How hive monitoring can help get your honey bees through winter
Updated: Nov 15, 2021
Winter is probably the most difficult time of the year for our precious honeybees. The survival of bees during the winter is a story of great preparation, from both bee and beekeeper, and a huge collaborative effort within the hive. As we know, the bees in our hives are not individuals, they function as a colony, even more so at this time of year when the bees form a cluster in which they huddle together in order to keep warm. The main objective of this cluster is simple, to reach the spring with a healthy queen and enough workers to restart the foraging and expand the colony all over again.
One of the most important questions we ask as beekeepers before winter sets in is "Do my bees have enough stores?" If you're happy they do, or you have fed them in preparation for winter, the next question we usually ask is "how do I know how much they have eaten?". Usually, a beekeeper will make a trip the apiary and gently lift their hives to see if the hives are light (and if so, they are fed again!). This is where remote weight monitoring can really help.
At the touch of a button, you can see how quickly your bees are eating through their stores and you can be alerted if your hive weight drops below a weight set by you. The graph below shows the drop in hive weight in 1 month at the start of winter - this particular hive used up 5.5KG (12lbs) of stores in just 35 days!
If the bees are eating stores and the weight is declining you know your bees are alive, but if you don’t have a scale, you can also use your in-hive sensor to tell if our bees are surviving the colder weather. Bees in the summer will regulate the brood nest at around 34 degrees C. In the winter, the cluster is generally regulated at around 18 degrees C at the core, cooling down, but still warmer than ambient temperature, in the space around the core known as the mantel. If you’re in-hive sensor is directly in the core of the cluster it will report around 18 degrees, however, the winter cluster will move around as they consume stores, so expect to see varying hive temperatures that will always be warmer than ambient.
The graph below shows in-hive temperature (green) versus ambient temperature (blue) from December to May. You can see the in-hive temperature is consistently warmer than ambient (if only by a few degrees).
However, if temperatures inside and outside of the hive follow a similar pattern (track) then it is likely that the colony has died or moved too far away from the sensor for detection. Remember - a healthy cluster should be able to maintain a semi-constant temperature, even throughout the coldest winter days.
Not sure whether you've lost the colony based on temperature alone? Colony acoustics, detected by the in-hive sensor, will help to determine whether there are still signs of life in the hive by picking up vibrations from bees in the cluster.
Honeybee colonies can easily survive very cold temperatures; however, they cannot survive wet or damp conditions and moisture in the hive is known to be a leading cause of colony loss during winter. Our in-hive sensor also monitors humidity within the hive.
Usual humidity levels within a hive are between 40 and 60% - if humidity rises above this then the hive is at increased risk of condensation forming. By monitoring the relative humidity, alerts can be triggered for beekeepers to increase hive ventilation.
The below clearly demonstrates this, where during the first week of February relative humidity in one hive reached levels of 90% and even 100% (red line). This means condensation is accumulating inside the hive which could drip onto the cluster.
Our remote hive monitoring technology is not designed to replace the beekeeper, but helps us to make better decisions based on data. During the winter, colonies are at increased risk and technology can play a crucial role in protecting honeybee welfare and ensuring that hives make it through to the following spring.
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