It was a red-hot summer day on Lake Ray Roberts, in more ways than one, I might add.


With temperatures heading for triple digits that afternoon, catching any decent numbers of largemouth bass would seem to have been nothing more than wishful thinking.


But my good fishing buddy Steve Hollensed, then an environmental science teacher at Gunter High School and now an Orvis endorsed fly fishing guide on Lake Texoma, had other ideas.


Before we retreated for the AC and some ice cold lemonade, a good number of suspended Ray Bob largemouths had fallen victim to our soft plastic jerk baits fished several feet below the tepid surface of the 25,600-acre reservoir that will serve as the competition site for the Bassmaster Classic in March 2021.


On the boat ride back to the Buck Creek ramp that sizzling afternoon, I could only shake my head in amazement as Hollensed delivered the piscatorial goods once again. As his Flywater Angling Adventure website (www.flywaterangling.com; 903-546-6237) and Facebook photos attest to, Steve is one of those guides that always seem to be a step ahead in the fishing game.


In a conversation about that idea that I once had with Dr. Bill Harvey, a retired Texas Parks and Wildlife Department fisheries biologist, the concept of what makes good guides like Hollensed thrive no matter the water body they are fishing became a little clearer.


According to Dr. Bill, the good ones can find catchable fish no matter what time of the year it is. And that ability is not always because they’ve got the best electronics or the latest, greatest lures in the boats either.


Harvey, as I learned from the interaction we had during my days with ESPNOutdoors.com and as Fishing Fundamentals columnist for a Texas outdoor magazine, was much the same — he knew how to find fish whether that was on a Gulf Coast saltwater flat filled with tailing redfish or on an inland bass lake.


Why? Harvey shrugged his shoulders and said that he had observed over the years that most successful anglers simply use their noggin as much as they do their tackle box.


"I think when you actually talk to them (about their angling success), they’re always really thinking about it," said Harvey, now a talented nature and wildlife photographer living on the Lone Star State’s middle coastline during his retirement years. "When they catch that next fish, they always seem to be thinking about why that just happened right (there)."


And in the end, that thinking process of successful anglers usually ends up with them figuring out — whether they know it or not — the biology that drives the targeted fish into places where their daily and seasonal needs are met in the most energy efficient manner.


Take the largemouth bass for example.


"Bass are ambush feeding fish," Harvey explained. "God just made them that way. They’re perfectly designed for ambush feeding by sight, sound, and by hiding. If I know that about them, I have to assume that they’re going to do that – ambush their food. Their biology drives them. They are where we catch them for a reason because they’re biologically driven to be there."


One way to see this principle illustrated is to watch what summertime bass do on many Texas lakes and reservoirs.


"They like to move up in the shallows in the summer and you’ll get that early bite in shallow water," said Harvey. "They’ll move up there early in the morning because there is more structure there for a fish that’s an ambush feeder (to hide in). They’ll move up into that area where other fish will have more of a problem seeing them."


That helps to explain why a good place to target June bass early in the day is around shallow timber, the edge of grass beds, and near skinny water docks. I proved that this idea works earlier this week, catching a couple of largemouths in water measured by the inch.


As the mercury climbs along with the sun’s angle on a summertime day — including my trip last week — that all changes as bass seem to vacate the shallows. Why? In the former TPWD biologist’s experience, it’s not because they need their Ray Bans.


"I always thought they were moving off because they were light sensitive," said Harvey. "If that was the case, then how would they stand being up in that shallow water all of the time while they’re spawning. Nah, they’re moving off because they have lost their light advantage."


In other words, for an ambush predator often looking for that next meal, they never really stray too far from a lake’s proverbial refrigerator even if its location changes throughout the day.


Aside from understanding the biological forces at work that will cause certain species of fish like largemouth bass to be certain places at certain times of the year, Harvey noted that finding fish also boils down to understanding what their basic daily needs are and where those needs are most easily met at any given time.


"It ain’t rocket science," Harvey chuckled. "Good tournament anglers, they’re always talking about fishing a pattern. What they’re actually searching for is that optimal intersection of oxygen, temperature, food, and light."


Find that spot where the four basic daily needs of fish are met in the most efficient and energy conserving manner, and you’ve likely found a supply of fish according to Harvey.


"Most of their yearly life is spent in a feeding mode that allows them to gain the most amount of energy with the least amount of effort," he said. "For fish, life is all about energy in and energy out, or finding the maximum amount of energy intake with the least amount of energy being expended. In other words, they must maintain a positive energy balance."


"If I’m not catching fish, I start thinking about that. That place where fish will have that positive energy balance will be at the intersection of those four variables of oxygen, temperature, food availability, and light."


Even in the dead of summer, these principles are at play on your favorite bass water. To help demonstrate this idea more, Harvey offered this illustrative example.


"I could run to McDonald's and get one french fry and run home and eat it and then come back and do the same thing over again," he said. "But I’d probably starve to death because even though there are plenty of french fries there, I’d be expending far too much energy to get them and eat them. It would make far more sense to stay in the parking lot closer to the supply of French fries."


How do you put these ideas into play on your next summertime bassing trip?


"Pay attention to where you catch fish in one place," said Harvey. "It’s likely that there will be another one in a similar place."


In the summer months, that can mean shallow water early and late, shady docks and tire reefs later in the day, and on certain lakes like Ray Roberts and Fork, on underwater structure like humps, drop-offs, and other features that will hold schools of offshore bass.


The bottom line here is simple — no matter the season, one bass catch can offer up clues about where, when, and how your next catch is likely to occur.


"Where there is one, there’s often more than one," said Harvey. "Sometimes, when you throw a lure or fly in there, several will follow it out until one takes it. When one grabs it, the rest will sit right there and watch and kind of say, ‘Hey, where did he go?’ Often times, you can cast right back just short of the area where a fish was hooked and pick up one of those fish that are still lingering in the area."


If you’ve got a summertime bass fishing trip planned over the next few days, be sure to pack more than the latest fish catching lures in your tackle box.


Because on most days, understanding a little simple biology and using some angling brain power can go a long way in catching fish, far beyond the usual questions asked dockside of what lure and what color.


Just ask Dr. Bill.