According to Fisheries and Oceans Canada reports, the number of harp seal pups born in a year is estimated from time to time by using aerial surveys conducted in the spring, when the seals have pulled out onto the ice to have their pups.

Estimates of abundance of harp seals have been found using a population model that incorporates annual reproductive rates and periodic estimates of pup production as well as information on removals.

Scientist Garry Stenson says the seal herd is spread out over a much larger area than usual instead of congregating in a few areas.

Stevenson tweeted that he followed timing of births by identifying Newfoundland pups’ developmental stage.