The video of a bald eagle, seemingly hurt, swimming in the St Croix river in the US has gone viral on Twitter. Minnesota resident, Dan Goff, who filmed the video initially thought the bald eagle – who can be seen spreading its wings and trying to swim jerkily – was injured.

But it turned out that the bird was hampered in its movement because it was holding a huge, struggling fish between its claws, which it was dragging it to the shore for an afternoon feast.

While eagles usually swoop down from the air and scoop up fish swimming close to the surface of the water, this particular fish may have proved too heavy for the bird to fly with.

Once the eagle reached the shore, the large fish made one last attempt to struggle back into its watery home – but not on the bald eagle’s watch.

Another video posted by Goff from a few hours later showed the triumphant eagle basking on the shore, a half-eaten fish at its side.

Social media users were amazed at the powerful bird’s play for prey. While some discussed specifics about the bird, others dissected its hunting technique.

Yet others made political connections. The bald eagle is the national emblem of the United States and, though not endangered, is considered to be a threatened species. The bird has been in the news in the last few weeks after US President Donald Trump announced controversial changes to the country’s Endangered Species Act.

The Nixon-era act is credited with saving animals such as the grizzly bear and the Northern grey wolf from extinction, and the bald eagle, from the catastrophic effects of the pesticide DDT.

Activists and conservationists have reacted in alarm after the government announced a set of rollbacks to the act, including a decision to consider economic factors before categorising a species as endangered or threatened.