Since animals associate a large size with dominance and power.
Therefore, a vulture under threat will likely spread its wings to appear bigger than its normal size.
This also helps the vulture to flee at a moment’s notice.
That said,
Vultures habitually spread their wings in the early mornings to take sunbaths.
So, if are wondering:
Why Do Turkey Vultures Spread Their Wings?
Depending on the context, it may involve the following reasons:
1. Preparing To Fly
Raptors are rather large birds that cannot fly with mere fluttering.
And so, they have adapted to fly through gliding on the rising air drafts or thermals.
Now, these thermals are created via the uneven heating of the earth’s surface through sunlight exposure.
Therefore, a raptor’s flight is coherent with the presence of the sun.
Normally, these thermals form around the same sites.
However, their directions and paths are highly dependent on weather and sunlight intensity.
Raptors can either spread their wings to find the direction of the wind or look for other raptors circling in thermals.
So, if a turkey vulture is sitting with its wingspan wide open, then it may be looking for a thermal to take flight.
2. Appear Threatening
Animals under threat often expand themselves to appear bigger than their actual size.
It’s because large size is a declaration of dominance.
A predator is unlikely to attack a large-sized animal.
Now, a turkey vulture is quite a harmless raptor.
In fact, the first reaction of a turkey vulture in danger is to vomit and flee.
However, if a turkey vulture is nesting and has chicks around, then the stakes are higher.
So,
A turkey vulture may spread its wings to appear threatening while protecting its hatchlings.
3. Claiming The Prize
Turkey vultures have excellent vision and developed olfactory nerves that give them a strong sense of smell.
Did you know, Turkey vultures are usually the first scavengers to find a dead body.
This is precisely why scavengers like black vultures look for Turkey vultures instead of the carrion.
However, black vultures are extremely aggressive birds.
Black vultures often make turkey vultures wait while they feast first.
But if food is scarce, then turkey vultures spread their wings to deter the black vultures.
Thereby, claiming the prize.
Besides, this approach also helps turkey vultures flee a scene within moments.
4. Sunbathing
Vultures have been reported to take sunbaths in the early mornings.
Typically, this involves vultures sitting on the open grounds or tree-tops, facing away from the sun while spreading their wings.
Most vultures incline their backs like solar cells to maximize sun exposure.
This posture is referred to as “Horaltic Posture”.
Now, you may be assuming that vultures are sunbathing as lizards do.
However,
Vultures are birds while lizards are reptiles.
You see, reptiles are ectotherms or cold-blooded animals.
They cannot regulate their own body temperature.
Therefore, they need sunlight exposure for normal functioning.
Lizards need to bask in sun for controlling their body temperature.
In fact, most reptiles have adaptations to maximize sunlight intake within a short time.
For instance, crocodiles have hard skin and bony plates called “osteoderms”.
These bones are enveloped in an extensive vasculature.
Bones directly absorb sunlight and then warm crocodile blood, which circulates while warming the whole body within few minutes.
In contrast, birds are endotherms that can regulate their own body temperature.
Therefore, birds like vultures don’t need sunlight to create their body heat.
However, a bird does need heat conservation mechanisms to stop heat from leaking out.
But that doesn’t explain:
Why Do Vultures Take Sunbathe?
Ornithologists still don’t completely understand why a vulture would need a sunbath.
Scientific evidence supports the following reasons:
1. Temperature as Energy Boost
Like other birds, vultures need to conserve their energy.
Now, vultures live in relatively open areas where the temperature fluctuates significantly within a single day.
To prevent heat loss, hundreds of vultures huddle together to roost in rock crevices.
However, even communal roosting cannot do much good as the temperature drops to freezing points every night.
To avoid cold, vultures have adapted to slow down their metabolism, thereby reducing energy needs.
This also means that vultures’ functioning body temperature lowers down at night.
As the morning approaches, the temperature rises with sunlight.
However, vultures need to reach their normal body temperature.
For this they may have two options:
- Vigorous body movement through wing flapping.
- Basking in the Sun.
Soaking in sunlight is convenient and more efficient way of gaining heat.
In fact,
A vulture sunbathing is like human taking caffeine as an energy boost for the day.
2. Drying Wings
As the temperature drops every night, the moisture in the air accumulates.
This is precisely why we have dew drops on leaves and flowers.
Similarly, birds can also get water drops gathered within their wings.
So, perhaps:
Vultures take sunbaths to dry their feathers and avoid frizzy wings.
3. Pest Control
All vulture species have dark-colored feathers.
And dark colors absorb more heat in a short period of time.
Therefore, ornithologists argue that dark-colored vultures were naturally selected through the evolution of thousands of years.
That means that all light-colored vultures did not get the opportunity to reproduce because black vultures survived better.
This led to the assumption that:
“Perhaps vultures do need sunlight to survive better”.
Since vultures get exposed to the dead and decaying bodies on daily basis, they are likely to get exposed to numerous sorts of microbes and mites.
So,
Ornithologists suggest that vultures use sunlight to rid themselves of pests.
Several experiments were conducted on vulture feathers.
According to a study, a vulture feather can get about 120-140ºF when exposed to 10 minutes of Sunlight.
At this temperature, microbes may experience UV-radiation-based DNA damage.
Most pathogenic microbes on vulture skin can die through mere Sun Exposure.
You may be wondering, “How would temperature remove a mite?”
Now, imagine a black car exposed to sunlight on a sunny day.
If you were to ride this car, you will immediately switch on the air conditioning.
Otherwise, you may feel suffocated.
This is exactly what happens to mites or other pests.
They feel so suffocated as to move on feather midribs.
But as they accumulate there, they become easy to remove through preening.
“But can’t vultures remove mites without sunlight?”
Highly unlikely.
You see, a feather mite is about 1mm in length and even smaller in width.
Also, a mite infestation means thousands of mites.
And so, removing them through preening is both time-consuming and mostly inefficient.
Besides, sunlight exposure can also kill mites or slow them down.
4. Others
Perhaps, sunning helps vultures for more than a single reason.
Ornithologists describe a few more reasons for vultures taking a sunbath.
These include:
a. Anticipating Thermal
Since vultures tend to fly higher than all other birds.
Therefore, they are likely to wait for thermals to form well after the sun has risen.
And perhaps, they are basking in sun to wait for the rising air currents.
However, not many studies have been conducted to support this hypothesis.
b. Purifying Food
Vultures prefer to eat a sun-baked dead body.
Now, most ornithologists describe this as vultures waiting to ensure the dead is indeed dead.
However, few argue that vultures also use sunlight to ensure their food contains fewer pathogens.
So,
A vulture may be sunning around a carcass, waiting for it to become sterilized.
c. Depression Control
This one is a bit of stretch.
You see, sunlight exposure causes the release of serotonin, a hormone essential in relieving depression.
It also reduces Seasonal Affective Disorder, thereby uplifting mood.
So, perhaps vultures sunbath to avoid anxiety and mood swings.
However, no exclusive studies were conducted on vultures.
That said, vultures are not the only birds that spread their wings.
So,
What Does It Mean When Birds Spreads Their Wings?
Depending on the situation, it can mean anything.
Here are a few of the most common reasons:
1. Look Intimidating
The easiest way to avoid a predator is either hide or look invincible.
And so, birds spread their wings when they are threatened.
A common example is ostriches that spread their plumage to deter even wild cats.
2. Preparing For Flight
Birds like parrots or crows may half spread their wings, simply to flee at a moment’s notice.
This is also seen among young hawks and eagles.
3. Drying Wings
Most birds prefer living within trees.
Their feathers are bound to get wet through rain or dew drops.
Sometimes, even fog.
Therefore, several birds like doves, rails, or swallows have been reported to spread their wings on daily basis.
4. Attracting Mates
Like all other animals, mates that have favored traits are bound to survive better.
Since a large plumage and big size is associated with dominance.
Therefore, female birds prefer a male with large feathers. Consequently,
Bird mating rituals consist mainly of exhibiting the extent of wingspread.
One of the most magnificent shows of spreading wings is a male peacock dancing, showcasing its brilliant feathers.
5. Sunbathing
Vultures are not the only birds that spread their wings to sunbathe.
In fact, a bird sunbathing was first noticed in 1831 when ornithologist John James Audubon described a Great White Heron drooped its wings several inches than its normal posture.
To date, at least 50 bird families have been reported to take sunbaths.
These include doves, rails, finches, larks, swallows, thrushes, buntings, and birds of prey.
However, birders suggest that they may not be sunning for the same reasons.
But this may involve:
a. Temperature Regulation
Hummingbirds can reduce their metabolic rates to about 1/15th of their normal rates.
This adaptation is termed the “Torpor Effect”.
However, this also reduces body temperature.
These birds need a boost to temperature through flapping or simply basking in the sun.
Passerines take sunbathe for the same reason.
b. Feather Maintenance
On average, a bird spends about 9% of its lifetime maintaining its feathers.
Preening involves the removal of lice and dust, rearranging the fibers as well as adding natural oils to feather fibers.
If water gets locked onto feather fibers, it can cause bird wings to turn frizzy.
Therefore, Mousebirds in Sub-Saharan Africa dry their wings by sunbathing.
c. Removing Pests
Regular sunbathes can reduce bird pests and pathogens.
This was first suggested in a study conducted on doves and swallows at Virginia Commonwealth University in 1993.
When birds were sprayed with pesticides to remove mites, they spent less time on their aluminum roofs to take sunbaths.
Wrapping Up
All birds spread their wings to either take flight or look intimidating.
Some even do so to dry their wings or attract mates.
Vultures may spread their wings for the same reasons.
However, they are known for spreading their wings to take sunbaths each morning.
They may be doing so to maintain their body temperature, or to remove pests.
Here’s some related articles about vultures which you may find interesting so do check them out!