Honey Bee Super-Sisters

A reader asked a question about the mechanism in which honey bees pass their genes along to the next generation. Honey bees employ a reproductive scheme called “haplodiplodity.” For an informed answer, I called upon my friend, Jon Zawislak, apiary instructor with the University of Arkansas Cooperative Extension Service. I quote him below. It appears to me that an evolutionary advantage of haplodiploidity may be in altruistic behavior in which individual bees act for the protection of the colony over self. From Jon Zawislak:

“Begin with the strict Darwinian principle that an organism is considered to be most "successful" by passing on as many copies of its genes as it can.

Worker honey bees get half of their DNA from their mother. Of that 50%, about 25% is identical (basic Mendelian genetics). The same is true for humans, you get 50% of your DNA from your mother, of which you share about 25% identical maternal DNA with each of your siblings (although not the same 25% with each). The lopsided relationship among honey bees comes from the paternal side, from the drones. Drones have only one set of chromosomes, so their sperm does not undergo reduction division to halve the number of genes, which effectively mixes them up first. Each of the millions of sperm that a drone produces is identical, and contains his entire set of DNA. So when worker bees are "super sisters" they share 75% identical DNA: 25% from the queen and 50% from the drone (all he has, so all incidental). Workers who have different fathers share only maternal DNA, and are said to be 25% related. If this particular queen mated with 20 drones, on average each will be the father of only 5% of the workers in the hive, and each worker will share this super-sister relationship with only 5% of her family.

If a worker helps one of her super-sisters to become the next queen, she ensures that she is 37.5% related to every new bee in the colony (50% of 75%). Even if one of her half-sisters becomes the next queen, she will still be 12.5% related to all of them. But this is still better odds than if she has her own sons. If a worker becomes a laying worker, then she can produce only drones, which are 50% related to her. If one of her drone sons successfully mates, she will be 50% related to her granddaughters as well (because the drone passes on all of its DNA). But, each drone has a fairly slim chance of mating at all (a conservative estimate might say one in 1000 chance of finding a virgin queen). And if he does, he will only be one of perhaps 20 drones to do so. Therefore if a worker becomes a layer, she has less than one in 1000 chance of her son passing on 50% of her genes to just 5% of another colony.

A worker is more closely related to her super-sisters than she is to either of her parents or her own potential offspring. And even though she's only this close to as few as 5% of a colony, consider how many bees that is. In a colony of 40,000 bees, that's still 2000 super-sisters. Close kinship also promotes altruistic behaviors, where an individual promotes the well-being of close relatives, even at a potential risk to themselves. Bees demonstrate several examples... spring bees work themselves to death so that wintering bees will have food to eat during the cold months; individual bees sting and die to defend and protect the rest of the colony; and workers "give up" their own reproduction to help raise their sisters and nieces. But as we have seen, the family unit is more successful at passing on some of its genes if they all work to help their queen. Solitary bees that go it alone produce only a handful of offspring each year, rather than the thousands that a honey bee queen can produce.

Of course this idea of kinship and altruism assumes that bees know that they are closely related. Studies have shown that workers reared in isolation can distinguish between full- and half-sisters (Getz & Smith. 1986. Animal Behav. 34:1617-1626). Workers preferentially rear queens from more closely related larvae (Visscher. 1985. Behav. Ecol. Sociobiol. 18:453-460). Workers are most willing to groom and feed closely related sisters (Frumhoff & Schneider (1987) Animal Behav. 35:255-262). And workers may cannibalize eggs less closely related to themselves (Ratnieks & Visscher (1989) Nature 342:796-797).”

Today's photo: transitional top bar bee hives in Ethiopia.
--Richard

Traditional Thanksgiving

Winrock International, www.winrock.org, sends volunteers to developing countries around the world on USAID-funded food security projects. Africa is a fond memory now. I reflect on my assignment teaching beekeeping trainers in Ethiopia’s Oromia region. I travelled with Guta Abdi, the founder and managing director of Education For Development Association. Guta’s name means “full of hope” in Oromifa language. With Guta, I observed the beautiful, volcano-strewn land, resourceful farmers, and Oromia’s rich customs. My training sessions in the mountain-top village of Shambu began and ended with prayers by traditional belief elders. These people, numbering five million believers, deeply respect the land and attribute all existence to a single deity without praying to any prophet. They gather annually around six volcanic lakes for thanksgiving. Guta Abdi is shown at the thanksgiving in the center of today’s photo wearing a gray sweater and open collar. When he took me to the site, I knew I was in one of the earth’s special places.

Travelling through Oromia, I saw children proudly wearing banana leaf hats. The children of each village fold their banana leaf hats in a distinct regional design. Along mountain ridges, I saw “fachas,” tall poles with tin roofs covering a cape buffalo’s tail. The facha is a sign proclaiming that a man accomplished a feat such as killing a lion or leopard with a spear. In earlier times, a facha was placed to proclaim the killing of one’s tribesman has been revenged by killing nine of the opposing tribesmen. Fortunately, this is a past practice. I especially enjoyed sharing Ethiopian food with my host. A typical day started with eggs and red peppers, enjira, Ethiopia’s flat bread made from fermented teff grass seed, bread, and tea. Coffee and bread was served at morning and afternoon breaks. Lunch included enjira, potatoes, and a “wot,” or stew, of sheep. Supper included enjira, cabbage wot, roasted sheep with carrots, “tej” honey mead, Ethiopian beer, and “areke,” locally-made vodka. Thank you, Winrock and EFDA.

--Richard

This Will Not Be Kicked

Explaining that the natural home of the honey bee is a hollow tree, I relate that all beekeeping efforts should provide a bee hive similar to a hollow tree cavity. Each of the Ethiopian beekeeping trainers in my Shambu class sits quietly with pen and tablet listening to Tucho translate my beekeeping lessons from English to Oromifa. They take notes and write questions for me. As soon as Tucho reads their questions, I realize that my students are knowledgeable; they are paying close attention to me; and they are interested in exploring new techniques in beekeeping. They ask specific questions about ways to manipulate modern bee hives. The students see the usefulness of moving frames of brood to produce new queens, strengthen weak colonies, make colony divisions, and select for better genetics. They ask about working bees in the daytime. Their traditional practice of nighttime honey harvesting gives the beekeepers few opportunities to observe the bees’ brood nest. Having only used smoke to drive bees from the hive, they want to know how smoke works to calm bees. The students question the causes of migratory swarming and hive absconding, both frequent problems for Ethiopian beekeepers. Several follow-up questions come from my suggestion that increasing bee hive ventilation and requeening can lessen the incidence of chalkbrood, a common fungal infection of honey bees in this semi-tropical land.

Some question commonly held practices and beliefs. When they see pictures of Peace Bee Farm hives painted white with stripes of color, they ask why mine are not painted yellow like modern Ethiopian bee hives. They all laugh in understanding when I ask if they ever saw a hollow tree in the forest painted bright yellow. One asks if my hair is gray from touching it with honey on my hands; I explain that it is merely due to my age. EFDA-trained leather worker, Tolesa, crafted the soccer ball signed by my Ethiopian beekeepers in Amharic and Oromifa. This football will never be kicked.

--Richard

Shambu Area Projects

I see evidence of the influence the Education For Development Association, www.efhda.org.et, makes on the lives of Oromo farmers. Travelling Ethiopia’s western highlands, I see multiple projects in effect. Providing sanitation and clean water for drinking are great challenges, so the EFDA provides well water and fixtures to deliver spring water for drinking and cooking. A solar water disinfection project effectively purifies water in clear plastic soda bottles at almost no cost. Bottles are placed on the roofs of houses, and UV rays from the sun purify the water in six hours. Concrete drinking troughs for cattle and livestock reduce the animals’ pollution of streams as well as helping to keep animals healthy in times of drought. On individual farms and at the EFDA’s resource centers in Shambu and Walisso, farmers gather to learn sustainable agricultural practices, animal husbandry, water conservation, and methods of improving food production. EFDA pioneered in introducing apples to Ethiopia’s highland area to generate additional income for farmers.

This is Ethiopia’s rainy season, and the western highlands appear lush and green. Everywhere I look farmers are plowing the rocky volcanic soil with teams of oxen. A closer look reveals lean oxen with bones showing; the animals simply don’t have enough muscle to safely pull their plows. Tucho shows me horse and donkey harnesses used for plowing when the mighty oxen are not capable of pulling the plows. The green grass is grazed close to the ground. Tucho explains to me that this year’s rains are not sufficient to sustain the grasslands and fill the reservoirs. Fincha Lake remains unseasonably low. Tucho fears the land may not sufficiently support the population’s food requirements Tucho and Gedefa explain EFDA’ efforts to protect the environment, prevent the loss of topsoil, provide drainage systems, and encourage crop rotation. Oromo farmers are working to prevent deforestation, and degradation of the environment. They protect flood areas and forests. My beekeeping project is designed to take advantage of the resources of the forest.

--Richard

Steady, Little Donkey!

Riding with Gemechis Jeleta of Winrock International and driver, Kassahun, on a busy four-lane, divided road through the streets of Addis Ababa to meet my host Guta Abdi of the Education For Development Association, I see a startling sight: donkeys in the air! Yes, a herd of donkeys crossing overhead in a pedestrian crosswalk. I tell Guta about the sight; he laughs, and gives me today’s picture of five people and a donkey sharing a very small dug-out canoe. When a western Ethiopian river was impounded, forming Fincha Lake for hydroelectric power, area farmers lost land and were presented with a transportation problem. The EFDA taught craftsmen to build canoes at Chitu Island to cross the lake. As their boat-building skills improved, the size of their boats increased. With larger boats, the EFDA trained the farmers to fish for tilapia in this western highlands reservoir. The fishermen now face a lifetime of food security. In the next few days, I see first-hand the breadth of EFDA’s work. The boat building and fishing training are just two of EFDA’s job skills training projects designed to upgrade existing skills and introduce new skills. Among those trained are leather workers, blacksmiths, basket weavers, and clay workers who produce “jabena” coffee pots, clay water jugs, and fuel saving stoves. EFDA’s rural livelihood programs work to provide jobs for women. I meet women trained to build low-fuel cook stoves, distribute sacks of cane sugar and dig bicarbonate of soda from volcanic soil for the manufacture of medicine.

Guta states that development should first take place in the minds of the people. The EFDA, which operates in the Oromia and Benish Gumuz regional states, builds schools to increase the quality of life through quality education. Schools encourage children to learn traditional knowledge of their community. EFDA’s health projects include women’s reproductive health, HIV/AIDS programs, and a campaign that abolished female genital mutilation in the Jimma and Horro districts. Oh, I have much more to see.

--Richard

Traditional to Modern

The beekeepers in the Oromia region of Ethiopia collect honey and beeswax from traditional bee hives mounted in trees. However, problems the farmers encounter in handling and storing honey often mean a harvest of inferior quality that brings a low price. My Winrock International assignment is to teach modern beekeeping methods and to demonstrate how to move bees from traditional bee hives into modern hives. Most Ethiopians are farmers, and nearly all Ethiopian farms have bee hives. Ninety-seven percent of the hives is traditional hives like those placed high in trees for thousands of years. These hives are truly beautiful sights; tall trees holding the five to six-foot long cane cylinders resemble trees covered with weaver bird nests. One percent of Ethiopia’s honey bees is held in transitional bee hives, known as top bar hives. The remaining two percent of Ethiopia’s bee hives is the modern Zander hive, and half of the Zanders sit without bees. With the vast majority of Ethiopia’s bees being held in traditional hives high in trees, beekeeping in this semi-tropical land is based on attracting swarms of bees and then making a one-time harvest of honey and beeswax. The method of harvesting is destructive of the bees’ nest, and it usually results in the loss of the bee colony. Keeping bees in modern hives makes harvesting high-quality honey possible with no loss of the bee colony.

I planned a move of brood comb and bees from a traditional hive into a modern Zander hive. Unlike traditional bee work done at night using large amounts of smoke, I told my students, all seasoned beekeepers, that we would attempt to move the bees during daylight hours using a small amount of smoke. In today’s photo, I am shoulder-deep in the traditional hive cutting out brood combs which my helpers tie into modern frames with string. After I have removed all of the combs, I dump all of the remaining bees into the waiting hive with one sharp bump.

--Richard

Training in Shambu

My training of beekeeper trainers in Shambu includes both classroom and practical experience. Ninety-seven percent of Ethiopia’s honey bees are housed in traditional bee hives high in trees. Traditional beekeeping primarily involves placing in trees a number of hives, rubbed with a native plant as a bee attractant. In western Ethiopia, the plant is “kusaya” in Oromifa or “kosereta” in Amharic, a plant with a lemon odor similar to honey bee Nasanov pheromone. After swarms move into the hives, beekeepers wait for the bees to expand their colony and build up stores of honey. Then, at night, a beekeeper climbs a tree and lowers a hive down to a waiting partner. Using large amounts of smoke, the beekeepers drive the bees out of the hive and cut out the honeycombs. The evicted colony of bees is lost. The honeycombs are crushed by hand, and the honey and beeswax are collected together. The traditional beekeepers actually have little interaction with the hive and the bees. The students, each seasoned beekeepers, are extremely interested in the workings of a honey bee colony.

Ethiopia’s rainy season dictates our training schedule. Intermittent rains and power outages bring us indoors. Using a portable generator, we view photos of healthy bee hives and hive problems; many are the same photos seen in this blog. Some have not seen inside a hive with the bee colony intact. Their only experience involves driving bees from the hive at night. For practical experience, the beekeepers prepare a modern Zander hive and transfer the bees from a traditional hive to it. This procedure will allow beekeepers to catch swarms of bees in the treetops and then move them to modern hives where they can be tended allowing for continuous harvests without destroying the bee colony. First, beeswax is melted and cleaned to produce foundation. In today’s photo, skilled hands embed support wires into the freshly made sheet of foundation using a knife heated in an open fire.

--Richard