Most fawns are born roughly 6 months after mating. Most fawns are born in late May through early June.
Whitetail fawns are typically only 6 - 8 pounds at birth and will grow to be over 60 pound before their first winter.
Yearling does give birth to a single fawn. Older does can give birth to twins and even triplets as well.
The Reproductive Cycle of Whitetail Deer
The reproductive cycle of whitetail deer is designed to maximize the survival chances of their offspring. These deer, being short-day breeders, mate during the fall when day length is decreasing. This timing ensures that fawns are born in spring, when there is an abundance of lush, nutritious vegetation for both the mother to produce milk and for the offspring to supplement their diet.
Whitetail deer can come into heat multiple times a season, with their reproductive system regulated by hormonal changes brought about by decreasing daylight. Overall, the efficient reproductive cycle of the whitetail deer is a testament to nature’s success in preserving and furthering the species.
Birth Timing and Fawn Survival
Whitetail deer have adapted their reproductive cycle to give birth at the most optimal time for fawn survival. In the Northern region, a higher percentage of fawns are born during a brief period in late May and early June. This is when new lush vegetation provides excellent hiding cover for fawns and an abundant supply of nutritious forage, necessary for the doe to produce sufficient milk.
Late-born fawns face a higher risk of not achieving the physical size and fatness necessary to survive harsh winters, but those in the Midwest and the South tend to fare better due to more favorable conditions and longer hunting seasons.
Geographic Variations in Fawn Births
The birth timing of whitetail fawns varies geographically to ensure optimal survival rates. In the North, a higher percentage of fawns are born during late May and early June, when abundant vegetation provides excellent hiding spots and nourishing forage. Late-born fawns in the Midwest are often the result of ideal conditions and breeding among young does, resulting in births during July.
In the South, late-born fawns are more prevalent due to longer breeding and hunting seasons, leading to late breeding and birthing. This geographic variation in fawn births helps maximize their chances of survival in different environments.
Late-Born Fawns in the Midwest
Late-born fawns in the Midwest are often the result of ideal breeding conditions among doe fawns. In regions with rich farmland and low deer density, a high percentage of one-year-old does tend to produce their first offspring. These doe fawns breed about a month later than adult does, resulting in fawns born around July or August.
Though late-born fawns tend to be larger at birth, they also have a good chance of growing to a respectable size before winter if they have access to excellent nutrition, which is typically found in Midwest farmland areas.
Late-Born Fawns in Southern States
Late-born fawns are more prevalent in Southern states due to various factors. Unbred adult does in these regions might re-cycle and come into estrus as often as seven times during one season, leading to late breeding and birthing.
Additionally, many Southern states have long hunting seasons starting in August or September, resulting in skewed adult sex ratios due to the preference for hunters to harvest bucks. This further increases the chances of late breeding and birthing due to it taking a longer period of time for all of the does to be bred by a smaller number of bucks. Despite facing potential challenges such as overbrowsing and poor nutrition, late-born fawns generally survive and reach adulthood thanks to the abundant supply of lush vegetation in these areas.
Importance of Nutrition for Fawn Growth
The growth and development of whitetail fawns primarily depend on their nutrition, especially during their early years. Ensuring that fawns receive proper nutrients, such as colostrum from their mother within the first 24 to 36 hours after birth, is crucial for their survivability (Evers et al. 2017).
Fawns begin consuming solid food at around two weeks of age, and it is important to provide them with a palatable, high-protein diet (Short 1964). Adequate nutrition enables fawns to better express their genetic potential for antler growth, reproduction, and overall health, contributing to a more robust deer population.
Survival Challenges for Undersized Fawns
Undersized fawns face numerous survival challenges as they navigate their first few months of life. These fawns, typically born late in the season or to younger mothers, struggle to build body mass and fat reserves quickly enough to endure harsh winter conditions.
In the North, smaller fawns often fall victim to freezing temperatures and limited food sources. In the South, the situation is slightly better, but late-born deer still take longer to reach sexual maturity, which can impact population dynamics. Ultimately, it’s a race against time for these undersized youngsters, where ample nutrition and favorable weather conditions are vital for their survival.
Maternal Behavior During Fawn Births
During the late stages of pregnancy, a doe’s behavior changes dramatically in response to hormonal fluctuations and increasing day length. She becomes intolerant of other deer, including her yearlings, and isolates herself in a specific ‘fawning territory’ to give birth.
This isolation is essential for establishing a strong maternal bond with the newborn fawn during the critical imprinting period. The doe meticulously cleans her newborn fawn, consuming all traces of membranes, afterbirth, and even bloodstained leaves at the birth site. This noteworthy maternal behavior ensures the safety and proper development of the young fawn.
Importance of the First Week of Fawn Life
During a newborn fawn’s first week, they rely solely on their mother’s milk for nourishment. This period is also vital for the fawn to bond with its mother, who will help to keep it clean and protected from predators by consuming its urine and feces.
Additionally, the fawn’s reddish-brown coat with spots helps it blend into its surroundings, providing further protection from predators. Overall, the first week of life is an essential period for fawns to develop their strength and ensure their survival.
Yearling Bucks and Maternal Doe Behavior
Yearling bucks often experience a confusing yet crucial time during the week when whitetail fawns are born, usually in the last week of May or the first week of June. Since maternal herds consist of small groups of family-related females, the doe must separate from her yearlings to ensure the newborns bond with her and not other deer.
While most female yearlings remain nearby and later rejoin their mother’s group, most buck yearlings leave to seek out adult buck groups. However, if they remain in their maternal herd, they will eventually be driven away by the females in September or October.