Range of the Rio Grande
Here's a short primer on the lives and loves of Texas' original wild turkey.
By Larry D. Hodge
The wild turkey has been called the most challenging of North American game, and having been played the fool by more toms than I care to admit, I would not dispute that claim. But the Rio Grande subspecies - found in its greatest numbers in Texas - is much more than just a difficult quarry. It is a bellwether of the environment and the crown jewel of the Texas outdoors. If there is a prettier sight than a gobbler strutting in a field of bluebonnets, I have yet to see it.
I hunted my first Rio Grande in the heart of its range, the Texas Hill Country. So adaptable is this species that one can find them from northern Mexico to Kansas. Even though sound wildlife management practices do not include introducing species into areas outside their natural range, birds transplanted from Texas roam the slopes of Mauna Loa in Hawaii, and small numbers occupy limited ranges in other states. Yet their natural range is narrow, occupying roughly the southern half of this country's plains region in an area wedged between eastern forests and western deserts and mountains.
For all their adaptability, Rio Grandes need trees but not too many trees, open country but not too open, dry but not too dry. Country that receives between 20 and 35 inches of rainfall a year suits them best, and they don't do well where snow frequently covers the ground. In Texas they can be found roughly west of Interstate 45 and east of a line from Fort Stockton to Amarillo, although I've seen a flock roaming downtown Balmorhea and have photographed Rio Grandes crossing Calamity Creek on the Elephant Mountain Wildlife Management Area south of Alpine.
Appropriately for a bird named for a river, water plays a major role in the life of Rio Grandes. Rios prefer brushy areas near streams and rivers and appear, like white-tailed deer, not to have expanded into much of their present territory until after human suppression of fire enabled trees and brush to spread far from watercourses. They roost in the largest trees they can find, which also tends to concentrate them along streams. Bottomlands also generally provide better and more dependable food sources. And nesting hens rarely brood farther than a quarter to half a mile from water.
Besides the spread of brush into grasslands, two other modern developments led to the expansion of the Rio Grandes' range. Turkeys followed in the tracks of cattle as Texas ranchers spread westward and drilled wells to provide water for livestock. But perhaps the oddest thing to benefit Rios seems at first glance to be likely to do just the opposite: oil wells. As oil fields in West Texas sprouted derricks and electric transmission lines carrying power to the pumps, turkeys found predator-proof roosting places where none had existed before, and they moved right in. In some cases turkeys roost on power lines and oil tanks in such numbers as to be a nuisance, though occasionally one makes the mistake of touching two wires at once and pays the ultimate price.
While availability of water for drinking partly determines where turkeys can live, ultimately their survival depends on rainfall. Into every turkey's life some rain must fall - and it must come at the right time. Like all creatures, turkeys need food, water, cover and space in order to live, and three of those four essentials depend largely on rainfall - especially late summer and early fall rains. Plentiful rains, often from hurricanes and tropical storms, set the stage for good times for turkeys. Dependence on water begins early: Eggs are 71 percent water, and each contains just enough liquid - given the proper weather conditions and care from the hen - to develop its embryo.
The ideal conditions for turkey reproduction occur only in spring. At this time of year, moisture from fall rains lingers in the soil and brings on a bumper crop of forbs (weeds and wildflowers). Keen observers know that a good winter wheat crop in the Rolling Plains and abundant wildflowers in the Edwards Plateau generally accompany a good hatch of Rio Grande poults.
Heavy vegetative cover promotes nesting success by concealing eggs from predators and producing an abundance of insects. Turkey hens can obtain the high level of protein necessary for best reproduction from only one natural source: bugs. Laying hens get the calcium they need to produce eggshells from snails that feed on weeds. Poults depend almost exclusively on insects during the first weeks after hatching. One researcher estimates that each two- to three-week-old poult consumes 3,600 insects daily. Watching a flock of poults chase insects gives a whole new appreciation for the expression "grab a bite to eat."
An egg is an amazing thing, a self-contained life support system that carries within its protective wall everything needed to create a new turkey. Once an egg is laid it needs only two outside ingredients to carry out its mission: heat and humidity. And therein lies the problem - and the magic.
Turkey eggs remain viable only within a fairly narrow range of temperature. Hens lay one egg a day, sometimes skipping a day, until the clutch numbers eight to 12 eggs. During this time the hen is away from the nest most of the time and continues roosting in a tree at night. A late spring cold snap can chill the eggs and compromise hatching success. An early warm spell can begin embryonic development before the hen starts brooding. Development of the embryos inside the eggs does not typically begin until the hen begins nesting full time and maintains a fairly constant temperature of about 99.8 degrees and relative humidity of between 55 and 60 percent. Under these conditions the eggs will hatch in 26 to 28 days - if all goes well. Motherhood is tough on turkeys. By one estimate between 50 and 70 percent of turkey hens and 60 percent of poults are killed by predators during the time the hen spends her nights on the ground incubating eggs and caring for poults too young to fly.
Even though the eggs are laid as much as two weeks apart, they all hatch on the same day. This improves the odds of survival for the poults. But how does the hen manage to pull off this minor miracle? She may actually have nothing to do with it at all. Researchers at Texas A&M University believe that the embryos inside the eggs communicate with each other by peeping and that the sounds somehow stimulate all the poults to break out of their eggs at the same time.
Sound continues to play an important role in turkeys' lives as they grow older. (Any hunter who has made the mistake of clicking off a shotgun safety within 50 yards of a turkey knows they hear as well as they see.) A hen molds her poults into a flock within hours after hatching by clucking almost constantly. She is the center of their universe, and her clucks, trills, purrs and putts keep them in close orbit around her. Oddly, hens do not recognize the voices of their own poults, but every poult knows the sound of its mother.
This ability to discriminate between the sounds made by different turkeys bears much import for hunters. On the negative side, turkeys probably can learn to recognize the calls made by individual hunters or perhaps even particular types or brands of calls. That's why it's commonly said by turkey hunters that you cannot own too many turkey calls. If one doesn't bring a tom within range, another might. Turkeys that are hunted hard may also become call-shy. On the positive side, using several calls in quick succession when hunting can sometimes convince an ambitious gobbler that several hens desire his company, and he may well come to investigate.
Getting a gobbler to come to you is the ultimate goal and thrill of spring turkey hunting, whether you do it with a gun or a camera. Toms gobble to advertise their location to hens, and the normal procedure is for the hen to go to the gobbler. However, patient hunters can make turkey behavior work to their advantage. As soon as turkeys fly down off the roost in the morning, gobblers begin displaying for hens and breeding receptive ones. Once the hens begin laying, they typically leave the gobbler during the middle of the day to visit their nests and lay. As more and more hens are bred - and in Texas about half of them are by opening day of the spring season - the gobbler will increasingly find himself alone in the late morning and early afternoon. A lonesome gobbler is a vulnerable gobbler. So that's why afternoon hunting can often be successful when morning hunting is not.
Within the limits of its natural range, the Rio Grande turkey is a remarkably hardy survivor. However, they remain totally dependent on human cooperation for their continued existence. Turkeys appeared in Texas some 11 million years ago, according to the fossil record, yet it took little more than a century of exploitation to reduce their numbers to a few thousand. In 1897 trapping was banned, but only for five months of the year. In 1903 Texas instituted a bag limit of 25 turkeys per day during a five-month season. Not until 1919 was anything close to the current bag limit imposed - three gobblers per season, compared to today's four. With determined habitat protection and improvement by private landowners, elimination of market hunting, restricted harvests and restocking efforts by TPW, Rio Grandes number more than 500,000 in Texas today - 50 times the number of turkeys of all species found in North America in 1900.
A persistent myths of American history is that Benjamin Franklin championed the wild turkey (the eastern variety, not the Rio Grande) as the symbol for the nation's seal. This was not the case, according to the definitive work The Wild Turkey: Biology and Management (Stackpole Books: 1992). Franklin did complain that the artist in charge of creating one of the early images of the bald eagle for the seal produced something that looked more like a turkey than an eagle, and in a digression forgivable of an old man in his dotage, went on to enumerate the bad points of the eagle and the good points of the turkey. But this was done in a letter to his daughter in 1784 - years after the eagle came to adorn the nation's seal.
The Rio Grande, however, because of its majesty, beauty and close connection to the state, might well be called the national bird of Texas.
Wildlife editor Larry D. Hodge has been chasing turkeys for 10 years, and he wishes he'd started sooner.
Talking Turkey
How much (or little) do you know about wild turkeys? Answer true or false to the following questions. Some of the answers may surprise you. But don't be a turkey and peek before answering!
- Turkey poults will only recognize the hen that hatched them as their mother.
- Turkeys carry a "map" of their home territory in their heads.
- You can tell a gobbler from a hen by looking at its droppings.
- It's easier to hunt turkeys from an elevated blind than by sitting in plain sight on the ground.
- Turkeys can swim before they can fly.
- The scientific name for the Rio Grande turkey, Meleagris gallopavo intermedia, comes from the fact that its range falls between that of eastern and western subspecies.
- Turkeys are native only to North America.
- Partridges, quail, grouse and pheasants are close relatives of the turkey.
- When feeding, a wild turkey scratches in the dirt once with the left foot, then twice with the right.
- Wild turkeys can live to be 10 years old.
Answers
- False. Poults will imprint on, or recognize as their mother, the first creature that provides them with parental care - even a human being. In fact, this is how some of the most detailed observational studies of turkeys have been carried out, by imprinting poults on the researchers. Even stranger, poults assign a sexual identity to "their" human during their first year of life and thereafter react to the person as they would to a turkey of the same sex.
- True. As a veteran turkey hunter once told me, "When you call to an old gobbler, he not only knows where you are, he knows exactly what bush you are behind. That's why you have to sit so still when hunting turkeys."
- True. This is very helpful when scouting. A gobbler's droppings are usually in the shape of a J or an L. Hen droppings are looped, spiral or bulbous. And while we're on the subject, did you know that turkey droppings include not only feces but also urine? As with reptiles, the "white stuff" in turkey droppings is urine.
- False, provided you wear camouflage and keep still. Most turkey danger comes from above in the form of hawks and owls, so they are extremely wary of movement above them, even the slightest flash of a face or hand in the opening of a blind. You can get away with a lot more movement - though still not much - at ground level.
- True. They can swim at the age of only three or four days and fly at about a week. This enables them to keep up with the hen when she crosses creeks. The bugs are always juicier on the other side.
- Close, but not quite. The intermedia in the name refers to the coloration of the Rio Grande's tail and rump feathers, which are lighter than those of the eastern turkey but darker than those of the Merriam's or Gould's.
- Again, close, but not quite. There are two species of wild turkey. The North American turkey has five subspecies (one of which is the Rio Grande). The Central American wild turkey, the ocellated, is the other species.
- True. All these birds are what are called gallinaceous fowl, which means they prefer to feed by scratching in the dirt.
- So say the experts. Hunters can use this knowledge to their advantage when calling gobblers by scratching in leaves to simulate a feeding hen, helping to convince a gobbler to show himself.
- True, but this is highly unusual. Most turkeys live only to age 2 or 3. A 3-year-old tom is a true trophy for a hunter and can generally be identified by spur length. Spurs over an inch long generally indicate a bird 3 years old or older.
