Thursday, June 26, 2014

Summer serenaded by insect chorus


Have you taken the time to listen on a warm, summer evening? Trains, trucks and lawn mowers are the first sounds you may hear but if you tune them out you may hear a chorus of clicking, buzzing, chirping and creaking. You probably won’t see who is playing the sounds coming from the grasses, fields, trees and shrubs. As soon as you approach, the musicians--crickets, katydids and cicadas--will stop playing. 

Crickets, katydids and cicadas don’t all sing in the evening, some sing during the day and some sing at night. Since they are cold-blooded the insects need to warm up to begin singing, which is why we don’t hear them on cool mornings or cool rainy days. 

The singing of cicadas and crickets can be heard on warm summer evenings but most likely won't be seen. The snowy tree cricket, also known as the thermometer cricket, can tell you how warm it is (in Fahrenheit) if you count the number of chirps in 12.5 seconds and add 38 (this formula works for crickets west of the Great Plains). 

Like birds, each species has its own “song” but the insects don’t sing using their throats and lungs. Crickets, katydids and cicadas make sounds using specialized parts on their body. 

Thursday, June 19, 2014

First day of summer longest but not hottest


The warm, sunny days in early June made the last part of spring feel like summer. Summer technically doesn’t begin until the summer solstice on June 21 but we’ve enjoyed summer-like weather for a few weeks.

The summer solstice marks the day when the sun is at its farthest north position in the sky in the northern hemisphere north of the Tropic of Cancer just as the winter solstice marks the day when the sun is at its lowest position in the sky. On the summer solstice at the Tropic of Cancer (23.5 degrees north latitude), the sun is directly overhead at its highest point in the sky, such as in the Bahamas. 

Snow still clings to the mountains after the summer solstice but the heat of summer quickly melts it
For many locations the summer solstice isn’t the day with the earliest sunrise or latest sunset due to the tilt of the Earth and the Earth’s elliptical path around the sun. 

Thursday, June 12, 2014

Swallows provide valuable insect control


Pesky insects can bother us during gardening, barbecues and other outdoor activities but one bird species makes an impressible dent in the insect population for us--swallows. With some swallows eating 60 insects every hour from dawn to dusk, one swallow can eat more than 720 insects each day! By the end of the week, that is 5,000 fewer insects bothering you. 

Six swallow species take to the skies of North Idaho to feast on flying insects--barn, cliff, tree, violet-green, northern rough-winged and bank swallows. Purple martins are another swallow species but they do not reside in northern Idaho. However, European starlings are often mistaken for purple martins.

Cliff swallows will follow a successful neighbor back to its food source if they can't find food

Thursday, June 5, 2014

White wildflowers blooming everywhere

Early spring wildflowers, such as trilliums, are blooming at higher elevations as the snow recedes and the ground warms. At lower elevations summer wildflowers are blooming including several with white flowers. Starry Solomon’s Seal, false Solomon’s Seal, wild sarsaparilla, mariposa and Queen’s cup are some of our white wildflowers in North Idaho.

Starry Solomon’s Seal (Smilacina stellata)

Dense colonies of starry Solomon’s Seal bloom in the partial shade of forests. Alternating leaves growing along the stalk lead up to the creamy white, starry-looking flowers numbering 12 or fewer at the end. The stalk grows between 12 to 24 inches high. After pollination, the round, greenish yellow berries mature into dark blue/reddish black berries.

Starry Solomon's Seal

Thursday, May 29, 2014

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. 

Thursday, May 22, 2014

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.

Thursday, May 15, 2014

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.

Thursday, May 8, 2014

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.