And these U.S. Border Patrol agents, who now must carry guns and who are vastly outnumbered by the aliens, say they are lucky if they can catch one in five illegal crossers.

An additional 22,000 illegal crossers were apprehended by patrols within the ten-mile (16 km) border zone and turned over to military government.

Initial Government plans for the region had figured the terrain would be enough to stop most illegal crossers here.

Along the whole border from Texas to California, 146,000 illegal crossers were detained during January and February, up by 24 percent from 1995.

Mr. Perry defended his dispatch of National Guard troops to secure the border against illegal crossers but faulted the federal government's actions as inadequate and said he would seek $100 million from the legislature for more enforcement.

Border control requires cracking down on all illegal entries, regardless of the nationalities of the illegal crossers.

But a report in May 2009 by the Congressional Research Service found "strong indication" that illegal crossers had simply found new routes.

PAGE A9 Workaday World at Border Though the Border Patrol says their presence has deterred illegal crossers, National Guard troops at the Mexican border say their jobs can seem humdrum.

At the Tijuana Estuary, a national wildlife refuge, Brian Collins, a biologist, said illegal crossers trampled rare plants and the nests of endangered birds on their furtive way north, sometimes even eating the birds' eggs for breakfast.

Over the same period, arrests of illegal crossers dropped 10 percent, to 270,000 people.