Calf survival dependent on hiding or following

On wobbly legs, newborn deer, moose and elk are a precious sight to us but a tasty sight for predators such as wolves, bears and coyotes. Females will soon be giving birth to calves they have carried all winter and the newborns each have strategies to keep themselves safe from predators. 

White-tailed fawn hiding in tall grass

The white spots dotting a white-tailed fawn’s back are one way the fawn stays safe. The spots help the fawn blend into the dappled light of forests and thickets where it remains motionless waiting for its mother. 

Fawns retain their white spots throughout their first summer

Before the fawn is even born, the doe retreats to a fawning territory to be safer from predators. White-tailed does seek dense cover while mule deer does seek high, rough and steep ground. 

After the fawn is born, the doe licks the newborn and cleans the birth area (including eating the placenta) to hide evidence of the birth from predators. By eating the placenta, the doe also recaptures nutrients. Fawns remain scentless the first few days by frequent grooming from the mother who also eats their feces and urine. 

For the next few weeks, fawns rely on hiding to stay safe from predators. If an intruder is near, their heart rate and breathing slow down to help them remain undetected. Twins even hide separately to reduce the chance both will be found by predators. 

Elk calves also rely on hiding to stay safe from predators. Before the calf is born, the cow elk retreats to a wooded area for birth. The cow licks the calf and eats the afterbirth like deer. The cow also eat the urine and feces for the first few days to minimize scent and flies. 

Cow elk don’t remain away from the herd for long--they will often return to the herd almost immediately during the day while the calf stays hidden at the birth site. At first, a cow returns as often as every 20 minutes to nurse the calf. Like fawns, elk calves are cryptically colored, give off little scent and remain motionless when hiding. After two weeks, the calves join the herd and flee with the cows when threatened. 

Moose calves follow their mother everywhere

Unlike deer and elk calves which are “hiders”, moose calves are “followers”. Within a few hours of birth, the moose calf is standing and stays next to its mother. For nursing, the mother may lie down which is unique to moose and caribou in the deer family.

Like deer, cow moose retreat to a secluded area to give birth which tends to be in dense cover or at high elevations. The area usually has good forage to nourish the mother during lactation because the average newborn calf weighs 35 pounds at birth and gains two to four pounds per day. By the time the calves are weaned in the fall, they weigh 260 to 330 pounds. 

Surviving to autumn hinges on the moose calf staying close to mother. The calf stays close to its mother’s heels and if threatened, hides behind her and her defensive actions.

Moose calves stay close to their mother for protection

The threat of predators is high for newborn deer, moose and elk. Nearly 30 percent of mule deer fawns don’t survive to their first autumn and 75 percent don’t survive to the next spring. Some calves do beat the odds and live on to reproduce the next generation of calves which will face the same challenges of survival.

April showers bring May wildflowers

The saying “April showers bring May flowers” certainly rings true this year. After several days of rain followed by 70 degree weather, spring flowers are popping open everywhere including wildflowers. 

Arrowleaf Balsamroot

Depending on the location, some of the following wildflowers may already be blooming or will be blooming soon.

Small-flowered woodland star (Lithophragma parviflorum)

These small, white to pink flowers grace grasslands and open ponderosa pine and Douglas-fir forests. Not only are the flowers small but the plant is usually between three and 12 inches tall.

Small-flowered woodland star

The flowers somewhat resemble a star with the petals divided into three lobes at the tips. Flowers grow in clusters of five to 11 at the tip of the stem. Most of the leaves are clustered at the base of the purplish-colored stalk and possess deep clefts and divided blades. 

The slender woodland star (L. tenellum) is similar but has a green stalk.

Shooting star (Genus Dodecatheon)

Instead of the night sky, look in moist open meadows for these shooting stars. 

The arrangement of the petals give this wildflower its name. The bright purple to lavender petals are turned backwards and stream behind the yellow-to-orange style and anthers like the tail of a shooting star. 

Shooting star

The leafless flowering stalk stands between two to ten inches tall with lance- to spatula-shaped leaves at the base. One to several flowers droop from the top of the stalk.

If the shooting star looks familiar, it is closely related to the cultivated, potted cyclamen seen in floral shops. 

Arrowleaf balsamroot (Balsamorhiza sagittata)

The arrowleaf balsamroot is the showy sunflower on dry, open hillsides. The bright yellow, four-inch flowers bloom early on warm, dry hillsides and are large enough (up to three feet tall) to be seen from a distance.

Arrowleaf balsamroot

The balsam pitch aroma given off by the woody taproot gives rise to the flower’s name as do the large arrow-shaped leaves.

As a member of the sunflower family (Asteraceae), the arrowleaf balsamroot has composite-type flowers. Composite flowers are often mistaken for a single large flower but they are made up of many flowers of one or two types--ray flowers and disk (disc) flowers. Ray flowers have strap-like petals and look like the petals of simple flowers. Ray flowers form the outside ‘petals’ on arrowleaf balsamroot. Disk flowers have tubular petals and on arrowleaf balsamroot form the flower head’s eye (middle).

Other flowers of the sunflower family include hawkweed, dandelions, yarrow, daises, asters, goldenrod, thistles, knapweed, pineapple weed and burdock.

Heartleaf arnica (Arnica cordifolia)

Another sunflower of the woods is the heartleaf arnica. Smaller than the arrow-leaved balsamroot, the heartleaf arnica is six to 24 inches tall.

Heartleaf arnica

The heart-shaped leaves lend the flower its name. The leaves are opposite each other up the stem which is unusual in the sunflower family. 

Both ray and disk flowers compose the yellow flowers which have an aromatic odor. The wildflowers grow singly or in clusters from rhizomes (creeping underground stems that give rise to aerial shoots) in lightly-shaded wooded areas. 

Blue clematis (Clematis occidentalis)

You’ll most likely first see blue clematis at eye-level rather than on the ground. Solitary blue to light-purple flowers grow along a climbing or trailing vine that reaches up to 15 feet long. The leaves are clustered in leaflets of three along the vine.

Blue clematis

A unique aspect of blue clematis is that it has no petals. The blue flowers are actually four sepals (modified leaves that are usually green). 

Look for blue clematis in both moist and dry sites in open woods, rocky open areas or in mixed deciduous and coniferous forests. 

Bird nest diversity unparalleled in animal kingdom

Many birds are busy building their nests to capitalize on the insects and other food that will be abundant when the eggs hatch in a few weeks. Though some birds, like cedar waxwings, wait to nest until later in the summer when fruits will be ripe to feed their hatchlings. 

While the cup nest (covered in last week’s column) of the American robin may be the most familiar and visible type of nest, there are several other types of nests. 

Grebes and coots build plate-type nests. They are shallower than cup nests and loosely constructed. Their nests aren’t as elaborate as cup nests because they occupy the nest for a shorter amount of time than most songbirds.

On a larger scale are platform nests built by eagles, osprey, egrets and cormorants. The large conglomeration of sticks can weigh as much as two tons in the case of an eagle’s nests. Platform nests are built on the ground, on high ledges, in trees, on telephone poles or on man-made platforms. 

A red-tailed hawk sits on its well-camouflaged platform nest

A large platform nest of a bald eagle

While most songbirds don’t reuse their nests, those constructing platform nests typically reuse their nests. If a nest is reused, the bird will repair and add material to the nest for the next clutch of eggs. Sometimes a different bird species will reuse the nest such as a Canada goose nesting in a bald eagle’s nest.

Osprey nest on a man-made platform

Equally impressive to the large aeries of eagles are the pendants of orioles (the Bullock’s oriole inhabits the Inland Northwest). Pendant nests are hanging nests far out on a limb away from predators. Orioles weave pouches from plant fibers and then line the nest with hair, plant down, wool and fine moss. Incredibly, orioles weave plant material with only their beak and even tie knots to hold the nest together. 

Pendant nest

Birds utilize different tactics to keep their nests invisible or inaccessible from predators, including camouflage, placement out on a limb, or even enclosing the nest. 

Sphere nests and cavity nests both limit the ways predators can enter the nest. Sphere nests are globular-shaped nests with an entrance hole. Marsh wrens, magpies and American dippers all build sphere nests and camouflage them quite well.

The marsh wren builds a coconut-shaped nest from bulrush or cattail stems. To distract potential predators from the actual nest, the male marsh wren may build multiple other “dummy” nests--sometimes more than 20 nests. 

Black-billed magpies build two- to four-foot high bulky nests from sticks held together with mud. A canopy over the nest and a side entrance hole keeps the parents and eggs protected. 

Another way birds protect their eggs is by nesting in cavities. Half of all bird orders (not species) nest in cavities or holes, including kingfishers, owls and woodpeckers. The cavities can be natural cavities, excavated cavities, abandoned cavities or nest boxes.

Woodpeckers and nuthatches excavate their own holes and then chickadees, bluebirds, some owls, ducks (such as wood ducks and hooded mergansers) and flycatchers use the abandoned cavities. 

A mountain chickadee utilizing an abandoned cavity

Similar to a cavity nest is a burrow nest. Belted kingfishers dig a tunnel in the bank of a stream, river, lake or sand pit to create a nesting cavity at the end. Excavation can take three days to nearly a week. On average, most birds build their nest within a week’s time with only their beak and feet. 

However, one bird shirks nest building and nesting duties--the cowbird. Cowbirds lay their eggs in the nests of other birds and let them incubate and raise their young (known as host nests).

Each bird species has developed tactics to protect its eggs and young which has resulted in a diversity of nests that is unparalleled elsewhere in the animal kingdom.

Bird nests range from simple to elaborate

Just when I think the robin can’t hold any more grass in its beak, it leans over and picks up one more piece before flying to a nearby tree. Without any guidance, the robin knows exactly what materials to collect to build its nest and how to construct its nest. 

Nests are not random creations because all birds of one species tend to build the same type of nest with similar dimensions and materials. For example, American robin nests are deep cups constructed of mud and grass usually in the fork or crotch of a tree. There are exceptions like robins nesting on rail fences or in wood sheds but you wouldn’t find a robin nesting on a gravel bar. 

A cedar waxwing nest is hidden from view

Birds instinctively know how to construct a nest and where to construct it. Nests can be as simple as a scrape in the dirt to massive aeries weighing two tons. No matter the nest, they all serve the same purpose--keep the eggs and hatchlings warm and safe from predators.

The simplest form of nest is the scrape which is a small area cleared for eggs. Scrape nests are used by most shorebirds, terns, many ducks, pheasants, quail and some falcons. Terns and killdeer make a scrape nest among small rocks and rely on the speckled eggs to keep them camouflaged from predators.

A simple type of nest is a cleared area for eggs such as this killdeer nest

Arctic terns lay their eggs among small rocks without any other material

Mallards also use scrape nests but often line it with grasses or other soft materials. Many birds line their nests with soft materials for the eggs and hatchlings.

However, some birds don’t even clear an area for a nest. Some raptors and owls just lay their eggs in a safe place, such as on isolated ledges or in small caves on a cliff. Their eggs are often pointed so they roll in a circle instead of rolling off the ledge. 

The most common type of nest is the cup nest. Most songbirds, hummingbirds and swifts build cup nests. Cup nests are built with pliable materials, such as grass, to make a well-insulated nest. Robin nests are a familiar cup nest as well as barn swallow nests. 

A cup nest that has fallen out of a tree

The middle layer of a robin’s nest is mud and is shaped just right by the female sitting in the partially constructed nest and rotating her belly around while the mud is still moist so it can be smoothed and shaped. 

Barn swallows also use mud to build their nests but their nests are made of mud pellets mixed with grass, straw or hair and then attached to a vertical surface. Collecting mud is no small feat and one barn swallow made more than 1,200 trips to construct its nest. Swallows then line the nest with feathers or hair. 

Hummingbirds build the tiniest of cup nests using fine plant material held together with spider silk. As if the small size wasn’t enough to make the nest hard to find, hummingbirds camouflage the outside of the nest with moss or lichen. 

Often cup nests aren’t seen until the leaves fall off the tree or shrub. Most cup nests succumb to the elements over the winter and some of the materials may be utilized the next spring when most songbirds build a new nest (though some birds, such as robins, may reuse their nests). 

Winter weather slowly deteriorates bird nests

Other types of nests are reused more often than cup nests, including those of eagles and woodpeckers. Look in next week’s column to find out about these nests and other types of bird nests. 

Caterpillars utilize a variety of tactics to stay alive

As a slow-moving, plump morsel, caterpillars are an ideal target for a predator’s meal. However, caterpillars still exist because they have developed means to escape detection from predators or ward off predators.

Black swallowtail caterpillars use black and yellow coloration to warn predators of their toxicity

The most common way caterpillars, like many other animals, escape detection is camouflage. Their camouflage makes it hard for even us to find them when they resemble twigs, bark, leaves, buds, flowers, fruits and tendrils. Larvae of several swallowtail butterfly even resemble bird droppings--something even birds won’t touch. Others bear false eyespots that resemble snake’s eyes or look like hair balls or small furry mammals.

Another way caterpillars escape detection is by not being exposed. They gain protection by living concealed lives within stems, roots, galls, seeds, wood and other plant tissue. Tent caterpillars build silk tents to help protect themselves from hungry birds. Tent caterpillars also find safety in numbers. 

On the other end of the spectrum are caterpillars that are brightly colored and say “See me!” The black and yellow stripes of the black swallowtail caterpillar are easy to spot in the garden but birds have learned to avoid them. The bright colors are a warning to alert predators of the unpleasant taste or toxicity of the caterpillar. Black and yellow are two of nature’s most widespread warning colors as demonstrated with wasps and bees. 

Monarch butterflies advertise their distastefulness with their black and orange coloration. They obtain this distastefulness during their larval stage when the caterpillar eats milkweed and retains the toxins. 

Caterpillars can either obtain their toxicity from the plants they eat or they can manufacture the toxic compounds themselves.

Bristles and hair protect some caterpillars from predators

If taste isn’t bad enough, one caterpillar wards off predators with its bad breath! The tobacco hornworm dines on nicotine-containing plants and as a result has bad breath which keeps predators at bay. 

Predators also tend to pass over caterpillars with hair or bristles--who would blame them. While some caterpillars are just hairy, like the woolly caterpillar, others have spines and barbs. Some caterpillars have urticating hairs which are hollow hairs that discharge a painful irritant when broken. The urticating hairs even cause irritation on curious humans. 

Some caterpillars use multiple tactics, such as hair and colors, to deter predators

Bristles and hair also deter parasitizing insects from laying eggs within the caterpillar and then upon hatching eating the caterpillar’s insides. The hair and bristles act as an armor against these insects since they seek out the caterpillar by smell. 

If smell, coloration, bristles and hair don’t ward of predators, caterpillars often resort to thanatosis--playing dead. Have you ever touched a caterpillar and it has fallen to the ground? The caterpillar is playing dead and is hedging bets that if it remains motionless on the ground it may go undetected. 

Caterpillars exhibit a wide array of physical, chemical and behavioral tactics to avoid being eaten. However, predators keep adapting their search techniques to these tactics and help keep the caterpillar population in check.

Spring wildflowers bring first splash of color

As the weather warms, signs of spring are everywhere--green grass, emerging larch needles and spring wildflowers. The burst of color from spring wildflowers is a welcome sight after winter. 

There are several wildflowers to look for as the snow melts and the days become warmer in North Idaho, most notably the western trillium, western spring beauty, violets, yellow bells and yellow glacier lilies. 

Yellow glacier lilies and western spring beauty

Whether they bloom in early, mid- or late April depends on the weather but these five are usually the first wildflowers emerging. Depending on elevation, however, they can be found as late as midsummer in the high mountain meadows. 

These five wildflowers are the beginning of a palette of color that will paint the woods, mountain meadows and hillsides over the next several months.

Western white trillium (Trillium ovatum)

The western white trillium is one of the first wildflowers to emerge in the woods which is why it is often called the wake-robin. 

Western white trillium

The ‘tri’ in trillium is one way to remember the identifying characteristics of the trillium since all the major parts come in three-- three leaflets, three sepals and three petals. The single white flower sits above the three broad leaves and the three green sepals alternate with the three petals. After fertilization or as the flower ages the petals turn pink.

Trilliums add a splash of color to stream banks, open and deep woods, and other moist shaded areas. 

The petals of the trillium turn pink with age or fertilization of the flower

Western spring beauty (Claytonia lanceolata)

Soon after the snow melts on open, moist grassy slopes, the spring beauty will emerge. The white dime-sized flower sits atop a two- to six-inch tall stem. Pink veins adorn the five petals that are notched at the tip. 

Western spring beauty

While they may be pretty, the spring beauty is also an important spring food source for black bears, grizzly bears and burrowing rodents. Each plant has a carbohydrate-rich corm (a spherical portion of the stem underground about the size of a marble) that these mammals dig up and eat. 

A spring beauty with intense pink veins

Violets (Viola sp.)

Violets are another small flower that add color to moist woods and meadows. All violets have five petals with one petal developing into a spur-like pouch.

There are several species of violets in the region identified by the flower’s color. The stream violet (also called the yellow wood violet or yellow violet) is yellow. The round-leaved violet is lemon-yellow to gold. The Canada violet is white with a yellow base while the kidney-leaved violet has pure white flowers. The early blue violet ranges from blue to deep violet.

Round-leaved violet (Viola orbiculata)

Yellow bell (Fritillaria pudica)

As the name implies, the yellow bell is a small, bell-shaped yellow flower that droops from the stem. The yellow bell is also called goldcup or yellow fritillary. The yellow bell appears in meadows and open woods including open ponderosa pine forests. 

Yellow bell

As a member of the lily family, the flower is three-parted. Like most lily species the petals and sepals of the yellow bell are so similar that the flowers appear to have six petals.

The yellow bell also has a starchy corm sought after by grizzly bears, black bears, pocket gophers and ground squirrels.

Yellow glacier lily (Erythronium grandiflorum)

Painting mountain meadows with a carpet of yellow after the snow melts is the yellow glacier lily, also called the snow lily, fawn lily, dogtooth violet and avalanche lily. The yellow glacier lily is often found at the edge of retreating snowbanks taking advantage of the moisture. Often the glacier lily is intermixed with the western spring beauty.

The single golden-yellow flower droops down with the petals curving backward and the red or yellow anthers hanging below.

Mountain meadow filled with glacier lilies

Yellow glacier lily

Great blue herons more than excellent fishers

Standing motionless in stagnant water, a great blue heron’s head suddenly reels forward into the water and emerges with a small fish. Great blue herons are known for being excellent fishers. Their stealth and lightning-fast strike enable them to sneak up on prey. 

A great blue heron is poised to strike prey with its S-shaped neck

Several features help herons forage effectively. Their long legs enable them to wade into deeper water than other shoreline birds. They can stand still for long periods of time waiting for a fish to come into range or walk very slowly to stalk prey. 

When a fish is within range, their S-shaped neck allows them to quickly strike prey. Specially-shaped vertebrae allow herons to curl their neck in preparation to strike or while in flight (a helpful identification characteristic). 

For their impressive size of 38 to 54 inches tall, great blue herons only weigh five to six pounds

Depending on the size of the fish, the heron strikes in one of two ways. For small fish, herons grab the fish between the mandibles of its bill. For large fish, herons stab the fish with their sharp bill. They then shake the fish to break or relax the sharp spines before gulping down the fish whole. 

Despite their narrow-looking neck, herons can swallow large fish. Since they swallow fish whole, herons regurgitate the solid waste (bones, scales) in the form of pellets similar to how owls regurgitate pellets. 

Another adaptation for eating fish is the special feathers on their chest to help clean fish before they eat them. Herons rake the powder down feathers with their feet to shake off a powder that causes fish slime and oil to clump. This enables the heron to brush off the clumps with its foot before eating it. Herons also rub this powder on their belly feathers to repel swamp slime. 

Even though herons are known as excellent fishers, their diet is highly variable. They also feed on frogs, salamanders, snakes, small birds, small mammals, crayfish, dragonflies and grasshoppers. One study in Idaho found that voles comprised 24 to 40 percent of a heron’s diet. Voles are a major potion of a heron’s winter diet because the shallow, calm water they feed in is often frozen. 

Herons look for food, such as voles, in grassy areas

Their variable diet is one reason the great blue heron is the most widespread heron in North America. In some areas the heron resides year-round but in northern areas herons migrate south unless there is a reliable food source. 

Whether they are permanent residents or migrants, great blue herons are noticeable in the spring when they are nesting because of their noisy ruckus. Herons are solitary when they hunt but they nest in colonies. The heronries can include up to 500 nests in areas with plentiful food and nesting sites but typically range from a few to several dozen nests. 

Herons build their nests high in trees if trees are available otherwise they build them among grass on islands. In Idaho and Montana, herons favor cottonwood trees along rivers and lakes but they will also nest in the tops of ponderosa pine and willows. 

Heronries can consist of a few nests to several hundred nests

They build large, stick platform nests with the male bringing material and the female placing the items. Herons will often reuse nests and the oldest nests are the largest--sometimes up to four feet across. 

Like most animals, herons are most vulnerable when young with 69 percent dying before they are a year old. Eagles, raccoons, bears, turkey vultures and red-tailed hawks are a few predators of great blue heron young. If a chick or an adult is killed within a nesting colony the other birds will often abandon the colony. 

Once the young fledge, they return to the nest to be fed for up to three weeks, placing great demand on their parents’ fishing skills.

Shrews may resemble mice but they are different

Shrews are one of the smallest mammals in North America and the smallest one resides in North Idaho--the pygmy shrew. The pygmy shrew weighs between two and four grams, roughly the weight of a pencil. Other shrews that reside in North Idaho include the American water shrew, masked shrew, montane shrew and vagrant shrew.

Shrews may look like mice but they are significantly different because they belong to a different order containing insectivores and they have pointed noses, small ears and tiny eyes. Like voles, identifying a shrew on the species level is difficult.

Shrews resemble mice but they have a pointed snout, small ears and tiny eyes

One unique aspect of a shrew, if you can catch one or find one dead, is that they all have reddish tips to their teeth. Shrews can also be identified by five toes on all feet whereas mice have four toes on the front feet and five toes on the hind feet.

All insectivores use senses besides sight to find food, mainly hearing, touch and smell. Shrews have many characteristics that allow them to forage for insects. 

Shrews have tiny eyes because they don’t rely on sight to find their food. Their pointed snout helps them burrow through soil to reach grubs including earthworms, insects, spiders and other small animals such as young mice, salamanders, snails and slugs. Some shrews even use echolocation like bats to find insects. 

Since their sense of smell is extremely important for finding food, a larger portion of their brain is devoted to their sense of smell. Once shrews find an insect, they catch the insect with their two enlarged, pincer-like upper front incisors that protrude forward. 

As big eaters, shrews eat at least their body weight in food each day. If they don’t eat frequently they may die of starvation so shrews store food in their nest. This voracious appetite doesn’t keep shrews from being picky eaters. Shrews prefer fresh food, even fresh stored food.

With a diet of insects, storing fresh food may seem unlikely but shrews keep their catch fresh by crushing the prey’s skull and biting off the legs. This keeps the insect alive until the shrew eats it. Shrews have sharp, pointed teeth adapted just for crunching on insect exoskeletons. 

While shrews may have a voracious appetite and a unique way of storing food, they are not on the top of many predators food list. Many shrews emit a musky odor from scent glands that resembles a skunk odor and effectively deters most predators except for owls. 

Like some mice, voles and lemmings, shrews are mainly nocturnal but will also be sporadically active during the day. They burrow in the leaf litter or humus layer to travel or travel in the burrows or runways made by voles and moles (also an insectivore). 

Like the water vole, the water shrew readily takes to water and lives around streams and ponds. The water shrew can even run on water because of the long, stiff hairs between its toes and along the sides of feet that trap air bubbles. 

Many of the shrews, mice, voles and lemmings survive the cold winter temperatures by living in the subnivian zone. This zone stays within one to two degrees of freezing regardless of the air temperature if there is adequate snow cover. 

Occasionally, tracks of these small mammals can be seen on the surface of the snow scurrying between trees or clumps of grass. However, the small mammals don’t stay on the surface long because they are more prone to predation, even if they possess a musky odor.