“A very cool extra that can make a day on the stream more memorable.”
For trout fishermen there are a variety of highlights that can make a trip especially rewarding. Catching a trophy-sized fish from a given stream is usually the first instance that comes to mind. For others, it’s matching the hatch precisely and getting stubborn fish to rise to a particular fly, maybe even a homemade version.
But there’s another unique event that is universally regarded as an anomaly that is interesting and never disappoints. Tiger trout, particularly those that are wild and not hatchery bred, are a very cool extra that can make a day on the stream more memorable. Their colors and patterns blend in a way that satisfies the eyes and begs for the camera.
Tiger trout, as they are affectionately known as, weren’t always present in the wild. The invasive brown and rainbow trout weren’t brought over from overseas until the 1800s so the possibility of species intermingling wasn’t even possible. Slowly, brown and rainbow trout fell into favor with anglers across North America, and thus they were quickly stocked in waters anywhere they could survive. With the newly-introduced, invasive trout populations taking rampant hold in streams, rivers and lakes across this side of the world, the fight was, and still is on, for native brook trout. The natives must compete with the outsiders in the best runs, riffles and pools on any given water.
Over the last 100 or so years, brook trout have lost their much of their standing and disappeared from many waterways causing alarm in the freshwater angling community. The existence of tiger trout, despite being an indicator of competition on a stream, is a pretty neat outlier of what happens when two species of trout are attempting to procreate on the same real estate of a streambed. Redds, where new trout life begins, combine the genetic material from both species. So why aren’t more tiger trout caught where trout diversity occurs in the same pool or run? The fertilization has a dramatically diminished success rate that limits proper production of healthy tiger trout. Therefore, the tiger trout make up a minute portion of the trout population on a stream.
According to online source material (U.S. Geological Survey, Edwin Pister’s “Wilderness Fish Stocking: History and Perspective” and Rick Windham’s “What is a tiger trout?”) naturally occurring tiger trout were an impossibility prior to the 19th century as the native range of brown trout in Eurasia and brook trout in North America do not overlap, therefore the species could never have encountered one another in the wild. When the widespread stocking of non-native gamefish began in the 1800s, brown trout and brook trout began establishing wild populations alongside each other in some places and the opportunity for hybridization in the wild arose. Instances of stream-born tiger trout were recorded in the United States at least as early as 1944 and, despite being exceptionally rare, they’ve been documented numerous times during the 20th and 21st centuries.
Tiger trout result exclusively from the fertilization of brown trout eggs with brook trout milt, as brook trout eggs are generally too small to be successfully fertilized by brown trout milt. Tigers are known as intergeneric hybrids as the two parent species share only a relatively distant relationship, belonging to different classes within the salmon family. Because brook trout and brown trout have non-matching numbers of chromosomes, even in cases in which brown trout eggs are fertilized by brook trout in the wild, most of these eggs develop improperly and fail to yield any young.
Within The Fisherman’s readership region, wild tigers are most commonly that of a brook and brown trout. The browns are encroaching on brook trout streams and dominating favorable feeding locations. Often, it’s only a waterfall or impassable, natural barrier that keeps the brown trout from pushing to the headwaters hence threatening the natives. Where the brookies and browns coexist, there’s a reasonable chance that an angler can encounter a tiger trout.
The best way to target tiger trout is to fish tiny, small and moderate-sized streams where both naturally-reproducing species are present. If there are reliable reports that wild tigers were caught on a particular stream, there are sure to be more. The lower and middle portions are often the best spots to really target. Again, natural barriers may halt the expansion of brown trout toward the head waters so once a fisherman begins catching all brook trout, the odds of hooking a tiger trout diminish to near nothing.
Tactics are the same for those looking to score a tiger trout. The same flies, lures and approach will provide an element of chance. Then it’s kind of like a lottery ball, will one get bit by the tigers? Tigers born from brook and rainbow trout are more common in central and upstate New York along with New England. There, the wild rainbow population is greater than mountains and valleys closer to the coastline.
For those that have a wild tiger on their bucket list, each state lists Class A waters and will state where multiple species exist. This is the ideal starting point.
