Colony Loss Survey 2012 – 2013

A national survey of managed honey bee 2012-2013 annual colony losses in the USA: results from the Bee Informed Partnership

Total Winter Loss 2012-2013Abstract: For the past six years in which overwintering mortality of honey bee colonies has been surveyed in the USA, estimates of colony loss have fluctuated around one-third of the national population. Here we report on the losses for the 2012-2013 seasons. We collected data from 6,482 US beekeepers (6,114 backyard, 233 sideline, and 135 commercial beekeepers) to document overwintering mortality rates of honey bee colonies for the USA. Responding beekeepers reported a total 30.6% (95% CI: 30.16-31.13%) loss of US colonies over the winter, with each beekeeper losing on average 44.8% (95% CI: 43.88-45.66%) of their colonies. Total winter losses varied across states (range: 11.0% to 54.7%). The self-reported level of acceptable winter loss was 14.6%, and 73.2% of the respondents had mortality rates greater than this level. The leading self-identified causes of overwintering mortality were different according to the operation type; backyard beekeepers generally self-identified “manageable” factors (e.g., starvation, weak colony in the fall), while commercial beekeepers generally identified non-manageable factors (e.g., queen failure, pesticides) as the main cause of losses. For the first time in this series of surveys, we estimated mortality during the summer (total loss = 25.3% (95% CI: 24.80-25.74%), average loss = 12.5% (95% CI: 11.92-13.06%)). The entire 12-months period between April 2012 and April 2013 yielded a total loss of 45.2% (95% CI: 44.58-45.75%), and an average loss of 49.4% (95% CI: 48.46-50.43%). While we found that commercial beekeepers lost fewer colonies than backyard beekeepers in the winter (30.2% (95% CI: 26.54-33.93% vs 45.4% (44.46-46.32%) respectively), the situation was reversed in the summer where commercial beekeepers reported higher average losses than backyard beekeepers (21.6% (95% CI: 18.4-24.79%) vs 12.1% (11.46-12.65%)). These findings demonstrate the ongoing difficulties of US beekeepers in maintaining overall colony heath and survival.

AUTHORS: Nathalie A Steinhauer, Karen Rennich, Michael E Wilson, Dewey M Caron, Eugene J Lengerich, Jeff S Pettis, Robyn Rose, John A Skinner, David R Tarpy, James T Wilkes and Dennis vanEngelsdorp, for the Bee Informed Partnership

Read the full article online here:

Written By: The Bee Informed Team

has written 58 post in this blog.

The Bee Informed Partnership is a collaboration of efforts across the country from some of the leading research labs and universities in agriculture and science to better understand honey bee declines in the United States. Supported by the United States Department of Agriculture and the National Institute of Food and Agriculture, we’re working with beekeepers to better understand how we can keep healthier bees. The key to our success is the true partnership we maintain across a wide range of disciplines including traditional honey bee science, economics, statistics, and medical research that makes all these tools available to this important research. And just as important as the tools are the people. We not only have the leading researchers in the honey bee industry, we also have advisory boards from the commercial beekeeping industries, almond and other commercial growers, as well as naturalists and conservationists from across the country.


10 Responses to “Colony Loss Survey 2012 – 2013”