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An adult blue jay perched on a small branch.
BLUE JAY Blue jays are most often detected by their noisy calls. © Kent Mason

Stories in New Jersey

Species That Might be Tricking You

If you've been to TNC's preserves in New Jersey, you may have been fooled by one of these familiar species!

Camouflage, mimicking poisonous species and broken wing dances are just some of the many adaptations animals have made as important self-defense mechanisms. Explore five species found in New Jersey that have developed fascinating self-defense adaptations, some of which may have even fooled you! 

An adult killdeer sitting in the grass with its wings extended and held at an odd angle.
Killdeer To distract predators, killdeer pretend to have a broken wing. © Shutterstock
An adult killdeer flying over a body of water.
Killdeer Given their chatty nature, killdeer have been given the nicknames chattering plover and noisy plover. © Shutterstock

Killdeer

Killdeer, spotted frequently at our South Cape May Meadows preserve, use the art of distraction to trick their predators. Since they tend to lay their eggs in unsafe places, killdeer have developed a clever way to protect their nests. When a predator is near, the parent killdeer will pretend to have a broken wing. They call loudly and limp away from their nest to lure the predator away from it. 

The white, black and blue head of an adult blue jay.
Blue Jay Blue Jays are known for their intelligence and complex social systems. © Darrell Bodnar
An adult blue jay resting on a tree branch.
Blue Jay Blue jays are natural forest dwellers. © Darrell Bodnar
Blue Jay Blue Jays are known for their intelligence and complex social systems. © Darrell Bodnar
Blue Jay Blue jays are natural forest dwellers. © Darrell Bodnar

Blue Jay

Have you ever been birding and heard the call of an osprey or a Cooper’s hawk, but couldn’t spot one anywhere? It could have been a blue jay! With their impressive vocal repertoire, blue jays impersonate raptors: Osprey, broad-winged hawks, American kestrel, just about all raptors' calls can be mimicked by a blue jay. It's not fully known why blue jays do this, but one theory suggests they are trying to warn other birds that a raptor is nearby. 
A spicebush swallowtail larva, which looks similar to a black and white bird dropping, is sitting on a leaf.
Spicebush Swallowtail Larva The spicebush swallowtails' entire life cycle is marked by camouflage. © Shutterstock
A later stage spicebush swallowtail larva looks like a small yellow snake, complete with large eyespots.
Spicebush Swallowtail Mimicking snakes helps the spicebush swallowtail ward off predators. © Matt Kane / TNC
Spicebush Swallowtail Larva The spicebush swallowtails' entire life cycle is marked by camouflage. © Shutterstock
Spicebush Swallowtail Mimicking snakes helps the spicebush swallowtail ward off predators. © Matt Kane / TNC
A spicebush swallowtail butterfly pollinating common milkweed flowers.
Spicebush Swallowtail These butterflies get their name from their favorite host plant, spicebush! © Kent Mason

Spicebush Swallowtail

The spicebush swallowtail is a master of disguise. While the larvae are in the early stages, dark brown and white coloration causes them to look nearly identical to bird droppings, which encourages predators to leave them be. When these larvae reach later stages and are nearly ready to pupate, they change color and are marked by two large eyespots on top of their thorax, which creates the illusion that the caterpillars are snakes. Mimicking snakes allows the caterpillars to ward off predators, especially birds. In the adult stage, spicebush swallowtails use mimicry to resemble pipevine swallowtails, a foul-tasting butterfly that predators are likely to avoid. No matter what stage of life, the spicebush swallowtail has plenty of tricks up its sleeve.
An opossum shown in profile with its mouth open hissing to warn predators.
Opossum Hissing When threatened, opossums will let out a throaty growl or an intimidating hiss. © Shutterstock
An opossum lying on its side playing dead in a grassy field.
Opossum Although referred to as playing dead, this act is completely involuntary. © Shutterstock
Opossum Hissing When threatened, opossums will let out a throaty growl or an intimidating hiss. © Shutterstock
Opossum Although referred to as playing dead, this act is completely involuntary. © Shutterstock

Virginia Opossums

Although their open mouths and sharp teeth may tell you otherwise, Virginia opossums are not aggressive animals. They use this trick when they feel they are being threatened. The fear-ridden opossums will also let out a throaty growl or hissing sound, but this is merely a bluff to appear vicious to predators. 
An adult opossum sitting in the grass, looking at the camera.
Opossum Opossums prefer areas that are wet like marshes, swamps, and streams. © US Fish and Wildlife

When caught off-guard or seriously threatened by predators, opossums will enter a catatonic state, often referred to as "playing dead".  This behavior is not actually an act; it's an involuntary reaction to a threat.  In this state, the opossum has no reflexes and won't respond to predators. The opossum's body will begin to emit a foul odor similar to that of a decaying corpse. This awful smell combined with the appearance of being dead drives predators away and often leaves humans believing the animal is deceased.

Closeup image of a black and orange viceroy butterfly on a plant.
Viceroy Unlike their look-alike, the monarch, viceroys don't migrate. © Angie Cole

Viceroy Butterfly

Migrating monarchs fill our Garrett Family and South Cape May Meadows preserves each fall, but what if we told you there are some imposters in the mix? Although not closely related, viceroys practice mimicry and appear nearly identical to monarch butterflies. Viceroys use this tactic as a defense mechanism to avoid predators, as monarchs are poisonous to numerous predators like frogs, birds, and grasshoppers. Don't let this disguise fool you, there are some tips to properly tell them apart! Viceroys have a black line crossing their postmedian hindwing that monarchs do not have. Monarchs are larger than viceroys and have a less erratic, slower flight. Can you spot the difference below?

 

An orange and black viceroy butterfly with its wings fully expanded.
Viceroy Viceroys have a black line across their hindwing, which helps to distinguish them from monarchs. © Trisha Seelman
A black and orange monarch butterfly sitting on a flower.
Monarch Monarchs are slightly larger than viceroys. © Cheryl Rose
Viceroy Viceroys have a black line across their hindwing, which helps to distinguish them from monarchs. © Trisha Seelman
Monarch Monarchs are slightly larger than viceroys. © Cheryl Rose

Put Your Skills to the Test!

Our preserves throughout the state provide much-needed habitat for a wide variety of wildlife. Now that you've learned the tricks of these common five species, test your knowledge at one of our New Jersey preserves