Bumblebees!
Learn about the Honey Bee’s furrier cousin
There are a ton of reasons to love, and I do mean LOVE Bumblebees. They are super cool, super furry and super unique, so let's explore!
Why are Bumblebees so furry?
Well, if we look at all bees they are furry in one place or another, but bumblebees have what seems to be super dense fur which covers their body. This fur has been adapted to help in attracting pollen while she buzzes from from flower to flower. As bumblebees go from flower to flower they come into contact with the pollen laden part of the flower, the stamen, which releases pollen onto their body. Although the busy bumblebee continues to groom herself at each flower some pollen particles are missed and transferred between flowers - this simple process is also know as pollination! So her fur is what makes her such an essential and effective pollinator!
The Bumblebee's fur also serves as a great insulator, allowing her to keep warmer during flight and at rest. This means Bumblebees are able to remain active in colder climates where competitive pollinators may have to return home to conserve energy.
Her fur is more than just straight hairs across the majority of her body, it is forked or branched allowing her to trap more pollen then a smooth straight hair would. Other hairs have been adapted for special purposes such as those on her back legs which are long and rigid allowing her to store globs of pollen for safe keeping during flight.
Where do Bumblebees live?
Bumblebees live everywhere! They are spread across the entire world, either from their native range or by human intervention. They are easy to spot on the landscape as they have a distinct "hum" as they move from flower to flower. As bumblebees have moved across the world over thousands and thousands of years they have adapted different colors and nesting habits. Some are all yellow and remind us of the classic bumblebee from our childhood. Others are extra furry and have colors such as white and orange! There are many varieties of bumblebees and so many which look extremely similar to each other, that many times they are misidentified by even the most well versed. What is known though, is that nearly all bumblebees are facing declining numbers from a loss of habitat and forage. Some species, such as the Rusty Patched Bumblebee (Bombus affinis) has declined over 87% and is suspected to only be found in 0.1% of its native range (USFWS). There is an incredible documentary film made about the Rusty Patched Bumblebee which highlights its struggle to cope with continued human encroachment, if you are interested in learning more about the Rusty Patch Bumblebee you would do well in watching A Ghost in the Making.
Do Bumblebees Pollinate?
Bumblebees are prolific pollinators and current estimates place them at 200x more effective at pollinating than Honey Bees. They employ a tactic known a 'buzz pollination' - when they land on a flower they give a short burst of buzzing which releases pollen into the air and subsequently is attracted to the fur on their body. Buzz pollination is somewhat unique to the bumblebee and if you listen closely you can hear her as she lands on each flower!
As Bumblebees forage from one flower to the next they accumulate large amounts of pollen which needs to be stored during flight. Therefore they have developed special long rigid hairs on their hind legs called a Pollen Basket. As they mix the pollen with their saliva and a little nectar it becomes sticky and allows for it to be shaped into a circular orb stuck fast to these hairs.
Are bumblebees used in commercial agriculture?
Bumblebees as a whole, are an insane pollinator posse, so why do we always see Honey Bees being used in commercial agriculture? Well, there are specific industries which rely heavily on the Bumblebee for pollination such as tomatoes and strawberries grown in greenhouses. Yet, Bumblebees, unlike their more control-able Honey Bee cousins, are little wild at heart and do not always act as we would like them to. They often escape their greenhouse enclosures, are susceptible to diseases, are difficult to breed, and only last one season. These are some of the same problems facing a 'domesticated' Honey Bee as well, which begs the question - should we be looking at an agriculture overhaul of our food production system and distribution?
Bumblebee Nesting
Let's start with a common baseline on this discussion, so we can highlight the differences between a Honey Bee and Bumblebee. Honey Bees in the wild live high up in the tree canopies tucked away in a knot-hole, protected from predators. If managed by a beekeeper they live in large wooden boxes close to the ground with multiple movable frames. Inside their home Honey Bees draw out the classic wax hexagon cell which is built vertically, in which they store food and raise brood. Additionally, the Honey Bee Queen lives for many years as she is kept warm by her daughters through cold winters. Whereas each year the Bumblebee Queen dies as she sends her daughters into the wild to hibernate for the winter and start a new colony in the spring.
Bumblebees are unique in that they generally live underground - there are thousands of different species of Bumblebees and some do live in trees, but let's keep it simple for right now. In early spring a Queen Bumblebee emerges from her winter slumber and starts looking for a place to call home. She actively searches for a small abandoned rodent burrow with some left over fur in it to fluff up and start a family. In this new nest she will create small wax bowls referred to as 'honey pots' where she will store food and raise brood. She builds these horizontally across the floor of her home - continuing to build a pile. This cluster of pots grows over the season with new pots built upon the old discarded ones. At the end of the season the home they have built will be abandoned as newly mated Queen bees venture into the world to find a safe place to hibernate during the winter, and the original Queen Bumblebee succumbs to old age, predation or starvation.
Bumblebee Colony Structure
The hierarchical structure of a bumblebee colony is similar to that of the common Honey Bee, in that, there are three types of bees found: Queen, Workers & Drones. Let's start exploring them below!
Queens
Unlike Honey Bee Queens, Bumblebee Queens live for only one year, their journey starting in the late summer or early fall when they are born in an established colony nest. Within the nest they grow strong on gathered honey and after some time leave the nest to mate, after which they find a place to hibernate over winter. Where they choose to hibernate is highly dependent on the species, but generally it is underground, or nestled in a pile of woodland debris such as loose leaves.
If they are able to survive the winter in which they face an onslaught of challenges from starvation, freezing temperatures and predation from mammals, they emerge in early spring from their slumber and start to feed. After a meal of early season nectar, they start searching for their new nesting site, usually a small abandoned rodent burrow. In an ideal situation this rodent burrow still contains some fur which they happily fluff up and start creating 'honey pots' to store food in. During this early period, she is the only bee in the nest and bares the entire weight of the hive as its sole care taker - forager, cleaner, feeder and rearing of new brood.
As she continues to feed and grow, she lays daughter (worker) eggs first which will take over all the duties of the hive. Once there are enough daughter workers in the nest the Queen will only lay eggs and maintain order in the hive by headbutting and pulling off legs of her aggressive daughters. The Queen has the ability to determine the sex of the egg before she lays it - she does this by controlling if the egg is fertilized. If the egg is fertilized it will develop into a female (Worker), or if she is looking to create males (Drones) which will continue her genetic legacy, she will lay an unfertilized egg.
As summer passes into fall and her worker daughters die of old age her food supply will dwindle until she has too succumbs to old age and starvation. She has hopefully persisted long enough to foster the next generation of her species, having sent out dozens of new Queens to start the cycle over again next spring.
Workers
The workers in the nest are all the daughters of the Queen, as noted above, she has the ability to determine how many and when to increase or decrease the number of workers in the nest dependent on season and incoming pollen / nectar resources. Workers in the hive start off performing basic housecleaning duties, then progress to rearing brood and after a week take on the most dangerous job of foraging. Many of the workers will not live past 30 days as foraging presents many perils from insect eating mammals, disease, bad weather and much more! While she is out foraging she is actively looking for two things, pollen and nectar. The pollen she brings home will be mixed with nectar or honey and to be fed to the growing brood. The nectar will be dehydrated into honey and used to feed the colony.
Drones
If there is one bee that has a great life in the nest, it is the Drone. Drones are actually haploid, meaning they come from an unfertilized egg, therefore they have no father. Don't worry though, their life is on easy street, once born they relax in the nest eating honey and staying warm. After a few days to a week they leave the nest for the first time and do not return, from here on out they hang out on the undersides of flowers slipping nectar and looking for a virgin queen with which to mate. Outside the nest their only goal in life is to mate, and the chances of this happening are extremely slim, those that do not mate will perish with the oncoming cold weather or from lack of forage as nectar sources start to fade.
Additional Bumblebee Resources
Our hopes for the above information is to provide you with a jumping off place to further your understanding of the Bumblebee. If you are looking to dive deeper into this fascinating insect, and I would highly recommend that you do, start off by exploring the following links and books:
Buzz: the nature and necessity of bees - by Thor Hanson - Basic Books - 2018
