| Vulture Bee Classification | |
|---|---|
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Apidae |
| Genus: | Trigona |
| Species: | Hypogea |
Vulture bees are stingless bees whose earliest recorded data dates only back to 1758. However, it was not until 1982 that their carnivorous diet of dead animal flesh was discovered by entomologist Davi Roubik.
This was quite the groundbreaking revelation as bees have long since been firmly established as vegetarians. As vulture bees evolved, they adapted to this new food force through changes in anatomy as well as in their hive culture.
Only a few scientific studies have been conducted on this unique flier, so there is still a great deal to be learned about their species.
What Is a Vulture Bee?
The vulture bee, from the Trigona genus, appears reddish-brown in color and ranges from 8-22mm in size. Unlike other bees vulture bees do not collect pollen, intentionally pollinate other plants nor feed on plant nectar, instead they prefer to feast on carrion or dead animal proteins.
When feeding, vulture bees typically enter the carcass through the eyes, from there they’ll use their mandibles to effectively breakdown the flesh. In order to feed effectively, vulture bees have evolved to have five large, pointed teeth, which also supports their painful biting and aggressive reputation.
Instead of the sweet nectar honey most bees produce, vulture bees create their own unique honey from the protein-rich secretions of their hypopharyngeal glands derived from their diet.
Vulture bees have been recorded to have foraged from 75 different species of animals.
Why Are They Called Vulture Bees?
The vulture bee from the Trigona genus has established the name “vulture bee” and is classified differently to other bees due to its unusual carrion or dead animal proteins consumption/diet.
Though vulture bees are still considered foragers, they do not survive solely on the more common choice of nectar adopted by other bees. Vulture bees carrion consumption differs depending on their location, for example in jungle or rainforest climates vulture bees commonly feed on dead lizards and snakes.
To further define the given name “vulture bee” an experiment conducted by entomologists representing Cornell University, Columbia University, and the University of California Riverside, researchers used raw chicken to bait and study the vulture bees’ habits in Costa Rica.
They found that vulture bees did consume the raw meat, proving they’re not opposed to a varied diet. Furthermore, they observed they seemed to prefer the fresh, raw meat over recently rotted or slightly decaying flesh.
Why Are Vulture Bees Attracted To Meat?
Vulture bees are not the only stingless bees, but they are the only stingless bees that consume meat. Vulture bees are most commonly found in parts of the world where nectar-rich flowers are small in number and scientists believe due to stiff competition for little resources they have adapted their diet to reflect this.
How Are These Bees Adapted to Eating Meat?
Vulture bees are the only bees in the world known to have evolved in order to maintain a diet not produced by plants. Vulture bees have evolved an extra tooth on each mandible, this allows vulture bees to slice chunks of meat off the carcasses as they forage, storing the flesh in their crop (honey stomach).
Vulture bees have an acid-rich gut biome that aids in the digestion of these complex proteins, which produces a carrion-decomposing microbe that releases toxic compounds. The entomologists involved in the Costa Rica experiment believed this was likely in order to reduce competition of any other vertebrate scavengers in the area.
Common honey bees collect pollen in leg baskets but because the vulture bees do not need those, their leg baskets have evolved to be far smaller.[1]
Where Can Vulture Bees Be found?
Vulture bee colonies thrive in warmer, neotropical climates like rainforests and jungles found throughout South America including Mexico, Brazil and Argentina.
A unique disjunction among the vulture bees is that while they exist in moist and tropical environments, they seemingly do not cross large bodies of water.[2]
How to Identify a Vulture Bee?
Vulture bee bodies are small, robust, slender and parallel-sided. Vulture bees possess a more blackish-red or dark brown body color, ranging greatly in size from 8mm up to 22mm long.
Vulture bees unlike bees that collect pollen for honey production are not hairy and only have a few short pale hairs on their thorax (middle body). Vulture bees have clear but infuscated wings (tinged with brown)
The mandibles of the vulture bee workers have five large, pointed teeth on each one. The female vulture bees have four ovaries, and the queen has thirteen.
Where Do Vulture Bees Live?
Vulture bees, despite their frightening name are social bees that live in colonies made up of the typical bee hierarchy: queen, worker, drone, and larva.
Vulture Bees build their nests in cavities like tree hollows or underground and have also been known to take over abandoned termite nests. Outside of cavities, vulture bees have been known to nest high up in trees and on the branches themselves.
Nests of stingless bees/vulture bees usually have solid bitumen plate (a hardened wax substance that will seal the nest cavity) to protect the colony.
The vulture bee nest structure is typically made from a mixture of wax, resins, soils/mud, bee feces and decomposing vegetal particles. The nest entrance gives direct access to where the brood is being raised.
Around the vulture bee brood chamber and honey storage pots a protective layer is sometimes constructed (involucrum sheath, made of wax and resins).
Vulture bee brood cells can be clustered or they may be arranged in combs that are most frequently positioned in a horizontal plane. Vulture bee queen cells are slightly larger than the cells of the worker bees and are scattered around the edges of the brood comb. (Where the queen lays eggs) [3]
How Do Vulture Bees Eat?
Vulture bees collect rotted or recently deceased flesh and sometimes extrafloral nectar from native plants and fruits. When harvesting carrion, a vulture bee will enter the carcass usually through their eyes and root around inside.[4]
Using their extra-toothed mandible, they will slice and chew the flesh off, coating the meat in their acid-rich saliva before consumption. The bee will transport the chewed carrion back to the colony where it’s regurgitated into wax pots, different from the honey pots.
Here, the meat will be mixed with honey and left to mature over a period of 14 days. During this curing time, it will become a paste-like substance that is rich in free amino acids and sugars. This paste is fed to their young, who need it to grow.
To recruit their foraging nestmates, a guide bee will send out recruiting signals and can lead large numbers of other bees to the food source. The guide appears to show the direction by a short zigzag flight and by making occasional pheromone deposits along the way.[5}
Studies conducted at observation hives constructed in Panama revealed that a guide vulture bee recruited several hundred foragers in just two hours to two recently deceased lizard and toad carcasses. At the same hive, a freshly killed lizard was placed 15 meters away from the hive and was located within eight hours. Over the next two days, in groups of sixty to eighty vulture bees, they reduced the entire carcass to only a skeleton.
Entomologists believe the ability to recruit a large number of bees quickly enables the vulture bees to beat their foraging competition. Vulture bees have also been observed to possess a propensity to rob and attack competitors for food and nest sites, sometimes feeding on abandoned larva or even toad eggs.
It has also been noted that other small foraging creatures, such as ants, tend to steer clear of vulture bees.
How Do Vulture Bees Digest Meat?
The Costa Rican entomology study of vulture bees led to a better understanding of their gut microbiome. They reported that vulture bees lost some core microbes, retained others, and developed new ones.
Their stomachs were found to be full of acid-loving bacteria that helps protect the bees from pathogens found in their rotting meat diet. They use this bacteria in their saliva to coat the flesh before they eat it.[6]
One of the bacteria types, called Lactobacillus, is also found in fermented foods such as sourdough. Animals that are scavengers, like vultures, hyenas, and vulture bees, have evolved this biome to process the bacteria and still receive the available nutrients from the food source.
Do Vulture Bees Make Honey?
Vulture bees do make honey, and in a similar fashion to the more common honey bee.[7] The worker bees will forage for protein, in this case, carrion, as well as sugars from fruits and extrafloral nectaries.
Unlike other social bees, the foragers themselves deposit their crop contents directly into the pots without the involvement of receptor bees.[8]
The sweet paste-like substance is then stored in honey pots, separate from the protein pots, for 14 days where it will cure. This process is aided by the acidity of the vulture bee gut biome for preservation.
There are two primary differences in production, aside from the protein source, of note between common honey bees and the vulture bee. One is that vulture bees store honey in individual honey cells, rather than a comb. The second is that vulture bees, unlike the common honey bee, use mass provisioning.
Each larva is provided with all the necessary nutrients required to reach full adult development, not just the larva stage.
What Does the Vulture Bee Honey Look Like?
In its early stages, vulture bee honey is thick and described as a honeylike material or paste made of carrion, and bacteria. When it’s mature, it’s more honey-like, homogeneous, and yellow-ish.[9]
Is Vulture Bee Honey Safe to Eat?
Honey produced by vulture bees is a pleasant tasting and sweet smelling honey-like liquid.[10] However, it would not suit a vegetarian diet, being made from meat protein. There’s no concrete evidence that it is toxic to humans, which means there is also no assurance it is not.
Vulture bees do not produce honey in quantities that can be responsibly harvested and little is known about its flavor. However, the idea of honey made from rotten rainforest animal flesh is unpalatable to most human stomachs.
Do Vulture Bees Sting?
Being of the Trigona species, vulture bees are stingless bees and unable to cause harm via a stinger. This doesn’t mean they’re not aggressive. Certain species of vulture bees react in swarms at the smallest disturbance and will violently attack the intruder, usually by biting.
They have five teeth on each mandible to help them harvest meat from carcasses. Vulture bees have been observed to be highly protective of a feed site and with the absence of a stinger, use their teeth and acidic bacteria bites to dissuade competition.
Does a Vulture Bee Pollinate?
Vulture bees are not known to participate in pollination. They don’t collect or need pollen in any way and they have not been observed to visit flowers for nectar. Any pollen observed in their hives was determined to be only introduced accidentally or unintentionally.
Rather than the more common nectar, their protein source consists only of the foraged carrion which is broken down in their uniquely acidic gut biome.
Vulture Bee Reproduction And Lifecycle
As with all insects that undergo metamorphosis, vulture bees pass through egg, larval, pupal, and adult stages. Their eggs are fertilized by the one queen bee and that is her sole purpose — she does not forage.
In some species of vulture bees, the workers kill the queen if it mates with more than one bee. A vulture bee queen is only allowed to mate with one partner, presumably to uphold the genetic superiority of their colony.
As the queen’s pheromones fade, some species of stingless bees will combine an empty, emergency queen cell with a brood cell containing a larger larva. The larva will consume the contents of that cell and develop into a new queen.
The Carnivorous Vulture Bees
These unique bees are the only known bee species to eat carrion exclusively making them an evolutionary wonder.
Sources
[1] Apidolgie [2] press.jhu [3] Apidolgie [4] press.jhu [5] Science Direct [6] arstechnica [7] [8] [9] [10] Research Gate
