By Mark Kenyon
Craig Dougherty, a whitetail expert and current Executive Director of the National Deer Alliance, once told me that nothing happens in the whitetail woods by coincidence. There is always a reason for what we see or don’t see. And many times that reason is related to some kind of atmospheric or astrological factor that might trigger deer movement.
Recently, after interviewing folks like Mark Drury and Adam Hays about these very topics, I’ve been inspired to pay even closer attention than usual to the factors surrounding what I see in the woods – specifically mature buck sightings.
Last night I had just such an encounter that I think is worth analyzing, as 45 minutes before dark, one of my Michigan food plots became host to a whitetail party of epic proportions – as I saw nearly a dozen does and young bucks, and three potential shooter bucks out feeding (while scouting from a distance).
This is not a normal kind of sighting in this area, so immediately the question came to mind … Why?
To answer this question I performed a quick bit of online research to identify the current conditions at the time of my deer sightings, which I’d then analyze in an attempt to understand what most likely was the main influencer for movement. With this knowledge I would not only understand this specific situation better, but I might also be able to better identify future situations such as this, and be prepared to take advantage of them ahead of time.
That said, I believe that you too can benefit from asking this very question every time you see or capture a daylight photo of a mature buck on your hunting property this year. With this in mind, I’ve outlined below the factors I researched and the specific conditions present at the time of my buck sightings, and then finally, I’ve shared my analysis of the situation and the main factors that I believe likely triggered this tremendous daylight movement.
Take a look at how I did this, and then try this type of analysis next time you have an encounter of your own. The patterns and correlations you might discover, without a doubt, can help you become a more opportunistic and deadly deer hunter.
I’ve listed below the main weather/astrological related factors that I’ve come to understand can influence deer movement. I then used tools such as Wunderground.com and Intellicast.com to get the exact conditions for my area at the time of the sighting and the conditions on the way. Take a look below at those conditions, as well as a brief explanation of how each of these factors typically impact deer movement.
Deer sighting time: 7:15 PM, 35-40 minutes before dark (Deer move the most around dawn and dusk)
Temperature: High of 77, but dropping (During the fall, deer typically will move more when the temperatures are at or below the average temperature for that time.)
Weather Fronts: Cold front hitting overnight, dropping daytime highs by 10 degrees (A cold front dropping temperatures below average can often trigger increased movement)
Pressure: 29.99 (Mark Drury believes that high pressure days, relative to the average pressure at that time of year, are some of the best days for deer movement)
Wind speed: 0-2 (Many believe that very low or very high wind speeds can be detrimental to deer movement. Below 2 MPH or above 30 MPH, seem to be typical thresholds)
Wind direction/changes: SW to SSW (It’s important to look at the wind direction that coincides with a sighting, as you might be able to correlate his activity in a given area to the wind direction at that time. Additionally, the Drurys believe that the first time a wind direction changes after being consistent for numerous days can trigger increased movement. In particular, Mark Drury believes that the first S wind after many N days can be dynamite)
Moon Phase: 98% Full (Traditional theory has been that daylight deer movement might be lower during the full moon, as more deer move during night. But Mark Drury believes that some of the best hunting days are actually those around the full moon, as those days have the best rising/setting times. More on that in the next category)
Moon rise/set time: 7:57 PM rise, 7:58 AM set (More important than the phase of the moon, many believe that the position of the moon is the greater influencer of deer movement. Specifically, increased deer movement is believed to occur when the moon rising or setting time falls within the normal prime-time for deer movement of dawn or dusk)
Moon overhead/underfoot time: Overhead at 2:00 PM, underfoot at 1:40 AM (Similar to the above situation, it’s also believed that deer movement increases when the moon is precisely overhead or underfoot at those prime-time dawn/dusk timeframes as well)
Cloud Cover: Overcast (I’ve always thought that deer moved better under overcast conditions, but some disagree. Mark Drury in particular shared with us that he sees better movement on sunny days)
Precipitation: None (Deer oftentimes will move more during daylight in light precipitation, especially in areas of high hunting pressure)
So now that we’ve done our research, we need an answer. Why was there such great daylight movement last night?
If you take a look at the conditions listed above and then compare them to the triggering factors I explained in italics, you’ll see that there are a few of these factors that most definitely seem to be correlated with this increased movement.
The wind wasn’t particularly good, pressure wasn’t very high, and cloud cover/precipitation was mediocre too – but there were two triggers that most definitely were lined up for strong daylight activity.
First and foremost, a major cold front is hitting at the moment, which is dropping temperatures more than 10 degrees over 24 hours and nearly 20 degrees by the end of the week. Without a doubt, I believe this was the greatest influencer of movement, as deer will often feed earlier the evening before a front hits.
Secondly, it seems that this sighting coincided with an ideal moon position, as the moon was rising during that primetime dusk movement period. Temperature change is almost always the greatest influencer on movement, but when paired with a good moon position, it can enhance and exaggerate that movement. And I think that’s exactly what we got last night.
Pair these two movement triggers with a low hunting pressure situation (as the season isn’t open yet) and a quality food source (Whitetail Institute Winter Greens and Oats), and you’ve got a recipe for mature buck sightings. And that’s exactly what I got last night.
How To Use In The Future?
So how can we use the lessons learned from this type of analysis in the future? It all comes down to identifying the movement influencers that we see in each situation, and then recording those, either in your memory bank or in some kind of journal or deer log. The more sightings you have in which you can identify the likely reasons why, the more data you’ll have to look back on before future hunts. Then, for example, you can compare upcoming conditions to similar ones from the past and see what type of movement or activity you might be able to expect.
If you find that you consistently are having your most mature buck sightings on high pressure days with mid-range winds after a cold front, you better make sure you’re out hunting on days like that in the future!
All that said – this coming season, don’t just watch a mature buck and then move on with your daily life. Instead, make sure you’re asking why, and then do the work to uncover that answer!
Note: This analysis doesn’t even cover the other aspects of a mature buck sighting which are related to why that deer is in that given spot. More on that side of things another day!