Crows are omnivorous scavengers that eat almost everything, from grains and beetles to lizards, s, and even the carrion.
And so, snails represent nothing but a fresh meaty delicacy.
If a crow happens to find a snail, it will most likely eat it.
Perhaps, this idea of a snail in a crow beak may sound a bit off, especially if you have only come across large snails- the size of a human hand.
Snail shell seems to make it less appetizing.
So, you may even be wondering:
“Is it even natural for a crow to eat snails?”
Is Eating Snails Healthy For Crows?
Well, snail meat is as healthy as any other kind of raw meat.
You see, snails represent the freshest meaty delights in a wild setting.
Crows are to obtain the crisp meat chunks from these sluggish little gastropods.
Though, certain snails have evolved to release deterring mucous or repellents, crows have learned to avoid such snails.
Anyways, a crow may obtain the following nutrients from eating snails:
|Proteins||9g of protein/ 2ounces of snail meat||Helps in muscle maintenance and metabolism.||Similar to pork or beef meat. High levels of arginine and lysine amino acids, even more than egg yolk.|
|Carbohydrates||1g of carbs/ 2ounces of snail meat||Energy for daily function and metabolism.||–|
|Fats||1g of fat/ 2ounces of snail meat||Body maintenance.||Relatively low-fat content.|
|Vitamins||Vitamin A||Boosts immunity and strengthens eyesight.||–|
|Vitamin B6||Helps in metabolism.||Deficiency may cause slow growth and reduced hatchability.|
|Vitamin B9 or Folate||Red blood cells and Healthy Growth.||–|
|Vitamin B12||Essential for nucleic acid synthesis.||–|
|Vitamin K||Aids in blood clotting.||–|
|Minerals||Calcium||Helps in bone and feather maintenance, egg-shell production.||Deficiency may cause low reproductivity and thin-shelled eggs.|
|Potassium||Essential for fluid balance, nerve health, muscle contraction.||–|
|Magnesium||Maintains cranial nerves, digestive and reproductive health.||Also, essential for the calcium cycle.|
|Phosphorus||Needed for Egg content creation.||Deficiency is as common as calcium deficiency.|
|Copper||Increases immunity by acting as an antimicrobial agent.||–|
|Zinc||Boosts immunity and metabolism.||–|
|Selenium||Improves egg hatchability and contents.||–|
|Iron||Helps in synthesizing red blood cells.||Deficiency may cause anemia, headache, dizziness, or respiratory disorder.|
While all this shows how eating snails is healthy for crows, you may be wondering:
Wouldn’t the shell hinder a Crow from swallowing a Snail?
How Does a Crow Eat a Snail?
That depends on the type of snail.
Now, snails range in size from a few millimeters to 40 cm in length.
Among species, their shells differ in shape as well as diameter from 3mm to about 13cm.
Even the thickness of the shell varies.
Generally, large snail shells with large apertures are thinner compared to shells with narrow apertures.
Therefore, snail size decides not only its predator but even the frequency of its predation.
For instance, Oval Ambersnails (Novisuccinea ovalis) is a relatively large yet the most commonly hunted land snail as it has a thin shell making it prone to cracking.
Meanwhile, Maze Pinecone (Strobilops labyrinthicus) is a small snail with a thick shell, making it the least predated land snail.
So, indeed snail structure plays a vital role in how it will be hunted.
Crows will have two options for eating any snail:
If a snail is so large as not to even fit inside a crow beak, then the corvid must only swallow the soft tissue.
Crows have shown to do so in two ways:
- By inserting beak inside snail aperture or poking a hole through the shell to pinch out soft tissue, eating the snail alive.
- By cracking the shell and detaching the soft body from the shell, then eating the meaty portion.
If a snail is small enough to fit inside crow beak, a crow can even swallow it whole, with its shell intact. Eventually, the hollow shell comes out in bird droppings.
But then, a snail shell is to protect a snail from getting eaten.
So, it should help the snail resist some of the gastric juices.
But you may wonder if a snail can live through a bird’s digestive canal.
Can a Snail Survive Being Eaten By a Bird?
Interestingly, it can.
The phenomenon was first observed when Shinichiro Wada and his colleagues were studying droppings of a bird – Japanese White Eyes (Zosterops japonicus) and found an insane number of intact snail shells.
They then made two bird species – Japanese White Eyes and Brown-eared Bulbuls, eat hundreds of snails (especially Tornatellides boeningi).
These scientists found that 14.3% and 16.4% of snails survived through the guts of Japanese White Eyes and Brown-eared bulbuls, respectively.
Zoologists claim that snails that survived through bird guts used this method to travel long distances.
Thereby, distributing their genetic pool.
However, this form of gene dispersal still had geographical limitations.
A journey through bird gut is still a harsh road, taking at least 30 minutes to about 2 hours.
So, a more interesting question would be asking:
How Do Snails Survive Being Eaten By Birds?
By hiding and sealing themselves in their shells.
You see, snails have the ability to produce slimy mucus.
So, they can even seal themselves inside their shells by creating a mucus membrane on their aperture and sitting tight inside their shells.
The shells are composed of calcium-made barriers or lamella.
Since the shells don’t much erode through the digestive tract within a few hours, so, survival of snail in bird gut depends on:
- The thickness of its shell.
- Its ability to seal itself and have enough breathing air.
- Its ability to not move much.
- The corrosiveness of digestive juices within bird gut.
Hence, small snails with thicker shells are more likely to survive being eaten than moderate-sized snails.
Furthermore, several snails possess the ability to regenerate their shells, part of their foot, and even tentacles.
Anyways, a snail survives mainly because of its shell.
Therefore, even though slugs have an endoskeleton, they cannot survive through bird gut.
Obviously, crows eat both snails and slugs.
But they are not the only birds to do.
So, you may be wondering:
What Birds Eat Snails And Slugs?
Technically, all birds that can eat snails do eat them.
These birds include:
1. Specialized Snail Eaters:
Certain birds have specialized in exclusively eating snails.
Prominent examples are:
a. Everglades Snail Kite (Rostrhamus sociabilis)
This snail-eating kite has specialized in eating apple snails (Pomacea sp.).
These fly about 100-feet above shallow waters while skimming for snails.
On finding a snail, everglades kite uses its hooked beak to extract out the snail’s fleshy part and consume it in one go.
b. Limpkin (Aramus guarauna)
Limpkin pokes its beak inside shallow waters to look for snails.
Typically, it swallows the snail whole.
However, if a snail is large then, the limpkin detaches the snail from its shell to consume it.
c. Song Thrushes (Turdus philomelos)
Song thrushes grab snails in their beaks and repeatedly strike them on a special type of stone to crack open their shells.
These stones are often referred to as Anvils.
Once the snail shell breaks, the song thrush eats the flesh of that snail.
Interestingly several blackbirds and crows have also been reported to copy the anvil technique.
2. Opportunistic Snail Eating Birds
These are birds that don’t particularly look for snails but will eat one if they can find one.
Here is a list of such birds:
|Type of Bird||Typical Examples||Remarks|
|Small Birds||Thrushes, Red-winged, Blackbirds, Starlings, Robins, Blue Birds.||Typically, only eat small snails if they can swallow them whole.|
|Moderate to Large Birds||Blue Jays, Crows, Magpies, Rooks, Wild Turkey, Ravens.||Eat all kinds of snails.|
|Birds of Prey||Hawks, Owls, Eagles.||Prefer Large Snails.|
|Aquatic Birds||Herons, Storks, Cranes, Ducks.||Prefer shallow water snails of those living in marshes.|
|Domestic Birds||Certain Parrots, Chickens, Ducks, Geese.|
This sounds like only birds eat snails.
So, let’s ask again, this time a different question:
What Are Snails Eaten By?
Since snails are slow-moving but nutrient-rich animals, therefore, they are eaten by all kinds of animals.
Here is a list of snail predators:
|Type of Predator||Examples||Remarks|
|Invertebrates||Devil’s coach horse, boat-backed ground beetles, Millipedes, Flies, Mites, Nematodes, Spiders, Crabs.||Large beetles can sometimes crush smaller snails.
Small beetles can creep inside the aperture, eating the snail from within.
For instance, Cychrine Beetles have elongated bodies to eat snails from within.
|Other Snails||Decollate snail eats brown garden snails.
Rosy Wolfsnail eats African snails.
|Either drill hole inside the shell, or insert their face inside the snail shell through the aperture to eat it.
Predatory snails can be used for biological control of other snails.
|Amphibians||Toads, Frogs, Salamanders, Newts.||Eat only small snails.|
|Reptiles||Box turtles, snakes especially Garter Snakes.||Can wait for snail to come near them. Typically, only eat flesh.|
|Birds||From swallows to hawks, nearly all birds can eat snails.||See the above section for more detail.|
|Mammals||Shrews, Coast moles, Hedgehog, Squirrels, Mice, Humans.||Even small mammals can break snail shells. Some like shrews can stockpile snails for winters by eating about 3times their body weight.
Hedgehogs swallow snails whole.
But, humans typically cook to eat snails.
Crows are opportunistic scavengers that eat snails whenever they get a chance.
While they can swallow small snails whole, they can even break shells of larger snails.
Snails are nutritious, therefore, several birds and animals can eat them on daily basis.
However, certain snails have the ability to survive in bird gut, and so, they live even after being eaten alive.
Here’s some other interesting articles about crows so do check them out!