Experience and evaluation of colony loss monitoring in Scotland: survey methodology, response rates and degree of success

Surveys of beekeepers in Scotland have been running since 2006, with Scotland
joining COLOSS Working Group 1 in 2010. Since 2008 these surveys have been
based on stratified random sampling of the membership records of the Scottish
Beekeepers’ Association (SBA), and have used a postal questionnaire with a
covering letter. The surveys have run in late spring, after a small scale pilot run,
and allowing 3 to 4 weeks for response to the main survey. Late returns are
accepted and included where possible in the COLOSS return. A small prize draw
has been possible in recent surveys as an incentive to participate, and a postal
reminder is issued.
The SBA has approximately 1100 members. Sample sizes were 100 beekeepers
approached directly in the 2006 survey, 119 SBA members in 2008, and 200
hobbyist SBA members in the 2010 survey (plus 26 bee farmers), 200 SBA
members in 2011 and 250 in 2012. Response rates were 77% in 2006, 42.0% (50;
44 beekeepers) in 2008, 68.5% (137, of which 116 were beekeepers; plus 9 bee
farmers) in 2010, 47.0% (94; 64 beekeepers) in 2011, and 41.6% (104; 91
beekeepers) in 2012.
Our main observation regarding the success of the questions is that questions
relating to bee management lead to illogical results in a large proportion of cases.
Our attempts to allow for all possibilities in the answers to these questions have
not reduced the incidence of such unreliable results. We therefore use stated
colony numbers at the start of winter and stated losses to calculate overall loss
rates. As bee management is rare in Scottish winters, this should have little
impact on conclusions. Summer losses are very low.
For future surveys, we plan to operate an online questionnaire based on
LimeSurvey (http://www.limesurvey.org/), for speed and ease of data collection
and lower costs, possibly with a larger scale sample.