I’ve been closely watching the bees in our top bar hive the past few weeks, as winter approaches. Their comb building behavior changed about the end of August, from the straight and narrow and well defined, to a somewhat more erratic pattern, with individual combs attached to 2 or sometimes 3 top bars. If you catch them early they are easy to remove, realign or straighten, if not…and sometimes my attention gets stretched across too many projects…not unlike the combs…they can go several directions all at once and major reconstruction is required. This is, as you can imagine, troublesome for the bees, and for the beekeeper, certainly another reason to keep on top of things, no matter the beehive you’re working with.
The population of bees is small in our top bar hive. Certainly not the 40,000 or more like the 10-frame Langstroth hives have in the middle of September, which is down from the maybe more than 60,000 in July. Even our 8-framers are larger, but not as populous and the 10-frame giants. I’m often asked how you estimate the population and contents of a colony…adults, brood, eggs, honey. For hives with frames it’s pretty easy. I’ve developed a fairly good sense of how many cells each size of frame has for the mediums, and the very few deeps, which are all I use. A Langstroth frame is right about 90 cells wide…it varies depending on the manufacturer, but that’s a good estimate. Medium frames then are about 30 cells tall, again, depending on the maker. That gives about 2700 cells per side, or about 5400 for a frame. With not a lot of practice, you can begin to accurately estimate the percent of space open and sealed brood occupys on each side of a frame, and from there the actual number of individual cells inhabited…in the brood stage…that are on that frame. That tells you how many more bees there will be in a few days, or a couple of weeks or so in the hive. And, most hives have bees, brood and honey on only some of the frames of each box…this isn’t an all day task, you know.
Deep frames are right about 50 x 90 cells for about 9000 cells/frame. If you recall, there are about 10,000 bees in a three pound package (about 3200 bees per pound)…so a single deep frame can almost raise one of those three pound packages you can buy…for about $90 or so next spring.
Those figures are easy. But the top bar hive of course has a truncated triangle shaped comb…that is a triangle with the point removed…so the top and bottom are parallel, with the bottom about half as long as the top with sides sloping in at…ahhhh…there’s the rub…the angle and the depth of the comb. Well, my math hasn’t kicked in yet to give me the dimensions, and the cell numbers of each of the combs on our top bar combs, so I’m guessing at best on the amount of brood and honey on each comb.
I imagine experienced top bar beekeepers have this figured out, is that right Chirsty? Number of combs in September, what percent of each is brood, if any, and what percent of each is honey, and how many bees. Oh, I forgot – bees. To figure out how many bees you have in a hive with frames, again, calculate the number of cells on a frame… you already know that…and know that an adult bee, when standing on a comb, covers two cells…so a medium frame completely covered with adult bees…top to bottom, side to side…will have right about 1300 or so bees on it…about 2700 if both sides are covered. A deep, about 4500 adults if both sides are covered.
Figuring the area of a top bar comb isn’t hard, now that I look at it. Break it into three parts…two right triangles on the sides and a rectangle in the center. Count the cells on each side and BINGO! You have the numbers you need.
Here’s the easy way to get this down…take a photo. Digital cameras make this a no brainer for later counting. When you are at the hive, remove a frame, estimate brood, bees and honey, take a photo of both sides and later, count them exactly and see how close you were when at the hive. Practice makes perfect, but it doesn’t take much.
So…I still have to figure out how much honey this hive has. And how much it will need. Right away, I think it needs some more food, even though there’s a goldenrod flow on, there’s not a lot of comb that isn’t already full…this could get dicey later in the winter.
I know my 8-frame, medium colonies, with four supers weigh about 125 pounds when full, and about 60 of that is honey. I don’t know how much the top bar should weigh…less probably since there isn’t as much hardware to weigh…maybe about 100?
New territory here. Help me out Christy.