Federal wildlife officials have asked pilots to stay clear of a massive herd of walrus that has gathered in record numbers on a beach in northwest Alaska. An estimated 35,000 walruses were spotted about 5 miles north of Point Lay, Alaska, on Sept. 27 by scientists on a survey flight. The U.S. Fish and Wildlife Service (FWS) requested that pilots fly at least 2,000 feet above the walrus herd and a half mile away from it. Helicopters were asked to fly 3,000 feet above and a mile away from the walruses, who were forced to swim to shore due to the lack of the sea ice that normally provides resting areas this time of year. No flights had been rerouted away from the beach, as some outlets previously reported, the Federal Aviation Authority told NBC News. The request from the FWS warned that walruses are sensitive to engine noise — a problem when planes fly low to get a better look at the animals — and aircraft could cause them to stampede. "This big group at Point Lay is mostly cows with calves, and when they stampede, they tend to run over the calves," James MacCracken, supervisory wildlife biologist at the FWS regional office in Alaska, told NBC News. "The calves can get crushed and suffer severe trauma that could kill them immediately or lead to their death later on."

In this aerial photo taken on Sept. 23, some 1500 walrus are gather on the northwest coast of Alaska. Pacific walrus looking for places to rest in the absence of sea ice are coming to shore in record numbers, according to NOAA. Corey Accardo / NOAA via AP

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As sea ice wanes, 35,000 walrus come ashore on an Alaskan beach. The picture is incredible http://t.co/urOiX04T3T — Bill McKibben (@billmckibben) October 1, 2014

— Keith Wagstaff