A boa constrictor in Idaho!

Have you been lucky enough to see Idaho’s only boa constrictor? The rubber boa is smaller than the giant boa constrictor of South America and its secretive nature makes finding one noteworthy. 

Rubber boas are mainly active at night and twilight but females can occasionally be found basking in the sun

A few weeks ago, I saw my first rubber boa which was basking on the Long Canyon trail. Stretched across the trail in a sunny spot, the rubber boa was smaller than I anticipated since I had pictures of the giant boa constrictor in my mind. Rubber boas usually range from 14 to 28 inches long and this one was on the low end at about 14 to 16 inches. 

The rubbery appearance of the boa distinguishes it from the other two snakes that reside in North Idaho, the common garter snake and the western terrestrial garter snake, which have stripes running along their length. The rubber boa is uniformly colored on its backside with colors ranging from tan to brown to olive green. The boa’s underside is yellow to cream and may have black or brown mottling. 

A western terrestrial garter snake has stripes

Loose skin and small, smooth scales lend to the boa’s rubbery appearance and help it resemble a giant brown worm. 

Like a worm, distinguishing the head from the tail can be tricky (unless they are slithering away). The nickname “two headed snake” comes from the rubber boa’s uniformly thick body which tapers to two blunt ends. Their small eyes help keep the mystery of which end is which from a distance--especially for predators.

To protect its head from predators, a rubber boa coils into a ball with its head tucked underneath and its “second head” sticking out. The boa evens jabs its tail about as if striking to deter predators (such as hawks, coyotes, raccoons and skunks) and if that doesn’t work, the boa can release a smelly musk from its vent.

Often a rubber boa bears scars on its tail from predators and defensive rodents. When the rubber boa is raiding a nest of baby rodents, it uses its tail as a club to keep the mother rodent out of the nest as it swallows the nestlings whole. 

Rubber boas also eat adult rodents but will kill them by constriction. As the rubber boa wraps its body around the prey, it squeezes until the prey stops breathing and the heart stops. In addition to rodents, the rubber boa consumes bird eggs, nestling birds, nestling bunnies, small lizards, other snakes, salamanders, small chipmunks and even bats. 

The nocturnal nature of the rubber boa keeps its life secretive though females will bask in the sun in temperatures between 65 to 75 degrees. Pregnant females need the sunshine and warmth for the healthy development of the young born in August. 

Otherwise, rubber boas spend most of their time under logs, rocks, and forest litter or in rodent burrows. Researchers have even determined that rubber boas will rest beneath rocks of a certain thickness in order to thermoregulate more efficiently. 

The secretive nature of rubber boas and their nocturnal nature make seeing a rubber boa a real treat, so count yourself lucky if you see Idaho’s only boa constrictor. 

Hummingbirds feed on more than nectar

As I walked through the yard an unfamiliar buzz came and went that was louder than a bee. I looked around and finally looked up to see a hummingbird diving towards the ground. 

As I watched, the hummingbird climbed high in the sky and then dived towards the ground with a high buzzing sound before pulling up into a climb. The U-shaped aerobatics were repeated several times before the hummingbird rested for a few minutes on the power line. Then the hummingbird began the stunt again. 

Without a close glimpse at the hummingbird, I couldn’t tell the species. But most likely it was a male performing a courtship or territorial defense display since both involve steep climbs followed by rapid dives. The range hummingbirds climb up varies and the Calliope hummingbird will climb 100 to 130 feet before diving.

Hummingbirds, such as this female rufous hummingbird, often make daily rounds between flowers and feeders in a predictable sequence (known as trap-lining).

The Calliope hummingbird is one of three species of hummingbirds found in North Idaho along with the rufous hummingbird and the black-chinned hummingbird. Since hummingbirds can fly up to 60 miles per hour, distinguishing the species in flight isn’t easy. 

However, their ability to hover at flowers and feeders provides a chance to catch a glimpse of their magnificent colors. The males are more colorful than the females though the females aren’t drab. 

Often the easiest way to distinguish the males is by the patch of color on their throat which is called a gorget. 

The male Calliope hummingbird has magenta-red rays against white feathers. The aptly-named black-chinned hummingbird is for the males who have a velvety black upper throat and a violet iridescence on their lower throat. The male rufous hummingbird has a bright, iridescent orange-red gorget.

Rufous hummingbirds are also easy to distinguish from the Calliope and black-chinned hummingbirds because they are tinged with a rufous color (red-brown). The male has red-brown on his back, sides and top of tail while the female has rufous on her sides and top of tail. 

Both the male and female black-chinned hummingbird can be distinguished by the white spot behind their eye. 

While the best spot to watch hummingbirds is at feeders and flowers as they sip nectar, they don’t exclusively feed on nectar. Hummingbirds supplement their nectar diet with invertebrates, such as fruit flies, mosquitoes, aphids, spiders and caterpillars, to help meet their protein, vitamin and mineral requirements. They catch invertebrates mainly by hawking and gleaning. 

Hawking is when the hummingbird perches on a bare, open twig and scans the area for insects. When it spots a flying insect, the hummingbird quickly flies out and engulfs the unsuspecting insect. 

Gleaning involves a few different techniques. Hummingbirds search the leaves at the tips of branches for tiny moth caterpillars. They also glean by poaching arthropods trapped in spider webs and stuck in the sap of sapsucker wells. 

The rufous hummingbird also “leaf-rolls” for insects. By hovering over the forest floor, the rufous hummingbird will disturb the leaves enough so they roll over. Then it can scan the underside of the turned leaves for arthropods and their eggs. 

Hummingbirds also pick insects and their eggs from cracks and crevices of bark like nuthatches and brown creepers. However, hummingbirds will move about the tree by flying instead of walking because with their flight capability (and weak legs) it is easier for them to fly than walk. 

With the unique figure-eight motion of their wings in flight, hummingbirds can fly forward, backwards, sideways, up, down, upside down and can hover to feed and perform spectacular aerobatic displays.

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.