddis and kept watching for the noses of feeding trout to start poking through the surface. I wasn’t disappointed. Just as I had hoped some trout started working the surface where caddis adults skated laying eggs. This was going to be too easy. Twenty minutes later my caddis hadn’t so much as scared a fish, and I was having doubts.
Then I noticed a swarm of mayfly spinners in the air. Ah ha, that’s the ticket I thought. I should have realized when the rises were soft quiet rises that they weren’t feeding on caddis. Quickly I switched to a spinner pattern. More fish were working now, and it was easy to get a good drift over eagerly feeding trout. Nothing. Well * @ # # @! This wasn’t fair. I only had about a half hour of good light left so I needed to find the answer soon. Fish were coming up everywhere now and not one showed the least bit of interest in my fly. I started really watching the water and the rising trout. Finally I spotted midge adults popping up on the surface. While only about a size 20, much smaller than the caddis or mayflies on the water, they were quite abundant once I noticed them. With the light fading away I got a tiny Griffiths gnat tied on my tippet and quickly cast it out to a group of trout busy eating dinner. It only moved a foot or two when it disappeared and I was finally playing a fish. That was it – midges. I only had twenty minutes of fishing left, but it was enough time to get a few more decent fish before the canyon walls turned into eerie shadows against the dark sky and I knew I had to call it a day.
Once again a multiple hatch had toyed with me, and once again it took me too long to figure out just what was happening. I’ve since tried to discover a few key steps for deciphering multiple hatches. While my list won’t completely do away with frustration, I’ve found it can shorten the time it takes to figure out just what is happening and give you more time catching trout instead of casting to trout.
Multiple hatches will occur from time to time on any productive stream. Remember, there are easily 300 different species of aquatic insects in a healthy stream. Given that most species have a one year life cycle or less and emergence of different species is spread out through the year, there has to be periods when 10, 15, or even more species are emerging at roughly the same time of year. This doesn’t mean they are all equally available to fish or the fishermen. Some emerge at night; others lay their eggs above the water, etc. Still, it’s quite possible to have a half dozen different species actively emerging and laying eggs at the same time giving fish a variety of sizes, colors, shapes and behaviors to choose from. Because of seasonal patterns in many insect life cycles, spring and fall probably provide the highest chance of running into multiple hatches. In the summer terrestrial insects also come into play, and they add their own twist to multiple food choices for fish and confusion for the angler. While I’ve been discussing streams, lakes can also produce multiple hatch scenarios. The more productive and diverse the insect population of a lake the more likely multiple hatch situations will occur.
Key factors for deciphering multiple hatches
Observation:
The most critical factor for success during complex multiple hatch situations is observation. And don’t take what you see at face value. Our mind too quickly draws conclusions between what our eyes see and what we think we see. For example, in the introduction above I saw caddis adults over the water and fish rising. My mind immediately concluded the fish were feeding on caddis. Once that proved false I noticed spinners in the air and quickly concluded that was what fish were eating. Finally, I quit making quick assumptions and really looked at the water. By observing more carefully and not quickly jumping to conclusions, I finally saw the small midge adults on the water. I am completely convinced that observation is the single most important step in successfully fishing multiple hatches, or any fishing situation. But what should you observe?
Insect type and behavior:
Whenever you encounter actively feeding fish and a good number of bugs in the air try to assess exactly what type of insects are active. Is it three different types of mayflies; or two caddisflies, a stonefly and two mayflies? This doesn’t require that you identify them to a scientific classification, but it does mean you need to observe their size, color and shape, and thus know if there are three different insects on the water or four. However, it will help in the next step of assessing insect behavior if you can at least recognize the major types of insects: mayflies, stoneflies, caddisflies, midges, etc.
Once you have a good assessment of what is in the air and on the water, you still need to carefully observe their behavior. Different species and their particular stage of activity (emerging or egg laying for example) will result in different behavior, and thus affect what the fish are feeding on and the type of pattern you should choose. This will usually require even more careful observation then just seeing what’s on the water. Are the mayflies a dun or spinner? Or is the large mayfly a spinner and the small one a dun? Are the caddis emerging or laying eggs? And if they are laying eggs, are they laying them on the water’s surface or diving underwater to lay them? No matter what type of insect is on the water there are only about four different behaviors to looks for:
During a multiple hatch it’s likely several of these behaviors will be occurring at the same time. To make sense of all this different activity you need to take the next step.
Fish behavior:
Overall, fish behavior is the key to understanding what fly to choose and how to fish it. Because of the variety of insects and behavior occurring during multiple hatches, observing how the fish are feeding should provide the final clues about what to do. Just as with insect behavior, there are only so many possibilities of fish feeding behavior and what it means. In general feeding behavior falls into one of two types: quiet or active. Quiet feeding means fish can take their time. Rises will be small, even when the fish are big, often barely making a surface disturbance. It may also be very rhythmic with a steady pattern to it. Active feeding occurs when fish have to move quickly to catch their prey. Rises will typically be splashy and quite obvious, and usually not be as steady or rhythmic as during quiet feeding.
The feeding behavior is in direct response to the type of behavior the insect has on which it is feeding. Insects that emerge or lay eggs quietly without a lot of swimming or movement will produce a quiet feeding response. Mayflies, especially spinners and small insects like midges, typically behave quietly and produce a more quiet feeding response. Caddisflies are the best example of an insect with active emergence and egg laying behavior. As a result fish feeding on caddis often produce showy splashy rises and vigorous feeding behavior.
To be sure I’m seeing accurately what the insects and fish are actually doing, I often watch the water through a pair of small binoculars. It’s amazing how much more I can see with a little help. Now that you’ve observed the insects, their behavior and the fish feeding behavior, you’re ready to pick a fly pattern.
Selecting your fly pattern and tactic:
Based on your understanding of the different insects on the water and the way fish are feeding on them you can make an educated guess about what fly pattern to use and how to fish it. I say “educated guess” because even with your careful observation you won’t always pick the right fly the first time. Think about picking the fly with the highest probability of success. Maybe you have observed two different caddisflies, one emerging and one laying eggs, a mayfly spinner and stonefly adult on the water. The fish are feeding with splashy vigorous rises, so you pick a caddis pattern. It is still difficult to be sure if they are feeding on the emerging pupa, the adult flying off the water, or the other caddis diving below the water to lay eggs. In this case I’ll choose to imitate the caddis that appears most numerous and match it’s behavior. The best you can do in such situations is pick the option that appears to have the highest chance of success.
Change patterns and tactics:
The final step is to be ready and willing to change your fly pattern and tactics. Because, as the example above points out, you can’t be 100% sure you’re matching the right fly and behavior, don’t make the mistake of using a fly that’s not working. This is a mistake I have made many times. When fish are feeding all around you, and you know you have matched one of the insects on the water with a good pattern, it’s hard not to keep casting to rises, expecting those hungry fish to take your perfectly good imitation. But under multiple hatch situations don’t keep using the same fly and tactics for a long time if they aren’t working. Switch after ten or fifteen minutes to a pattern that matches the other caddis adult on the water. More often than not fish become selective, for some unknown reason, to an insect that’s not the most abundant or obvious. Heavy feeding activity also isn’t going to last that long, so fishing an hour with an unproductive pattern means you’ve probably missed your chance of finding the right pattern and catching a lot of fish.
Multiple hatches can produce some great fishing and great frustration. If you stop fishing long enough to really observe what’s happening, you will lower your frustration and increase your success.
Rick Hafele has been observing the insects and fish throughout the West for over 30 years, and tries to enjoy multiple hatches as often as possible. Rick, with co-author Dave Hughes has written Western Mayfly Hatches. This book will help you solve any mayfly hatch you encounter throughout the West. It will be available this summer or fall.
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