1. Winter in the Hive West Plains Beekeepers Association December 7, 2012 Jack Miller Topics:  Preparations for Success  Reasons for Failure  Winter Cluster Characteristics

2. Preparations for Success Consensus:  Enough honey and pollen located correctly in hive  Ventilated hive  Enough bees  Productive queen  Take Winter loses in the Fall  Room in the center for bees i.e. empty cells  Protection from invaders (mice, etc.)  Hive tilted slightly forward so water runs out  Locate hive away from Spring water level

3. Preparations for Success #2 Recommendations Generally Agreed To:  Stores on the sides of the cluster in the bottom box and above the cluster in the top box  Sheltered from the wind  South facing for maximum sunlight  Top entrance hole  Accessible throughout the Winter

4. Differences of Opinion:  Need a colony covering 20 frames in a 2 story hive; 130 pound gross weight; 10 pounds of bees 18K - 35% 4.5K - 85%  Minimum of 60 pounds of honey  Equivalent of 4 frames of pollen  Entrance NOT blocked with reducer for ventilation

5. Reasons for Failure Starvation  Run out of honey/food  Honey/food not where it is needed Lack of ventilation Too few bees to maintain cluster Over-management of hive Bee's digestive tract compacted Mites

6. Infrared Hives http://www.beebehavior.com/infrared_camera_pictures.php

7. The Winter Cluster Winter Bees  Larger hypopharyngeal glands  More body fat Size of Cluster is a Function of Temperature  +50 F14 inches  +20 F11 inches  -14 F10 inches  -26 F 4 inches Heat Loss is Proportional to Cluster Size Shape is Oblong Sphere Internal Temperature 90 degrees F

8. The Winter Cluster #2 Structure  The outside shell of bees or mantel is from 1 to 3 inches thick with the bees filling the spaces between the frames and empty cells.  Inside the shell or core the bees are less tightly packed and warmer. They are able to move about and care for brood, queen and to perform maintenance  The outside bees rotate with the inner bees based on hunger not temperature. Average 8 days with maximum of 16 days with a full honey stomach.  Temperature regulation is by endothermic heat production in the core and insulation control by the mantel.  It’s only the cluster temperature that is controlled by the bees – the hive temperature is close to outside temperature.

9. The Winter Cluster #3 Temperature  Bees start to cluster at 57 degrees F  Bees use winter stores most efficiently at 45 degrees F  The lowest temperature the hive can survive depends on how many bees, how many stores, and duration of cold spell  In moderate temperature the bees move honey closer to the interior of the cluster  In colder temperatures the bees compact but must always maintain contact with honey stores  Mantel temperature 48 – 57 degrees  Core temperature 64 – 90 degrees.

10. The Winter Cluster #4 Bee Movement  Bees will organize the nest in preparation for Winter.  During warm spells bees will move supplies to the cluster.  Cluster will migrate toward the warm side of the hive when temperature is above 48 degrees.  Cluster will follow the heat in the hive up, as supplies are consumed.  Cluster size shrinks and expands in response to temperature.  The inside of the hive is the same temperature as outside the hive.

11. The Winter Cluster #5 Differences of Opinion Too large a Fall cluster can be detrimental because the bees can go through their stores too rapidly Wrap hive for the winter Significant variations on bee behavior from one race of honey bee to another: When they stop rearing brood How large the winter cluster How soon they begin rearing brood How efficient they are with stores Medication and disease control

12. Winter Schedule  August/September – Prepare hive for winter (location, stores, ventilation)  October – Any further preparation such as additional feed  November/ December – Check for use of feed only if weather permits; clear obstructed ventilation access as needed  January -- Brood rearing starts in January as days lengthen; clear obstructed ventilation access as needed  February/ March -- Colony inspections on first warm days in late February or March; clear obstructed ventilation access as needed

13. Bibliography  ABC and XYZ of Bee Culture by A.I. Root  Better Beekeeping by Kim Flottum  Honey Bee Biology and Beekeeping by Dewey M. Caron  The Journal of Experimental Biology “Hot bees in empty broodnest cells: heating from within” by Marco Kleinhenz, Brigitte Bujok, Stefan Fuchs, and Jürgen Tautz  Natural Beekeeping by Ross Conrad  The Thermology of Wintering Honey Bee Colonies by CHARLES D. OWENS, Agricultural Engineering Research Division, Agricultural Research Service