Whitetail Breeding Dates by Latitude and State

"When is the rut?" has no single answer, because whitetails breed on a day-length schedule that lands on different dates in different places. This guide lays out the conception and breeding-date measurements we could read in full, from Pennsylvania and Wisconsin to south Texas and Florida, and keeps conception dates, collar peaks and harvest reads apart. By the end you should know how wide the spread is, which herd's date to borrow for a trip, and why a "late rut" sighting may be fawns. The day-length mechanism is in Why Day Length, Not Weather, Sets the Whitetail Rut, and the moon claims are in Moon Phase and the Rut.

Every number below is one of three things, and mixing them is how a trip gets planned a week off. A conception date comes from aging fetuses or newborn fawns and counting back. Texas Parks and Wildlife dated breeding from fetus length and used 200 days as the average span from conception to birth (TPWD, written 1996). Researchers in southwest Wisconsin aged newborn fawns by the umbilicus and counted back 200 days (Hunsaker et al. 2025). Pennsylvania measured fetuses in road-killed does (Penn State), and Illinois did the same with fetuses from tested females (Green et al. 2017). A collar peak comes from GPS units on bucks and marks when they travel most, which is tied to breeding but is not the day does conceive. Harvest timing comes from check-in counts, like the Ohio work near the end of this guide. A county harvest total on its own is not a breeding date.

A median or mean is the center of a cloud of dates. Pennsylvania's yearly adult medians from 1999 to 2006 sat between 9 and 16 November, the pooled adult median was 13 November, and fawns pooled to 25 November (How to Predict the Rut).

Penn State's weekly bars show why mid-November feels sudden. About 20 percent of females had been bred by the last week of October, with more than 10 percent of them bred in that last week alone. Over 40 percent were bred in the first two weeks of November, and by the end of the month more than 85 percent had been. Breeding then trails into December, January and even March, which Duane Diefenbach traces to does that missed their first cycle and to fawns, most bred in late November and December (Why 2 Weeks Later?).

In Illinois, Green and colleagues tested 3,884 females. About 66 percent were pregnant, with pregnancy rising from 20.5 percent in fawns to 85.8 percent in adults. The breeding season peaked in November, and mean estimated conception dates were 8 November for adults, 11 November for yearlings and 2 December for fawns (Green et al. 2017, abstract).

Southwest Wisconsin adds a collar view. Researchers followed 188 collared males from 15 October to 1 December, 2017 to 2020, in parts of Dane, Iowa and Grant counties. A changepoint analysis of daily movement placed the peak breeding season from 23 October to 12 November; across ages and metrics the start fell between 23 and 27 October and the end between 9 and 15 November. The movement-based peak ran 20 to 21 days, while conception dates back-dated from 307 of 347 captured neonatal fawns gave a peak about 16 days long. Average hourly movement was highest in the week of 5 to 11 November (Hunsaker et al. 2025). That collar window opens before the mean conception dates measured in Illinois (8 November for adults) and Pennsylvania (13 November pooled adult median). The states and methods differ, so treat that as a rough comparison and not a measured lead time. It does fit Penn State's note that males' home ranges grew in late October, when about a fifth of females had been bred.

Farther south, on the Savannah River Site in South Carolina, Novak and coauthors estimated conception dates. After correcting a bias toward early dates in fall-collected data, mean breeding was 13 November plus or minus 15 days for adults only, and 20 November plus or minus 27 days with fawns included, because fawns conceived later and skewed the curve (Novak et al. 1991, abstract).

TPWD examined 2,436 does on 16 study areas over three years, which it described as the largest number of deer ever used in a Texas breeding study. In most areas the rut varied very little from year to year, but across ecological regions it did not (TPWD).

Statewide, 92 of every 100 sampled does were pregnant, and TPWD reported that no matter when the rut occurred, the vast majority of does were bred. The lowest rate was 81 percent in the Trans-Pecos, a region TPWD says was in drought for the last two years of the study. South Texas had the latest rut, and even there fawns were born before August: 90 percent by 19 July in the east and 25 July in the west.

Mississippi State's Deer Lab reports peak breeding from late November in northwestern counties to mid-February in southeastern counties. Within each region the season is fairly steady at about 30 to 45 days, with most breeding inside a 21-day period around the peak and a smaller second peak three to four weeks later from recycling does and fawns (Ecology of the Rut). Dye and coauthors' analysis of wild Mississippi populations put the overall mean conception date at 1 January, with a standard deviation of 13.4 days (Dye et al. 2012, abstract).

On private land along the Big Black River, an MSU Extension collar study defined peak rut as the two weeks from 25 December to 7 January, when 50 percent of does are bred, with another 20 percent bred in each of the two-week periods before and after. Adult bucks there moved about 4,800 yards a day in the pre-rut and over 7,500 yards (about 4 miles) a day at the peak, and the higher daily distances in that dataset come in December and January, not October and November (Strickland et al., Publication 3927).

Florida is wider still, and it was measured herd by herd. Richter and Labisky examined 380 does collected monthly from July 1978 to January 1981 in four sectors. Mean breeding dates were 10 August at Rotenberger in southern Florida, 7 October at Tosohatchee in central Florida, 2 November at Camp Blanding in northern Florida and 22 February at Eglin Air Force Base in the northwest, as much as six months out of sync (Richter and Labisky 1985, abstract). A 2019 FWC bulletin describes Florida's rut as the widest ranging of any state, from July in extreme south Florida to early March in extreme northwest Florida and the Green Swamp Basin. FWC biologist Elina Garrison said the agency's breeding chronology study found conception dates within one area varying by as much as 9 to 110 days, averaging 45, with most does bred inside 60 days. She said it seems likely, though difficult to prove, that the south Florida timing follows hydrology, with fawns born in the driest time of year before the wet season starts in June. She added that restocking from Wisconsin, Texas, Louisiana and Pennsylvania may play a part but is unlikely to be the only explanation (FWC bulletin, 4 February 2019).

Latitude explains the coarse pattern and breaks down between neighboring herds. Sumners and coauthors compared adjacent southern populations: six pairs whose breeding dates differed by an average of 35 days, and four pairs that differed by no more than 2 days. Mitochondrial DNA, which comes from the mother, differed more in the mismatched pairs (differentiation of 0.408 against 0.140 on the FST scale, P = 0.03), while biparentally inherited markers did not differ significantly. That points to male dispersal keeping the populations connected and to a maternal genetic effect on breeding timing. The authors hypothesize a legacy of restocking and remnant local herds, and say the dates may be a fixed trait that managers must account for (Sumners et al. 2015, abstract). MSU's own summary says peaks in populations less than 30 miles apart can differ by 30 days, held in place because daughters tend to stay near their mothers (Ecology of the Rut).

Age does the same job inside one herd. Fawns conceived later than adults in Illinois (2 December against 8 November), Pennsylvania (25 November against 13 November) and the Savannah River sample, and TPWD notes that a young doe or a doe in poor condition may not breed until late in the season. Our reading is that a December "late rut" sighting in a northern herd can come from fawns and recycling does while most adults were bred weeks earlier. Herd and habitat changes can also move a peak, and the mechanics are in the day-length piece.

Every number above is a conception date or a collar peak. FDR's Ohio work adds a third view from harvest. Ohio's mandatory telecheck produces a weekly county harvest tally in season (Watching the Rut Happen). In The Rut Moves South, we split 13 northern counties along Lake Erie from 12 southern counties along the Ohio River, about 2.5 degrees of latitude or roughly 150 miles apart. For each of the 2023, 2024 and 2025 archery seasons we computed the harvest-weighted center of the archery report weeks, weeks 2 to 11. The northern harvest centered earlier every season, by 1.4 to 2.9 days.

Across 150 miles inside one state, the harvest center moved by days. The Texas regions in the table above sit weeks apart, and paired southern herds can sit a month apart. The Ohio figure is harvest timing and not conception, and our paper says it is confounded by hunter effort (weekends, weather, mast) and should not be extrapolated beyond Ohio.

The measurements support one conclusion: plan from a local date. The steps below are our method for doing that.

We believe a state average is the wrong planning number, and hunters should plan around the nearest measured herd instead. We would not book a south Texas hunt from a Midwest calendar, and we would not tell a Pennsylvania hunter to wait until Christmas because the South ruts late.

This guide draws on Pennsylvania, Illinois, southwest Wisconsin, the Savannah River Site in South Carolina, Texas, Mississippi and Florida. Hunters in Georgia, Alabama, Louisiana or elsewhere should look for their own state agency's breeding chronology or fetal study. Some samples are old: Florida's were collected from 1978 to 1981, South Carolina's from 1974 to 1984, and TPWD's write-up dates to 1996, and herd or habitat changes can move a peak. Methods differ too, from fetal length to back-dated births to collar changepoints, so compare within a method first. The Green, Novak, Richter and Labisky, Sumners and Dye results were read from published abstracts.