When Whitetails Move: What Collar Studies Say About Sunrise and Sunset

Legal shooting light, the first real deer movement and the moment air starts moving on a slope are three separate appointments, and hunters often book them as one. Collar studies speak to only one of the three. Across a Michigan reserve, Oklahoma and southwest Wisconsin, whitetail movement peaks near sunrise and sunset and sags at midday, including through the rut. What changes at peak rut is how deep the midday sag runs and which bucks are moving in daylight. None of these studies measured scent or air movement, so they tell you when deer are on their feet and nothing about where your air is going.

Beier and McCullough published the George Reserve activity study as Wildlife Monographs 109 in 1990 (Northern Arizona University record). In most months the deer showed a daily pattern with peaks at sunset and just after sunrise. The sexes matched except in September and October, when males were more active at night and females more active by day.

The abstract also puts a temperature shape on activity: it peaked at 6 to 16 degrees Celsius and fell at both higher and lower temperatures, with the effect varying by time of day, season, cloud cover, wind speed and habitat. Snow depth cut activity even at slight depths, which the authors tied to food. Deer used closed vegetation by day and open types at dusk, night and dawn. The measure was percent of time active, which is not the same as distance moved, and the abstract is the part we read.

Webb and colleagues took a location attempt every 15 minutes from 17 female and 15 male deer over seven years and three seasons in Oklahoma (Webb et al. 2010). Their abstract calls the movements of both sexes primarily crepuscular. Moon phase had no effect on daily, nighttime or daytime movement, and short-term weather had an inconsistent influence within a season. The authors say their data suggest hourly and daily weather variation has minimal impact on movement at southern latitudes, and they presume that routine crepuscular movement helps deer regulate temperature and lower predation risk. The presumption is theirs; the movement pattern is the measurement. Our guide to movement scores takes up the moon-phase point.

The most useful data set for a rut sit is Hunsaker and colleagues' study of GPS collars on 188 males in parts of Dane, Iowa and Grant counties, Wisconsin, from 15 October to 1 December in 2017 through 2020 (Hunsaker et al. 2025; publication record). Collars logged locations hourly. The area is mostly private land: deciduous forest on hills, grassland valleys and corn, soybean and alfalfa fields.

The authors defined the day with the sun, not the clock. Dawn was the hour of sunrise and the hour before it, dusk was the hour of sunset and the hour after it, day fell between, and night was everything else. Their windows slide with the sun across a six-week study, and your sit should slide with it too.

Changepoint analysis of daily movement put the peak of the rut between 23 October and 12 November, and estimated conception dates, backdated 200 days from captured fawns, agreed. Movement and range size climbed into early November and then fell. Two-year-olds moved fastest. Bucks 3 and older showed the highest variance in daily movement rate, which the authors read as alternating between high-movement searching and lower-movement tending; the difference between two-year-olds and older bucks in that variance had P = 0.06 and did not clear the authors' cutoff. They add that a drop that looks like tending does not prove a completed breeding.

The within-day breakdown is the part that changes a sit plan. Movement across ages peaked in the week of 5 to 11 November. In that week bucks 3 and older moved less at dawn than yearlings and two-year-olds, while yearlings and two-year-olds moved slightly more in daylight than the older class. At dusk all ages looked similar. At night, two-year-olds and older bucks moved more than yearlings, and the oldest class showed signs of shifting from a crepuscular pattern toward a nocturnal one at the peak.

For the harvest side of the rut in another state, see Watching the Rut Happen, which reads Ohio's weekly reports.

A November 2025 write-up of the study by the National Deer Association reads the paper's chart for hunters (NDA). It describes the familiar U shape, a peak around sunrise, a midday slump and a peak around sunset, present in all six weeks even while the whole curve rose and fell. It reports that midday movement was 50 to 100 meters per hour higher in the third and fourth weeks (29 October to 11 November) than in the two weeks before or after, and still below the dawn and dusk peaks. Coauthor Dan Storm is quoted there saying that a hunter is still likelier to see bucks moving on the evening of 15 October than at noon on 4 November. Those lines come from the article, not from a numbered result in the paper, so read them as the researchers' public interpretation of their own figure. The NDA piece itself calls these the two weeks when the odds favor an all-day sit more than at any other time of the season.

The practical reading is a trade. An all-day sit in the peak weeks buys a rising midday, but it does not buy a midday that beats the edges of the day.

Two negatives matter as much as the peaks. The top individual-level model did not identify a significant effect of weather, year, hunting season or the timing of opening weekend of the firearm season. The authors considered daily minimum temperature, maximum temperature and the daily swing between them. The firearm season opened on the third Saturday of November, after the peak. Movement was already falling and the opener did not add a detectable break. In a descriptive comparison, not a test, mean movement on 23 November was about 6 percent lower than on 17 November across the four years and 19 percent lower comparing 23 November 2019 with 17 November 2018. Across that same pair of years, male firearm harvest in Iowa County fell 25 percent when opening day moved from 17 November 2018 to 23 November 2019. The authors treat the match as a trend, and harvest has many causes.

The Michigan and Wisconsin results do not conflict, because they measured different things. Beier and McCullough found a temperature band for activity across a year on one reserve. Hunsaker's model tested daily temperature inside a six-week rut window. Our reading is that temperature can shape a year's activity budget while the calendar dominates inside the rut window, as Storm's comment about the day of the year suggests. The Wisconsin model tested daily movement rate, so it does not say whether a front changes where deer feed within the day.

Two collar studies from hunted properties separated the two twilights (both are also in our guide to collar studies and hunting pressure). On South Carolina's Brosnan Forest, mean movement per half hour was higher at dusk than at dawn for both sexes: 129 against 95 meters for bucks and 114 against 55 meters for does (Stewart et al. 2022). In Maryland's shotgun season, bucks moved more at dusk and night than at dawn and day, and movement during the day dropped from the dawn level (Karns et al. 2012). The Maryland authors' likely explanation is that deer returned from the fields to bed earlier in the morning after repeated disturbance from interior roads used to transport hunters, while their evening trip to feed stayed steady. Mississippi State's extension bulletin adds that adult bucks entered food plots at greater rates right around sunset (MSU Extension P3927).

Wisconsin fits loosely: in the peak week the oldest bucks were the class that moved least at dawn while dusk looked similar across ages. Treat that as a lead from three studies. In the ones that split the two twilights on hunted ground, the weaker twilight has been dawn.

Everything above is the deer clock. The other clock is the air on the slope, and no collar paper here measured it. Our wind-forecast guide says to expect downhill drainage from before first light until the sun warms your slope, often the first 60 to 90 minutes after sunrise, and our thermals paper explains why the morning and evening switches fall in the same windows deer use. That is FDR's reading of the air, not a finding from these studies.

A map layer that flags risky air screens for risk. It does not tell you this morning's drainage, and none of the studies above can say which way your scent will go.