PHOENIX - Deaths of migrants entering the country illegally along the Southwest border have remained steady at an average of 150 a year since 2002, while deaths of border crossers from nations other than Mexico have increased, according to a report from the University of Arizona released Wednesday.
University researchers from the school's Binational Migration Institute reported the Pima County Office of the Medical Examiner processed the remains of 2,238 migrants from 1990-2012, of which more than 750 are unidentified.
The authors contend the findings highlight how many migrants intent on crossing the border into Arizona have been pushed into more remote areas where travel is dangerous due to extreme conditions across wide open desert and mountainous terrain. The move comes amid increased border security at traditional crossing points closer to urban areas with easier access into the U.S.
The findings are based on studies of demographic characteristics of the identified remains and the locations where bodies have been found over the past 22 years.
However, the authors acknowledge the research is only an extrapolation of the data available, since there is no definitive way to determine exactly how many people are crossing the border illegally, and can only be roughly gauged using the numbers of remains found and apprehension data from U.S. authorities. The report also does not take into account the likely hundreds more who have died while attempting to cross into the U.S. whose remains are never found.
"The magic question is how do we know how many people are really crossing?" asked Daniel E. Martinez, an assistant sociology professor at The George Washington University and one of the study's authors. "Border Patrol apprehension statistics are not ideal but it is something we can use to understand at least where people are crossing."
The study also found that from 2000 to 2005, roughly 9 percent of remains found in the desert were those of people from countries other than Mexico. That number increased to about 17 percent from 2006 to 2012, largely made up of migrants coming from Central America.
"That's a pretty significant shift," said study co-author Robin C. Reineke of the University of Arizona.
While Mexicans still make up the largest majority of the border crosser remains discovered, Martinez said the shift to more bodies being found from other nations is likely indicative of slightly rosier economic conditions in Mexico, while many Central American countries continue to grapple with poverty and increasing drug violence.
In addition, the rate of female crossers found dead has dropped from about 22 percent from 2000 to 2005, to roughly 16 percent in the ensuing years through 2012.
The researchers theorize that many of the traditionally male border crossers began staying longer in the U.S. rather than returning to their home countries after seasonal work, leading to an increase in female migrants aiming to reunite with families. The findings indicate, also merely theorizing, that the numbers of female crossers have declined after they successfully made it into the U.S. over the past decade and are now living with families in the U.S.
The report also found that of the 2,238 remains examined by Arizona officials from 1990-2012, 45 percent were confirmed deaths from exposure to the elements, 36 percent died from undetermined causes, 9 percent were from vehicle accidents, 6 percent miscellaneous and 4 percent were ruled homicides.