More exceptions than rules when distinguishing moths and butterflies

Black and yellow patterned wings with a small ‘tail’ flutter between flowers, an identifiable characteristic of the tiger swallowtail. Certain butterflies are easily identified by their colors, such as the monarch butterfly.

Swallowtail butterfly

Color can be a factor in distinguishing a butterfly from a moth but not always. Typically butterflies are more colorful than moths which are drab colored. As with any generalization, there are exceptions and that seems to be a common theme when distinguishing a butterfly from a moth. 

Both butterflies and moths are insects that belong to the order Lepidoptera. They differ from all other insects in that they have tiny colored scales on their wings, a coiled proboscis (mouthpart) and big showy wings. 

The proboscis of butterflies and moths uncoil like a party noise maker to draw in fluids

Butterflies and moths are more closely related than most people think. Lepidoptera contains over 150,000 species and approximately 18,000 of those species are butterflies. 

Even though Lepidoptera is dominated by moths, they are not as visible as butterflies because moths tend to be nocturnal (active at night). However, there are some moths active during the day (diurnal) along with butterflies.

Butterflies are considered a very specialized group of diurnal moths that have a few distinguishing characteristics.

The most reliable way to distinguish a butterfly from a moth are the antennae. A butterfly’s antennae are a long shaft with a club at the end, much like a golf club. A moth’s antennae are either simple filaments tapering to a point or feathery and complex, like a television antenna. 

Male moths tend to have more feathery antennae than females in order to detect the pheromone emitted by females.

Most butterflies hold their antennae out and forward while moths sometimes tuck their antennae alongside their bodies while resting. 

Dogbane tiger moth

Arctic Skipper (butterfly)

The next most visible difference between butterflies and moths are their wings. Most butterflies hold their wings together and upright over their back when at rest, except while basking in the sun. Moths tend to rest with wings open or tented over their back (so the hindwing is not visible). 

During flight, a structure, called the frenulum, that hooks the forewing to the hindwing causes moths to have a stiff, jerky flight. A butterfly’s lack of frenulum results in a more graceful flight pattern. 

Sometimes, it may seem that a butterfly or moth flies by at certain time intervals and it may be rightfully true because males are territorial and will continually circle their territory. Females, on the other hand, fly around haphazardly. 

Another difference between males and females are their bodies which consist of a head, thorax and abdomen. Females may have a round abdomen tip to lay eggs while males have a slit at the tip of their abdomen. 

The bodies of moths and butterflies differ slightly. Moths tend to have plump, fuzzy bodies while butterflies have smooth, slender bodies. 

Before moths and butterflies become adults with showy wings, they are caterpillars. There are no generalizations to distinguish moth caterpillars from butterfly caterpillars. 

However, the pupae of moths and butterflies are distinguishable. A moth’s pupa stage is spent in a silken cocoon that is woven around the pupa. Some moths don’t spin cocoons. Butterflies do not weave a cocoon either but instead have a hardened outer skin made of protein called a chrysalis. 

Despite all the exceptions to the generalizations, Lepidoptera species are amazing insects to watch whether they are classified as butterflies or moths. 

Note: Published in the Bonners Ferry Herald on June 27, 2013.

Killdeer protect eggs by faking injury

The loud piercing “kill-dee” or “dee-dee-dee” call of the aptly named killdeer alerts all to the presence of predators or a disturbance. The noisy vocal nature of the killdeer is why early common names included chattering plover and noisy plover. Even the killdeer’s scientific name (Charadrius vociferus) describes its noisiness with the Latin word vociferari meaning “to shout, yell”.

A killdeer’s call can be heard anywhere from gravel bars to golf courses to gravel driveways. They are adapted to a wide range of habitats, including close proximity to human development. They need a nearby water source which can even be a lawn sprinkler. Killdeer are common across most of North America in the summer except for northern Canada and most of Alaska. 

As a ground nester, close proximity to humans can sometimes be detrimental. A killdeer’s nest is often no more than a scrape in the ground. They nest in open areas, including pastures and gravel driveways. Sometimes they add a few pieces of nesting material but not many. The pigmentation and spots on the eggs camouflage them extremely well with their surroundings.

Abandoned killdeer egg in nest

To draw predators and unaware humans away from their nest, killdeer will emit their loud piercing call and use distraction displays. 

The most common distraction display is the killdeer bluffing an injury. As a predator approaches, the bird crouches low and drags a wing as if it were injured. The killdeer leads the predator away from the nest and if the predator gets too close for comfort, the killdeer alternates flying and sprinting until the predator is far enough away from the nest. 

Predators of killdeer eggs and young include skunks, raccoons, foxes, mice, weasels and cats. 

Both parents incubate the eggs and if one parent is distracting a predator, the other (if it is nearby) sounds the alarm with their piercing call.

After almost a month of perilous incubation, downy chicks hatch from the primitive nest. As soon as their down dries, the chicks are led away from the nest by their parents to a feeding area. The chicks stay with their parents for approximately one month until they fledge.

In some latitudes, killdeer nest twice in a summer. Often the male guards the first chicks while the female starts a new nest of three to five eggs.

Living in a wide variety of habitats, killdeer eat a wide variety of insects, including grasshoppers, beetles, caterpillars, ants and dragonflies. They also eat mosquito larvae, ticks, centipedes, snails and earthworms.

They bob their heads as they walk searching for food and then grab food with their black bill from the ground, shallow water or low plants. Their running-stopping-bobbing gait makes them easy to identify.

Bold brown, black and white coloring makes killdeer easy to identify but also camouflages them. Both male and female killdeer look the same except that some males have more black on their head. However, juvenile plumage is paler and the downy chicks only have one black breast band. 

Killdeer are one of the easiest plovers to identify (particularly in Idaho where they are the only plover) not only because of their bold colorings but also because of their distinctive piercing call.

Note: Published in the Bonners Ferry Herald on June 20, 2013.

Wandering painted turtles seeking place to lay eggs

Western painted turtles typically don’t wander far from their pond unless it is time to lay eggs. Finding two turtles on the West Side Road over Memorial Day weekend signaled that the females were looking for a suitable nesting location, which can be up to half-a-mile away from water.

A female turtle on its way to a suitable nest site

Being a reptile, turtles lay eggs. Female painted turtles seek out a sunny, south-facing slope with sandy soil to dig a hole. Starting with her front legs and switching to her back legs, the female digs a hole four inches deep and two inches wide. She then lays six to 20 leathery eggs, covers them with soil, and then walks back to her pond. 

The sun keeps the eggs warm and the rain keeps them moist until they hatch in the fall. Some of the hatchlings will travel to a pond right away, others will stay in the nest until spring. 

Spring and early summer are when painted turtles are the most visible--basking on logs, rocks or vegetation mats. They tend to bask on objects surrounded by water to reduce their exposure to predators.

Basking keeps a turtle’s body warm. As a reptile, turtles are cold-blooded, meaning they are the temperature of their surroundings and cannot generate their own heat like us. 

Basking warms a turtle's body

Basking in the sun allows the turtle to warm its muscles and move faster. Basking also helps turtles rid themselves of parasites, such as leeches, because they dry up and die in the sun.

At night, painted turtles swim down to the bottom of their pond and rest in the mud because water has a more constant temperature than the air and fewer predators. 

As summer progresses and the water warms, turtles spend less time basking and more time foraging. They are opportunistic omnivores and feed on insects, snails, earthworms, frogs, tadpoles, algae and aquatic plants. Turtles swallow food underwater because swallowing dry food is difficult. 

Studies show that painted turtles prefer animal food but eat whatever is available. Juveniles tend to be more carnivorous than adults and turtles living in northern latitudes consume more animal food than their southern counterparts. 

Life in northern latitudes isn’t easy for a cold-blooded turtle. Northern populations mature later (closer to eight years of age instead of four) and reproduce less often but lay more eggs, grow bigger and grow faster. 

Painted turtles can grow to the size of a dinner plate with females being larger (up to nine inches) than males (up to seven inches). 

The markings on the plastron vary slightly between individuals

The brightly colored shells and skin colorings that lend to the western painted turtle’s name are similar for both males and females. The markings on the plastron (shell covering the belly) vary between individuals.

Certain anatomical differences distinguish males from females and having both males and females next to each other makes it easier to distinguish them. 

First, males have longer front toenails than females. Secondly, males have a long, thick tail and females have a thin, short tail. 

Females have shorter toenails than males

A third way to distinguish turtles almost requires holding the turtle (but be careful because they can urinate on you). The males rear vent is situated farther from the edge of the shell than the female’s vent. 

One other difference is that adult females are the only ones crossing the road and risking their lives to perpetuate the population.

Note: Published in the Bonners Ferry Herald on June 13, 2013.

Crab spiders ambush prey

Stopping to smell a wildflower--particularly a yellow or white one--may bring you eye-to-eye with a crab spider. Perched motionless with legs outstretched like a miniature crab, the crab spider waits for the unsuspecting insect while being incredibly camouflaged.

The crab spider's stance is true to its name

Movement on the flower reveals the location of the generally white or yellow crab spider. Those that spend their time on flowers are often referred to as “flower spiders”. True to its name, the crab spider is more skilled at moving sideways and backwards than forwards. 

With the two front pairs of legs longer than the back legs, crab spiders move about on their back legs. The specialized front legs quickly grab prey that visits the flower for nectar or pollen, such as honeybees, moths and flies. 

Crab spiders can catch insects two to three times larger than themselves, such as butterflies, because their toxic venom quickly paralyzes prey. 

Crab spiders can capture prey two to three times larger than themselves

After a crab spider pounces on its prey, it injects the paralyzing venom through its hollow fangs (the venom is harmless to humans). Their fangs are small compared to other spiders. Once the prey is subdued by the venom, the crab spider vomits digestive juice into the prey so the digestive enzymes liquify the insides. 

Crab spiders do not have teeth like vertebrates and cannot eat their prey. Instead, they drink the liquified insides of the prey through their chelicerae (jaws) and leave the exoskeleton of the insect relatively intact.

Successful predation relies of the quick reflexes of their strong front legs, toxic poison, camouflage from prey and predators, and their eyes. 

Not only does being camouflage with the flower they are waiting on help crab spiders catch prey but it also keeps them from being eaten by birds. 

Being camouflaged helps the crab spider eat and not be eaten

The goldenrod crab spider has the ability to change its color from yellow to white over the course of three days. The spider is aware of the flower’s background color by being sensitive to the reflected light. If it moves from a yellow flower to a white flower, the spider will reabsorb the yellow pigment, sequester it or excrete it to turn white. When moving from a white flower to a yellow flower, the spider will mobilize the sequestered yellow pigment or synthesize new pigment.

Insects are not a steady food source and crab spiders can survive for months without food because of their low rate of metabolism. Females are known to turn on males after mating and eat them. However, females don’t consume their offspring if they live long enough to see them hatch.

In cold climates, the adults typically die in the winter and the eggs persist through winter. A female protects her eggs by folding a leaf over the eggs and wrapping silk around them. 

Spiderlings look like miniature adults. As the spiderlings grow they shed their skin until adult-sized. 

All spiders spin silk and wrapping eggs in silk is one way crab spiders use their silk. Like other spiders, they use silk as drop lines to quickly drop out of harms way. They don’t build webs but instead ambush prey.

Crab spiders can successfully ambush prey because their eight eyes create sharp images at short distances and they can see in all directions. By being able to perceive motion up to eight inches away, they are sure to get a good look at you when you stop to smell the flower they are perched on. 

Most "flower" crab spiders are yellow or white

Note: Published in the Bonners Ferry Herald on June 6, 2013.