I’m trying to finish some projects so I can go hunting this afternoon!  The temperatures are approximately 20 degrees cooler this afternoon than they’ve been in weeks!  I believe decreases in temperature of this magnitude prompt increased activity of mature bucks during daylight hours.

I and several other scientists have attempted to determine the weather conditions that prompt deer to move during daylight.  We’ve analyzed huge datasets of deer movement collected by personal observations, radio telemetry collars, GPS collars, trail camera images, etc.  Unfortunately, no reliable trends have been reported.  That’s not to say that some patterns don’t exist.  The deer are just keeping them a secret.

It’s probably because we scientists haven’t analyzed the appropriate combination of factors yet.  It becomes a very complicated analysis to consider deer activity data compared to multiple factors simultaneously.  It would be simple if when the barometric pressure dropped two percent, deer activity increased 20 percent.  However, using barometric pressure as a single factor rarely yields predictable results.  When barometric pressure, temperature, the difference of temperature from normal, the change of temperature during the past 24 hours, cloud cover, moon phase, moon declination, precipitation, etc., etc., etc., are combined the data and results often are a useless mass of charts.

It’s very difficult to have a large enough data set to ensure the results of the analysis are meaningful.  For example, I’m working with a grad student at the University of Georgia to analyze 11 years of observation data from one of my research projects.  The observers that collected data for this project were trained and consistent throughout the project.  We logged more than 1,000 hours of observations annually for each of the 11 years.  We harvested more than 1,000 deer as part of that project.

Deer are champions at surviving.  They not only respond to changes in the weather, they also respond to predators and other threats.  It’s tough to sort out why deer are moving because the researcher never knows all the factors wild, free-ranging deer are analyzing and responding to.

It’s frustrating!  However, the ongoing research is fun!  In fact, I’m ready to go collect some more data this afternoon!

Growing (and studying) Deer together,

Grant