Hi everyone!
For the past few days I've been working on a document. I've been trying to figure out why beeks say that march is a make or break month for many colonies. to that end I put some of my thoughts down on paper.
I'd love to have your comments on this. Criticism and corrections are welcome, but be gentle
The goal of this is the create a high level look at what might go on in our hives at this time of year. I make some basic assumption just to make the math and the example easier to digest.
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Is March Really a Tough Month for Honey Bees?
Question:
Why is it that beekeepers claim that March is the month that makes or breaks a colony?
Assumptions:
• The colony in this example is coming out of winter with 3 lbs (~9000) of bees still alive.
• The queen started laying eggs on March 1.
• Worker bees take 21 days to mature and emerge.
• Once there are enough workers to cover the brood and maintain the inside of the hive, some get reassigned as foragers.
• A deep langstroth frame has ~3500 possible cells per frame side or 7,000 cells in total per frame.
• ~2/3 of the deep frame is available for eggs. For this example we will use 4800 or 2400 per side
A note about my numbers: Please just accept the numbers or take them with a +/- n. There are always exceptions to the rule, I know that, but the goal here is to highlight a potential colony situation.--------------------------------------------------------
Now for the fun part: We are going to work out the numbers to see what is happening in the colony as
Winter starts to loosen her grip on us here in RI.
We know from our assumptions that our colony is coming out of February with 3 lbs of bees. For the sake of argument we will agree that 3 lbs of bees can cover 5-6 frames.
Now, here we are on March 1 and the queen says: “Time to lay me some eggs!”, and she starts laying 1,000 eggs per day, every day, from March 1 to well past the end of our target time frame.
We know from the assumptions above that it will take 21 days for the first of her brood to emerge. Every day after that we will see another one thousand new workers added to the colony.
Now, bear in mind that as this is happening, the old winter bees are starting to fly off never to be seen again or their carcasses are being pushed out of the hive. I’m going to say that 250 a day die off from March 1 until they are gone. Are you starting to see where this might become an issue for the colony at that rate, assuming it started spring with ~ 9 thousand bees? We have until the first week of April until the old guard is gone. If we haven’t replaced the old with new by then, the colony will be gone.
So, at 250 per day gone over the first 21 days or 5250 bees not in the hive anymore we are left with
~3750 winter bees to do the heating, cleaning, foraging, etc. until the new girls grow in numbers and take up their positions.
Furthermore, the colonies dwindling population can probably only support 2-3 frames of brood. This means that the queen can only lay as many eggs as she has bees available to keep them warm and cared for. With less than 4000 workers she only has room to lay ~10,000 eggs. This means that she has to take a break from laying after only 10 days of production. She now has 11 days where she has to wait for the new workers to emerge before she can lay again. Even once they start to emerge she has to wait until their numbers grow sufficiently before she can steadily lay 1000 eggs per day every day for weeks to come.
Using my example above, the numbers could look something like this:
Now the warnings given by seasoned beekeepers start to make sense. You can now see why the middle of March is a very precarious time for the colony. The low numbers around the 21st in our example means that if a heavy cold snap hits and the cluster tightens up to survive we could be in for some chilled brood. Or, maybe the decrease in numbers means that the colony might not be able to reach supplies while they are clustered tight. Not a big deal overnight, but over a three or four day cold snap it could be devastating.
Day 21! The new workers start emerging at a rate of 1000 per day! This means that the attrition rate of the hive has ended. From here on out the colony should be increasing in number. But that’s not really the case. There is a brief step while we wait for the new workers to build up their numbers before the colony really starts to increase in numbers.
By mid-April, egg numbers in our example have stabilized as has the number of workers in the hive. Foragers are plenty and growing daily. The colony is now firing on all cylinders.
I would be remiss if I didn’t point out that getting your colony through March is not a process that starts on March first. It is a year-long process of caring and cultivating your bees. Making sure that they have the stores, the health, and the colony size that they need to overwinter well is a great first step toward making it through late winter and early spring.
So now we know. Management of the colonies you have needs to be on point in the late winter months. Not paying attention during this crucial time could be devastating. I guess the guys and girls who have been keeping for years really do know what they are talking about!
Keith
