Identifying what fish are eating

[tmohler]

Different times and at different places I've seen fish rising and eating off the surface. However, it's often difficult for me to identify what it is specifically that they're eating, even if I'm familiar with the hatches and insects on a given stream. Is there anything I can do to better identify what a fish is eating?

 

[ryansheehan]

Alot of the time they are taking something just below the surface where it is very tough to see what they are eating. Dropping a small pheasant tail or midge pattern a few inches off a dry often will solve the problem.

Also try to read the different takes. Are they splashy, sipping, porpoising takes? They can all clue you in to what they might be eating. However the best advice I can give you on what they are eating is......a great drift.

 

[Brianh]

Usually you can see the flies they are taking on the water. For me, when I see naturals drifting over a feeding fish and there is no takes, I try a BWO. I have have a hard time seeing them on the water.

 

[outsider]

Carry a fish aquarium net or a small and net the surface of the stream.

 

[redietz]

Also try to read the different takes. Are they splashy, sipping, porpoising takes? They can all clue you in to what they might be eating.

A bit more detail:

Splashy rises with fish coming out of the water often indicate fish chasing either emerging or ovipositing caddis flies. Try an EHC/softhackle combo. (Splashy rise can also simply mean small fish.)
Consider fishing downstream, and twitching the EHC.

Otherwise, look for a bubble in the rise. If you see one, they're taking something off the top. (They sucked in air with the bug and it has to go out again.) The size of the rise is a clue to the size of bug being eaten.

Porpoising rises a are clue that they're taking something both small and numerous. Think midges, tricos or small olives. Time of year might help here. the actual bugs may be in the film, or just below, and probably not doing a lot of moving.

If you don't see a bubble, they're probably taking below the surface. Try a dry/dropper or a team of wet flies, depending on your own preferences.

 

[MKern]

Usually it's not fly selection, but rather fly presentation. If your dry is dragging at all along the surface, even if you can't see it, that will turn fish away.

Sometimes it's a timing issue too. Occasionally, fish will rise rhythmically. Find it's pace and try to time your cast and drift.

If it is fly selection, try to narrow it down by size and then color. If you have to go 1 size smaller than you think.

 

[Dave_W]

redietz wrote:

Otherwise, look for a bubble in the rise. If you see one, they're taking something off the top. (They sucked in air with the bug and it has to go out again.) The size of the rise is a clue to the size of bug being eaten.

Porpoising rises a are clue that they're taking something both small and numerous. Think midges, tricos or small olives. Time of year might help here. the actual bugs may be in the film, or just below, and probably not doing a lot of moving.

If you don't see a bubble, they're probably taking below the surface. Try a dry/dropper or a team of wet flies, depending on your own preferences.

This, especially the part about looking for a bubble, is worth repeating.

 

[krayfish2]

I'll agree with some information provided and disagree with some information provided. I don't think you're going to find a one type of rise that 100% guarantees you've got it figured out.

Best information I could provide is "observe". Watch the fish, look at the water, look in the water column, watch the fish and make your own informed decision. A fish holding in soft pocket might dart into faster water to grab a mayfly dun resulting in a splashy rise. A majority of people will say "They are slashing at caddis. Go to the EHC". Well, caddis hatches often overlap mayfly hatches so you might get away with an incorrect identification. Not always though.

Fish taking just under the surface often make a rise where their nose doesn't break the surface but they'll show their back, dorsal and tail. An unweighted nymph in the film or greased to be just under the surface can be deadly but difficult to detect a take unless you can see the fish. A soft hackle can also be quite effective.

Just keep your eyes open, observe and make mental note for following trips. Presentation is typically more critical that pattern. General fly shape and relatively close size will get takes when presented properly. Read up, fish with a mentor and take in as much info as you can. Some nymphs are fast swimmers, some crawl to shore, some caddis bounce and others dive. Identify what's going on, match it and you'll be taking hero shots with the camera in no time.

 

[foxtrapper1972]

They are very often taking Griffiths Gnats which can be hard to see. A well presented Adams will sometimes take these fish.

 

[PennypackFlyer]

I overturn a few rocks in the river/creek to see what they may be eating.

At age 57, it's hard for me to see some of those small dry flies that fish are taking at the top. I have some that are, hook size at 22 or 25 - hell I can barely put them on my 2lb line.

Casting dry flies to get their take can be challenging. If I know where the trout are sitting and se ethem taking on top I try to get the fly around 12" from them. I find that if I put it right on top or to far in front of them my hook up ratio drops. It's like you want to get it to attract their attention and not give them time to look at it, at the same time.

 

[outsider]

Griffith's Gnats are not an insect, they are an imitation fly developed by George Griffith.

 

[melvinp]

From the last 2 rainbows that found the frying pan(Golden stones,Helgermites,little black beetles and some sort of little white worm.)No minnows or crawfish was surprised.

 

[pcray1231]

In addition to the above as well as knowing your insects, you should know ABOUT the insects. Where, when, and how.

That will narrow it down to a few possibilities to figure out whats going on.

As a random example. Lets say you're on a stream with the usual mayfly suspects in earlyish May, mid to late afternoon. Too early in day for spinners. Most likely hatches to encounter are March Browns and sulphers. Could have olives, caddis, craneflies, midges.

Ok, March Browns hatch on bottom, in heavy water, and "fly" to surface. If you are seeing agressive, splashy rises in heavy water, thats probably what it is. Sulphers are often in smooth, slower currents. And they hatch by nymphs swimming to surface, sitting just beneath, then the backs break open and they emerge on top. If you see beaks, they're probably taking duns. If just dimples or subsurface boils, probably the floating nymphs, even if there are duns on the surface! Try an emerger or float a nymph behind a dry. If the rises are very sporadic and lazy and mostly in eddies and such, then craneflies, midges, or olives could be it. If sporadic but out in main current and they are launching out of water, try skittering a caddis. If nothing at all seems to be happening, try nymphing. March browns in the riffs or sulpher nymphs in the smoother water.

I usually have in my head 2 or 3 things that COULD happen before i ever set foot on the water. Then its using the observational stuff to figure out what it is.

 

[redietz]

pcray1231 wrote:


I usually have in my head 2 or 3 things that COULD happen before i ever set foot on the water.

I do, too, but there's a downside to doing so: you sometimes see what you expect to see, rather than what's there. It's called confirmation bias.

For example, you're expecting sulfurs, see a few in the air, and fish rising. It's only after a couple of hours of not touching a fish that you notice the little black caddis...

That particular scenario happened to me about 20 years ago on Falling Spring. It's not the only time I've seen what I expected instead of what's there, but it sticks out because it was my 10 year son who noticed the black caddis first, and started catching. That made it particularly humbling, and I remember like it was yesterday.

That caution aside, it's still usually a good thing to have some idea of what might be hatching at that time and place, and to make sure that you're carrying flies that work over each of the possibilities. It doesn't hurt to keep a log, either. It won't help immediately, but after a few years, you'll have a better idea of what to expect.

 

[pcray1231]

Yes, im an engineer and well aware of confirmation bias. And yes, it has happened to me too. Dang BWO spinners when sulphers are falling! Lol.

Those times are humbling. And educational. The "aha" moment is almost worth the frustration that leads to it!

I still feel its good to go in with some educated expectations of what is likely to happen. When not sure whats going on, it makes you start with whats most likely. Those times you get fooled just add another possibility to the mix for next time. Its how you learn.