Colony losses monitoring

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The colony loss monitoring group has been active since the start of the COLOSS COST action, now the COLOSS Association, to study reasons for colony losses.

Participating countries each carry out an annual survey of beekeepers by questionnaire, with the aim of collecting information from a nationally representative sample of beekeepers. This makes it possible to compare colony loss rates between countries and to use the international data collected to understand better the risk factors for colony loss. To enable proper comparisons, a standardised beekeeper questionnaire was developed and is updated each year by the group for use by each country. We also contributed a chapter on standard survey methodology to the COLOSS BEEBOOK (van der Zee et al., 2013).

About 30 countries currently participate in monitoring, mainly but not exclusively in the northern hemisphere, with others interested. The number of member countries is continually increasing. At the individual level, many thousands of beekeepers take part each year. This is an example of citizen science/crowdsourcing, with the voluntary participation of many beekeepers enabling much wider scale data collection than would otherwise be possible.

Participating countries return their data for analysis annually before an agreed deadline, usually 1st of July, and the results are used for press releases and scientific publications. We produce jointly authored journal papers for dissemination of results to the research community. Our publications not only produced for the first time internationally comparable loss rates of honey bee colonies, but have also used advanced statistical modelling to investigate risk factors. The risk factors identified so far include beekeeper management (such as treatment strategies to control the parasitic mite Varroa destructor, and the age of queens), operation size, and environmental factors (e.g. local weather or certain forage available to honey bee colonies).


Brodschneider, R., Gray, A. (2021). How COLOSS Monitoring and Research on Lost Honey Bee Colonies Can Support Colony Survival. Bee World Volume 99, 2022 – Issue 1: A Special Issue on COLOSS, Pages 8-10. Full Article

Brodschneider, R., Schlagbauer, J., Arakelyan, I., Ballis, A., Brus, J., Brusbardis, V., … & Gray, A. (2023). Spatial clusters of Varroa destructor control strategies in Europe. Journal of Pest Science 96: 759-783 Full Article

Gray, Adjlane, Arab, Ballis, Brusbardis, Bugeja Douglas, Cadahía, Charrière, Chlebo, Coffey, Cornelissen, da Costa, Danneels, Danihlík, Dobrescu, Evans, Fedoriak, Forsythe, Gregorc, Ilieva Arakelyan, Johannesen, Kauko, Kristiansen, Martikkala, Martín-Hernández, Mazur, Medina-Flores, Mutinelli, Omar, Patalano, Raudmets, San Martin, Soroker, Stahlmann-Brown, Stevanovic, Uzunov, Vejsnaes, Williams, Brodschneider, R. (2022). Honey bee colony loss rates in 37 countries using the COLOSS survey for winter 2019–2020: the combined effects of operation size, migration and queen replacement. Journal of Apicultural Research, 1-7. Full Article

Brodschneider, Gray, Adjlane, Ballis, Brusbardis, Charrière, Chlebo, Coffey, Dahle, de Graaf, Dražić, Evans, Fedoriak, Forsythe, Gregorc, Grzęda, Hetzroni, Kauko, Kristiansen, Martikkala, Martín-Hernández, Medina-Flores, Mutinelli, Raudmets, Ryzhikov, Simon-Delso, Stevanovic, Uzunov, Vejsnæs, Woehl, Zammit-Mangion, Danihlík (2018) Multi-country loss rates of honey bee colonies during winter 2016/17 from the COLOSS survey. Journal of Apicultural Research, 57(3), 452-457. Full Article

Brodschneider, Gray, van der Zee, Adjlane, Brusbardis, Charrière, Chlebo, Coffey, Crailsheim, Dahle, Danihlík; Danneels, de Graaf, Dražić, Fedoriak, Forsythe; Golubovski, Gregorc, Grzęda, Hubbuck, İvgin Tunca, Kauko, Kilpinen, Kretavicius, Kristiansen, Martikkala, Martín-Hernández, Mutinelli, Peterson, Otten, Ozkirim, Raudmets, Simon-Delso, Soroker, Topolska; Vallon; Vejsnæs, Woehl (2016) Preliminary analysis of loss rates of honey bee colonies during winter 2015/16 from the COLOSS survey. Journal of Apicultural Research, 55: 375-378. Full Article

van der Zee, Brodschneider, Brusbardis, Charrière, Chlebo, Coffey, Dahle, Drazic, Kauko, Kretavicius, Kristiansen, Mutinelli, Otten, Peterson, Raudmets, Santrac, Seppälä, Soroker, Topolska, Vejsnæs, Gray (2014) Results of international standardised beekeeper surveys of colony losses for winter 2012-2013: analysis of winter loss rates and mixed effects modelling of risk factors for winter loss. Journal of Apicultural Research 53: 19-34. Full Article

van der Zee, Gray, Holzmann, Pisa, Brodschneider, Chlebo, Coffey, Kence, Kristiansen, Mutinelli, Nguyen, Adjlane, Peterson, Soroker, Topolska, Vejsnæs, Wilkins (2013) Standard survey methods for estimating colony losses and explanatory risk factors in Apis mellifera. In V Dietemann; J D Ellis; P Neumann (Eds) The COLOSS BEEBOOK, Volume I: Standard methods for Apis mellifera research. Journal of Apicultural Research 52(4): Full Article

van der Zee, Pisa, Andonov, Brodschneider, Charrière, Chlebo, Coffey, Crailsheim, Dahle, Gajda, Gray, Drazic, Higes, Kauko, Kence, Kence, Kezic, Kiprijanovska, Kralj, Kristiansen, Martin Hernandez, Mutinelli, Nguyen, Otten, Özkırım, Pernal, Peterson, Ramsay, Santrac, Soroker, Topolska, Uzunov, Vejsnæs, Wei, Wilkins (2012) Managed honey bee colony losses in Canada, China, Europe, Israel and Turkey, for the winters of 2008-9 and 2009-10. Journal of Apicultural Research 51: 100-114. Full Article


To communicate with beekeepers in the participating countries the national co-ordinators write articles for their respective beekeepers’ journals, and/or post results on a relevant website, for example the Austrian website at:

Older press releases can be found here: << Press releases >>


We have an email discussion list for our monitoring group. We welcome participation by new countries wishing to join in monitoring.

Instruction for the use of the international limesurvey on

Welcome to the international limesurvey setup of the Coloss monitoring group annual monitoring of winter losses. The aim of this setup is to give the participants of the annual monitoring of the winter losses an easy access to a limesurvey template, where you easy and fast can translate the monitoring questionnaire to your local language. This is an offer for the participants to share a common platform. Others will prefer to use other platforms. If you use another limesurvey server, you can import the Coloss template. is hosted on a dedicated server run by in Hamburg. is owned and financed by the Danish Beekeepers Association. perform daily backup of the database. The basic template is produced and tested by the support team of

It is the responsibility of the users regularly to export the data of their respective country. The Danish Beekeepers Association is not responsible for any kind of losses of data. Due to regular backup no data losses is expected to occur.

The users are themselves responsibly for translation, launching their questionnaire, exporting the data and forwarding them according to the annual codebook to the given coordinator for the international data collection. Since the use is free, no or little support can be expected. Instruction videos are given and should cover all questions.

Annually the Coloss monitoring group will produce a codebook in English (normally in February/March). Hereafter we will put up a template in Limesurvey. Each country participating in this setup will get access to a copy of their own questionnaire. You will receive username and password from the administrator as soon as you are accepted as the local representative for this survey. Each country, one login. You will also get a link for video instructions on how to make the translation, how to delete questions and how to add your own questions, how to find the link for your country questionnaire, how to see simple statistic and how to extract the data for an excel spreadsheet, how to activate and deactivate your questionnaire. If you need to make paper versions, you can also produce that. The setup is very user-friendly and easy to use.

f you decide not to use this setup because you have access to other systems, but have received a password please notify us, so that we can delete you as user from our list of participants.

Time window. As soon as the codebook is finished, we will produce a template in English. This happens normally in the period of February and/or March and no later than April. You can start your translation as soon as you receive an e-mail from us. Normally the international questionnaire is running in the period of 1th of May-1th of June. Some countries, due to late spring etc. are using a later time window.

Testing again. You should test your translation and limesurvey by running your survey several times. Try to have a small testing group filling out all questions. Test the export facility and control that all answers are in the excel spreadsheet when exported. Then reset the questionnaire and launce it when appropriate.

There are several instruction videos. Since this is free, you cannot expect any support from our side. However, everything should be given in the instruction videos.

Workflow in Limesurvey
When you are accepted by the monitoring group as coordinator for your country for this survey, administrator will setup a copy with your language for translation.


Username and password you have recieved via e-mail.

Translation. Very easy to do. See instruction videos. Note for one of the major languages (English, German, Spanish) the questionnaire might already be translated, so consider the possibility of receiving an already made translation. You should anyway run through the translation and make your control and adjustments.

Instruction video. On this link, you can see short instruction video on how to use the Limesurvey

First login:
Quick add:
Remove questions:
Add questions
How to publish and simple statistics:
How to export:

For an overview (giving you an overview, for a straightforward translation – made originally for the b-rap group).

For further questions contact
Flemming Vejsnæs or Robert Brodschneider,

How to add own logo


Are you interested in joining this COLOSS core project?

If so, please contact one of the core project co-chairs below.