Attractive male turkeys use their genes better, study says

Four Phases Of Gobbler Season

Turkey breeding season progresses through definite stages in which turkey behavior varies considerably. The time when you hunt may coincide with any of these stages. Depending on the phase of the breeding period, turkeys may be more or less vocal, be alone or in bigger or smaller flocks, and be easier or harder to call.

Beginning in March and advancing through May in most areas, the stages of breeding season include the following: turkeys gathered in large, unbreeding flocks; toms recruiting hens; breeding flocks consisting of one gobbler and several hens; lone turkeys (gobblers abandoned, hens nesting).

Stage 1: Unbreeding Flocks
Before breeding activities begin, turkeys are gathered in large flocks with a mix of gobblers and hens. In these cases, every turkey within thousands of acres may be gathered in a single flock. Locating turkeys at this stage may be very difficult, but when you do, you usually hit the jackpot. You may top a ridge to find an immense flock with two dozen strutting gobblers. Turkeys, both hens and gobblers, are very vocal at this stage, but because there is so much competition with real hens, gobblers respond very little to calling.

A decoy helped this hunter bag his gobbler.

Innovative tactics must be used. Perhaps the most effective strategy during this period begins with monitoring the flock. Because it is so large, the flock leaves lots of sign and makes lots of noise. You may be able to pattern the flock's movements and find a good point to intercept the turkeys, or you may be able to locate the vocal flock from long distance, figure its direction of movement, and head it off that way. There's a chance a gobbler may walk right into shooting range with no need for calling. More likely, you'll have to call. But what if no gobblers respond? Call the hens.

Big turkey flocks take orders from a master or "flock" hen, who holds her position through assertiveness -- generally vocal assertiveness. There is a definite hierarchy among the hens, and if one hen challenges authority, there is a confrontation. If you vocally challenge the boss hens, they may come to confront you, and the gobblers will follow. To make this work, you have to play the role of a lone hen that has approached the flock and wants to take over. Yelp and cackle very loudly. Make it coarse, frequent, and insistent. If you get a response from the flock hen, make your call louder and bossier than hers. If everything works right, it won't be long before she comes swaggering over to have it out with you -- and the rest of the flock comes to watch.

Stage 2: Harem Gathering
The second phase of turkey mating is a time of high activity among gobblers. As their hormone levels increase, gobblers begin establishing territories, fighting each other, and gathering hens into small breeding flocks. This period, which just precedes the opening of turkey hunting season in most areas, is the easiest time to locate and get close to gobblers. It is the first of two peak gobbling periods during the breeding season. The furious and frustrated toms often gobble all day long with little provocation. If hunting season hasn't started when this peak arrives, use the time to locate several gobblers. They are establishing territories at this time, and will stay in the same general vicinity.

If this gobbling peak coincides with hunting season, you may encounter three situations. The first is the gobblers or the jakes that are subordinate to the harem-keepers. These birds, especially the jakes, are upset with the state of things -- their big social group has broken up, maybe they've gotten their tails whipped by a big gobbler, and they're lonely. These birds are the easiest of all to call. You may find a gobbler with a few hens who is looking for some new recruits.

These birds may be easy to call, or they may be reluctant to go far from their hard-won harem. You may have to sneak in very close for calls to work. Then there is the gobbler that refuses to leave his hens. The hen-calling tactic described earlier may work. If nothing else works, a last resort is to challenge the gobbler himself.

Assume the role of another tom and, approaching as close as you dare, gobble hard with a gobble tube, box call, or diaphragm. If he gobbles, gobble back -- only harder. Ideally, the tom feels bold from having just won a few fights, is enjoying the benefits of his battles, and will not hesitate to mix it up with the intruder. Mix in a few hen calls, making him think another gobbler is with a hen in "his" territory, and you will really make him mad.

Stage 3: Breeding Flocks
When the frenzy of initial courtship and dominance battle subsides, things settle down a bit. Harems are established and have a routine. There are few unspoken-for hens in the woods. Gobblers have no pressing need to announce their availability, which makes it difficult for hunters. Non-gobbling toms are hard to locate, but once you do find a breeding flock, there's a good chance you can pattern it.

Toms still gobble from the roost, unless encounters with hunters have silenced them. These are the most effective approaches to hunting during this stage. If you do locate a flock during this stage, but the gobbler won't respond to your calls, stay with him. Hens are nesting at this time, laying eggs daily. If you can follow the flock long enough without being detected, you may get lucky and be there at a time when all the hens have gone off to their nests, leaving the gobbler alone. Now is when he'll be vulnerable to a few soft clucks

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Stage 4: Deserted Gobblers
When hens have laid their last egg, they abandon the harem to sit on their nests. When all the hens have gone, leaving the gobbler alone, the old boy becomes very distressed. This is the second gobbling peak of the season. While gobblers are again easy to locate, they are usually very hard to hunt. Chances are he's had a bad experience or two with hunters (maybe with you) and he is very leery of calling. The gobbler may be desperate for a hen, but it is likely he will stay put and gobble, trying to encourage her to come. Catching the tom coming off the roost is the best tactic in this situation. Call very sparingly and stick with clucks. If the gobbler has been educated to calling, it was probably with the loud and constant yelps of an inexperienced hunter. Gobblers that haven't become hunter shy can be easy to call at this phase of the breeding cycle. Those that have will be tough to fool in every aspect of the hunt.

What makes a female turkey swoon? The secret isn’t better genes, but better use of them, according to a new study.

In most cases, the more masculine a male’s physical traits, the more attractive he is to females. But why are some males more masculine than others, even when they’re brothers with similar DNA? Could the answer have to do with epigenetics: how genes are expressed -- turned on or turned off -- in different individuals?

Researchers at Oxford University and University College London turned to wild turkeys to answer the question, because the males come in two types. Dominant males are large and have an array of exaggerated masculine traits that females find attractive, including iridescent plumage, long beards and enlarged wattles.

Subordinate males are smaller and less ornate. 

To establish the pecking order, male turkeys viciously duke it out with their brothers the winter before they reach sexual maturity. The winner adopts the dominant form, while his brothers become subordinates. Although subordinates don’t father offspring themselves, they act as their dominant brother’s wingmen, helping him woo females by mimicking his feathered display.

In other words, turkeys show a “gradient” of sexual characteristics, the researchers wrote in the journal PLOS Genetics on Monday. To examine how this continuum was related to the turkeys’ gene expression, the researchers sequenced RNA -- the molecule that carries out DNA instructions, creating the proteins that drive processes in the body -- from seven males (including five dominant individuals) and five females, all of breeding age.

The researchers then identified genes that were expressed differently in males and females. They found that dominant males had high levels of male-associated genes and low levels of female-associated genes. Female turkeys showed the opposite pattern. Subordinate males were somewhere in the middle.

“We were very surprised that the pattern was so clear,” said Judith Mank, an evolutionary biologist at University College London and a study coauthor.

What caused the changes is still a mystery, though. Mank and her colleagues initially thought that testosterone “turned on” the male-associated genes. However, they didn’t observe this interaction. “We’re not sure what’s going on yet,” she said.

The findings could apply to a number of species, Mank said. “When we think about sex differences, we usually think of two forms. In reality there’s more of a spectrum” -- including in humans, she said.

Lisa Martin, a molecular biologist at UCLA who was not involved in the study, added that the findings could help identify genes involved in “feminization,” a process that leads men to develop female characteristics. Feminization can be triggered by environmental factors, such as chemicals that mimic estrogens, she said.

The study has its limitations, however. Alan Krakauer, an evolutionary biologist at UC Davis who was not involved in the study, pointed out that the researchers “assumed that dominant males are more masculine,” which would mean that any gene expression differences they saw between dominant and subordinate males must have been associated with masculine traits.  

But some of these differences “could just be due to being more or less dominant,” such as variations in genes related to aggression or the ability to find food quickly, he said. In a future study, the researchers could confirm whether genes whose levels differed between dominant and subordinate males are in fact related to head color, plumage and other masculine characteristics.

“The picture might be more complicated,” Krakauer said. “But it’s an exciting first start.”

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