Although some tortoises are large (upwards of 3 feet or bigger), they’re vulnerable to predators. Aside from the mature Galapagos Tortoise (or giant tortoise), all tortoise species have natural predators.
Predatory animals can get around a tortoise’s natural defenses, like its hard shell. For most tortoises, the main threat is a bird of prey. So, if you keep a pet tortoise outside, you must protect it from birds.
Large birds of prey are the most common tortoise predator due to their unique ability to lift and drop tortoises. This process makes getting through tortoises’ tough shells significantly easier.
Can Birds Pick Up Tortoises?
Most birds can pick up a tortoise, but it depends on the species and age of the tortoise and the bird.
For example, smaller tortoise species (and hatchlings of any species) are easy for any bird species to pick up. Meanwhile, larger bird species in good health can lift much bigger tortoises.
Surprisingly, even small birds can lift and kill a tortoise because they don’t need to haul the tortoise a long distance. They only require seconds to ascend into the air. Once they’ve gained appropriate altitude, they release the tortoise and let it fall to the ground.
The impact will crack the shell, providing the bird with easier access to the tortoise meat that’s normally hidden and protected by the shell.
Depending on where the tortoise landed and how fast it fell, it may even crack it wide open, ensuring the bird can feed without needing to pick between shell pieces.
Lifting and dropping a tortoise is the primary hunting method. Avian predators commonly target animals that can defend themselves on the ground but poorly (if at all) in the air.
For example, rabbits are common prey for hawk species but would bite, kick, and otherwise put up a strong resistance if tackled on the ground.
Avian predators use their natural advantages to avoid potentially damaging struggles. In the case of a tortoise, it wouldn’t fight back, but predator birds would be unable to scratch or peck through its shell. Using gravity to crack it is its only option.
That’s why large avian predators may land on and peck or maul a tortoise hatchling. Until the age of 5 years, most tortoise species have soft, malleable shells that can be torn or cracked with less energy-intensive methods. Birds usually leave the “pick up and drop” method when possible.
Do Birds Eat Tortoises?
If predator birds can catch, kill, and breach the shell of a tortoise, they’ll eat it. They don’t attack tortoises for fun or entertainment, and it’s exclusively a means of hunting for meat and nutrients.
If a predator bird kills but doesn’t eat a tortoise, it’s likely because it couldn’t sufficiently breach the hard outer shell. Otherwise, a larger predator might have driven it off.
So, you should be particularly careful with young tortoises and hatchlings, as they have soft shells that won’t offer the same level of protection.
A medium-sized, opportunist hunter like a magpie could easily lift and kill a hatchling tortoise. The predator may even eat the hatchling while it is alive.
Which Birds Eat Tortoise?
Many birds, whether common or rare, will kill and eat a tortoise if given the chance. More birds will eat a dead tortoise if they find a carcass.
The average owner will only need to be concerned about active hunters. These are the birds you’ll need to safeguard your tortoise against:
Large birds of prey, such as eagles, are the most widespread predators of any wild tortoise species (even large species, like the spur-thighed tortoise).
Golden and bald eagles will attack, kill, and eat tortoises as large as themselves. Fully mature golden eagles are known to hunt and kill moderately sized mammals, such as goats.
If you have eagle species in your area, create a robust outdoor enclosure with a top covering that can withstand the force of a large, strong bird.
While smaller birds of prey might target smaller, easier-to-handle prey, a bald eagle will target a larger animal, as it’ll offer more protein and meat to sustain it. A semi-mature tortoise will be ideal.
Many types of hawk hunt and kill tortoises. For example, the Galapagos hawk is one of the only natural predators of the Galapagos tortoise.
Of course, these birds only target immature or newly hatched Galapagos tortoises, as the sheer size of grown adults make it impossible to get through their shells or lift them.
Other hawk species, like the goshawk, will target smaller tortoise species if given the chance. They’re opportunistic hunters that’ll attack animals normally outside their prey pool as long as they believe they can be successful.
So, if you have a pet tortoise outdoors and live in a mountainous or forested area, goshawks pose a serious risk to their health and well-being.
Despite being the smallest member of the falcon family, kestrels (also called sparrowhawks) are fierce little predators. Roughly the size of a common pigeon, kestrels aren’t big enough to lift most grown tortoise species. However, they’ll certainly injure one if they decide to attack it.
While adult tortoises are off-limits, kestrels can lift a baby tortoise and drop it. They’ll also kill one with their claws and eat it if allowed. The same is true of its larger cousin, the peregrine falcon, which can better harm larger tortoise species.
Most owners don’t think of owls when they consider avian predators that may threaten their pets. It’s certainly less common for owls to attack and eat domestic pets, like tortoises, because of their nocturnal hunting patterns.
If your tortoise is outside (even within its enclosure) at night, nearby owls may watch it to see if it becomes vulnerable.
For example, failing to shut the cage lid or leaving your tortoise out in the open (believing it’s too large to be threatened) could give an owl the right opportunity. Even if it can’t successfully lift the tortoise, it may try to harm the reptile with its viciously sharp claws and beak.
Large owls are the most dangerous for tortoises, including:
- Barn owls
- Snowy owls
- Eagle owls
They’re more capable of and motivated to attack tortoises. Meanwhile, smaller kinds, like dwarf owls, are most likely to target small mammals or rodents.
Ravens and other corvid species, such as crows, are perhaps the most likely predators to successfully attack and eat a tortoise. This is partly because of their size (ravens are much larger than most people realize) but also because of the intelligence of corvid species.
According to Ecosphere, the common raven presents an overwhelming risk to endangered tortoise populations. Crows and ravens are often found across North America.
Because magpies are small, especially compared to other prey birds, they’ll only attack smaller tortoise breeds or hatchlings. They’re aggressive hunters, so even if they can’t properly kill your tortoise, they are likely to injure it grievously.
Magpies may not be able to lift tortoises, especially larger tortoises. Still, they have sharp beaks capable of puncturing soft shells or the soft underbelly of most tortoise species. Thankfully, magpies are unlikely to actively attack larger tortoises as they primarily hunt smaller birds and rodents.
As large, powerful, sea-faring birds, seagulls are accustomed to targeting difficult prey. Tortoises may not be a part of their natural diet, but seagulls will take an opportunistic chance if a tortoise is vulnerable.
How To Protect Your Tortoise from Avian Predators
Keeping your tortoise inside is recommended for avoiding avian predators., but this isn’t possible for all owners as you may:
- Lack the indoor space.
- Struggle to provide the right light exposure.
- Own a large tortoise species needing more space to explore.
- Want to give your tortoise a more normal and realistic living space.
If avian predators are native to your area, that doesn’t mean you can’t keep your tortoise outside. Instead, it would help if you took precautions to safeguard it against dangers.
Whether you own a small or large tortoise, ensure its enclosure has a wire-mesh lid. This will create a fully enclosed space that still lets ample sunlight and fresh air in. Most importantly, a bird can’t access it and could even be deterred by the reflecting metal, depending on the type you use.
Alternatively, put up a strong perimeter fence and cover it with netting used for aviaries. Aviary netting is robust, weatherproof, and readily available via pet supply retailers.
Ensure the edges are properly secured, as intelligent predator species like corvids may take advantage of loose edges and become trapped in your tortoise enclosure.