Limited information exists on the growth and development of beluga whales (Delphinapterus leucas). Accurate information regarding weight and length at known ages over time from belugas in the wild is impractical to obtain. The data that is available on animals in wild populations is impossible to interpret due to lack of known age reference points.

Sea World of Texas, San Antonio, Texas, the Aquarium for Wildlife Conservation, Brooklyn, New York, and the Vancouver Aquarium, B.C. Canada, have collected data on 11 beluga calves born at their facilities.

Sea World of Texas has had five successful births and one term stillborn since August of 1992. The Aquarium for Wildlife Conservation has had four successful births since August 1991, and the Vancouver Aquarium has had one successful birth in 1995. Weight compared to age is illustrated in Figure I and length compared to age is illustrated in Figure 2. Four calves in Texas were first observed eating solid food at 172, 194, 207, and 328 days of age. Figure 3 illustrates food consumption from the first day three of these calves were observed eating fish through 200 days. The calves in New York first consumed solid food at 199, 255, 415, and 698 days of age. One calf never ate consistently and died at 791 days of age.

As with other animals, age and size are closely related, particularly prior to maturity. The figures illustrating length and weight compared to age may be useful in accessing the age of collected animals and the expected growth and development of future beluga calves born in oceanariums.

Figure 1. The mean + standard deviation (std) weight verses age of the beluga whales. The 4th order polynomial regression (r2 = 0.97; y = βo + β1X + β2X 2 + β3X 3 + β4X 4) of weight vs age, with the 95% confidence interval (CI) (solid line) and the 95% prediction interval (confidence interval for the population PI) of the regression are also illustrated.

Figure 2. The mean + std. length verses age of the beluga whales. The 4th order polynomial regression (r2 = 0.96) of length vs age, with the 95% CI (solid line) and the 95% PI of the regression are also illustrated.

Figure 3. Mean + std, 4th order polynomial regression (r2 = 0.96) with 95% CI and PI) daily food consumption from three Sea world calves. Day zero is the first day postpartum of regular food consumption.

The authors would like to thank the Vancouver Aquarium and Skip Young for the data on their calf included in this paper.