T.R.'s Tips: Reaction to Meteorological Conditions
By T.R. Michels, Trinity Mountain Outdoors

While food availability, breeding behavior and hunting pressure are fairly predictable on a yearly basis, and most hunters know how game animals react to these conditions, the weather may change daily; in as little time as a few hours. As a result of my studies, and after reading the research of several wildlife biologists, I have come to the conclusion that the current weather is a primary factor in determining daily game activity. Weather affects when and where the animals move each day. Dramatic weather changes in a short period of time often reduces game movement and curtails feeding and breeding behavior.

Light, Cloud Cover

One of the first things I noticed during my study was that the turkeys began gobbling and flew down later than normal when there were cloudy skies. Turkeys rely heavily on their sight to alert them of danger, and because they are daytime animals, they wake up when the sky begins to get light, and they wait to fly down until they can see well enough to detect danger. On cloudy days the toms would begin gobbling 10 to 20 minutes later than they did on days when the sky was clear. Both the toms and hens flew down 10 to 20 minutes later than normal on cloudy days. The dominant toms usually flew down and arrived at the strut later than the hens.

Temperature/Wind-chill

In their study Haroldson, Svihel, Kimmel and Riggs found that when the air temperature was between 18 and 52 degrees, the body temperature of resting wild turkeys declined rapidly during sunset, declined a little during the night, and rose rapidly again at sunrise. When the air temperature was between -8 and 18 degrees the body temperature of the turkeys remained higher than it did in warmer temperatures, and increased at a lower rate during sunrise and throughout the day. This suggests that turkeys are most active when the temperatures or windchills are above 18 degrees. When it is 30 degrees, a 10 mile per hour wind produces a 16 degree windchill factor.

During my study most gobbling occurred when morning temperatures/wind-chills were between the upper 30’s and lower 60’s. Gobbling was severely reduced when the temperature dropped below 30 degrees, although this may have been because most of the cold days were cloudy, windy, and rainy or snowy. Because turkeys inhabit a wide variety of habitats they are accustomed to different temperatures and wind-chills. Noted turkey biologist Lovett Williams Jr. told me that turkeys in Florida gobble when morning temperatures are below 32 degrees. I shot my first Merriam’s turkey in Nebraska while it was gobbling at 10:30 in the morning, it was 96 degrees.

On cold days the birds not only called less, they also began calling later than normal, usually after it had warmed in the mid-morning hours. They also flew down later than normal. Once they were on the ground the turkeys often sought areas that were open to the sun, usually out of the wind, where they were warmer because of solar radiation. During extremely cold weather they sought food sources out of the wind, and fed for quite some time before they returned to the woods. I often saw them feeding on top of an open corn crib, at a silage pile not far from a cattle barn, and in a field where the farmer spread cattle manure every few days.

Precipitation

A research paper by Kienzler, Little and Fuller, sent to me by Dr. James Earl Kennemer of the NWTF, stated that when there had been precipitation during the last 12 hours, gobbling activity was reduced. That started me wondering if rain affected the movements of the birds as well, so I began to pay particular attention to when and where I heard and saw the birds on rainy days, and on days after it had rained. The first thing I noticed was that when it was raining, or had rained during the night, the birds flew down later than normal. If it had rained during the night, but wasn’t raining in the morning, I often saw the birds sitting in open areas out of the wind, especially if the sun was shining, with their wings outspread, trying to dry out.

If it was still raining in the morning the birds often stayed in wooded areas later than normal, and fed and rested in wooded areas with sparse or low ground cover. When the vegetation was wet they preferred to stay on game rails, old roads, and in areas with low vegetation. If the birds came out into the open to feed they used areas with low vegetation; new growth meadows, picked agricultural fields and pastures. But, not all birds are alike. The state wildlife habitat manager and I were reviewing our habitat improvement program one day when we saw a hen standing in the middle of a gravel road in a pouring rain.

I also found that the birds were late on their daily travels if it had rained in the last twelve hours. When the skies were still cloudy the morning after it had rained, the birds flew down later than normal, and arrived at traditional feeding/strutting areas later than normal, later than they did when the skies were cloudy but when it had not rained. When it was both cloudy and raining in the morning the birds flew down even later still.

I didn’t understand why the birds were so late after it rained until I watched them feeding one afternoon. They were in a soybean field about a half mile from a group of white oaks where they often roosted. When they were in this area the birds usually fed in the field on the east side of the woods, moved around to the south side of the woods, and then flew into the trees about 50 yards from the field edge. The next morning they would fly down from the trees and land in the bean field, about fifty yards from the edge of the woods.

On this particular evening the turkeys had been feeding for about a half an hour when it started to rain. Within minutes the birds moved into the woods, and as it continued to rain they flew into a group of elms, where they roosted for the night. Because it was raining in the afternoon, before the birds normally roosted, they had stopped feeding earlier than normal, flew up into trees they didn’t normally use, and roosted earlier than normal. Because they were farther away from their traditional feeding/strutting area the next morning, they couldn’t fly down into the field like they normally did. Because it rained during the night the birds flew down later the next morning. When they did fly down they landed in the woods, and eventually worked their way to the soybean field. But, they got there about an hour later than they normally did.

There were several times during the study when it rained in the afternoon before the birds flew up to roost in one of their normal roosting areas. When this happened the birds flew down later than normal the next morning, they often used different travel routes than they normally used, they were more likely to feed in wooded areas, and they usually arrived at open feeding/strutting areas later than normal.

Wind

When it was not windy the birds often roosted on the upper two thirds of east or south facing slopes. I suspect this was because the prevailing winds were westerly, and because the birds might gain the benefit of late evening and early morning sunlight. When there were strong winds, or when it was both cold and windy, the birds roosted on the downwind sides of slopes or wooded areas, in heavy cover if they could. In areas where there are conifers, turkeys often roost in them during cold weather. On windy days, especially when it was cold or rainy, the birds usually fed in areas out of the wind; low-lying areas, wooded areas, and the down wind side of hills or woods. When they did feed in areas open to the wind they ate quickly and then moved into protected areas earlier than normal.

Barometric Pressure

According to noted waterfowl biologist Dr. Jim Cooper, birds have numerous air sacs in their bodies that allows them to detect slight changes in barometric pressure, and warns them of approaching storms. Some hunters believe birds, including turkeys, feed heavily up to two days before a storm because they know it is coming. This would allow them to wait out a storm and resume feeding after it passes.

Lunar Factors

With all the hype, in seminars and in print, about how the moon supposedly affects animals due to its gravitational pull, I felt I should some information on how the moon may affect turkeys. I have spoken to several different researchers about the "lunar game activity predictor tables": the Solunar Tables, Dan Barnett's Fishing and Hunting Times, Vektor Game and Fish Activity Tables, Jeff Murray's Moon Guide and the Lunartic's Moon Card, and found that none of them had any evidence suggesting that the gravitational pull of the moon had any effect on the hourly activity of turkeys.

During my research I kept track of breeding behavior, peak breeding dates, and noted the moon phase; to see if there were any correlation’s between turkey activity, lunar factors, and the lunar game activity predictor tables. One of the first things I noticed was that none of the game activity tables accurately predicted daily turkey activity. While there were a few days each month when I saw turkeys on the days and times predicted, most of the predicted days were during nice weather, and many of the predicted times were in the morning, when turkeys normally feed. During mid-day hours, and when the weather conditions were poor, I saw very few turkeys at the times predicted. That’s because lunar predictor charts fail to take into account the current weather conditions, food availability, breeding behavior and hunting pressure, which all affect turkey behavior, and which can over ride any influence the moon has on daily turkey activity.

However, during my 1998 turkey research I did notice that gobbling activity was cyclical, and that gobbling seemed to peak during two different lunar cycles. I didn't think much about it for the next two years, until I again noticed that average weekly gobbling peaked at regular intervals, and that the peaks often correlated with two different lunar cycles. I now believe that peak gobbling, which is when tom turkeys are the most willing to come to a call, can be predicted.

This article is an excerpt from the Turkey Addict's Manual, by T.R. Michels.

T.R. Michels is a nationally recognized game researcher/wildlife behaviorist, and outdoor writer and speaker, who has been studying game animals for several years. He is the author of the Whitetail, Elk, Duck & Goose, and Turkey Addict's Manuals. His latest books are the 2002 Revised Edition of the Whitetail Addict's Manual, the 2002 Revised Edition of the Elk Addict's Manual; and the 2002 Revised Edition of the Duck & Goose Addict's Manual.