SWANSEA, Mass. (WPRI) — It’s a mystery that’s concerning Swansea residents — something is affecting the town’s swan population.

Over the last few weeks, residents tell 12 News a number swans have been found dead along Cole River.

It’s unclear at this time what’s killing the birds.

Joan Duffy estimates that she’s come across at least six dead swans within the past week alone.

“This water used to be full of them,” she said. “Now, we’re finding them [dead] day and night.”

For some, like Debra Manning, the swans are more than just wildlife.

Manning said one swan who recently lost his mate became attached to her while she was kayaking. She described the swan as her “buddy.”

“He’s just so sweet,” she said. “I [used to] feed him all the time … he died three days ago.”

And it’s not just the swans that are dying.

Manning said she watched a goose die right in front of her the other day.

“He died right at my feet,” she recalled.

Both Manning and Duffy have been tracking where the birds have died, but so far there’s no pattern.

Swansea Animal Control tells 12 News it has sent some of the swans out to be tested for avian flu. The results are still pending.

“If it’s the avian flu or some sort of a bird flu that we can’t do anything about, then that’s fine,” Manning said. “But if we can do something to save the rest of these birds … they’re dying.”

“What would Swansea be without swans?” Duffy added. “They’re not dying out in the water, they’re dying on land. They’re coming to us for help and we need to help them.”

Anyone who comes across a dead swan or goose is urged to contact Swansea Animal Control at (508) 679-6446.