We all want to catch big fish. Big fish eat big meals. There is no better way to catch large trout then fly fishing with mouse flies both day and night.
The sport of fly fishing continues to evolve. Like all sports, innovations are made and glass ceilings are broken. In the last few decades, fly fishing mouse flies has exploded in popularity. Night time fly fishing wasn't even on most anglers radars, and those who did were considered statistical outliers in the sport.
Mousing is now mainstream. The results speak for themselves. Huge brown trout are often caught at night, and many times they are caught on a mouse pattern. Big trout grip and grins littering the feeds of social media are often in the dark, with an angler wearing and head lamp, and a mouse fly hanging from a gargantuan brown trout's mouth. Those early pioneers cracked the big fish code, and mice play an important part in that sequence.
In this article, we are going to discuss the ins and outs of fishing mouse patterns, gear, tactics, and the best ways to find big trout. Before we tackle those topics, it is wise to better understand why mousing is so successful at targeting big fish.
Understanding Brown Trout Behavior
Giga Brown Food Choices
Brown trout are interesting creatures. They change radically through their lives, and the lifestyle choices between a 15" brown trout and 28" brown trout couldn't be more different.
From the moment a brown trout is born, it is in survival mode. It is at the bottom of the food chain. It's food choices are comprised of the aquatic insect populations that are in the river environment. Aquatic insects are small, and these could be any number of forage items: scuds, mayflies, caddis, stoneflies, midges and craneflies to name a few.
It is rare for a fish to receive large high calorie meals. A small trout under 20" spends most of it's life laying in prime lies, eating insects, and spawning in the fall. For smaller trout, most of this activity occurs during the daylight hours, which is what we see as anglers when fish are actively feeding on hatches.
Once a trout reaches 20" plus inches in length a transition occurs. Fish in the 20" plus range stop feeding on insects and start eating other fish. This behavior, in conjunction with the fish moving to the top of the food chain in its ecosystem creates a radical change in behavior. It starts to hunt. Not only will eat other fish, but it also eats mice and just about any other large calorie food item that meets the energy needs of a fish this size. This accelerates the fishes growth too. The result is a giant apex predator that eats animals not insects.
Nocturnal v.s. Diurnal
In addition, to the change in diet. Piscivores go from being diurnal juveniles to nocturnal predators. While all the other fish are keeping their time with the daylight hatches, giant brown trout will lay in the best prime lies dormant during the daylight hours. Prime lies include logjams, undercut banks and deep holes.
Once the sun sets, they move out of their prime lie and start looking for feeding opportunities. They will move long distances looking for food. In addition, brown trout have adapted eyesight to low light environments, making them ideal night hunters. The night time offers them both safety from birds of prey, anglers, and other predators. Plus, their night vision makes them king of the jungle. It is during these times that anglers can take advantage of one of the most under utilized angling opportunities. Swinging large mice patterns at night can be rewarding!
When is the Best time to Fly fish with mouse patterns
Mousing, as it is often referred to, is at its peak from late spring to fall. Night fishing is usually the most productive time to fish mouse patterns. It is important to choose the correct night to fish mouse flies. Paying close attention to the moon phase is important because a full moon will actually make fishing more difficult.
I prefer to fly fish with mouse patterns in total darkness. Other then being able to see your fly a little easier, full moons cast too much light, and in my opinion it is best to fish at night for brown trout on the darkest of nights. I am sure there are others out there that will disagree on this point, but pure darkness has worked well for me. If there is full moon or half moon, cloud cover that obscures the moon can make the fishing more productive.
Mouse fishing in the fall is prime time to catch the largest fish. This is simply a matter of statistics, as big brown trout will move out of lakes and reservoirs, and into shallow rivers in preparation to for the fall spawn. There will be more big fish in the river system increasing your chances of success. This is one of the best times of the year for trout fishing with large mouse patterns.
Mousing during the Day
Don't discount the power of the mouse during when the sun is shining. Daylight hours can produce good mouse action. Big brown trout aren't the only ones that will eat a mouse pattern. Other species, like pike, rainbow trout, and brook trout will eat mice too.
Fishing mouse patterns during the day can be rewarding. Mousing for giant rainbows in Alaska is almost always done during the day.
I too have had success fishing mouse patterns in broad daylight. Often times, these are just periods in the day where I am experimenting with different flies. While it happens less frequently, much to my surprise, a mice pattern will draw strikes from both small and large trout. Don't be afraid to tie a mouse pattern on during the daylight hours.
Where to Find Big Brown Trout For Mousing
Catching big brown trout requires an angler to hunt for the fish. Fishing mouse patterns is more akin to hunting a large mule deer or whitetail. Big trout aren't everywhere, they are in very specific locations in the river.
First, focus on rivers and streams that are connected to lakes. Larger bodies of water typically hold large fish. It doesn't take much effort, but a quick google search will often bring up lots of pictures and information of big fish being caught and what lake they were caught in. If there are big browns in the lake, then you can bet that there will be some resident big browns in the tributaries that feed that lake. You can also assume that in the fall, those large fish in the reservoir will leave the lake and travel into the streams and creeks to spawn.
Not all water is equal. Look for water that is flat and moving, but not too fast. Fast moving water makes a surface presentation difficult. Turbulent water is no good as your pattern will be lost in the confusion of the water. Similar to how a submarine finds a target, trout hone in on the vibration and disturbance that is emitted from a mouse swimming across the surface of the river.
Water depth is an important factor to consider as well. Look for deeper runs and holes with a depth of 1 to 3 feet. In a perfect world, the areas described above will converge to form the ideal location to swing and skate mice patterns.
Finally, choose your bank wisely. On the Henry's Fork River, where I have done most of my mousing, there are two types of banks. One side is rocky, dotted with small shrubs, and the other side is mostly agricultural fields. The flat agricultural fields always seem to produce more strikes and opportunities for eats. This makes logical sense, as they are called field mice, and there are more mice in the grass then on the rocky banks. Choose banks that are flat and grassy over ones covered in shrubs and trees.
Fishing Mouse Patterns to Structure
Brown trout love structure. Similar to other apex predators, they ambush prey, and use cover to their advantage for safety and stealth. Fish your mouse pattern around logjams, downed trees, grass beds, rock gardens and undercut banks.
Don't underestimate the holding power of undercut banks as they will often hold the largest fish in some of the smallest water. I was night fishing the South Platte River in Colorado, and as I walked along the banks prior to sunset, I moved several big fish out from under the undercut banks. To my surprise, they were well over 22" fish holding just out of sight in an undercut bank in a foot of water. They were invisible to my line of sight from the bank, tucked tightly under the overhanging bank.
Mousing Techniques for Success
Although you are fly fishing at night, stealth and a soft approach are required. As you walk along the banks, focus on soft steps. Heavy foot steps on undercut banks will magnify your footsteps and alert fish your presence.
There are several points to consider when fly fishing at night time in total darkness. First, you still need to approach the water with stealth. If you need to use your headlamp between casts, turn away from the water and avoid shining your light directly on the surface of the river. This can spook fish. In addition, every time you turn light on and off this ruins your night vision. It will take a while for your eyes to readjust to the darkness and make it more difficult to see.
Second, unless I am ultra familiar with water I'm fishing, I prefer to stay out of the river, and keep my feet planted safely on dry ground. This is primarily for my own safety. It is easy to step in a hole, fall down, or step off a shelf.
Third, have confidence in your cast. You are casting large flies in total darkness. It is easy to hook yourself in your face or worse your eye. Wear clear safety glasses if you feel the need to. Practice casting a heavier rod or large mouse pattern during the day. It is not easy to work out casting kinks in the dark.
Detecting strikes is completely different at night then in the day time. Instead of seeing strike and hearing the strike, at night you will only hear the fish eat the fly. Strikes sound like an aggressive splashing noise (a toilet flushing) or a very distinct slurping sound. When you hear the strike, keep your rod tip low and strip set the fly. With your hands out in front of you, take the fly line in your line hand, and strip the line toward the pocket of your pants.
When wade fishing and casting mouse patterns, I prefer to start above my intended target and work down stream. Unlike fishing in the daylight hours, approaching from upstream is ok because it is dark. Fish facing into the current will not be alerted to your presence.
Cast your fly out and across at a 45 degree angle to the other bank. The current will swing your fly in a wide arc. Your mouse fly can be eaten anywhere in the river, especially if you are fishing small streams. However, in my experience most eats will happen anywhere from 8 feet off the bank to right on the shoreline.
Presentation of Mouse Flies
There are several different strategies for presenting mouse patterns. We will go over those here. Trial and error is key, so getting on the water with a mouse fly will naturally lead to your own techniques. Below are several retrieves that have worked well for me.
The Dead Drift
The dead drift presentation is simple and straight forward. With the right amount of current and a well built mouse pattern that appears to swim naturally as it is swung through the water, you can start mousing your local streams and rivers. Simply cast the fly out at a 45 degree angle and let the fly swing to the bank. If I am trying to cover lots of ground, then this is the approach that I use.
Keep your rod tip pointed at your surface fly and unlike a traditional trout set, use a strip set. Setting the hook is not done visually, as it is dark. This takes practice, and anglers with a keen sense of awareness focus in on the sound of a mouse fly being eaten on the surface of the river. Wait until you hear the strike. Sometimes, the strike is violent and loud. Other times it is more of a slurp. In my experience, smaller fish will smash a fly, and the larger ones slurp them.
Short strikes will give away a fish. Speed up the retrieval just a bit to simulate a fleeing rodent. Similar to a labrador chasing a tennis ball, the instinct of fleeing prey will often provoke a second charge and eat. The worst tactical move is to slow the fly down, as prey speeds up when chased.
Active Retrieval
Using your rod tip to impart movement to the fly as it swings to the shore is an excellent technique as well. This simulates an active rodent struggling to make it back to the shoreline. Movement is critical too, if you are fishing in a lake or pond or out of a drift boat where there is no current or the current is minimized by the movement of the boat.
I prefer a steady retrieve, as most mice do not stop swimming once they hit the surface of the water. This means the angler needs to make continuous strips in order to simulate a mouse swimming through the water.
My favorite technique when fishing from a boat is to move the fly in a similar way to fishing foam surface patterns for salmon flies. I cast to the shoreline, and slightly elevating my rod tip I vibrate the rod tip back and forth and retrieve line with the non casting hand at the same time. This creates a nice wake off the fly pattern, and really makes a mouse fly swim in a realistic manner. Vary your retrieval speeds and experiment with the best active retrieval, as I have had success with different retrievals in different bodies of water.
Gearing up - Choosing The Right Mousing Gear
Most mousing situation requires an upgrade in gear. Heavy flies requires heavier rods and extra strong leaders. The fish most mousers are after is the fish of a life time, so level up your gear and anticipate catching a once in a lifetime fish.
Use a 7 or 8 weight 9 foot rod with an extra fast action tip. Pair your rod with a reliable reel with a disk drag. A heavier rod paired with the correct reel is important to keep fish out of structure when they make their initial run on the hook up.
Floating lines are the traditional lines that most anglers use when fishing with a mouse fly. If you are fishing a super buoyant fly with a foam body, then pairing your rod with a light sink tip fly can be an option too. A light sink tip will pull the fly down in the surface of the water with out drowning it. This modification will cause the fly to throw a larger wake by sitting lower in the water.
Choose heavy tippet and leader material. I like to fish 3' to 4' of straight 20-30 lbs mono. Heavy mono turns the fly over, and it helps the angler pull fish out of cover. You do not need to worry about fish being leader shy, it's night time and they cannot see the leader material.
Choosing the Right Fly Patterns For Mousing
One has many options when choosing a mouse fly. In years past, it was rare to find a mouse fly in your local fly shops fly bins. Now a days, there are many options. Some even have ears which adds to the overall aesthetic of the pattern. Choose patterns based on how they swim and sit in the water.
Whether you choose patterns that are tied with deer hair, a foam body, or combination of materials, I like to pick patterns that ride low in the water and push a huge wake. A big wake and the surface disturbance it emits is what attracts big rainbows and brown trout to the fly. Mice don't swim high on the water, so neither should your surface fly.
I also like a mouse fly that incorporates a trailing hook. In my opinion this increases you chances of hooking up with fish that charge the fly and short strike the pattern. This happens frequently especially with smaller fish.
Similar to fishing swim baits with conventional gear, don't be afraid to go large. Large baits have drawing power, and while it might seem absurd to fish a 6"-7" mouse pattern, don't be afraid too. You might only catch one fish all season, but it most likely will be a gargantuan trout.
Setting Realistic Expectations
Before you head out onto the water, set realistic expectations. Fishing at night is different, so managing your rod and line takes getting use to. The first few tries might be frustrating, but after a while fishing at night seems routine. Plus, there is a good chance you wont see another angler on the water.
Most nights I go mousing I am happy if I get just a few strikes. If I catch a fish I am ecstatic, even if it is just a 20" fish. You have to think of mousing as hunting, you are looking for that fish of a thousand casts. It takes work and time on the water, but it will pay off eventually.
Choosing a few mouse patterns for the Fly Box
The Morrish Mouse is a stellar pattern. Tied by Ken Morrish, a famous fly tyer with over 90 fly patterns in production, the Morrish mouse has been around for a while. The pattern features an extended hook that faces upward making catch and release that much easier. In addition, the foam over body and splayed deer hair body makes the fly buoyant and it pushes a large wake.
The Rabbit Fur Mouse is a great fly, because unlike foam, once it saturates with water it rides similar to a mouse swimming. As the fly is stripped, the tail moves and jerks, giving it a realistic swimming action with a sizable wake. It has a wide hook gap too, making hookups easier. This fly is best fished when it is treated with some sort floatant prior to wetting the fly. That is the only drawback to this pattern, if it is not treated appropriately it will sink.
Mallard's No Miss Mouse fly is one of my favorite mouse patterns. It incorporates a rabbit fur belly so it lies low in the water and the high buoyancy foam upper body is tied in over the rabbit fur. The detached traileing hook is an added bonus for fish that short strike the fly. In addition, rubber legs add increased movement and life like swimming action.