WESPEN Online Order Form print this page
US Fish & Wildlife Service FieldNotes

SAN JOAQUIN RIVER NWR: Young California Sea Lion visits the San Joaquin River NWR

Region 8, April 14, 2014
"Hoppie" the sea lion is placed in a Marine Mammal Center crate and awaits transport. - Photo Credit: n/a
A young sea lion, later named Hoppie by refuge staff, was discovered by workers on private property adjacent to the San Joaquin River National Wildlife Refuge.
A young sea lion, later named Hoppie by refuge staff, was discovered by workers on private property adjacent to the San Joaquin River National Wildlife Refuge. - Photo Credit: n/a
Likely exhausted from an arduous journey in unfamiliar territory, Hoppie quickly fell asleep once safely inside the transport crate on the way to meet with Marine Mammal Center staff.
Likely exhausted from an arduous journey in unfamiliar territory, Hoppie quickly fell asleep once safely inside the transport crate on the way to meet with Marine Mammal Center staff. - Photo Credit: n/a

By Madeline Yancey

The refuges of the San Luis National Wildlife Refuge Complex in the northern San Joaquin Valley are known for their grassland, riparian, and wetland habitats and the diverse wildlife species they support. On March 31, an aquatic resident of a different sort visited the San Joaquin River NWR in Stanislaus County – a California sea lion nicknamed “Hoppie” by refuge staff.

Hoppie certainly was far from his natural “wetland” home in the Pacific Ocean, but he is not the first California sea lion to visit the refuge complex. In February 2004, another of his kind – “Chippy,” a 300-pound male sea lion, swam farther up the San Joaquin River to find himself just outside the San Luis NWR in Merced County.

Hoppie was a much younger and smaller sea lion than the one before him – only about 50 pounds, but like his predecessor, probably entered the San Joaquin River hot on the trail of big fish like large-mouth bass, striped bass, carp, or catfish. Sea lions can travel 15 to 20 miles per hour in the open ocean, so it would not have taken him long to wind up in Stanislaus County.

Hoppie was first spotted about 7:30 a.m. about a half mile from the San Joaquin River by field workers. He was later captured in an almond orchard bordering refuge lands at about 11 a.m. According to Assistant Refuge Manager Eric Hopson, during his three-and-a-half-hour journey, Hoppie likely travelled through a side channel of the San Joaquin River, moved overland through riparian forest on the San Joaquin River NWR, along the edge of a refuge crop field, and finally along a dirt road bordering an orchard where he was rescued. After first being sighted near the refuge boundary, Hoppie travelled a total of about one and a half miles from the river. Sea lions are quite mobile on land compared to seals – a similar marine mammal species with which they are often confused.

Hopson first received word of Hoppie when a refuge associate called him about 8 a.m. saying, “Good morning, you won’t believe this!” Hopson and refuge staff spent the next couple of hours making contact with the Marine Mammal Center on the coast. Meanwhile, neighbors followed the wanderer to keep track of its whereabouts. By 10 a.m., Hopson had made contact with the Marine Mammal Center (MMC) in Sausalito and arrangements had been made to transfer the sea lion to a MMC volunteer who would deliver him to the Center, but first, Hoppie had to be captured.

Hopson said at first contact, the sea lion let out a series of mournful “barks” and was indignant at being “trapped,” but after he was secured inside an animal carrier lined with towels and covered, like a dark cozy cave, Hoppie fell asleep – and started snoring! He was exhausted and probably had not eaten properly for some time. The head of the rescue division of the MMC said that after evaluation by their marine mammal specialist veterinarians, Hoppie was determined to be a young adult male that was emaciated, but otherwise in good condition. He was neither ill nor injured. Hoppie is currently undergoing re-conditioning with a “power diet” of all the fish he can eat. When he is back in full form he will be returned to his proper aquatic home in the Pacific Ocean.

Madeline Yancey is a Park Ranger (Visitor Services) at the San Luis NWR Complex.

Contact Info: Jack Sparks, 209-826-3508, jack_sparks@fws.gov