Not only is BIP  survey data self-reported, be very careful of what and how the data is reported by BIP.
For example, the press releases about losses are not, as the media assumes, number of colonies lost over-winter or annually, but rather number of beekeepers who lost colonies.
In the year of 44% losses, that the press was all over the 44% colony loss, which was not true.
 
I did a collation of the BIP data.  I've a spreadsheet  buried somewhere, the 44% applied only to hobby/small scale beekeepers and it was 44% of them who lost colonies.  That was about 30,000 respondents, who lost one or more colonies.   By far, the majority of BIP respondents were hobby/small scale beekeepers.
 The other problem, where BIP reported estimated numbers of colonies lost, the stats could still be skewed.  A beekeeper with one colony, losing  one colony, reports 100% loss of colony; if the beekeeper loses one of two colonies, that would be reported as lose of 50% of colonies.   

The self-reported losses by commercial beekeepers, who constitute, as I remember, no more than 2% of the respondents, had and have had on average self-reported their losses at about 23-25% per year, year after year.




             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html