The giraffe calf, or fawn, is born after a gestation period of about 15 months. Weighing between 130 and 150 pounds at birth, a calf can grow up to an inch per day in its first week. This rapid development requires a constant, energy-dense diet. This diet transitions from a purely liquid source to solid vegetation as the calf matures.
Initial Nutrition: Mother’s Milk
For the first few months of life, a giraffe calf relies entirely on its mother’s milk as its sole source of nourishment. The first milk produced, known as colostrum, is ingested within the first few hours after birth and provides the newborn with crucial antibodies for immune defense. Without this early intake of colostrum, the calf’s chance of survival is significantly lowered due to a lack of passive immunity.
Giraffe milk is rich in both fat and protein, sustaining the calf’s rapid growth rate. The fat content is particularly high during the first month of lactation, averaging around 11.0%. This concentrated energy allows the calf to gain an average of 1.0 to 1.5 kilograms (2.2 to 3.3 pounds) per day. The period of exclusive nursing typically lasts about four months.
The Weaning Process and Solid Introduction
The transition from a liquid diet to solid food is a gradual process tied to the development of the calf’s digestive system. As a ruminant, the giraffe has a four-chambered stomach, and the largest section, the rumen, must develop the necessary microflora to break down tough plant material. This development is triggered by the introduction of solid food into the digestive tract.
Calves usually begin to sample browse, such as leaves and twigs, around two to four months of age, often by mimicking their mother’s feeding behavior. This early nibbling is a behavioral curiosity more than a nutritional requirement initially, as the mother’s milk still provides all necessary nutrients. The introduction of solid food encourages the colonization of the rumen by specialized microbes, preparing the calf for its future herbivorous diet.
The weaning phase is prolonged and variable, lasting anywhere from six months up to 15 months. During this time, the calf slowly increases its reliance on vegetation. The gradual decrease in nursing volume allows its four-chambered stomach to adapt to the change in food source. This long weaning period ensures the calf is ready to process the complex carbohydrates found in foliage before becoming nutritionally independent.
Post-Weaning Diet and Adult Food Sources
Once fully weaned, the young giraffe’s diet mirrors that of an adult, consisting primarily of browse (leaves, shoots, and buds of trees and shrubs). Giraffes are selective browsers, choosing food based on nutritional content and moisture, with a preference for plants like Acacia and Commiphora. These trees, which often have formidable thorns, require specialized anatomy to consume.
The giraffe utilizes its long, dark-colored, prehensile tongue, which can be up to 18 inches long, and tough lips. These features help navigate thorny branches and strip leaves without injury. The lining of the mouth is coated with thick tissue for protection against sharp plant defenses.
A significant portion of the giraffe’s water intake is derived from the moisture content of the leaves. This reliance on foliage is an important adaptation for survival in arid environments. It allows them to go long periods without drinking standing water.