As the US government border agency makes its selection of a company to build President Trump's "great wall" at the US-Mexico border, BBC science reporter Victoria Gill joined a team of scientists studying the impacts of such a fence on desert wildlife.

In a collaboration between scientists in Arizona and Mexico, the researchers are working in the Sonoran Desert, which stretches across the border and is home to some of the most endangered mammals in the US.

Filmed and edited by Phillip Edwards