The ongoing deportation program is resulting a "new type of immigrant" trying to cross the border into the United States, namely undocumented foreigners who have lived illegally for many years in this country and "the only way of life they know is that of the United States," Jason De Leon, an assistant professor of anthropology at the University of Michigan, said.

De Leon heads a project documenting the evolution of immigration between Mexico and the United States through the collection of objects left by immigrants during their trek through the desert on the southern border.

In 2009, De Leon set up the Undocumented Migration Project aimed at understanding the process and evolution of immigration along the border and in northern Mexico.

"The stories of the immigrants are changing. They're telling us that now they are walking much more and suffering much more," De Leon said in an interview with Efe.

Before, many people from northern Mexico crossed the border into the United States, but now there are more migrants from central and southern Mexico and from Central American countries, the expert said.

Also, now a new "type" of migrant is being seen, people who have spent many years illegally in the United States and who were then deported because of the programs established by the federal government, De Leon said.

"These are people who have been educated in the U.S., who haven't set foot in Mexico in years and who are trying to cross the desert because the only life they know is in this country," De Leon, who grew up along the Texas border, said.

Some of the items collected during the course of the project make up an exhibit in Michigan, and De Leon hopes in the future to bring the exhibit to Arizona or even to take it to Mexico. EFE