Elk Activity Graphs

  The graphs below are the result of T.R. Michels' elk research project in 2001 and 2002. The data provided here is taken from elk herds in southern Minnesota, however, the results may apply to other areas.


This graph shows the daily bugling activity of approximately 165 bull elk. It has been theorized that elk bugling should correlate with the activity of the cow/calf herds. The results of these studies support that theory. This graph shows that bugling generally begins to pick up 45-60 minutes before sunrise, as the cows begin to feed in the morning, and decreases within 2-3 hours of sunrise, as the cows go back to wooded areas to bed down for the day. Bugling begins to increase again about an hour before noon, when the cow herds often get up to stretch and eat for a short time, and generally decreases within an hour of noon, as the cows bed again. Bugling then begins to increase again about 2-4 hours before unset, as the cows get up to feed in the afternoon/evening, and decreases within 1-2 hours of sunset, as the cows bed down for the night. Research studies show that elk may often begin moving at about midnight, when bugling may increase again.



This graph shows that, from mid August to late October, bugling was slightly higher in the morning that it was in the evening. This was probably due to the fact that morning temperatures were generally lower then evening temperatures.



 This graph shows that elk bugling increases with the temperature, peaks at about 70-80 degrees, and then decreases.


Monthly Bugling Peaks and the Moon


This graph shows that during 2001 there were semi-regular bulging peaks, with peaks in mid September, mid October and early November. As can be seen by the dates of the Full moon and Perigee of the moon, these bugling peaks were not correlated with either the Full moon, or the Perigee of the moon; this shows that bugling is not affected by the moon.



Bugling and Breeding Date Differences by Bulls with Different Aged Cows



This graphs shows the difference in bugling peaks of bulls with 3+ year old cows, and bulls with 1-2 year old cows. It has been suggested that peak bugling should correspond to peak breeding. This graph supports that theory, and shows that peak bugling by bulls with 3+ year old cows occurs during mid September, and that peak bugling of bulls with 1-2 year old cows occurs 1-3 weeks later, in late September or early October. The results of this study show that peak breeding of 3+ year old cows occurs 1-3 weeks before peak breeding of 1-2 year old cows.

Yearly Variations in Bugling Peaks



Peak bugling of the same may elk herd may occur during different weeks in different years. This graphs shows that peak bugling, of the same elk herd, did not occur during the same weeks in 2001 as it did in 2002. It also shows that peak peaks was not correlated with any lunar factor during either year. Since peak bugling was correlated with peak breeding, but peak breeding was not correlated with any lunar factor, this study shows peak breeding is not affected by the moon.

The late bugling peak in September of 2002 was attributed to the fact that September temperatures were higher in 2002 than they were in 2001. There was no fourth bugling peak noted in 2001, because the study ended in mid November. When the study was extended to early December in 2002, a fourth bugling peak was noted. Studies have shown that a decrease in testosterone levels late in the rut often lead to an increase in rut related activities. This is probably the reason for the high bugling peak during late November in 2002.


All information, data and graphs on this page are the sole copyrighted property of T.R. Michels/Trinity Mountain Publishing. Copying and use of this information, data or graphs, without written permission of the owner, is expressly forbidden by Federal law.


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