Monitoring the weight of your beehive will yield fascinating results and insight into the state of your honeybee colony and help you care for your hive. Here are some typical weight characteristics you may encounter.
The Nectar Flow
Graphically viewing a nectar flow is one of the most exciting things about monitoring the weight of your beehive. A strong nectar flow will have you wanting to check your hive weight regularly, even several times a day! This particular nectar flow has two distinct flows: one mid-July to mid-August and the other one in late September.
Interestingly, the weight curve is not continuous, even during a very strong nectar flow... it follows a regular pattern. If you zoom in closer, possible with our web app software, you will see distinct daily ripples in the flow.
Zooming in even closer you can make it daily patterns in the ripples. Do you "see" when the bees leave the hive in the morning?
Post Nectar Flow
Beekeepers want to know exactly when the nectar flow ends so that they can maximize their honey economics. Otherwise the bees start consuming the honey right away. Here is how the post nectar flow looks like if the beekeeper does not intervene. A hive can lose between 5 and 10 lbs of honey a week (consumed by bees).
When a beekeeper harvests honey
Harvesting honey is reflected by a sharp drop in weight, as would be expected. Here is an example:
Swarming
The effect of swarming is visible on the hive weight. When bees swarm, the weight of the bees is reflected on the weight graph. here are two examples. You can see that the weight of the swarmed bees is approximately 4 lbs.
Example 1:
Example 2:
Bee Nutrition
Making sure a honeybee colony has enough food is a major concern for beekeepers and one of the main reasons why bee colonies die - they just plainly run out of food and die of starvation.
To prevent that, the beekeeper must assure that bees have sufficient protein and energy to survive through times where nectar and pollen is not available. Monitoring the weight and feeding when stores are low can prevent starvation.
Here is how feeding one gallon (almost 4 liters) of sugar solution looks like on a weight graph.
Weather Effects
The weather will also affect the weight of a hive. It helps to recognize these effects so that they are not mistaken for bee related weight changes.
Fortunately, they are relatively easy to recognize. Rain shows up as temporary weight gains and a subdued temperature curve will confirm that the weight gain/loss is due to rain. None rain days have clear wavy temperature curves as the sun heats and then the night cools the air.
Here is another example. The nectar flow was doing well until June 12 when suddenly a long cold and wet period stopped the flow. It resumed on June 18 as temperatures increased and the rain stopped.
Hive Inspections
Hive inspections are a necessary part of a beekeeper's job. They will also often show up in the weight graphs as the inspection involves temporarily removing hive bodies and frames. Very sharp dips in the weight are clear signs of hive inspections (see graph above).
Equipment additions/removals
Equipment changes in the hive such as adding or removing supers will readily show up in the weight graphs. It is best to add remarks to the Logbook so that these are recorded for future use.
Robbing
Robbing is made visually evident when weighing hives. Below are two profiles of two hives very close to each other ... who is robbing from whom?
Here is a fascinating example of robbing submitted by Isidore Venetos of NJ, owner of an HM-5. The colony with the HM-5 was doing the robbing so its weight increased significantly (see below). Notice that the robbing occurred on relatively warm days (above the Too Cold To Fly line) and that it happened on three different occasions. The robbing was confirmed by visually seeing the bees rob an abandoned/dead colony nearby.
