The deer rut, a period of heightened breeding activity, is a recognized event in the annual cycle of deer. While the primary rut is well-known, a distinct, later breeding period, often called the “second rut,” also occurs. This secondary phase continues reproductive efforts. Understanding its timing and biological factors provides insight into deer population dynamics.
The Biological Basis for a Second Rut
A second rut occurs because some does re-enter estrus after the primary breeding period. Not all does are successfully bred during the initial rut. This can happen if younger does, such as yearlings, reach sexual maturity later in the season, or if does were not successfully bred during their first estrous cycle or lost their fawns early.
Unbred does re-enter estrus approximately 28 days after their initial cycle. This physiological response creates a secondary breeding window. White-tailed deer are polyestrous, meaning females can be in heat multiple times per year if not successfully bred. The estrous period is short, lasting about 24 to 48 hours for an individual doe.
Typical Timing and Variability
The second rut’s timing directly links to the primary rut’s peak in a given area. It usually occurs about one month after the main breeding activity subsides. For many northern regions, where the primary rut peaks around mid-November, the second rut is often observed from late November through mid-December. In some areas, it can extend into early January.
Timing varies significantly based on several factors. Photoperiod, or the amount of daylight, is the primary trigger for the breeding season. Local environmental conditions, such as deer population density and buck-to-doe ratio, also play a role. For example, areas with a skewed buck-to-doe ratio might experience a more pronounced second rut as some does may have been missed. Southern regions, with less extreme seasonal changes, often show more variation in rut timing and duration compared to northern areas, where consistent timing is important for fawn survival through harsh winters.
Key Indicators and Deer Behavior
Observable behaviors indicate the second rut’s onset and progression. While activity intensity may be lower than during the primary rut, bucks often show renewed interest in seeking does. This includes increased scraping, where bucks clear ground and urinate, and rubbing, where they rub antlers on trees. These actions serve as visual and olfactory signals to other deer.
Mature bucks, less visible after the primary rut’s peak, become active again searching for receptive does. They may exhibit renewed chasing behavior, pursuing does entering estrus. Unbred does display signs of receptivity, attracting bucks. Observers might notice increased deer movement, particularly around food sources, as bucks continue their search.