Young deer, known as fawns, have unique dietary needs that evolve rapidly as they grow. Their initial diet is entirely dependent on their mother, transitioning to diverse natural vegetation as they mature. Understanding these nutritional requirements is important for their early development and survival in their natural habitat.
Mother’s Milk: The Essential Start
For the first two weeks of life, a fawn’s diet consists exclusively of its mother’s milk. This milk provides fat, sugar, and protein, enabling fawns to double their birth weight within two weeks and triple it within a month. The initial milk, colostrum, is a nutrient-rich fluid secreted by the doe immediately after birth. Consuming colostrum within 24 to 36 hours transfers antibodies, providing passive immunity.
Colostrum is vital for developing the fawn’s immune system, protecting it from diseases and infections. Doe’s milk also supplies essential hydration. While fawns can be weaned around 10 weeks, many does continue to nurse their offspring for 12 to 16 weeks, or longer.
Gradual Shift to Foraging
Around two weeks of age, fawns begin to supplement their milk diet by nibbling on tender vegetation. This gradual transition involves learning foraging behaviors by observing their mothers. Their digestive system adapts, allowing the development of the rumen, a specialized stomach chamber that processes plant matter.
Fawns initially seek easily digestible natural foods such as soft-stemmed plants (forbs) and young shoots. They also consume leaves and twigs from shrubs (browse). As they grow, their diet diversifies to include grasses and, seasonally, acorns, important for building fat reserves before winter. The deer’s four-chambered stomach relies on microbes to break down plant material, enabling nutrient extraction.
Harmful Foods for Fawns
Introducing human foods or garden plants to fawns can be detrimental. It is advised not to feed wild fawns; contact a wildlife rehabilitation center if a fawn appears orphaned or injured. Human-provided foods can disrupt a fawn’s specialized digestive system, which is adapted to natural forage.
Cow’s milk, for instance, is harmful to fawns because they are often lactose intolerant, leading to digestive upset, scours (diarrhea), or bloat. Bread and other baked goods offer little nutritional value and can cause digestive blockages or lead to a buildup of lactic acid. Corn, while seemingly natural, is high in starch and low in protein, and its sudden introduction can cause acidosis. This disrupts the delicate balance of bacteria in their rumen, making them unable to properly digest food and potentially leading to dehydration, neurological problems, or death.
Other human-introduced items like bird seed, alfalfa cubes, or livestock feed are not suitable for fawns and can cause health issues. Certain ornamental garden plants are toxic, even in small quantities. Japanese yew, azaleas, and rhododendrons are examples of plants that can be highly poisonous to deer and fawns. Fawns are vulnerable to these dietary disruptions due to their rapid growth and limited fat reserves.