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Thursday, March 16, 2017

Why Bees Drink Dirty Water & Honey bee Immunity -- 2 Talks by RachaelE. Bonoan

In terms of finishing up posts that I have in mind, I'm way, way, way behind schedule. I haven't even opened my hives yet this year, and I'm grateful for the freakish snow and freezing temps we've had lately because now I don't have to feel guilty about that.

Anyway, several weeks ago, Rachael Bonoan, a PhD candidate at Tufts and president of the Boston Area Beekeepers Association, spoke at our bee club meeting. She was positively delightful -- sweet, humorous, and insightful -- it was a joy to hear her talk.

She gave two talks -- one on why honey bees drink dirty water and another related to the effect of diet on honey bee immune systems. Sadly, I've misplace my detailed notes, but I'll share the highlights. Also, you can read the full paper on the "dirty water" study here.

Talk 1: Seasonality of salt foraging in honey bees

  • Beekeepers have long observed that honey bees seem to prefer dirty puddles of water to fresh clean ones. One study has even shown bees to drink human tears! [Banzinger H, et al. Bees (Hymenoptera: Apidae) That Drink Human Tears. J of the Kansas Entomological Society. 2009; 82(2): 135-150.)]
  • Bonoan hypothesized that honey bees are selectively foraging in soil and water for minerals that nectar may lack. 
  • She sampled and tested water from around the university where honey bees were known to collect water (barrels, cinder blocks, puddles, truck cabs, puddle behind gym) and found that the water in these places were rich in calcium, magnesium, potassium, and sodium. She focused on these minerals because of they are known to be necessary for certain biological functions.For the study, she set up watering stations (basically watering tubes on a table). Each station contained water mixed with a different salt (NaCl, KCl, CaCI2, MGCL2, NH4CL, KH2PO4). The control tubes contained sucrose and deionized water. She also had another screened in table with tubes full of the same solutions so that she could account for evaporation.
  • One of the things I found fascinating was seeing bees come to the tables, tasting a solution and then moving on to one they liked better. So they definitely showed preferences.
  • Additionally, the results showed that overall, the bees had preferences for certain minerals during different seasons. Preferences also varied depending on which floral sources were available.
  • As part of the study, she also measured the effect of salt foraging on hive health. Colonies that gathered a wider variety of salts were healthier overall than ones that didn't.
  • She recommended providing bees with a supplemental mineral source. It could be as simple as giving them a dirty puddle or a mineral salt lick. Also, bees should have diverse floral resources throughout the year. 
If you are interested, you can view a copy of the slides for this presentation.

Talk 2: Physiological and behavioral immunity in the honey bee

  • Honeybees have 3 types of disease resistance: Genetic, Physiological (Individual Behavior), and Group Behavior
  • Honey bees have far fewer immune genes than other insects (about 50). Fruit flies and mosquitoes have closer to 200 immune genes. This is why genetic diversity is so critical for honey bees. The more baby-daddies a colony has, the more likely that the population will have a greater mix of immune genes. This provides population-level resistance. In other words, while certain bees with one immune gene might be susceptible to a disease, other bees in the population with different genes may not be.
  • Bees also exhibit various behaviors that increase their disease resistance. Some of these are individual behaviors like grooming, biting, etc. Others are group behaviors like collecting propolis, balling invaders, and thermoregulation. 
  • She called thermoregulation a "honey bee fever" because it acts just like a fever in humans. Bees raise the temperature of the hive in order to kill an infection like chalkbrood.
  • She discussed her research infecting colonies with chalkbrood and measuring their ability to raise hive temperatures. Here my memory is spotty, but I believe that her group also fed various pollen mixes (monofloral vs. polyfloral) to the bees to see if that affected their ability to thermoregulate. They chose to provide monofloral and polyfloral pollent because pollen is what the young bees eat. Pollen contains protein, 10 essential amino acids (EAAs), and trace minerals that are essential for honey bee health. However, not all pollens contain the same EAAs in the same amounts. Bees cannot get all 10 EAAs from monofloral crops like almonds, sunflowers, etc. 
  • What she found is that colonies fed pollen mixes from diverse sources had better overall health. Also, the amount of protein that bees receive from pollen is not as important as the diversity of EAAs that they get. In other words, pollens with higher protein content did not necessarily translate into better colony health. However, pollen diversity did.
I'm really bummed about misplacing my notes because she had mentioned some fascinating tidbits about different floral/pollen sources and the minerals they provide as well as the functions that these minerals support. If I find them, I'll definitely update this post. However, I recommend checking out her website since she has quite a few interesting articles and resources posted.

Monday, February 20, 2017

How Many Colonies Should I Get?

We still have a ton of white stuff on the ground thanks to a couple of snow days, but the weather is warming up. Temps for the past week and predictions for the near future are in the 40 F range, which means it's time for maple sugaring! Ok, no, I don't tap trees, but rising sap means that the maples, one of our earliest flowers, will be blooming soon. And blooms mean BEES!!!

It's also the time of year when everyone is ordering bees and lots of newbies are asking, "How many colonies should I get?" The traditional answer is "Have a minimum of 2 hives." However, I'm going to disagree with this because newbies, who are already shelling out a lot of money for bees, tend to focus on the "2" and not on the "minimum" part of that statement.

Starting with two hives is fine. However, as a beekeeper, you need to be thinking ahead and planning for winter and even the following spring. If you want to ensure that at least one colony will survive  through winter, I recommend having plans for a minimum of 4 healthy, thriving colonies by wintertime.

So why do I recommend a minimum of 4 going into winter? 
If you want to skip this rest of this post, the short answer is this: Increasing the number of colonies you have increases the chances that at least one of them will survive winter. That's basically this entire post in a nutshell.

However, I actually feel that the number of hives you enter winter with should depend on how many you hope will live to see spring. If you want 4 colonies in spring, go into winter with 8. If you want a 100, enter winter with 200 colonies. However, for the new backyard hobbyist, it would be nice to have at least 2 hives make it until spring. You always want to have at least 2 hives so that you have resources to switch back and forth -- even in spring. Therefore, I recommend a minimum of 4. (PS. Mike Palmer has some great talks online for making winter nucs.)

Bees & Probability
I'm not a mathematician, so perhaps someone like Don from Buddha & the Bees will correct me, but let's say all factors are equal, each colony in your beeyard has the same potential outcomes for winter -- survive or die. So all factors being equal, every hive has a 50% chance making it. 50/50 odds are pretty terrible. That's essentially flipping a coin. Let's say H = Heads and T = Tails. According to the theory of probability, there are 2 possible outcomes for this flip:
H      T
However, when you flip a coin multiple times, your chances of landing on a desired result -- let's say landing on heads at least once -- increases. If you have 2 coins and flip them, each coin has 2 possible outcomes, so flipping 2 coins has 2x2=4 possible outcomes. The possible combinations of this flip are:
HH      HT
TH      TT  
Wow! Already the possibility of at least one coin landing on heads is vastly improved -- 3/4 (or 75%)! The chance of landing on just tails though is 1/4. 25% chance is still kind of high, but it's much smaller than 50%.

If you double the number of coins again to 4 coins, what is the probability that at least one coin will land on heads? 2x2x2x2 = 16 possible outcomes. Let's look at them:
HHHH      THHH      HHHT      THHT 
HHTH      THTH       HHTT      THTT
HTHH      TTHH       HTHT      TTHT
HTTH       TTTH       HTTT       TTTT
As you can see, the chance of landing on just tails gets much, much smaller -- 1/16 (or 6.25%). The chances of having at least 1 coin land on heads are 15/16 (93.75%).

If you doubled the number of coins again (don't worry, I'm not going to list out the combinations), you'd see an even greater probability that at least 1 coin lands on heads and an even smaller chance that all the coins would land on tails. Of course, there is also the law of diminishing returns, so after a certain point, you might want to stop flipping coins. Anyway, moving on...

How does this apply to bees? Bees aren't coins.
Exactly. That's why I added that condition to my earlier statement -- if all factors are equal. The problem with bee colonies is that each one is a living organism and can have all kinds of funky things going on. Some of these variables include colony size, health, parasites, location, hive construction issues (e.g., leaks, cracks, ventilation, insulation...), forage, colony age, queen quality, appropriate winterization, weather conditions, etc. If all factors were equal, you might not need more than 2 hives as a hobbyist, but bees are not nearly as predictable as coins. That's why I recommend going into winter with double the number of hives that you want to make it through to spring -- to account for losses that will occur due to some of those variables.

By the way, some of the variables that need to be addressed have nothing to do with bees and have more to do with the beekeeper's knowledge and experience. That's a whole 'nuther layer of issues!
My first year of beekeeping, I didn't get to experience winter since a bear ravaged my bees. As a result, by the time my second winter rolled around, I hadn't yet figured it out and had 4 colonies going into the season. Condensation killed 3, 1 survived. But the one that survived... that was crucial because most of my current 8 colonies are descended from that hive. While I still have a lot to learn, ongoing reading, sharing with other beeks, and some hard lessons learned through experience have made me a better beekeeper than I was when first started. (Hopefully.)

How can I expand my beeyard to 4 hives before winter?
If you're willing to spend the cash, you can certainly buy 4 packages or nucs to start out.
However, if money is a consideration (and for most of us, it is -- especially when local treatment-free (TF) packages go for $165 and up. TF TBH nucs are even pricier, starting around $200-$300), you have some options:

  • If your package bees are bustling and local forage conditions are good, splitting your bees is a definite possibility for expansion. The benefits of this are that you save a little dough, you're almost guaranteed to be able to make splits, and splits help protect your bees from the ravages of mites. Being fortunate enough to have good spring forage, I have pretty much always needed to split colonies started from packages, so don't let anyone tell you it can't be done. Another thing is most newbies don't know when to stop feeding. As a result, they feed and feed all year, which causes massive colony growth. If this happens, don't be afraid to split! If you scroll down to the Managing the Hive section of the FAQs I'm in the process of compiling, you'll find some info on making splits.
  • Find some local TBH beeks who might be willing to give you a shook swarm when their own bees start swarming. Since TBHs are not expandable, they tend to swarm once a year. Once my bees start making swarm cells, I split them and make up shook swarms with the old queen. Since I've reach maximum capacity for my yard, I've begun giving those shook swarms away. If you're on FaceBook, Christy Hemenway has created TBH groups for each state, so that is one way to connect with local TBH beeks who might help you out.  (To find your local group, just search for [Your state name] Top Bar Hives, replacing "[Your state name]" with the name of the state in which you reside.)
  • You can try capturing swarms. If you have places you can put traps, great. Otherwise, see if you can sign up for any local swarm capture lists. Your state agriculture department might keep a list. No doubt any local beekeeping clubs have a list. Your local police or fire department might have a list as well.  Swarms are kind of iffy, though, because you have to have bees in your area, but they're a possibility.
  • Try getting cut-outs. I'd recommend this option only if you're a handy kind of person, though.


Going into winter with four hives might be overkill...
Of course, I'm writing from my own experience in a northern climate with long, cold winters. Having double the number of desired colonies going into winter may be overkill if you live in an area with year-round forage where bees are active during all four seasons. For example, in central or south Florida, Instead of having double the number, you might only want 50% more.

Also, while I've been going into winter with double the number of colonies I actually want in spring, I've been coming through winter with a greater than 50% survival rate. That's ok. I'd rather have more bees than I want than fewer. Finding new homes for some of them is a snap since the demand for local bees outstrips supply by a great margin.

If you've been keeping bees for awhile, what is your take on the optimal number of hives going into winter?

Tuesday, January 24, 2017

Don't Code Your Hive Until It's Spring

Today, the weather is in the mid-30's F. Not too cold to go outside and look at the hives. (Ha! This tropical/sub-tropical girl must be adjusting to New England to believe that temps only slightly above freezing are ok. But I digress.)

Why did I want a look-see? Saturday was lovely -- upper 40's -- and bees were flying. But certain hives had less activity than expected. Thought I'd put a stethoscope on them to see if I could detect a heartbeet (sic -- get it?)

I started with Peach, then Austeja, and Hippolyte. The thing is, I really couldn't hear anything in any of the hives. So then I checked Elsa because, based on the number of bees pouring out of her on Saturday, I knew she was alive and extremely well. Dang it. I couldn't tell a difference between her and the others.  (Note to self: Get a Flir next year.)

What to do? What to do? I popped open Austeja's observation window. Not a single bee in sight. Had she absconded?

Hmmm... I tried one more thing. There is an almost foolproof scientific test for determining whether your bees are alive. It's called Kick the Hive. 

After some kicking and banging, a few heads began poking out of Buttercup, Celestia, and Persephone. Bummer. That gave me 4/8 colonies. However, after waiting another 5 minutes, some bees started pouring out of Bubblegum as well. Cool. 5/8 hives was fewer than I'd hoped, but not bad.

Bees starting to check out the banging 

Before heading back inside, I figured I might as well take some photos of Austeja's empty comb. That's when she gave me a surprise. On opening the window again, bees started breaking cluster and crawling toward the window. Now I'm up to 6/8!

The window is really dirty, but if you look really hard, you'll see some bees on the combs

What about my remaining two colonies? Until we get several consecutive days of 50+ F temps, I've decided not to diagnose them dead -- hence today's post title. 

So what's happening with my bees. I have some naive theories:
  • They may just be very tightly clustered, which is why Austeja's bees were originally not visible through the window. Maybe that's why I had trouble finding the clusters with the stethoscope.
  • They may simply be very quiet and conserving energy. Mike Palmer in VT says that the bees that overwinter best in his brutal climate are the ones that barely make a buzz in freezing temps. These are the ones he breeds. I got my original bees from Sam Comfort, who in turn collects local wild bees, but he's also got genetics from Mike Palmer and Kirk Webster in his stock. Could this just be a quality that my girls have inherited? I don't know.
  • Even though Elsa was alive, I gave her some good kicks and poundings, too, just because I wanted a Kodak Moment. Yet no amount of abuse would induce her bees to come outside. Hippolyte and Peach could be dead (seriously, I didn't have high hopes for Peach going into winter), but they could also be ignoring me like Elsa. So I'll just wait until the weather is warmer. After all, bees that I could've sworn would die/were dead have surprised me on more than one occasion.
In any case, I'm pleased to even have 6/8 alive. 8 hives was a lot of work last year, so if a few are dead-outs, that's fine. They'll provide space for new splits in the spring and give me a chance to retrofit a couple hives with insulated roofs/walls.

Going forward, I'll probably open the hives to make sure they have some sugar near the clusters, but that's for another day. A warmer one.

In any case, it's amazing how different I feel this winter compared to my first winter, or even last winter. My first couple of winters, I was on tenterhooks the entire season, praying every day that my bees would survive. Last year, I thought at least one or two hives might make it through winter, but I was still uncertain. Finally, I've reached this calm, confident place where losing 1, 2, even half of my colonies is not the end of the world. It's ok. I like this feeling.