Northern elephant seal populations appear to be shifting northward along the California coast, with ever-increasing numbers taking to the sheltered beaches of Point Reyes to breed. For the third winter, elephant seal bulls have taken over the Ken C. Patrick Visitor Center at Drakes Beach, despite efforts to reroute them. Females were successfully shooed into an area west of the visitor center that’s been designated for the breeding colony. “Some years these efforts are more successful than others,” said Sarah Codde, a marine ecologist for Point Reyes National Seashore. Winter is breeding season for the seals, and though they can be spotted in the seashore year-round, the largest numbers are present from December through March. Most females have weaned their pups and left by late February, but males hang around until the last female is gone. Weaned pups are found through April, spending their solo months playing in the water and learning to swim, dive and find food. Pups born on Point Reyes have a very low mortality rate, and though elephant seals have an urge to return to the place where they were born, in stormy seasons they will find the safest beach. This combination of factors has caused the particularly calm waters of Drakes Beach to become a refuge for growing numbers of seals. Between 2005 and 2021, seal counts averaged 1,600, but this year, at the peak of pupping season, the park counted more than 2,600. Scientists apply flipper tags to track individuals, and tagged seals from Año Nuevo and San Simeon, in San Mateo and San Luis Obispo Counties, are increasingly sighted in Point Reyes. Yet researchers monitoring those southern seal colonies have not seen a similar influx to their sites. Ms. Codde said scientists understand little about the northward trend. “There’s a new colony in the Lost Coast area, and a good number of tagged individuals from the Point Reyes area have been sighted up there,” she said. Locally, docents were posted at Drakes Beach seven days a week during pupping season to ensure the area could remain open to visitors. Though male seals are somewhat more tolerant of people, protective mother seals can be dangerous, and individuals can be skittish, which puts pups at risk of becoming separated from their mothers. Park officials encourage keeping a distance of at least 25 feet. “Typically, with any wildlife, if they’re looking at you, you’re too close,” Ms. Codde said. If seals start to move at all, “your presence has forced them to change their behavior.” Northern elephant seals are not small animals—bulls weigh up to 5,000 pounds—so their presence hardly goes unnoticed and brings ecological impacts. The pinnipeds are accustomed to very cold water, and when the air temperature is too hot, they will flip wet sand onto their bodies, lowering their body temperature through evaporation. “They like to flip sand, and they can really change the shape of beaches with all the flipping they do,” Ms. Codde said. Park scientists have been concerned the behavior could impact snowy plover habitat if the South Beach elephant seal colony continues to expand. The federally threatened plovers nest in the sand, digging fragile “scrapes” in which to lay their eggs. Additionally, as predators at the top of the food chain, elephant seals eat a diet that contains high levels of mercury; the metal builds up in their skin tissue and researchers have found it in high levels on beaches where they molt.