A recent sighting of Southern Resident orcas off the coast of California near San Francisco is helping researchers gain a better understanding of the whales’ winter migratory pattern as they search for sustenance.

Susan Berta, Greenbank resident and co-founder of the Orca Network, said the organization has been working with the Center for Whale Research and the National Oceanic and Atmospheric Administration (NOAA) the past few years to increase coastal sightings and reports of the endangered whales.

“It’s always exciting when we get calls from the California or Oregon coast with reports that sound like it may be ‘our’ whales, the Southern Resident orcas, and even more exciting when someone takes photos that confirm the sighting as a Southern Resident pod, as recently happened off San Francisco,” Berta said.

Ken Balcomb of the Center for Whale Research based in Friday Harbor has been traveling up and down the coast, putting up posters imploring people to report orca sightings to the Orca Network Whale Sighting Network. The posters have effectively increased the number of reports each year, including reports from commercial fishers, crabbers, and charter boats as well as from people living on or visiting the coast.

The Orca Network received a call on Jan. 14 as a result of Balcomb’s coastal poster campaign reporting a large pod of more than 20 orcas spread out several hundred yards, heading south in Half Moon Bay, 30 miles north of Santa Cruz, Calif.

“Given the time of year, number of orcas and location, we had a pretty good idea this was a Southern Resident pod, likely K or L-pod or both, as they are the two pods known as traveling as far south as Monterey, Calif., and as far north as Queen Charolotte Sound in search of salmon during the winter,” Berta said.

The Orca Network received an e-mail from a whale researcher out of Monterery, Calif. last week that reported a pod of orcas spotted and photographed near San Francisco. In several photos taken during the encounter scientists were able to positively identify an individual female known to researchers as K20, traveling with her 3-year-old offspring, K38, born in 2004.

“This sighting makes it very likely that the Jan. 14 sighting we had of 20 orcas north of Santa Cruz was also K-pod as they were heading south,” Berta said.

Orca researchers are unsure if the new sightings signal a new travel pattern for the killer whales, or if the migration has been a pattern that has historically gone unreported or unidentified.

“The Southern Residents have been confirmed at least 10 times since 2000 off the California coast, and there have been many other sightings of orcas that have not been confirmed as Southern Resident orcas but that may have been,” Berta said. “There is speculation that the orcas may be having to travel further south to find food, due to lack of salmon in Washington State waters.”

Every coastal sighting adds another piece to a puzzle that will ideally reveal where the Southern Residents are traveling to find food in the winter. Researchers are able to observe the orcas regularly from summer through late fall or early winter when they are off the San Juan Islands or in Puget Sound, Berta said. But data has been sorely lacking in the past during winter months. The sightings are slowly filling in the data gaps and confirming suspicions that the entire west coast is an important habitat for the Southern Residents, a habitat that was not included in the Critical Habitat Plan finalized by NOAA as part of the Orca Recovery Plan and Endangered Species Act listing.

“If we can collect enough data to prove the coast is consistently used by the Southern Residents, hopefully the Critical Habitat Plan will be amended to include this area and the salmon runs they are feeding on as important to the survival of this fragile community of orcas,” Berta said.