A baby moose, known as a calf, is the largest newborn of any deer species in the world. The calf’s size at birth provides a necessary head start for survival in harsh northern environments. Understanding the initial dimensions and the incredible rate of growth illustrates the biological demands placed on the mother and the young animal.
Size at Birth
A newborn moose calf typically weighs between 28 and 35 pounds (13 to 16 kilograms) at birth. Some individuals can weigh up to 45 pounds (22 kilograms). This initial mass is a considerable advantage, allowing the calf to stand and walk within hours of being born, a necessity for avoiding predators.
The calf’s shoulder height often exceeds 3 feet (0.9 meters). Calves born as twins are generally smaller than single-born calves. Twin calves may weigh considerably less, sometimes around 14 pounds (6.4 kilograms) each, making them more vulnerable in their first weeks of life.
Rapid Growth and Development
The moose calf exhibits a rapid growth rate, a biological adaptation that is necessary for surviving its first winter. While nursing, a calf can gain an average of 2.2 pounds (1 kilogram) per day. This accelerated weight gain continues for the first few months of life.
Calves begin to sample solid food, such as vegetation, just a few days after birth, though they remain dependent on their mother’s milk for several months. By the time they are weaned, typically around six months of age, the calf will have increased its birth weight by more than ten times. By the fall, a calf can weigh between 300 and 400 pounds (136 to 181 kilograms).
The calf remains with its mother for approximately one full year, until she drives it away shortly before the birth of her next calf. At this point, the young moose is considered a short yearling and is forced to become independent. It will continue to grow until it reaches full maturity between four and six years of age. A larger body size significantly improves the young moose’s chances of surviving the deep snow and limited forage of winter.
Adult Size Context
The calf’s size at birth is put into perspective when compared to its fully grown parents. A mature bull moose can stand an average of 6 feet (1.8 meters) tall at the shoulder and weigh as much as 1,400 pounds (635 kilograms). The largest subspecies, the Alaskan moose, can reach nearly 7 feet (2.1 meters) at the shoulder and weigh over 1,600 pounds (725 kilograms).
Cow moose are generally smaller than bulls, typically weighing between 595 and 1,080 pounds (270 to 490 kilograms). The difference between a 30-pound newborn and a 1,400-pound adult illustrates the growth trajectory the calf must follow. This size difference highlights the physical challenge of the calf’s first year, where it must quickly grow from a vulnerable newborn to a formidable young animal.