Working with decades of data compiled by countless state wildlife biologists, Louisiana deer hunters have the most complete breeding calendar ever released by the Department of Wildlife and Fisheries.

It’s not that breeding dates across the state’s deer hunting areas have never been known — former State Deer Study leader David Moreland revealed breeding dates hunters call “the rut” in the major areas as far back as 2004 — but the recently released map comes after a concerted effort by LDWF biologists to fill in holes in the state’s five different deer habitats.

“We’ve had data compiled for years,” state Wildlife Division chief Kenny Ribbeck said recalling numbers, dates and locations from as early as the 1960s. “When Dave Moreland was the study leader, he collected more intensive and more new data from biologists across the state.”

That was in the 1990s and into the turn of the century before Moreland later moved to head the Wildlife Division and before he retired. Scott Durham took Moreland’s place to lead the Deer Study Program.

“When Scott came into the position, he initially looked at the map and knew we were missing big areas of the state. It was our decision to give him the manpower needed over several years to get up to par where he felt comfortable putting out a map with this kind of detail.”

For years, Moreland and the biologists before and after him have set up hunting schedules to get hunters into what once was more than a dozen deer-hunting zones. Zones have changed over the years, and were reduced to as few as seven. There are 10 deer-hunting areas in Louisiana.

“We want to provide the best hunting opportunities for the hunters, and that means setting seasons around those peak rutting dates,” Ribbeck said. “Scott working with our GIS (geographical information system) guys to develop the program for the map. They used several years of data to get additional information to further pinpoint localized areas of breeding intensity.”

Moreland led studies to identify rutting dates with diverse habitat such as the pine thickets in northern and central parishes, the coastal areas with unique environs in east and west of the Atchafalaya River and along the lower Mississippi River, the bottomland hardwoods, farming areas and swamps along the Mississippi River north of New Orleans and in the Atchafalaya Basin.

Ribbeck said hunters were, and have been, involved in data collection, but “... we try to get as much as we can from hunters, but that’s not enough information,” so state biologists tied breeding studies to disease collection — they took females from herds — to maximize the information on breeding cycles and the overall health of deer herds across the state.

“This is not the ‘end’ document,” Ribbeck said. “We want this to be a living document and we’re going to continue studying areas where there is the weakest data. The more we get, the better we can strengthen that map.”

Durham explained that deer breeding periods are primarily determined by the genetics of the does, but can be influenced by other factors such as the health of herds in specific areas, population density, sex ratios and habitat conditions.

For instance, it’s been known for years that deer in and around lands near the Mississippi and Atchafalaya rivers have later rutting dates than whitetails in more upland habitat. The main reason given is that deer along these major rivers have adapted to flooding conditions and give birth to fawns after the threat of flooding has passed. That accounts for fawn “drop” as early as June in some areas and as late as August along the state’s major rivers.

Durham further explained that dates on the map is a “best estimate” of the average two-week peak breeding periods, and that the entire breeding range usually will be longer than what is shown on the map.

He said hunters should remember there is annual variation in breeding timing, and that peak breeding times are not necessarily peak buck movement times, and Ribbeck said the map does include secondary rutting periods.