The Deer Hunter star has teamed up with officials at The Humane Society of the United States to front a new public service announcement, in which he encourages people to avoid having wild animals put down where possible.

In the "Be a Humane Neighbor" advertisement, he says, "The wildlife in our country is diverse, abundant and awe-inspiring, but when they get too close, in our backyards or in our communities, they are perceived as nuisances.

"Due to urban development, we are losing wildlife habitat leading to increased wildlife encounters. This often ends badly for the animals, who are killed using inhumane methods. Thankfully there are humane and sustainable solutions that communities can implement. Join me and support the creation of a peaceful co-existence with our wild neighbours."