The white population is shrinking in more than half of the nation's major counties, including the two that make up the Buffalo metropolitan area.

That's according to an On Numbers analysis of the latest U.S. Census Bureau estimates for 979 counties with more than 50,000 residents. The study covered the period between July 1, 2010, and the same date in 2011.

The number of white persons declined in 517 of those major counties during that span, accounting for nearly 53 percent of the study group. Increases were reported in 461 counties, and one was unchanged.

The white population of all 979 counties, taken collectively, actually grew slightly between 2010 and 2011, rising by 0.2 percent. But the minority population of those same counties increased nine times faster, 1.9 percent.

Erie and Niagara counties were among the decliners. Erie County's white population dropped by 2,910 persons in a year, while Niagara County's total fell by 1,036.

Go to the On Numbers website at http://www.bizjournals.com/bizjournals/on-numbers/ for a database with breakdowns for all 979 major counties. The same site contains charts that accompany the other stories below.

The sharpest decline in white population occurred in Nassau County, which is just east of New York City on Long Island. It lost 8,029 white residents in a year. San Juan County, N.M., had the biggest drop in proportional terms, losing 3.1 percent.

At the opposite end of the database is Miami-Dade County, Fla., which led the nation by adding 23,257 white residents between 2010 and 2011. Maverick County, Texas, increased by 12.8 percent to finish first in that measure.

Black growth rate surpasses U.S. average

The growth rate for America's black population is ever-so-slightly faster than the rate for the U.S. population as a whole.

The nation's 979 major counties had 34.67 million black residents as of July 2011. That was up 0.87 percent from 34.38 million a year earlier.

The total population of those same counties grew by 0.84 percent between July 1, 2010, and the corresponding date in 2011.

The number of black residents increased in the vast majority of major counties: 841 of 979. The other 138 experienced declines.

Erie and Niagara counties registered small gains. Erie County added 141 black residents during the 12-month period, while Niagara County picked up 53.

Eight counties added more than 5,000 black residents during the year, led by Hillsborough County (Tampa), Fla., at 8,803 and Fulton County (Atlanta), Ga., at 8,286. The biggest declines were 14,747 in Wayne County (Detroit), Mich., and 11,179 in Cook County (Chicago), Ill.

Hispanics seek distinct identity

America's Hispanic population is growing rapidly. Everybody agrees on that.

But there is broad disagreement about the appropriate definition.

The U.S. Census Bureau says that Hispanics constitute an ethnic group, not a race. So it puts every person of Hispanic heritage into an existing racial slot, such as white, black or American Indian.

(A change in this policy is currently being considered, though it's far from guaranteed.)

Others insist that Hispanics form a separate race, and should be placed on an equal footing with all minority groups, as well as whites.

"Many, if not most, Hispanics in the U.S. think of their ethnicity (also known as Latino) not just in cultural terms but in a racial context as well," says Time magazine.

On Numbers has taken the latter tack, removing Hispanics from other racial categories and consolidating them in a group of their own.

This approach shows that the Hispanic population grew in all but 14 of the 979 major counties. The overall increase was 2.4 percent in 12 months - from 47.94 million Hispanics in mid-2010 to 49.10 million in mid-2011.

Western New York followed the majority trend. Erie County added 1,384 Hispanic residents during the year, while Niagara County gained 335.

Large urban areas in the West and Southwest experienced the biggest rises in Hispanic population.

Los Angeles County, Calif., led the nation by adding 58,978 Hispanic residents in one year. The runners-up are both from Texas: Harris County (Houston) with a gain of 46,109 and Dallas County with an increase of 27,847.

Forty-seven counties had year-to-year growth rates in excess of 10 percent.

California sets pace for Asian population

The Asian-American population is expanding at a brisk pace in most parts of the nation, but especially in California.

Twenty-three counties added more than 3,000 residents of Asian heritage between July 2010 and the same month in 2011.

Ten of those counties are in California, including the only three that gained more than 10,000 Asian-Americans in 12 months: up 11,087 in Orange County (Anaheim), up 10,547 in Los Angeles County and up 10,114 in Santa Clara County (San Jose).

Rounding out the top five are King County (Seattle), Wash., where the Asian population grew by 8,049 from 2010 to 2011, and Kings County (Brooklyn), N.Y., where it expanded by 7,714.

The 979 major counties had a collective Asian population of 14.79 million in 2011, up 2.1 percent from 14.49 million a year earlier.

That's above the corresponding 2010-2011 growth rates for blacks (0.9 percent) and whites (0.2 percent), but behind the pace for Hispanics (2.4 percent).

Virtually all of the counties in the study group (907 of 979) had more Asian residents in 2011 than in 2010. A sizable majority (733 counties) posted growth rates of 2 percent or better.

Niagara County was well above that threshold. It added just 126 Asian residents, but that translated to an increase of 6.8 percent. Erie County was up 437 persons, or 1.8 percent.