Winter Loss Survey 2012 – 2013: Preliminary Results

Preliminary Results: Honey Bee Colony Losses in the United States, Winter 2012-2013


May 1, 2013
Dennis vanEngelsdorp1*, Nathalie Steinhauer1, Karen Rennich1, Jeffery Pettis2, Eugene J. Lengerich3, David Tarpy4, Keith S. Delaplane5, Angela M. Spleen3, James T. Wilkes6,
Robyn Rose7, Kathleen Lee8, Michael Wilson9 , John Skinner9 , and Dewey M. Caron 10
for the Bee Informed Partnership.

Note: This is a preliminary analysis. A more detailed final report is being
prepared for publication at a later date.

The Bee Informed Partnership (, in collaboration with the Apiary
Inspectors of America (AIA) and the United States Department of Agriculture (USDA),
is releasing preliminary results for the seventh annual national survey of honey bee
colony losses. For the 2012/2013 winter season, a total of 6,287 U.S. beekeepers
provided validated responses. Collectively, responding beekeepers managed 599,610
colonies in October 2012, representing about 22.9%1 of the country’s estimated 2.62
million colonies.

Preliminary survey results indicate that 31.1% of managed honey bee colonies in the
United States were lost during the 2012/2013 winter. This represents an increase in loss
of 9.2 points or 42% over the previous 2011/2012 winter’s total losses that were
estimated at 21.9% (Figure 1). This level of loss is on par with the 6 year average total
loss of 30.5%2.

On average, U.S. beekeepers lost 45.1% of the colonies in their operation during the
winter of 2012/2013. This is a 19.8 point or 78.2% increase in the average operational
loss compared to the previous winter (2011/2012), which was estimated at 25.3%. The
difference between average loss and total loss is explained by the respondent pool: while
a majority of the respondents (95%) were backyard beekeepers, they managed a small
fraction of the colonies represented in the survey (6%). For this reason total loss (which
is more heavily influenced by commercial beekeeper losses) is more representative of
national losses.

Survey participants indicated that they considered a loss rate of 15% as “acceptable,” but
70% of them suffered losses greater than this.

1 Based on NASS 2012 figures
2 Previous survey results found a total colony loss in the winters of 21.9% in the winter of 2011/2012, 30% in 2010/2011, 34% in 2009/2010, 29% in 2008/2009, 36% in 2007/2008, and 32% in 2006/2007 (see figure attached)

The Bee Informed Partnership is funded by the National Institute of Food and
Agriculture, USDA.

1. University of Maryland; 717-884-2147;
2. USDA-ARS Bee Research Laboratory
3. The Pennsylvania State University,
4. North Carolina State University
5. University of Georgia
6. Appalachian State University
7. Robyn Rose, USDA Animal and Plant Health Inspection Service,
8. University of Minnesota
9. University of Tennessee
10. Oregon state University
*Corresponding author


Written By: The Bee Informed Team

has written 27 post in this blog.

The Bee Informed Team regularly announces the release of results at The Bee Informed Partnership is an extension project that endeavors to decrease the number of honey bee colonies that die over the winter. A listing of all project activity reports can be found at the 'Results' tab above. Results published in scientific journals are included as links. Who's on the team? See the Team Pages.