Observation of adoption in polar bears (Ursus maritimus)

We observed a case of adoption of a single four-month-old polar bear cub (U rsus maritimus) into an existing litter of two cubs on Hopen Island, Svalba rd. We believe the high density of maternity dens in the study area may inc rease the likelihood of natural adoption. Speculation about theoretical imp lications of adoption is of scientific interest. However, we believe that t he probability of adoption may increase when family groups are captured, an d the scientific interpretation of such events is of questionable value. We urge researchers to exercise caution in handling family groups in high-den sity den areas.