When we watch a caterpillar spinning a cocoon or a butterfly emerging from its chrysalis, we are witnessing part of the remarkable life cycle of an insect. Insects live their lives in stages, changing form as they develop from egg to adult. In some, young and adult are so different, it’s hard to believe they could be the same species. A caterpillar becomes a butterfly, a garden grub becomes a shiny beetle, a wingless creature crawling on the bottom of a pond becomes a dragonfly skimming above it. Is there a connection between insect life cycles and the incredible success of this group of animals? Continue reading Insect Life Cycles – Background
Wandering through a meadow, a child stops by a jewelweed plant, on the lookout for its plump seed pods. As she reaches in and touches one, it suddenly bursts open and ejects a seed, startling and delighting her. This child is inadvertently helping with an important part of a plant’s life cycle, the dispersal of its seeds. Producing seeds for the next generation is only part of a plant’s job. It needs those seeds to reach a place where they can grow. Spring-loaded seed capsules like those of jewelweed are just one of the many fascinating mechanisms plants use to disperse their seeds.
A seed is the fertilized, ripened ovule of a cone-bearing plant (gymnosperm) or a flowering plant (angiosperm). Continue reading Traveling Seeds – Background
As days get shorter and cooler in the fall, birds that stay year-round begin preparing for a long, cold winter, while others get ready to migrate. Both face challenges that seem daunting for such slight creatures. Yet birds continually amaze us with their ability to survive the harshest weather, travel incredible distances, and navigate to faraway places.
Some birds are permanent residents, living year-round in one place, while others migrate twice a year, traveling between winter homes and summer breeding ranges. Continue reading Birds on the Wing – Background
The ever-changing cycle of seasons is one of the pleasures of living in a temperate climate. From the emergence of tender life in spring and the abundance of summer, to autumnal ripening followed by the long, cold winter, each season has its unique conditions. Survival demands that plants, animals, fungi, and even bacteria are adapted to survive all the seasons, and, for most, winter is the most difficult. This might seem obvious, but the implications are important.
Because of the tilt of the northern hemisphere away from the sun in the winter, we experience shorter days and lower temperatures, often below the freezing point of water. Continue reading Winter Ways – Background
The much-loved sugar maple tree provides food and shelter for wild animals, leafy shade in the summer, spectacular colors in the fall, firewood in winter, and the finest syrup in early spring. Learning to know sugar maples better and understanding how they produce the sap for the syrup we love so well can only increase our appreciation of these delightful trees.
Maples are easy to identify if you take a closer look at their growth habit. Continue reading Sugar Maples – Background
Mysteries abound in the winter woods. Besides animal tracks in the snow, we might find nipped-off twigs, gnawed branches, debarked trunks – signs made by animals feeding on trees in winter. To figure out which animal has been doing the eating, we often need to identify the tree species. But, without their leaves at this time of year, trees can be mysteries to us as well. Animals that feed on woody plants have no trouble recognizing which twigs, buds, and bark make the best meals, but for us identifying trees in winter requires a close look and attention to detail, the skills of a good detective.
At the tips of branches, twigs offer many clues to a tree’s identity. Take a closer Continue reading Trees in Winter – Background
A stand of goldenrod, its rugged stalks standing tall in a wintry field, is a good place to look for galls, one of nature’s small wonders. Many of the stalks sport hard, round swellings about an inch in diameter. Cradled in each, awaiting spring, is the larva of a gall-making insect. Its life cycle, like those of many other gall-makers, involves a remarkable relationship between an animal and its particular plant host.
A gall is an abnormal growth on a plant caused by another organism, most commonly an insect or a mite but also by nematodes, viruses, fungi, or bacteria. Continue reading Galls Galore – Background
As the days grow longer in spring, chickadees start singing a different tune. Besides the familiar chickadee-dee call, we now hear a whistled “hey, sweetie,” often answered by another chickadee: “Hey, sweetie! Hey, sweetie!” Soon a cardinal takes up the theme, “Come here, come here,” and later a bluebird, back from migration, joins in the chorus: “Ain’t I pretty!” By May, the orchestra, in full swing, fills the dawn with a symphony of birdsong. Why do birds sing so much in the spring? Why make noise that could betray your presence to predators? What role does birdsong play in the annual cycle of a bird’s life, to be worth so much energy and risk?
Many birds communicate with sounds. Ducks quack, geese honk, loons yodel, and songbirds sing. Continue reading Songbird Songs – Background
Even the smallest child recognizes the common yellow dandelion. Their sunny flowers, bundled and offered as bouquets, announce that spring is here. Whether they bring a smile or a frown, you can’t help but admire a plant that seems to be able to grow anywhere – from lawn to roadside, from parking lot to playground. Dandelion flowers serve the same function as all other flowers: to produce seeds for the next generation. Though not native to North America, dandelions are here to stay, thanks to a whole host of strategies that ensure their fluffy seeds will float on breezes far and wide.
The dandelion, or Taraxacum officinale, gets its common name from the French dents de lion or teeth of the lion, thought to describe its jagged leaves. Continue reading Dandelions – Background
From the time the pussy willows open in early spring until the last of the asters, spring, summer, and fall are the seasons of flowers. They are glorious – but why do they exist at all? Like the singing of birds and the taste of ripe strawberries, they give us great pleasure, and for some that’s enough – but flowers are essential to the lives of flowering plants. Blooming is the culmination of months or years of growth, and understanding their parts will illuminate what they do.
Flowers have four kinds of parts, and they are in predictable positions. Continue reading Flowers to Fruit – Background
Hanging under eaves, tucked in the cracks on tree bark, hidden in tall grass, spiders and webs can be found nearly everywhere you look in late summer. Not all spiders spin webs, however. Some actively hunt for prey, scurrying over dirt in the garden or ambushing pollinators visiting flowers. Whether wanderers or web weavers, spiders abound in nearly every habitat on Earth, with estimates of one million individuals living in each acre of grassy field. There are about 2,500 spider species in North America, all different and each well adapted to its role as a small but effective predator.
Spiders are arthropods, which means that they have jointed legs and hard exoskeletons, as insects do. Continue reading Spiders: Web-Builders and Wanderers – Background
Towering above us, branches reaching to the sky, trees are a familiar feature of the landscape, whether a forested hillside, a busy city park, or our own backyard. In the summer, trees form a green canopy shading and cooling the ground below. In winter, they stand silently braced against the cold and snow. With some 100,000 different species worldwide, trees come in a variety of shapes and sizes and thrive in a wide range of habitats. But what makes a tree a tree?
By definition, trees are large, woody, perennial plants. From underground roots to leafy branches, each part plays an important role in the survival of the tree. Continue reading Tremendous Trees – Background
Compared with lacy ferns, showy flowers, and towering trees, the grasses seem hardly worth noticing. Yet these modest plants flourish in harsh conditions, cover much of the land masses of the world, support huge populations of grazing animals, and produce prodigious amounts of seeds – the grains that feed our livestock and us. Grasses have fascinating and unique adaptations that make them extremely resilient and set them apart from other kinds of plants.
Grasses grow just about anywhere – in fields, wetlands, saltmarshes, mountaintops, deserts, and even in shady forests. There are ten thousand species worldwide, and – in prairies, savannahs, pampas, and steppes – they cover a quarter of the earth’s land. Grasses dominate in conditions that are challenging for most other plants. They thrive in open plains that are dry and windy, lacking in shade, exposed to rain and snow, blizzards, and tornados. They are also built to survive fire and grazing by hordes of animals, from swarms of insects to herds of elephants. Continue reading Grasses and Grains – Background
What makes the fox clever and the deer swift, and why do both have a keen sense of smell? Predators and prey face different challenges in getting their food. Predators must find their prey, chase and catch it, subdue it if it fights back, all before they eat it. Prey animals must forage for food cautiously, always on the lookout for predators. The anatomy and the behavior of predator and prey animals reflect each species’ needs and way of life.
Both predators and prey need keen senses, but the position of eyes and ears, the functioning of noses and sense of smell, can be very different. Continue reading Predators and Prey – Background
Have you ever stumbled across an animal skull in the woods and found your mind filled with questions about it? What kind of animal was it? What did it eat with those teeth? Were the eyes really that big? Was the brain really that small? Finding a skull tends to bring out the private investigator in all of us. As we examine these bony shells, built to protect the brain, hold the teeth, and house many of the sensory organs, we can find clues about the animal’s life.
The first thing to notice when you find a skull is its size. Is it the length of your thumb (squirrel, rabbit, weasel); does it fit in your hand (fox, bobcat, raccoon, beaver, opossum); is it as long as your foot (deer, bear), or even bigger (cow, horse, moose)? Size can be deceptive since skulls lack the covering of muscles, skin, and fur of a live animal and thus often seem much smaller than you would expect. Still, by considering its size first, you can often narrow down the possibilities. Continue reading Skull Sleuthing – Background
In the fashion world of birds, anything goes. From crimson cardinals to loons in elegant black and white, from portly turkeys with rusty fan-tails to sky-diving falcons in steely gray, birds carry it off with panache. The diversity of birds is amazing, with 10,000 species worldwide living in habitats as different as tropical jungles and frozen tundra, and ranging in size from the tiniest hummingbirds to condors with ten-foot wingspans. Birds’ fashions may seem exotic, but they are also functional, adaptations for each bird’s particular environment and way of life. Continue reading Birds of a Feather – Background
Many of us have stories of owls flying across the road in front of our cars, calling eerily outside our windows, or quietly staring at us from a tree on a misty gray day. We recall these encounters vividly, for owls are such fascinating and mysterious creatures. As nighttime hunters, owls have incredibly specialized eyes, ears, feathers, feet, and digestion, all of which contribute to their superior predatory ability. Their calls are unique too, and, though strange and foreign to our ears, they are an important adaptation for owls to communicate with each other. Continue reading Calling All Owls – Background
Plants and animals need defenses to keep from being eaten. Nearly all animals have predators of one kind or another, and eluding capture usually means running away, hiding, or both. But when avoidance fails and the predator gets too near, most animals still have an effective last line of defense. Plants need defenses too, for protection from the many animals that feed upon them. Plants can’t run away or hide, but they have evolved a diverse armory of useful adaptations for fending off herbivores. Continue reading Daunting Defenses – Background
Beavers and muskrats, both rodents with round, furry bodies, twinkling eyes, and dexterous front feet, have a certain charm that endears them to us, even though they can be a nuisance. Both animals live in wetland habitats, and, though they are only distantly related, they have many similarities in their behavior and physical adaptations. Muskrats are beneficial to other wetland animals because they keep waterways open and clear of vegetation. But beavers far outshine muskrats in their skill as engineers and in the profound effect they have on their environment. Continue reading Beavers and Muskrats – Background
The hum of honeybees as they flit from flower to flower from spring through fall carries the promise of summer fruits and autumn harvest. Many flowers depend on bees and other insects to transport their pollen, and that pollen is needed to fertilize the flower’s eggs so they can mature into seeds. The relationship also benefits the bees because they depend on nectar from flowers to make honey and to mix with pollen to feed to their young. When we look at the amazing adaptations of honeybees, both physical and behavioral, we learn much about the life and work of these busy, buzzy insects.
Honeybees are social insects, living in colonies of many thousands of bees. Each colony is a single family comprised of the queen and her offspring. Working together in a highly organized way, honeybees accomplish remarkable feats of construction, navigation, decision making, defense, and honey making – far beyond what an individual insect could do on its own. Continue reading The Buzz on Bees – Background