The U.S. Department of Agriculture in its Honey Bee Colonies report said operations with five or more colonies, which account for about 98% of U.S. honey production, had 2,594,590 colonies on Jan. 1, 2016, down 8% from a year earlier.
Bee losses in 2015 were “pretty standard” for the past decade, said Walter Thurman, Ph.D., professor of agricultural economics at North Carolina State University, who has studied bee patterns and pollination for more than a decade. Annual changes in colony numbers have averaged 4.5% over the past 10 years, ranging from up 7% to down 8%, he said.
“Eight per cent is a pretty big number, but it’s not out of the realm of what we have seen,” Mr. Thurman said.
“There is no trend over the last decade,” Mr. Thurman said, despite the increased attention paid to bee losses during that time, adding that bee numbers are in fact up from a decade ago based on U.S.D.A. data.
Honey bee colonies lost in the first quarter of 2016 totaled 428,800, or 17%, compared with 500,020, or 18% in the same quarter a year earlier. The smallest quarterly loss was in April-June 2015 when 352,860 colonies, or 12%, were lost, the U.S.D.A. report said.
Honey bee colonies added during the January-March period of 2016 totaled 378,160, compared with 546,980 added in the same quarter of 2015. The highest number of colonies added was in April-June 2015 at 661,860 colonies, and the lowest number added was in October-December 2015 at 117,150 colonies.
There were 158,050 colonies renovated during the January-March period of 2016, the lowest number during the five quarters surveyed, the U.S.D.A. said.
Mr. Thurman said that worker bees typically live only six to eight weeks during the summer, while queen bees live two to three years, adding that worker bees don’t live as long when they are active compared with survival over the winter.
Meanwhile, the Bee Informed Partnership, in collaboration with the Apiary Inspectors of America and the U.S.D.A., said in its preliminary annual report in early May that an estimated 28.1% of the colonies managed in the United States were lost over the 2015-16 winter (Oct. 1 to April 1), an increase of 5.8 percentage points from the previous winter but close to the 10-year average total winter loss of 28.6%.
Some 5,756 U.S. beekeepers, managing 389,083 colonies that account for about 15% of the nation’s 2.66 million managed honey producing colonies, provided responses for the Bee Informed Partnership’s survey.
About 60% of respondents reported winter colony loss rates in excess of 16.9%, a figure viewed as normal and sustainable.
“Beekeepers not only lose colonies in the winter but also throughout the summer,” the Bee Informed Partnership report said. “In 2015, summer losses, at 28.1%, were the same as winter losses. When all results were combined, beekeepers lost 44.1% of their colonies between April 2015 and March 2016. This high rate of loss is close to the highest annual loss rate over the six years we have collected annual colony loss numbers.”
Mr. Thurman said it was inaccurate to consider only bee losses when discussing U.S. honey bees. The number of colonies is a factor of colonies lost and colonies added during a specific period, and may vary as colonies are moved between states during pollination and renovated each period. Bees replace themselves and bee keepers also replace lost colonies, he said.
The U.S.D.A.’s 8% decline in bee colonies in the past year was “the number to be taken seriously,” Mr. Thurman said.
However, Mr. Thurman acknowledged that the industry wasn’t without challenges, in part related to the rapid growth in California almond production, which requires three-fourths of all the honey bees in North America to pollinate trees during about a two-week period in late March to early April. Such a concentration of bees may leave them more susceptible to spread of diseases or other problems.
Researchers participating in the colony loss assessment of the Bee Informed Partnership came from schools that include the University of Maryland, Oregon State University, University of Georgia, Texas A&M University, University of Tennessee, Appalachian State university; and U.S.D.A.’s Agricultural Research Service.
It should be noted that the Bee Informed Partnership survey, funded by the U.S.D.A’s National Institute of Food and Agriculture, and the Honey Bee Colonies report, from the U.S.D.A.’s National Agricultural Statistics Service (NASS), were conducted independently and by different methods. The conclusions drawn by the Bee Informed Partnership were not those of NASS, a source involved with the U.S.D.A. Honey Bee Colonies report said.
Mr. Thurman noted that the Bee Informed Partnership based conclusions on only five quarters of data Jan. 1, 2015, to March 31, 2016, for its study compared to U.S.D.A. data on bee colonies going back to the 1930s. He said the size and methodology of the two surveys were different.
“You can’t compare one with the other,” he said.