Oklahoma’s 16-day deer rifle season opens Saturday, and state wildlife officials say the rut is happening at the right time for hunters. The whitetail deer breeding season, or rut, typically occurs around the second week of November. Deer activity during the rut picks up, but the amount of activity can be influenced by factors like day length, temperatures, moon phase and herd condition. In northwest Oklahoma, last weekend’s cooler weather seemed to boost deer activiity, said Wade Free, northwest region wildlife supervisor for the Oklahoma Department of Wildlife Conservation. "The cold rainy weekend — 35 degrees, rain, drizzle, and overcast — gave the bucks a needed jolt, and there has been a considerable increase in buck movement, mostly cruising, the past three mornings,” Free said. "The hard chasing in the northwest is on track for the gun opener.” Food sources now being used by deer in the northwest include agricultural crops such as wheat, rye, alfalfa and milo. The rut also is picking up in southwest Oklahoma, said Rod Smith, southwest region supervisor for the state Wildlife Department. Larger bucks are just now beginning to chase does, and Smith predicts strong rutting activity heading into opening day. Deer are shifting to winter-type food sources in the southwest. In central Oklahoma, pre-rut activity was observed at the end of muzzleloader season. While most hunters may have expected the rut to peak in mid-November, above normal temperatures continued until this past weekend, and the rut also appears to be continuing. The deer harvest has been higher this year in central Oklahoma, said Rex Umber, central region biologist for the state Wildlife Department. "If the acorn crop is good in your area, that’s where your deer will be,” Umber said. "Do your scouting a few days in advance of your hunt, but stay out of your honey hole at least three days before because bucks will be on the move.” In northeast Oklahoma, the rut appears to be winding down, while in the southeast it is in full swing. Whitetails in eastern Oklahoma are still feeding on large quantities of acorns produced this year by both black and white oak trees.