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How Trout See, with Jason Randall

Description: Can trout see color? Can they see UV light? How does a trout's window on the outside world affect how they feed and how they notice predators like us? How can a trout see so well at night and also in bright light when they have no eyelids, and their pupils don't constrict? Jason Randall [31:10] is an experienced fly fisher and scientist, and he stays up on the latest scientific papers on trout and also talks to leading scientists, and is one of the best at distilling this information for us ordinary anglers. This is a fascinating podcast and Jason does a great job of explaining trout vision.
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Podcast Transcript:

Tom: Hi, and welcome to the "Orvis Fly Fishing" podcast. This is your host Tom Rosenbauer. And my guest this week is a guy who I've been trying to get on the podcast for quite a while. We've both been busy, but we finally got it together. Jason Randall is an angler and an author and a teacher. [00:00:30.338] And he's a biologist by profession. And he is one of the best people at staying up on the scientific literature and reading it, and then distilling that information and bringing it to non-academics like us, and helping us understand trout more and helping us understand how to catch them and why they behave the way they do. [00:01:00.309] I use Jason's books a lot in researching topics when I'm doing my own writing, and I hope I credit him when I do that. But anyway, he's a fascinating guy. And the topic of today's podcast is Trout Vision. You know, do trout see color? Do they see UV? How do they spot us? Can they see us everywhere? And how do they see at night? And then how do they see in bright sunlight? How do they adjust? Because they don't have eyelids. [00:01:30.907] So, anyway, it's a fascinating topic. I think it's a great podcast, and I really enjoyed talking to Jason, and I think you will as well.
Before we do the Fly Box, just a product that you might be interested in, that you might have missed, Orvis has had these for a long, long time, but they're called super magnifiers. And they're a very high-quality [00:02:00.618] pair of, like, half glasses, except they're in 4X and 5X magnification, which is not something you can typically buy when you buy reading glasses. And, you know, even from an optical shop, it's difficult to get this high power. And I use them both for fly tying and on the water because magnification is so important. Even if you've got perfect closeup vision, [00:02:30.293] threading, say, a 7X tippet through a size 24 hook, or even sometimes a, you know, 5X through a size 16 hook can be difficult, or tying a blood knot, or tying a surgeon's knot. And we all need a little bit of closeup help both on the river, on the water, and in fly tying. So, these are a great aid no matter how good your vision is. These are a great aid [00:03:00.342] for getting close up on things both in the field and at the fly tying. So, check them out.
You know, I really like meeting podcast listeners in person. It's always so much fun to talk to people about what they like about the podcast, and sometimes they have a question that they're too embarrassed to ask by sending it into the Fly Box. And I always enjoy it. So, I am going to be in the Dallas, Texas [00:03:30.386] area this coming weekend. I'm gonna be doing four different presentations on trout tactics for different ones, and also I'm gonna be there with some fine people from Green Baker Lodge and El Pescador Lodge. So, you can talk to someone about a dream trip to Belize or to Chilean Patagonia, and I'll give you the dates and what I'm gonna be talking about.
[00:04:00.339] On March 28th, I'm gonna be doing a presentation on reading the water at Orvis Southlake from 4:00 p.m. to 8:00 p.m. I'll be there from 4:00 p.m. to 8:00 p.m. Probably, the presentation will start around 6:00 or so. On March 29th, I'm gonna be in Fort Worth, and I'm gonna do a presentation on fishing small streams, again, from 4:00 p.m. to 8:00 p.m., again, probably starting at 6:00. And then on March 30th, I'm gonna be in [00:04:30.442] the Dallas Orvis Store, the Downtown Dallas Orvis Store, from 9:00 a.m. to 1:00 p.m. So, the presentation will probably start about 10:00 or 11:00 or so. And I'm gonna be talking about taking your trout fishing to the next level. And then finally, on the same day, March 30th, I'm gonna be at the Plano Orvis Store from 2:00 p.m. to 6:00 p.m., and I am going to be talking about hatch strategies.
[00:05:00.301] So, there'll be maybe some light refreshments. And I would advise you if you wanna go to one of these, or you can go to all of them, they're all free, no charge at all, you gotta buy a Helios rod, of course, before you leave, but no, there's no charge at all. But I would call the store first because I'm quite sure there's limited seating in these stores. So, if you wanna go, it's a good idea to call the store and reserve a spot. And you can find the phone numbers for those stores on [00:05:30.783] the Orvis website. And, of course, you can also get directions to the stores there. So, hope to see you in Texas this coming weekend.
All right, let's do the Fly Box. And the Fly Box is where you ask me questions or increasingly send along tips that I can share with other listeners. In fact, I've been getting so many tips lately that maybe I can retire as a podcast person because there are lots [00:06:00.753] of great tips coming from listeners and really appreciate you sharing those. I still like the questions, and I hope I get lots and lots of questions because I enjoy answering those when I can. But the tips are great and there's a lot of tips in this week's podcast, which are good ones. The first one is a question, though, from Jackson.
Oh, I think I forgot. If you have a tip or a question that you'd like to share [00:06:30.648] or ask, you can send it to me at This email address is being protected from spambots. You need JavaScript enabled to view it.. Either attach a voice file to your email or just type it in your email. All right. So, the first question is from Jackson. It's an email. "Was recently targeting steelhead on a popular river in New York. After a great morning on the main river, I decided to hit a favorite tributary. Water was low, sun was high, and I was on a gorgeous stretch in the middle of a field with deep undercut banks. On my way [00:07:00.207] in, I spooked a huge fish from under a log, which initially made me feel foolish. However, I came back about two hours later and managed to spot and hook him in the same stretch after crawling up on it. This got me to thinking, when the water is low, sun is high, and fish are really tucked away and spooky, which tactic would you recommend? Working upstream and spotting them as you can, working upstream and blind casting, walking downstream to spook them, eat lunch and come [00:07:30.520] back later to key in on that fish?"
Well, Jackson, I think all of those would work. You know, you're gonna be able to approach the fish closer and get a more accurate cast and actually see the fish better by coming from downstream. And so, that would be my approach. And, you know, I would sightfish where I could. Sometimes you can't see them when they're really tucked into cover on a bright day like that, so I would blindfish [00:08:00.535] in the likely spots as well. And, you know, as you pointed out, you might be able to spook them and then come back and catch them later. Steelheads seem to not stay spooked as long as, you know, a resident feeding trout. So, you can come back, you know, in an hour or two and maybe hook them. But part of the problem is that they're moving, they're migrating, so the fish may not be where you spooked it before, it might be somewhere else in the river. [00:08:30.901] But on a bright, sunny day, probably not gonna be moving much until the light level gets lower. So, not a bad idea. Anyway, I think you answered your own questions, but thanks for sending them in.
Tim: Hey, Tom, thanks so much for the podcast and everything else you contribute to fly fishing. So, I guess this would fall in the tip category. A couple weeks ago or a couple podcasts ago, you had a question about rooftop rod lockers and whether the heat would damage rods in them. And I just wanted to, like, [00:09:00.715] add my experience. The heat certainly has not damaged my rods as you accurately answered. What I have experienced is over the course of putting them in there and leaving them in there for several days or weeks, running around last summer dusty Colorado roads, the ferals where the white spot in the rod got a little bit of a sanded look from just rubbing against the inside of that rod locker, and I didn't really like that, so I got [00:09:30.647] the Chinese finger puzzle style rod sleeves and slide my rods inside of those and then put them in the rod locker and that has prevented that. So, there's my tip on rooftop rod lockers. Oh, and the 1.5 tip would be if you're thinking about getting one, get a larger one than you think you wanna get at first. I got the two-rod locker, and I wish I had the four. All right, thanks, Tom.
Tom: Well, Tim, thank you very much. Those [00:10:00.552] are great tips. And, yeah, I think your idea of getting the larger rooftop carrier is a good one because you never know when you're gonna wanna get a longer rod or a two-handed rod. Actually, I don't think two-handed rods fit in most of those rooftop carriers unless it's a short one. But anyway, you may wanna get a longer rod, like a 10-footer, 10.5, or 11-footer, and getting the longer rooftop carrier is a good idea. [00:10:30.467]
All right, here are a bunch of fly-tying tips from Steve from North Sunderland, UK. "I'm a longtime subscriber, and like your other listeners, appreciate and look forward to the regular updates from your podcast, enjoying the truly global shared content with something there for everyone. As an old-timer fisherman, I don't beat myself up anymore about it's a must to do, try all the new trends [00:11:00.532] and processes that come our way. It took some time, and I must admit, however, I'm confident to mix and match if it interests me, and it makes my day better if I use light-wading gear with technical clothing, etc., etc. I have a couple of tips that might be interesting, Tom, as I hear these subjects coming up regular in your podcast by listeners.
First one, I use a needlecraft measuring gauge to get proportions right when tying flies. [00:11:30.968] It's especially useful if you're batching up some new flies. It's a small, flat plastic multi-sided measuring tool that works. When buying vintage cape saddles, do not trust them or assume they have been cared for as your own products. If in doubt, I remove all the feathers, wash them in hot water using a borax detergent mix available online, rinse them, then wash and conditioner, dry with hair dryer, and then store in freezer Ziploc bags from [00:12:00.715] IKEA with a couple of mothball pellets. All my skins, capes, etc., are in separate airtight zip bags, then in see-through storage bins. Check all your fly-tying materials regularly. Don't leave nice things in new packets for years, then wish you had used them. I mean, get everything out then you know roughly what you have. Serious fly-tyers are collectors, and we end up with expensive inventory that we should use before it's too late. And [00:12:30.651] lastly, I keep all threads and materials out of direct sunlight when not in use to slow down deterioration from the rays, especially vintage silk threads."
Well, thank you, Steve. Those are great tips. The only one that I would kind of question is buying a vintage cape or saddles. You're right that a lot of the bugs will be in the skin and not on the feathers. And [00:13:00.135] so, removing all the feathers is probably a good way to keep all the bugs away. However, I find it makes it really difficult to use those feathers when they're all separated from the skin. You know, when you use a hackle cape, you can go from the bottom to the top to go from smaller or larger flies. And if they're all in a jumble, you're gonna [00:13:30.659] have to sort through those. It may take a lot more time, plus the chances of bending those, you know, it must be a lot of work to dry each one of those feathers with a hair dryer and make sure they're not crammed into a bag. So, I applaud you doing that, but I think what I would do with an unknown cape would be to wash it on the skin, in that borax [00:14:00.412] detergent mix, and then I would just dry it carefully, lay it out on a piece of cardboard, and then I would just put it in a Ziploc bag, and separated from other materials for a couple of years until you're sure that there's no bugs in there. I used to use mothballs a lot, and I don't think that's probably a good thing to be inhaling all the [00:14:30.704] time. And I think it's overkill. So, just washing a cape and keeping it isolated might be good enough for most of us.
Here's an email from Dennis. "Longtime listener here. Thank you for all you do with the fly fishing community. My question is regarding the Helios lineup of rods. I'm a little torn between the 10-foot Helios F3 weight and the 10-foot Helios D4 weight. I'm looking for a longer rod, good [00:15:00.229] for Euro-nymphing, but also dry flies in the occasional small streamer. Here on the East Coast, in my home state of New Jersey, I find myself fishing a lot of smaller streams for usually smaller fish. Occasionally, I will travel to New York or Pennsylvania, and I want to also find my way out west at some point. I currently use an 8-foot 6-inch, 3-weight Orvis superfine touch rod and have a 9-foot 5-weight recon. Would you recommend the 3-weight or 4-weight Helios to be able to handle [00:15:30.413] a larger variety of fishing conditions, fish sizes, and, of course, fly sizes? Which rod would be more practical for a general-purpose rod? With the cost of these rods the way they are, I want to try and make the best choice with a high-end rod like the Helios for a variety of fishing situations and not just a very specialized version. Any insights would be greatly appreciated. Thank you."
Well, Dennis, in my opinion, for what you're looking for, I think, definitely, the 10-foot 4-weight [00:16:00.364] would be a better rod. You can Euro-nymph with it, it's not gonna be quite as sensitive, and you're gonna have to work a little harder when casting a mono rig with the 4-weight. However, when you're going to fishing with indicators or streamers or standard fly line, think you're gonna be happier with the 4-weight, particularly on the streamer end of things. So, I would go with the 4-weight. I think it's gonna be more versatile [00:16:30.645] for what you wanna do.
Zach: Hey, Tom. My name's Zach. I'm from Ohio, originally from Western PA. Thanks for all that you do for the fly fisher community. I really appreciate the podcast. I really love listening to it while I'm at work. It helps pass the day. I just finished a book called "Wild New World" by Dan Flores. And it's really good, kind of just goes over the history of animals [00:17:00.711] in America and our, as in humans, relationship with those animals from before European contact to post-European contact to, like, today. And it's got me thinking. I know that you did a podcast episode about must-reads for fly fishers, and I was wondering if you had any suggestions for books that specifically talk about the history of trout in America. His book is great, but it doesn't [00:17:30.791] talk about trout and it's got me wondering what it was like pre-Europeans and as Europeans came over and brought brown trout and rainbows and just how all of that played together. So, I was wondering if you had any suggestions, if there's a book that's out there that maybe talks about this, or if maybe even any listeners have [00:18:00.526] any suggestions. That'd be great. Thanks.
Tom: Zach, I don't know of a book that will do everything you wanna do. The best book on trout species in North America is definitely a book called "Trout and Salmon of North America" by Robert Behnke. And I believe it's out of print, but you can get a used copy. [00:18:30.381] A couple of other books that will also give you some detail on trout and their history and their distribution are James Prosek's book called "Trout: An Illustrated History." Prosek is P-R-O-S-E-K. That's a great book. And he's a wonderful writer and a fine artist. So, the pictures in there are beautiful. And then finally, not specifically [00:19:00.493] about the history of trout, but kind of the history of fly fishing in America and how it changed when browns were introduced in North America and when rainbows were more widely distributed by stocking is one of my very favorite books. It's called "American Fly Fishing: A History" by Paul Schullery, and Paul Schullery's [00:19:30.963] last name is S-C-H-U-L-L-E-R-Y. So, those are all good books, you know, to give you a broad understanding of the history of trout in North America. So, I hope that's helpful.
Here's an email from Jeff. "In response to the question the gentleman had about snakeheads, to start, I'm a guide in Maryland and Virginia. I target snakeheads and trout. Fly fishing for snakeheads is a love-hate relationship. They're hard to [00:20:00.115] hook. But anyway, I prefer to use a 6-8-weight fast action rod with a 10-foot, 20-pound straight hand-tied piece of mono leader. They're not leader-shy. As for flies, anything that will move water, they're reaction feeders. I love using mice and gurglers or big bass poppers. They will also readily take frog patterns. Make sure your flies have strong hooks. You have to be fast on the hook set when they strike to [00:20:30.767] prevent them from swallowing your fly as they have very sharp teeth."
Well, that's great. And thank you, Jeff, for those tips. It sounds like probably part of the problem is finding snakeheads, although we don't like finding them because they're invasive, but if you can find them, sounds like they're pretty easy to get to take a fly, but I've never caught one, and I'll take it from you.
Here's an email from Elijah. "I've emailed once [00:21:00.722] and your answer was so helpful, I thought I would email again. My question today is about vises. As I said in my previous email, I'm a 15-year-old on a budget. And as of late, I have been fishing primarily for bass. I'm hoping to invest in a vise, and I was wondering what your opinion on budget." By budget, he means $160 to $220-vises. "I think I have narrowed my options down to the Renzetti Traveler 2000 and the Regal Medallion. I know these are [00:21:30.488] very different vises, and I'm curious about the benefits of the rotary feature if it applies to bass flies, and if the Regal jaws are strong enough to hold bass-size hooks. I still find it hard to believe that I can tie on a 1/0 hook held only by a spring."
Well, Elijah, both of those would absolutely be my choices. And that's not an inexpensive vise. You know, inexpensive vise, you can get a vise for 50 bucks or [00:22:00.339] 75 bucks or even less, but, you know, they're not great, and they won't last long, and they won't hold a hook very well. So, when you get up into the, you know, $150 to $250 range, you're getting an American-made vise that's gonna last a lifetime, really. And when you spend much more than that, you're just adding features that you may or may not use, depending on how you tie. Both of those vises will tie rotary. [00:22:30.455] And I think, you know, if you like to tie rotary, it'll help in bass flies, particularly if you're winding a lot of materials on the body. I don't do it that much, but once you get used to it, it will speed things up for you and it's kind of fun. So, either one of those vises will be great, and I would not hesitate to use the Regal Medallion [00:23:00.375] for big hooks. That spring on the Regal vise is very strong. In fact, Regals are really known for being great for holding larger hooks. So, the Renzetti will do it, too, but I would not hesitate if you like the idea of the Regal vise design better, it will absolutely hold that 1/0 hook without any problem at all.
Here's an email from Jim from Colorado. [00:23:30.710] "I'm two years into fly fishing now. My commute to work is along a 15-mile stretcher river, so I stop along the way a couple of times a week to try out whatever I am working on at the time. I can work through things pretty quickly doing that. When I first started out, I tried out different leader lengths and sizes. When I had, say, a 9-foot 4X leader, I had every confidence in adding 5X to the first fly and then 6X to the lower. I had no problem landing the 17 to 19-inch fish. [00:24:00.312] So, I tried a 9-foot 6X leader, not the same confidence at all. I would break the line just trying to tie on flies, snap, snap, snap. I would easily lose 2 feet of the leader for various breaking reasons before I would go get to strengthen the line I could use.
So, I landed on a 9-foot 4X as my regular. I recently decided to start using more premium brands since I will be doing this for a long time. I figured I would try again. Maybe a better quality brand would yield different [00:24:30.662] results. Nope, basically, the same result. I went through the 6X and now I am working on the 5X, hoping to get better results there. Should I even care? Should I just stick with a 4X as my final taper and not worry about it? Am I failing some test I am unaware of? At this point, I have amassed a great deal of streamer-length leaders. I guess I'll have to learn to like streamer fishing. This is probably not that important, but I do think the leader is one of the most important pieces of equipment since [00:25:00.506] it is the item that is ultimately presenting the fly. Any thoughts would be appreciated. Thanks for all you do."
Well, Jim, you know, I've heard of similar problems, and typically, I don't start with, like, a 9-foot 6X or a 12-foot 6X leader, just because I like to tie on my own tippet section so I know exactly how long my tippet is. And, like, if I [00:25:30.808] start with a 9-foot 4X and I need a 6X, I'll cut the 4X back a little bit, add a short, like, 6-inch piece of 5X, and then put my 6X tippet on there. And I have heard other people complaining about the same thing. And I think that the way these knotless leaders are extruded, that sometimes you can have a weak spot in the tippet. [00:26:00.086] And I don't know exactly why, but they are stretched and extruded and heated and cooled to make that knotless leader. So, I think it's best if you just keep with the 9-foot 4X, and if you need to go 6X or, you know, 5X, just tie on another piece of tippet material, tie on an intermediate section. I don't like to go more than 1000th of an inch. You can go 2000ths, but I don't like to go more than 1000th of an inch when I [00:26:30.333] taper down my leader. So, yeah, I think that's the way to go. And, again, I don't know exactly what happens with those shorter 9-foot 6X leaders, but again, I've heard similar problems from other people.
Here's an email from Jeremy from Ohio. "Hello, Tom and the crew. New Ohio fly fisher here with less than a year of experience. I've learned so much from listening to six or seven years of the podcast so far [00:27:00.373] and watching the YouTube channel and the new fly fisher content. I'm an active member of our TU chapter now and a member of the Columbus, Ohio, Project Healing Waters Fly Fishing program, which has been very rewarding. I'll keep it quick, but thank you so much for everything, including the live tying sessions with Tim.
Yesterday, March 12th, I was on the Rocky River targeting my first steelhead and ran across some of the guys from Covered Bridge Outfitters, an Orvis-endorsed guide here in Cleveland, that brought me [00:27:30.445] along to a spot that should help. And wouldn't you know, I wasn't in the water 20 minutes and had my first steely on a white deathfly that I tied. I started walking back to the bank to net it, and Alex, one of the guides, was already in the water with that huge wide-mouth guide net waiting to net it for me. I couldn't be happier with my first chrome, and I'm hooked for sure. Shortly after this, John, the store manager of the Cleveland Ohio Westlake Store, came over after watching me for quite some time [00:28:00.733] to look at my setup and quickly walk me through what may be a better way to run it and cast it and asked me if he could retie it and set it up differently and showed me how that would be more effective and easier to cast. I could not believe how both of these crews saw a guy they had no connection to and invested their fishing time into me. Thank you so much to the entire Orvis family. You are all truly the best there is." Well, that is [00:28:30.413] so nice, Jeremy, and I'm so glad you had a wonderful experience on the water with these fine people.
Jason: Hey, Tom, Jason from Cropseyville, New York. I stopped by the Orvis Manchester Store the other day to take advantage of the 20% off fly sale. However, I ended up walking out with a pair of brand-new Orvis Pro Guide Waders and a Guide Sling pack. I did not buy any flies, but I wanted to say kudos to Forest [SP], [00:29:00.332] who is the sales associate in the fishing department. He did an excellent job and was extremely helpful, spent a lot of time with me, much appreciated. Next, I would like to say you guys have to do another Tie-Off with you, Cheech, and Tim. It was fantastic. Really great stuff, and I love the fly that you picked. Years ago, my sister bought me a book by Rick Talleur, "Mastering The Art of Fly Tying." I still refer to this book all the time. It's absolutely amazing, and if [00:29:30.589] anybody can find a copy of it, I suggest they purchase it. Wonderful illustrations, photographs, and just a great way of explaining how to tie flies.
Finally, I was wondering if you could do a podcast regarding New York State brook trout. The New York State Department of Environmental Conservation is getting ready to release its brook trout management plan, and I would appreciate it if maybe you could talk to one of the DEC biologists [00:30:00.531] and do a podcast on it. Recently, I've heard that the Adirondacks are endangered of only 5% of their waters supporting brook trout, so that would be great. Thanks for all you do. Much appreciated.
Tom: Well, Jason, thank you. And we will have another Tie-Off with Cheech and Tim. In fact, we may do this on a regular basis because people really enjoyed it. The next one will be April 15th, [00:30:30.658] and we're gonna be tying a Paraloop Sparkle Dun. So, stay tuned for that. It'll be announced. Regarding a podcast on Adirondack brook trout, yeah, I'm gonna look into finding the right person and talk about that fishery. I don't have anybody in mind right now, but I will do some investigations and find the right person to interview for a podcast.
All right, [00:31:00.710] that is the Fly Box for this week. Let's go and talk to Jason about trout vision. So, my guest today is Jason Randall. And if you are at all interested in trout and their natural history and their senses, you probably read one or more of Jason's books. Full disclosure, I use Jason's books an awful lot for reference when I'm doing my own writing [00:31:30.791] because he has done such a great job of covering things like currents and trout senses and trout behavior. Jason, welcome to the podcast. And how do you get your information, first of all?
Jason R.: Tom, thank you so much. It's a pleasure and honor to be on your program. I am a big fan. You have [00:32:00.623] done more, I think, for education within our sport than pretty much anybody else. And I admire what you've done and your writing as well. So, thank you for your impact and your contribution.
Tom: Thank you, Jason.
Jason R.: Typically, I do a lot of research on these topics. I am blessed with having a scientific background, and so the scientific information [00:32:30.434] is usually fairly readily available to me. And I tap into that an awful lot. Through that, like, working on the book "Trout Sense," which does cover all this trout senses and how that relates to us as anglers, I was able to contact some of the leading researchers in trout physiology and specifically in the area of trout vision and, you know, [00:33:00.351] be able to have dialogues with them and be privy to some of the work that they were, at that point, working on and sharing some of that information with the angling world.
Tom: Yeah. And that's great because there's a lot of stuff out there, scientific stuff, unfortunately, it's often behind a paywall and it's often difficult to decipher, you know, if you're a layperson. So, what you do to bring that [00:33:30.799] information into the general public is really admirable.
Jason R.: Well, thanks, Tom. I appreciate that. I enjoy it. I enjoy that aspect of our sport. It's a sport for life-learners. You never are gonna know it all, and you're constantly learning. And I like to say that when you are not learning anymore within our sport, you're at that point the best angler you'll ever be. And nobody, I don't think any of us are [00:34:00.362] satisfied with that.
Tom: No. If you're at the point where you're not learning anymore, you should probably give up and play golf or something.
Jason R.: That's true. Yeah, start another project.
Tom: Yeah, really. So, today, we're not... Sorry.
Jason R.: I like digging into that material. And, you know, I had memberships for many, many years with my background in streams and in river ecology and trout physiology. I was in the society, North American Benthic Society [00:34:30.759] and the Society for Freshwater Science after that. And I had access to that, and it gave me a perspective that I could look over the volume of information, and try to let that data draw its own conclusions. And sometimes you can go into the body of scientific information or literature trying to prove a thesis or a point, and you can [00:35:00.469] probably find one or two papers, they may have been older or outdated, that might support that premise or your belief. But I think the best thing when you're looking in and if people do look into the scientific literature, to go in with an open mind and let the data draw its own conclusions. And I think a great place to start, the bibliography for "Trout Sense" was over 20 pages, and most [00:35:30.592] of those are scientific papers.
Tom: Yeah. Well, we're gonna talk about trout vision today, right? I wanted to originally talk about all the trout senses, and you talked me out of it because it would probably be like a five-hour podcast, right? So, we may take this in bits and pieces, but probably the most important and the most interesting, and the one that I get the most questions on is trout vision. How similar is their vision [00:36:00.214] to ours? How different? How does the aquatic medium affect how they see? Can they see color? Can they see UV? Let's cover all those things.
Jason R.: Oh, wow. That's ambitious. That'll take us a full hour.
Tom: Well, we'll do the cliff notes version of trout vision.
Jason R.: Well, let's start with some basics then. There's certainly some physics that comes into it with transmission of light and [00:36:30.360] refraction and things like that. There's also a lot of physiology that comes in sight with the function of the trout's eye and their retina and how it's different from ours, how it's similar to ours, but let's just start with that. Their eye is similar to ours in many ways. They have a retina that has photoreceptors, cones, and rods like ours do, and they see [00:37:00.725] a full spectrum of color like we do. They also have a tremendous sense of nocturnal vision. They have a very high ratio of cones and rods. But rods are the ones, they're the photoreceptors that discriminate black and white with high acuity, though, and contrast. And they're very sensitive. And the cones are [00:37:30.884] similar to our cones in our retina. They see color.
Interestingly enough though, when they adjust between low-light and bright light conditions, it's far different from how we do that. We have a pupil that constricts or dialates to limit the amount of light that reaches the retina or to maximize the amount of light that reaches our retina in dark conditions. And we also [00:38:00.527] have eyelids that we can squint to further limit the amount of light that enters the eye during bright daylight conditions, but trout don't have either of those. And so, how they do it is quite unique. They actually will either engage the rods or the cones, disengaging the other. So, it's kind of an all-or-none type of response for trout. In bright light conditions, they literally will [00:38:30.680] disengage the very light-sensitive rods, protecting them from being overstimulated. And then at night, they disengage the cones and fully engage the rods to get the maximum vision in low-light conditions.
But interesting then, if the cones are color and the rods are sensitive low-light receptors, at night when they're using exclusively the rods, they don't [00:39:00.575] see color. So, there's no color. You know, the sensation for trout at night, even us, we don't have a lot. I mean, colors can really dim and turn to gray in low-light conditions for us as well. But for trout, you know, it's exclusive. And so, when we think about then the lightings that we're going to use at night, we should be focusing on contrast because any color they see is gonna be registered as a shade of gray.
Tom: [00:39:30.585] It leads me into a question. So, at night, they lose their color vision because they're mainly using the rods.
Jason R.: Correct.
Tom: During the day, when, let's say, a fish is out in bright sunlight during a mayfly hatch in early spring, eating bugs off the surface, what part of their vision do they lose because the rods aren't engaged? Does it change the way they see things at all?
Jason R.: Well, it's gonna be [00:40:00.430] predominantly color and it's gonna be very accurate vision because the cones that are used during the day are very accurate in their visual acuity. And the colors will be very, very evident. But another note, if we look at the physics side of it, trout live in an aquatic medium, essentially, that is very subject to color shifts and [00:40:30.806] changes in color saturation and water clarity and water staining. These all affect color tremendously. And so, color is not extremely reliable until you get into close range. That's where color is most accurately perceived because it'd be like you and I, you know, living in a smoke-filled room, you know, the colors are gonna be attenuated and certain colors will be enhanced a little bit and other colors will be [00:41:00.673] de-emphasized. And so, the reliability of color in stained water or turbid water is very much affected. You've had this happen to you before. You've had a trout that's kind of followed your fly, you know, 6 inches below the fly and then turned away.
Tom: Yeah.
Jason R.: You know, that's frustrating. But we can learn something from that because that [00:41:30.558] is a color-based refusal, because he got close enough to the fly to determine that it was the wrong color, and that's when he turned away. There's four items that trout really use visually to decide what to eat. And this goes back to some research that was done in the last century, in the 1930s, '40s, and '50s. So, one of the ones key researcher was Tinbergen. [00:42:00.344] And he came up with a concept of a search image. And he was studying songbirds that had to discriminate the speckled moth that they ate when it rested on the bark of a tree that, you know, caused it to virtually disappear. Well, he identified criteria then that the birds used to try to decide what is edible and what is not edible. And it's been since broadened out to all predators, including [00:42:30.117] trout. And it really comes down to four criteria. And this is the checklist, if you will, that trout use to decide what to eat, whether it's a natural food type or our fly.
And the first item on that criteria is size. And size is critical. If the size is wrong, they won't even give it a second look. And size is obvious from a long ways off, Tom. If you look down the road, you [00:43:00.410] can tell a semi from a sports car from 2 miles off based on the size. The second item is shapes. So, that includes profile and proportion, and once again, very obvious from long distances. The third item is color. And color is only accurately perceived at relatively short distance in [00:43:30.526] the water environment. And the fourth item is animation.
If we match those four things, you know, with what the trout are looking for prey-wise, we're gonna have a better chance of catching fish. But if you passed your fly four or five times over that trout, and he hasn't moved up on a 4 feet of water to come close to your fly, that is a refusal based on size or shape, those things that are the first and second items on [00:44:00.652] the criteria that are obvious from great distance. But if he came up close to that fly and turned away, you already passed the size and shape test, you got the wrong color. And that's a color-based refusal, and that's when you wanna keep the fly the size, and the fly itself, but change the color.
Tom: See, I always assume it's drag, not color.
Jason R.: Well, drag is pretty obvious from a distance as well. And drag is a whole nother [00:44:30.635] thing that we deal with as anglers, a whole different abyss of deep discussion.
Tom: And I've noticed from taking underwater pictures that drag is so much more noticeable from underwater than it is above the surface. You know, when we're looking 20 feet away, it's really apparent from underwater.
Jason R.: You bet. It's because the surface [00:45:00.682] of the water is like a magnifying glass. It just accentuates those errors in presentation. The same is true of the fourth item on that list is movement. And there was a kind of a push a while back, you probably remember this, where we were tying very rigid flies that were just virtual imitations of the natural, but they were rigid and had rigid materials, and plastics, and proxies, and things, and they didn't catch [00:45:30.295] very many fish. But if you put a rubber-legged hopper on, those legs just move with every little bit of movement in the current, and boy, do they look realistic? And, again, that's one of the things that they're using.
Tom: I've also heard that speckled materials like grizzly hackle give the impression of movement because of the light and dark contrast.
Jason R.: [00:46:00.366] You're right. I think that's true, too. I think contrast is hugely important because trout usually feed on organisms that have contrasting colors. But also, I think that really goes to the success of like UV materials that have this kind of almost holographic chatoyants, or they have a, you know, like, iridescent quality to them. If you hold them in the light, they change, [00:46:30.771] you know, in color hues and things like that. It's like a mallard duck or a peacock curl. You know, you can hold it at different angles in the light. It could look green or black or even dark blue. And I think that's really what is selling trout on some of those materials. Ultraviolet materials are hugely successful. It has nothing to do with a trout's ability to discriminate ultraviolet light because they don't. It has more to do with these [00:47:00.481] other features of the materials that I think do imitate natural appearance, but also that illusion of movement.
Tom: So, you're not talking about the UV treatments. You're talking about more the pearlescent materials and the fluorescent materials.
Jason R.: Right. The UV treatments, I think are selling anglers rather than fish. I don't really have much, you know, faith in some [00:47:30.597] of those products.
Tom: No. And you've done the research, and you've determined, I know from reading your books that trout lose their UV vision once they get to be, what? Three inches long or 4 inches long?
Jason R.: Well, you are well-informed.
Tom: Well, I read your books, Jason.
Jason R.: Well, you're right on the mark. And a lot of that came from one of the leading researchers in trout vision, Dr. Flamarique. [00:48:00.562] And I had many discussions with him. He actually even proofread that book for me...
Tom: Oh, wow.
Jason R.: ...just to make sure that that it was... And I offered to take him fishing, too, but I still have yet to do that, so I have to probably reach out to him again. But a lot of the material came from some of his and his colleagues' research, and it really showed the very low role that UV sensation and UV perception plays in trout vision. [00:48:30.725] They really don't use it, as you said, much beyond a couple inches in length. And there was some early studies. Some of the confusion I think that came into our sport was presented from some of the earlier research that looked at some very, very immature salmonids. And they did see some degree of UV light sensation. And that would be a plus [00:49:00.765] for them, you know, very small trout that are eating diatoms and phytoplankton and zooplankton and stuff that would give them an advantage to be able to see maybe a birefringent effect to identify their very, very small food types. But that sensation is lost. Any ability to perceive ultraviolet light is, you know, mostly gone throughout the rest of their life. And [00:49:30.488] it also makes sense, too, because the lights that we perceive are all based on wavelengths, and the wavelengths, those types of wavelengths are not transmitted well in freshwater anyway. So, ultraviolet light doesn't go very far in its transmission in freshwater.
Now, in the marine situation, the saltwater environment, ultraviolet light probably plays a more important role, and some of that research is probably still out not having [00:50:00.673] been completed on the importance of ultraviolet light for, you know, marine fish in that type of an environment.
Tom: So, it may have some application in saltwater fly-tying.
Jason R.: Probably does. My suspicion is it probably does. And I've been away from that part of the research for a bit now, so I'm not as familiar with some of the more current studies that might have been out there. But, you know, when I was really heavily into, you know, [00:50:30.814] the visual aspect of fish, there was some speculation and probably a little more than speculation that marine fish probably had a larger role of ultraviolet light in their feeding.
Tom: So, how does a trout's perception of surface food versus subsurface food change based on the way their eye is structured and, you know, how they see?
Jason R.: Well, interesting. [00:51:00.139] Their eye shape is very unique as well. We have a very circular spherical orbit to our eye. And theirs is very elliptical, and they don't have a macula, which is a concentration of receptors that we use to do things like reading, or tying flies, or trying to thread 7X into a size 22 hook, you know, when we get into some of those [00:51:30.424] really detailed visual challenges, and we have an area of very densely concentrated receptors in our retina that we can focus on. But trout have a more evenly distributed arrangement of receptors throughout the retina. And with this elliptical eye, they have different focal lengths because of the shape of [00:52:00.493] that orbit. And so, they can be looking in perfect focus at a mayfly 3 inches in front of their nose, but they can see in perfect accuracy off to the side. So, it'd be like you reading the newspaper and recognizing someone that came through the door nearly behind you at the same time, and you could read a billboard sign to your side while you read [00:52:30.370] the newspaper in front of your nose.
And so, that makes trout really hard to sneak up on, you know, even though we think they're looking at that mayfly, but boy, they're looking you right the eye, to the side as well. And so, that is a tremendous, you know, advantage to them because they grow up as prey, but they turn into predator, but they never lose the visual capacity of a prey species like a horse or [00:53:00.152] a deer that really looks to the side. They also have the predator's vision like an owl that looks straight ahead. And so, boy, I'll tell you what, it makes them a worthy adversary, but it also helps in their feeding, back to your original question. You know, when they're looking up at their prey, they can see pretty much the whole entire underside, the footprint of that as it dimples the surface of the water, [00:53:30.699] but then they also have an upward-looking window that they can look through and see the world above. And, oftentimes, they'll hold that prey right in the edge of that window, and it acts like a natural magnifier. And it can almost look around to the top. So, I've got some photos, I'll post those on my Instagram account of how trout will hold a bug or [00:54:00.433] a fly at the edge of that window using nature's magnifier, and they can literally see the full top of your dry fly. We didn't use to think they could, but they can. And I tell you what, Tom, I think they could count your hackle wraps on your coat.
Tom: So, they move their position to keep that object in the edge of the window?
Jason R.: If they're really studying it, yes, they will.
Tom: Interesting.
Jason R.: And again, you'll see that with your dry fly when they're really just kind of floating underneath [00:54:30.095] that dry fly for a few seconds. And I think they're both looking at the color as we described before, but I think they're using that magnifier to check out your tying skills.
Tom: Fascinating. Wow.
Jason R.: Yeah. It's pretty cool. But, yeah, they also see, you know, because the rest of that undersurface of the water that's not the window, the transparent window to the upper world is a mirrored reflection. [00:55:00.398] So, as the fly passes over their head before it gets into the window, they can still see in the mirrored reflection, they can see the top of your fly, too. So, they do have a, you know, pretty accurate ability to discriminate and decide what to eat.
Tom: Now, how about when they're feeding underwater, when there's nymphs and a lot of debris floating by and they're distinguishing between food and not food. How [00:55:30.600] does their vision differ there?
Jason R.: Well, I think they make some mistakes.
Tom: I hope so.
Jason R.: [inaudible 00:55:36.883] Yeah, I know, right? If it weren't for a few mistakes, we'd be out of business.
Tom: Yeah. Really.
Jason R.: Yeah. But they obviously... I mean, you know, you look at some of the stomach contents, you'll see bits of debris, you'll see wood chips, you'll see cigarette butts and stuff like that. They're curious, too. It's just like a baby. They put everything in their mouth, you know, but they can chuck it out pretty [00:56:00.627] fast, too. So, obviously, there's some inquisitive curiosity with it, but they're pretty successful with it. It's amazing how successful they are when all the food is whisking by. It'd be like trying to snatch a cheeseburger out of all the debris that's whisking by in a tornado. So, I don't know how, but they really are pretty successful. But they do rely [00:56:30.545] on that search image. They can go through that checklist pretty quickly with approaching food types and they can, you know, decide to eat or not eat very, very quickly. It's pretty amazing.
Tom: Do you know how far, let's say, in clear water, clear water, a size 12 mayfly nymph, you know, if there's not a lot of bubbles [00:57:00.838] in the water, how far away can they see that mayfly nymph from?
Jason R.: Boy, that's a good question. I'm not sure I even know the answer to that. But I know you see the move to food well in advance of the arrival of the food sometimes. You look at some of the underwater footage, and I'm a big fan of one Ozzie Ozefovich as well, Underwater Oz, they used to call them. And he had a lot of underwater videos [00:57:30.263] of trout in different situations and feeding. And it was shocking really how well they could see, and at fairly decent distance, I think as well.
Tom: Do you think they can see floating objects from further away because, you know, if it's in the film like a grasshopper, they can see a floating grasshopper further away than they can see a sunken grasshopper?
Jason R.: Well, they're gonna see [00:58:00.861] everything that breaks the surface of the water from distance because that's gonna be in the mirrored part of their upward look. You know, the window part doesn't occur until it gets pretty close to them. It's based on the depth they are and the distance they are from the surface. But the window can be quite small in shallow water. And so, when something's floating to them, you know, in a current, they're gonna see what breaks the surface. [00:58:30.277] They're gonna see the footprint, essentially, of our fly. And that is just a myriad of trapped air bubbles. And looking at photos, I'm sure you've seen these as well, some of the still photos of, like, a fly or a bug that's dimpling the surface before it approaches the window. It's just full of tiny little air bubbles, which means that the footprint, how our fly rests on the water and breaks the film, that pattern [00:59:00.398] of air bubbles has gotta match the naturals.
I had one time, I was fishing the [inaudible 00:59:05.669] river, and it was a beautiful, Green Drake spinner fall, and there's rising fish all over. And I'm throwing a borcher special, which is a wasn't a parachute style, it was actual collared style. And I just wasn't getting any love at all, you know? And then I watched one of these go by, and they were so low in the film [00:59:30.637] with their big body and their outstretched wings, and I'm like, "Hmm." And so, I put my fly next to one, and it just rode so much higher. And so, what I did is I took my scissors and I cut off the underside of all the hackle wraps around the neck of that fly. I just cut them flush. So, that allowed that fly to settle down on the surface much more effectively resembling the natural. And I started catching fish right away. [01:00:00.350] And I think it's just because the pattern of how that fly rests on the surface is so obvious compared to the natural because of all these little bubbles that it traps in the materials. And it's just like it's very obvious that this is an imitation. And when you make that kind of an adjustment, looking more like the natural, it can be highly successful.
Tom: Do you wanna talk a little bit [01:00:30.636] about the size of approaching trout and the size of the window, and the fact that... I tell people this all the time, and I get questioning looks that you can get closer to a trout that's in shallow water than one that's in deep water. You wanna talk a little bit about that?
Jason R.: Yeah, you're right. And the window is much smaller in shallow water than when they are at depth. And they live in...if you could imagine this, they live in [01:01:00.530] a room with a mirrored ceiling that is overhead, but it has one single circular transparent skylight that allows you to look up through and see the sky or the birds or the trees overhead. But instead of just having one cylindrical view, it's almost like having a fisheye lens because that lens captures not completely 180-degree [01:01:30.491] panorama of the world above, because we have about a 10-degree angle of drop off on either side. And so, that drop-off is what we could use to hide under because, you know, I've got some photos, too, that show an angler about 10 feet from a trout. But because of this fish eye lens effect, as they see us, it looks like we're looming over them ready to jump on them because it just really [01:02:00.846] distorts our image. It's crazy.
You can just see that it looks like we're ready to pounce on them, even though we're 10 feet away. But by crouching down or being a little further away, we can get more and more of us beneath that 10-degree angle drop off because that 10-degree might only be a few inches, you know, maybe a foot or two from the trout. But if you get 30 feet away from the trout, that 10-degree drop-off could hide 4 feet or more. And so, if we can crouch [01:02:30.726] down, we can get below that effect, and we can be much less perceptible to the trout. So, definitely, it all goes right back to our stream craft, you know, what we can do. You see some of these competitive anglers that are really, really getting low. And even I fished with Joe Humphrey several years ago, and he was probably already close to 90 at that point, but God bless him. He got pretty low when he was approaching fish [01:03:00.260] because he's a good fisherman and he knows stuff, too.
Tom: He's amazing.
Jason R.: Yeah. And so, that can really help us, though, you know, when it comes to stream craft, just staying out of their visual window.
Tom: Speaking of that, we should talk about something that I recently wrote about in "Trout Magazine," the "blind spot" behind a trout.
Jason R.: Yep. We have a blind spot, too, but we don't really pay much attention [01:03:30.412] to it. If somebody comes up from directly behind us, we're not gonna know they're there unless they make some kind of noise or some kind of a movement that does play into our visual field. So, we're limited as well. But we've learned to adapt to it. You know, we face our food, if you will, and so does the trout. They do have kind of a more panoramic [01:04:00.493] view than, obviously, that we have because we have forward-facing eyes where there's our position, you know, to take advantage of their life. As a prey species, they can really see quite a bit around to the sides and not quite fully behind them. But it's not bad. But the key to that is what can we learn from that as anglers to help us is that trout are gonna be facing up current, [01:04:30.645] and if we can approach them from a downstream approach angle, we're gonna be less visually offensive to them, and less visually obvious, for sure.
Tom: Yeah. Let me just give you my theory that I wrote about, and you tell me if I'm right or wrong. So, my premise is that they don't have a blind spot. A feeding trout doesn't have a blind spot because they're always moving from one side to the other. And then [01:05:00.672] that peripheral vision is gonna be swiveling into what was a blind spot when they were stationary in the current. But since they're moving back and forth, they don't have a blind spot. However, behind them, they're using their peripheral vision instead of binocular vision. So, we are less likely to be noticed. And that's why we approach them from downstream.
Jason R.: Well, that's a really [01:05:30.637] good point. I like all those points you made there. Monocular versus binocular vision is a big thing. You know, the overlap, you know, what we call binocular vision is when both eyes can see the object is straight in front of them for maximal depth of field, for in-depth perception for feeding. And then they do have not fully, but they do have a pretty wide angle to both sides. And I think you're right. The blind spot [01:06:00.298] has probably been overstated because I've never heard the theory that you propose, though, about their movement from side to side. That really makes a lot of sense to me.
Tom: Well, yeah. If somebody's trying to sneak up behind you and you're facing forward, yeah, you're not gonna see them. But if you're looking to one side then to the other, you don't have really have a blind spot, you'll notice them.
Jason R.: You're right. Yeah, I like that, you know, and I think that does another thing that makes them so [01:06:30.706] worthy an adversary. Right?
Tom: Yeah. But I still think...
Jason R.: I'm gonna have to steal that, Tom. I'm gonna steal that, that theory of yours because I think it really, it's very logical. Makes a lot of sense.
Tom: Wow, I taught something to you. That's a...
Jason R.: Come on.
Tom: That's a shocker.
Jason R.: You're killing me.
Tom: But... Oh, what was I gonna say? But we still have better...despite the fact that I don't believe they have [01:07:00.659] much of a blind spot at all. The fact is we can still get closer to them by coming up behind them.
Jason R.: You're right. You're right, and I do think there is, you know, the difference between monocular and binocular vision. And I think, you know, they won't have much depth perception, you know, to the back. So, I think it makes sense to take that approach. [01:07:30.619] We're certainly gonna be a lot less visually offensive to them.
Tom: It seems to be.
Jason R.: [crosstalk 01:07:35.988] backing up, and also, you know, looking at how deep they are. And if they're in deeper water, boy, that window, as you said, gets really wide and large, and their fisheye lens then is much bigger that they can see the surface. And it's really hard, even as low as you can get when they're in deeper water, you're still probably gonna be apparent [01:08:00.879] to them.
Tom: Yeah, I think that sometimes when they're in deep water, they feel a little more comfortable, and we could probably get close to them.
Jason R.: Oh, for sure.
Tom: But that's...
Jason R.: Yeah, we call that confidence in position. And confidence in position means that they are less vulnerable to being the source of predation like overhead birds, they never lose their fear of overhead birds and predatory birds. And when they're in deeper water, they're much safer. [01:08:30.751] And as a result, because of their higher level of confidence in their safety, we can get a little bit closer as long as we don't just rush in and startle them. The depth of the water raises their sense of security, if you will, and we can get a little bit closer because of that. And also, rough water, really rough turbid water, you know, any of that type of a situation raises [01:09:00.403] their confidence in their safety, too. That's why short-range nymphing methods like Jack and Polish nymphing work well, but if you used them in slow-moving gin-clear water, you're never gonna catch them because being that close, you're gonna scare them all away. But in a confident position where they're feeding with confidence in their security which would be depth, darker water shade, rough water with broken surface, all those [01:09:30.194] are ideal situations for short-range of fishing techniques.
Tom: All right. So, of course, this is gonna bring up all kinds of questions from people about their hearing and their use of the lateral line and their sense of smell. So, we're gonna have to do another podcast because I know they're gonna come up.
Jason R.: Those are pretty deep wells of information as well. We could get down there [crosstalk 01:09:58.107].
Tom: Maybe we'll treat them one [01:10:00.092] at a time. Although scent, we could probably pass by pretty quickly because we're probably not gonna be scenting our flies.
Jason R.: Well, I tried that, to be honest with you. When I researched the book, I took minnow skins and tried to put pheromones and attractors and saturate my flies. And I went to great lengths in researching some of this material. And honestly, in a moving water [01:10:30.214] environment, obviously, it plays a big role in catfish and some of these fish that feed in very stained and turbid water, muddy water, as they use their whiskers and their remote sensors on those whiskers to forage. But for a trout that live in a moving water situation, you know, for feeding, anyway, I don't think the sense of smell is largely [01:11:00.753] engaged.
You have to remember that trout are visual predators. You know, they're like a mountain lion or a wolf. You know, they do have an accurate sense of smell, but they are relying on their sense of vision really to discriminate their prey. That's why that fourth item on the search image is so critical, movement. Movement, like, if a mountain lion is stalking, you know, or hunting, and all of a sudden that deer twitches a tail or an ear, [01:11:30.336] boy, that like laser focus, that mountain lion's right on that animal, they see that. Those movements are very, very obvious. And, you know, I think sometimes we need to make sure that we're giving our flies the right movement and the right animations and things like that, that all can help our success.
Tom: Yeah. Absolutely. All right. What else did we miss on vision? Talked about the window, talked about color vision.
Jason R.: [01:12:00.609] I think we did like three or four chapters on vision in the book. And so, there's a lot of stuff that you just don't have time to cover. You know, some of it is from our perspective, some of it's from the trout's perspective. It's like how do you, you know, kind of discern where that trout is when you have refraction and the beam bending? You know, [01:12:30.697] and when, you know, you tend to misestimate the depth and position of trout subsurface, we usually end up fishing over their heads and too far away because of where we perceive the trout, because of the refraction of light, the bending of light, and where that trout actually is. So, there's a whole range of things that we probably don't have time to do in a single podcast. But, you know, I can post some of that stuff on my social media as well for people to take a look at. [01:13:00.564] And certainly, they can do some reading on their own as well, if they have more interest.
Tom: Yeah. I mean, I thought we would limit it to actually trout's vision and, you know, how they use it and how we can use it to our advantage. You're gonna make me pay more attention to color and flies now?
Jason R.: Well, you know, it's one of those four. It's an important one. Remember, if they came up to your fly to within a foot and turned away, you [01:13:30.012] already sold them on the fly itself and on the size and shape.
Tom: And it probably wasn't dragging if they at least came and looked at it.
Jason R.: Could've been. But usually, if a fly is dragging, they won't even get close because that's obvious from afar.
Tom: Right. Yeah.
Jason R.: That is usually pretty evident. And, you know, I just did a whole program, you know, on dry flies and dry droppers, and we really did a deep dive into drag and how we can minimize it. And some of that stuff is on [01:14:00.540] my Instagram account as well. Really, that's crucial from an angling perspective of all the things that we can do to minimize drag and to add lifelike movement and animation.
Tom: I'm gonna have to get you on like a half dozen podcasts now. You got all kinds of good ideas coming out here.
Jason R.: Well, I enjoy talking with you, Tom. Like I said, it's an honor to be here. I mean, you are one of the mainstays of education [01:14:30.546] in our sport. I admire your work.
Tom: Well, if I am, it's because I make people like you available to the public. Right? No, seriously.
Jason R.: One of the quotes I used was in the book that...I can't remember which book it was, but I think it was Isaac Newton said that if I can see far into the horizon, it's merely because I stand on the shoulders of giants.
Tom: Yeah. Well, Jason...
Jason R.: We all stand on the shoulders of giants, don't we?
Tom: [01:15:00.655] We sure do. Yeah. We sure do. Well, I wanna thank you for exploring the topic of trout vision with us. And I'm sure this is gonna be a popular podcast, so people are gonna ask me to have you back, and we'll do some more. I got a bunch of them I'm thinking of now. So, anyway, you know, I love people like you that, you know, really think about these things and geek out on trout behavior, and [01:15:30.517] it's always fun and always fascinating.
Jason R.: Yeah. That's what we do. I mean, you sit down, you know, with a couple of other anglers, that's the beauty of, like, going to the shows and hanging around after the show's up because these discussions around the bar room at night, sometimes we get pretty esoteric, but boy, they can be really enlightening, and we learn so much from each other, I think.
Tom: Yep. We sure do. We sure [01:16:00.108] do. Every time we meet somebody else, right? Even if it's a beginner. I've learned so much from people who just started out because they don't have any preconceived ideas, and they come up with this crazy wild idea that I never would've even considered. And it works. So...
Jason R.: Absolutely. Yeah.
Tom: We learn something from everybody we come in contact with.
Jason R.: You're right.
Tom: All right, Jason. Well, thank you very much. Do you want to just list the books that you [01:16:30.811] have? I know people are gonna be interested. List the books that you have on this topic and who the publisher is so people can find them.
Jason R.: Absolutely. I'd be happy to. I should also share my Instagram account, too, if I'm referring to it. It's @jasonrandallflyfishing on Instagram. And I do try to post... I have the obligatory pictures of my grandkids and my dog, everything. So, you're gonna get some, but I try to post a lot of the educational material [01:17:00.364] that we're referring to there as well.
Tom: Great. Cool.
Jason R.: And then I field questions through that as well so people who wanna open up a discussion, you know, then other people can chime in, or sometimes they will just send me a message, and that's fine too. But the first three books that I wrote were with Jay Nichols at Stackpole. And he had a tremendous concept for a kind of a reference set for our sport of, [01:17:30.551] you know, more of a scientific base literature that people could refer to. Maybe certainly not for a beginning angler, somebody that maybe needs to spend more time focusing on some elementary skills. But, you know, it was a concept that we kind of developed together, but he gets a lot of credit for it. Just having a real deep dive into certain topics within the sport, and that's called [01:18:00.855] "The Fly Fisher's Guide Trilogy." So, the first one was "Moving Water: A Fly Fisher's Guide to Currents." And it studies, you know, flow dynamics and food distribution where the food ends up in rivers, and how trout relate to current, and how they feed in current, how their bodies have adapted to it. And it really is a deep dive into hydrodynamics and why pocket water is so difficult to fish and, you know, that type of thing.
And then [01:18:30.347] the second book is called "Feeding Time: A Fly Fisher's Guide to What, Where and When Trout Eat." And it's a really deep dive into trout feeding behaviors and mechanisms and different strategies they employ at different points in their life, you know, as they feed. When they're really young, they're herbivores, they're eating, you know, algae and plankton and things like that. Then they shift to being a first-level predator, eating invertebrates. [01:19:00.757] And then finally, they shift to a second-level predator where they eat other predators. And they'll eat other trout or other fish, and they become piscivorous, or, you know, what some people would term as meat eaters, eating those big meaty-looking flies.
And then, the third book in that was called "Trout Sense," and that's a fly fisher's guide to their sense of vision, hearing, and smell. And that's pretty much the one that we worked off of mostly today. [01:19:30.713] And that was the trilogy. The fourth book was called "Moving Water..." I'm sorry. No, that was the first. The fourth book was called "Nymph Masters" and that was fly fishing secrets from expert anglers. And actually was a collaborative effort from some of the greatest nymph anglers in our sport. People like, you know, Gary Borger and George Daniel, Landon Mayer, Ed Engle, Lefty Kreh, and Ed Jaworowski did the casting. And we just shared different ideas [01:20:00.454] and tips from 10 different nymphing, you know, experts that all have kind of a different approach to that area of the sport. So, that was really fun. Got to fish with some great fishermen, and I learned a lot, you know, from all the books. You know, I think you'd dive into something like that, you're gonna end up learning a ton.
Tom: Oh, yeah. Absolutely. All right, Jason, well thank you again. Really [01:20:30.886] appreciate it. This has been fun, and fascinating, and educational, and thanks for taking the time.
Jason R.: Well, thanks, Tom. I enjoyed it.
Tom: All right, I will talk to you soon.
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