Thursday, September 19, 2013

Alpine larch usher in autumn in the high country


As autumn begins, a golden color will highlight timberline as alpine larch turn from a light green to a golden yellow. Turning color and losing its needles a month earlier than lower elevation western larch, the alpine larch ushers in autumn in the high country.

Alpine larch eke out a living in sites too cold, too rocky, too boggy or too snow-covered for other trees, such as subalpine fir, whitebark pine and Engelmann spruce. Other high-elevation trees have a broader distribution than alpine larch, which only exists above 5,000 feet elevation in portions of the Rocky Mountains and Cascade Range. 

Alpine larch in late autumn

Within the Cascades, alpine larch grow in a 120-mile north-south stretch and in the Rockies, its distribution is limited to a 430-mile stretch between central Idaho and just north of Lake Louise, British Columbia.

The rugged terrain the alpine larch exists in makes the often park-like groves of golden-yellow trees a sight to remember. Being a deciduous conifer helps the tree withstand the extreme conditions that prevail at high elevations. Without any needles in the winter, hurricane-force winds have less surface area to pummel and for snow to collect on. 

A deep root system anchors alpine larch in rock crevices to help them withstand the winds and snow. Young saplings concentrate growth on roots before extending upwards significantly. An eight- to sixteen-inch tree, which may be 16-25 years old, can have a taproot 16 to 24 inches deep. Growth during the first 20-25 years is focused on the root system because a short trunk is protected by the snowpack.

Rarely does one find an uprooted alpine larch blown over by gale-force winds, but will instead find trunks snapped off and exposing the hollow, rotten inside of old trees. 

Dense wood helps alpine larch endure the strong winds and avalanches that batter the high country. Before a tree reaches five inches in diameter and twenty feet tall, it can withstand being flattened in annual snowslides before straightening again in the summer. Once larger, the strong trunk and lack of foliage makes the tree resistant to breakage in snowslides.

Growth in avalanche chutes is common and helps stabilize snow loads and reduces the severity of avalanches. 

The lower reaches of avalanche chutes can be one place where alpine larch extend down to the uppermost reaches of western larch. Several features distinguish the two larches.

Alpine larch exhibit long, spreading limbs that form a broad crown, whereas western larch have a narrow crown. 

The first hint of autumn in the high country
Upon close inspection, the new twigs and buds of alpine larch are covered in woolly hairs, whereas new twigs of western larch appear smooth. The needles of alpine larch grow in clusters of 30-40 whereas those of western larch grown in clusters of 15-30. Needles of both larch grow singularly on the first year’s growth.

The needles of alpine larch are square in cross-section while those of western larch are triangular in cross-section. 

While western larch attain greater heights, alpine larch can attain sizable proportions for the rough terrain in which it survives. In sheltered basins, mature alpine larch can attain heights of 95 feet when 500-700 years old. The tallest alpine larch exists in the Cabinet Range of Montana at an impressive 152 feet.

Whether short or tall, alpine larch survive in the cold, snowy high country and host a golden finale in autumn that is not to be missed.

Note: Published in the Bonners Ferry Herald on Sept. 19, 2013.

Thursday, September 12, 2013

Don’t be surprised by songbird swimming in mountain streams


Standing on an almost-submerged rock in the mountain stream, the chunky gray bird waded into the fast-flowing water and stuck its head underwater. Snorkeling, the bird made its way to another rock downstream. 

As North America’s only aquatic songbird, the American Dipper has filled a niche left open by other songbirds. While most songbirds stop at the water’s edge, the dipper capitalizes on the aquatic insects within mountain streams. 

The dipper can skim the water for insects or search underwater, even turning over small stones, to find food. They also easily catch insects in mid-air. Dippers forage for aquatic larvae of mayflies, mosquitoes and caddisflies, along with dragonflies, worms, small fish, fish eggs and tadpoles. During insect hatches, they often fly just above the water’s surface to catch the swarming insects.

American dippers look like a cross between a thrush and a wren
Many adaptations allow the dipper to thrive in cold, swift streams. Nostril flaps prevent water from entering the nasal passages when snorkeling or swimming. A third eyelid acts as a windshield wiper when underwater--they can remain submerged for 15 to 30 seconds. With a high amount of hemoglobin in their blood, dippers possess the greatest oxygen capacity of any songbird.

Dippers counteract their natural buoyancy by “flying” underwater with powerful strokes from their short wings and paddling with their feet. They also use their strong toes to grasp rocks below and above water.

A dense coat of feathers insulates the dipper from the cold water year round. On average, a dipper has 4,200 feathers compared to a robin’s 3,000 feathers. A thick layer of down feathers is protected by a dense layer of waterproofed contour feathers. 

Dippers maintain the waterproofing by preening extensively to spread the waterproofing oils over all their feathers. Compared to other songbirds, the preen gland containing the waterproofing oils is 10 times larger for dippers. 

The waterproof oil and thick down coat are essential to a bird that doesn’t migrate south for the winter. Instead, the dipper seeks patches of open water to forage, whether a hole in the ice near rapids or where two streams meet. With an efficient internal system of thermoregulation, the dipper survives winter as far north as the Brooks Range in Alaska.

Even above the babbling sound of mountain streams, the dipper can be heard singing its sweet, bell-tone. Both males and females can sing for 10 minutes straight. 

American dippers are North America's only aquatic songbird
As the name implies, the dipper is also known for its habit of dipping or bobbing while perched on a rock or ledge. The reason for this behavior is unknown but scientists think the behavior may help in visual communication, predator concealment or in spotting prey. 

The gray dipper blends in well with the earthen-tone rocks of the streams and it creates a nest even more camouflaged. The volleyball-sized nest is covered in an outer shell of moss. Unlike other songbirds who build an open-cup nest, the dipper builds an enclosed ball with a side opening to prevent stream-side water spray from entering the nest. 

The nests are built on cliff ledges, caves in boulder piles, dams and bridges. The life-long pair returns to the same nest every year. After nesting is completed, the pair removes the dried grass lining of the nest in preparation for the next brood. 

When leaving the nest, the fledgings readily swim to begin their lives among the rocky boulders of mountain streams where competition is scarce.

Note: Published in the Bonners Ferry Herald on Sept. 12, 2013.

Thursday, September 5, 2013

Benchmarks lay the foundation for maps


“Where am I?” “How high am I?” These questions are easy to answer today with a GPS. People have always wondered where in the world they were located. Where is Bonners Ferry in relation to New York City? 

The National Geodetic Survey (NGS) was established in 1807 to provide the framework for all positioning activities in the nation, including latitude, longitude and elevation. Without knowing the latitude and longitude of a location, no relationship could be established between faraway places except for a general direction. 

The benchmark on Parker Peak was placed in 1924 with no trails to the peak
Beginning in 1833, the NGS placed the first survey disc north of New York City. Today, these discs are found on mountaintops, bridges, post offices and prominent landmarks across the nation. Numerous peaks around the county bear a small metal disc with an identifier and other information. 

Benchmark is the generic term for all geodetic control points. There are two main types of benchmarks: vertical control points and horizontal control points.

Vertical control points, as the name suggests, marks a precise elevation above sea level. Vertical control points are true bench marks with the word “BENCH MARK” printed on the rim of the disc. 

Horizontal control points mark a precise latitude and longitude. Professionals refer to horizontal control points as stations or marks. 

Besides metal discs, benchmarks can be a bolt, rivet, chiseled square or cross, or prominent landmark, such as a church spire or water tower. Each benchmark is linked to an identifier and a datasheet describing the location. 

Not all metal discs represent a precise elevation, longitude or latitude. Some discs contain arrows, RM or AZ and these discs help surveyors locate the bench marks, stations or land boundaries.
This benchmark references the Goat Mountain Lookout which no longer exists.
Benchmarks were primarily placed by two sources: the NGS and the U.S. Geological Survey (USGS). Between 1878 and 1970, the NGS was called the U.S. Coast and Geodetic Survey. 

Over 730,000 benchmarks exist in the United States (including Alaska and Hawaii) with precise elevations or coordinates. However, many more exist because of the USGS. The USGS placed thousands of benchmarks to assist them in creating topographic maps. However, they are not in the NGS database because they were not “bluebooked”, meaning they did not undergo a process that ensures the disc meet minimum geodetic quality requirements.

Those with GPS units may find disparities between the elevation on the GPS and the elevation printed on the map. This difference may lead to the question, “How high is the summit?”

NGS suggests that traditional leveling techniques are more accurate than GPS databases. However, differences in elevation occur over time due to inaccuracies, new surveys and tectonic movements.

Surveying across an entire mountain range and beginning with an inch discrepancy can lead to slight inaccuracies in the end.

Many benchmarks offer the finder a commanding view of the surrounding country
One of the reasons for the difference between the true elevation and the elevation stated on a map is the original reference point. Originally, all elevations were based on NGVD 29, a reference based on mean sea level (an average from several locations). Later, elevations were based on NAVD 88, one sea level measurement at the St. Lawrence Seaway. Many maps have not been updated to reflect the switch to NAVD 88, which resulted in a several foot difference in some locations. 

Lastly, the Earth is in constant flux with mountain ranges lifting up or eroding down as tectonic plates move. Mt. Borah, Idaho’s highest peak, gained seven feet of elevation in 1983 when a 7.3 magnitude earthquake shook the land. 

The question of “how high am I?” can change in an instant but for the most part the early surveyors used techniques that provided accurate positions. Surveyors ranged across the countryside without the help of today’s trails or helicopters to satisfy their curiosity of “Where am I?”

Published in the Bonners Ferry Herald on Sept. 5, 2013. 

Thursday, August 29, 2013

Turkey vultures picky eaters of rotten meat


The ruckus of magpies and ravens caught my attention as I walked up the road. As I approached, the magpies, ravens and eagles flew off but the large, red-headed turkey vulture kept its place on the limb above the scavenged deer. 

Without a doubt, I could see why the turkey vulture was named after a turkey--the red, featherless, wrinkled head. One ugly bird. 

Turkey vultures only spend the summer in North Idaho. Come autumn, they migrate to Mexico, Central America or South America.
The featherless head serves the turkey vulture well when it buries its head deep into a carcass to pull out meat. Instead of needing to clean feathers, the turkey vulture allows the sun to bake any parasites or dried bits of meat off its head.

Turkey vultures primarily feed on carrion, including roadkill, dead livestock and fish carcasses. They will also ingest maggots, worms and other invertebrates while feeding on carcasses. While sight may help them find carrion, their noses are the primary detectors of the next meal. Turkey vultures possess an extremely strong sense of smell and can smell a rotting mouse from 200 feet up in the air. 

Even though they are part of nature’s clean-up crew, turkey vultures are picky eaters by preferring “freshly dead” meat. Turkey vultures usually won’t find fresh carrion on the day it was killed because there isn’t enough odor. They almost always find the carrion on the second or third day when it begins to rot. Often by the fourth day, they will rarely visit the carrion because the meat is too rotten to eat. 

Eating rotting meat requires a strong stomach and turkey vultures combat this with powerful enzymes in their digestive juices that kill bacteria--even bacteria that causes serious food poisoning. 

Not only does the turkey vulture clean up nature’s freshly deceased, it kills the bacteria and diseases within the animal. Researchers have found that the turkey vulture’s scat contains no trace of diseases present in the carrion. 

Turkey vultures will roost for more than two days if it is raining
Few animals harass turkey vultures and their nestlings. If an animal doesn’t heed the loud, hissing warnings of being too close, the vulture can projectile vomit partially digested rotten meat up to 10 feet away. 

Predators also stay away from turkey vulture nests because of the repulsive smell of regurgitated rotted meat fed to the young. 

Turkey vulture nests are the most basic of nests--a spot to lay eggs. They lay one to four eggs with no nesting material in crevices, caves, stumps, hollow trees, cliff ledges or on the ground. Occasionally, they will lay eggs in an abandoned stick nest of a large bird.

Young vultures are noisy like other young birds but the adults are quiet birds. Turkey vultures lack the same vocal structures of other birds and can only hiss, grunt and make barking sounds. 

Unlike other birds that prey on meat, turkey vultures have weak legs and feet because they feed on dead meat and don’t capture prey. Their legs aren’t strong enough to carry food away from the kill site, so they gorge themselves until full. Then they fly to a limb and sit sleepily while they digest the meat. 

Carrion can be few and far between but turkey vultures are amazing gliders. With their six-foot wing span, they can ride thermals and mountain updrafts for nearly six hours without flapping. Compared to other soaring birds, the turkey vulture holds it wings in a deep “V” as it flies. 

Once the sun has warmed the land to create thermals, turkey vultures take to the skies to sniff out carrion at just the right stage of rotting. Scavengers don’t live a glorious life but the world would be dirtier without them. 

Note: Published in the Bonners Ferry Herald on Aug. 29, 2013.

Thursday, August 22, 2013

Speed of lightning incomprehensible


Flash, boom, rumble. The night sky lights up for an instant before the booming thunder overpowers all other noises. Again and again, the lightning and thunder flash and boom until the thunderstorm passes over. 

While thunderstorms can occur year round, they are most common in spring and summer in the afternoon and evening because of unstable air. The hot air rising from the Earth’s surface creates unstable air masses visible in the form of cumulonimbus clouds. 

The rapidly growing towering thunderheads create an imbalance of electrical discharge that is responsible for lightning. In the cumulonimbus cloud, rising ice crystals and falling hail collide and free electrons. The ice crystals gain a positive charge and rise to the top of the cloud through convection while the hail assumes a negative charge and sink to the bottom of the cloud. 

Cumulonimbus cloud
Only an electric current, in the form of lightning, between the two charged areas can balance the difference. Lightning within a cloud is called intracloud lightning and is the most common type of lightning.

Cloud-to-ground lightning occurs because the bottom of the thundercloud is negatively charged and the ground is positively charged beneath the cloud. The lightning begins by negative charges racing towards the ground (at about 200,000 mph) through a channel which is called a “stepped leader”. 

As the stepped leader approaches the ground, positive charges rise through trees, buildings or people to meet the leader. These positively charged channels are called streamers. 

When the leader and the streamer meet, a negatively charged electrical current rapidly flows from the cloud to the ground and a visible flash of lightning streaks upwards through the channel at 200,000,000 mph. While lightning may appear to strike downward, we are actually seeing the return stroke of light streaking upwards. The entire process is completed in about 200 milliseconds. 

The air around a lightning bolt can be five times hotter than the surface of the sun
Each bolt of lightning can contain up to one billion volts of electricity and is extremely hot. During a flash of lightning, the air around the channel of electrical current can be heated to temperatures five times hotter than the sun’s surface, causing the air to rapidly expand and vibrate. This vibration is the thunder we hear.

Even though lightning and thunder occur at the same time, we see lightning before we hear thunder because light travels faster than sound. A good estimate on how far away a storm is from you is the difference in seconds between the lightning and thunder. For every five second difference between seeing lightning and hearing thunder, the storm is one mile away. 

Lightning can strike more than 10 miles away from a cumulonimbus cloud through “positive lightning”. Positive lightning is a type of cloud-to-ground lightning that originates in the positively charged top of the thundercloud. The positive charged stepped leader seeks out negatively charged ground away from the storm cloud (since underneath the storm the ground is positively charged). The reverse flow of negative current from the ground to the cloud is stronger and more destructive than regular cloud-to-ground lightning. 

If you can hear thunder, there is danger of a lightning strike nearby. Thunder can be heard up to 15 miles away in quiet areas. Lightning can be seen 100 miles away, which allows for some spectacular storm watching at night when a line of thunderstorms is passing nearby.

Note: Published in the Bonners Ferry Herald on Aug. 22, 2013.

Thursday, August 15, 2013

Wasps prolific this year with dry weather


Warmer, drier weather this spring not only helped gardeners and farmers but also stinging insect populations. Cold, rainy weather in April and May can reduce nest success because queens have a harder time building a nest and collecting enough food for their offspring. Wasps, yellow jackets and bald-faced hornets are plentiful this year in part to the nice spring weather. 

European paper wasps resemble yellow jackets but are slimmer and have longer legs
Bees and wasps are both stinging insects but they are different. The body of a bee is partly covered in fine hairs, such as a bumblebee. The body of a wasp is bare and shiny. 
Bald-faced hornets, yellow jackets and paper wasps are all species of wasps. Bald-faced hornets are a species of yellow jackets.

Bees have fine hairs on their bodies
Each wasp has distinct characteristics that help differentiate it from other wasps. All wasps are more slender than bees.

Yellow jackets are black with irregular, jagged yellow bands while bald-faced hornets are black with a pale yellow face and a few whitish markings on the abdomen. Paper wasps resemble yellow jackets in color but are slimmer and have longer legs that hang down during flight. 

Another difference is the nests. Bald-faced hornets build large football-shaped nests in trees with a single opening on the bottom. Yellow jackets typically build the same type of nest as the bald-faced hornet but it is underground in animal burrows, stumps or any cavity. 

However, the aerial yellow jacket builds a nest above ground like the bald-faced hornet but is more likely to build it on roof overhangs or protected building surfaces. Aerial yellow jackets don’t add leaves and twigs to the outer nest walls like bald-faced hornets. 

Inside of an aerial yellow jacket nest

Aerial yellow jackets build nests similar to bald-faced hornets
Paper wasps build umbrella-shaped nests with the comb visible from the bottom. The nests are smaller than other wasps and are built in protected places, such as light fixtures, eaves, utility boxes and patio furniture.

While yellow jackets are the most blamed for stinging, paper wasps are actually the most common stinging pest in Idaho because their nest sites are closer to human activity. Paper wasps are relatively docile compared to yellow jackets when their nest is disturbed but they will still sting to defend their nest. Only female wasps sting because the stinger is an egg-laying tube modified to inject venom.

In late summer and fall, wasps (especially yellow jackets) tend to be more easily provoked because natural foods are scarce and they are raising the new queens in their nests. Only the queens overwinter to begin new nests in the spring.

Food sources vary throughout the season but wasps are highly beneficial to the ecosystem. Bald-faced hornets feed almost entirely on living insects including yellow jackets. Paper wasps prey on caterpillars, soft-bodied leaf-feeding insects and nectar.

Bald-faced hornet nest
Yellow jackets primarily feed their offspring insects, such as caterpillars, beetle grubs, grasshoppers, flies and spiders. Adult yellow jackets ingest some of the prey’s bodily fluid but feed mainly on nectar. They do not produce honey like bees. As insects become scarce, yellow jackets feed on dead protein and sugary food and, thus, become a picnic pest.
With a primary food source of insects, bald-faced hornets and paper wasps tend to be less of a picnic pest. 

The threat of stinging, whether at picnics or while mowing the yard, will be present until cold weather kills all but the queens.

Note: Published in the Bonners Ferry Herald on August 15, 2013.

Thursday, August 8, 2013

Insects instigate abnormal growth on plants


Odd growths on plant leaves or stems ranging from tiny bumps to red, spiny growths to pinecone-like growths on willows are a unique plant/insect relationship. These growths, called galls, typically don’t harm the plant but are extremely beneficial to the insect.

In the plant/insect relationship, the insect lays egg(s) in a plant and the resulting abnormal growth in the plant creates a gall. Typically ranging from one-sixteenth of an inch to over two inches, the gall grows with the egg and larva until it pupates and emerges. 

Spiny rose galls containing gall wasp larvae
Each insect and plant combination results in a specific type of gall. If several different insects lay eggs on the same plant, different galls are produced. Over 2,000 insects produce galls in the United States, of which 1,500 species are wasps or gnats. Organisms that instigate galls include beetles, moths, aphids, flies, wasps, bacteria, mites, fungi and nematodes (parasitic worms). 

Generally, an insect targets one plant species to lay her eggs on which results in a gall of a certain size, shape and color. Galls can be round, oblong, egg-shaped, spindle-shaped, bottle-shaped or an odd-ball shape. Gall flies lay their eggs on willows and produce a pinecone-looking gall. Other specific galls are called oak apples, honeydew and ambrosia galls.

Insect gall makers lay their eggs in different parts of the plant: buds, leaves, stems or roots. Gall insects are more attracted to certain plant families, such as willow, rose, daisy and oak. Goldenrod is another plant that certain insects target for galls.

Gall on a lodgepole pine

Generally, insects lay the eggs in the spring during the plant’s accelerated growth period. Mature plant parts don’t react to gall-making insects.

The exact mechanism for gall production is uncertain but scientists believe the growth results from a chemical released by the eggs and larvae and/or mechanical damage to the plant. The gall begins forming through increased production of normal plant growth hormones, resulting in localized plant growth.

After the egg hatches, the larva continues to release the chemical that stimulates plant growth and keeps the gall growing to match its size. The mass of tissue around the larva is a defensive reaction by the plant to contain the larva from eating the rest of the plant. To the larva’s benefit, the gall is edible and highly nutritious with the concentrated new growth. 

Spiny rose gall spines mimic those of the rose plant
Some larvae spend the majority of their lives within the gall. Many overwinter within the gall, pupate in the spring and emerge as adults to begin the process all over again. Wasps, moths and flies (all possessing chewing mouthparts) chew their way out  of galls when adults. Other species almost chew their way out as a larva (when they have chewing mouthparts) and then force their way through the remaining thin layer after they pupate.

Overwintering larvae may be protected by the elements but not from predators. Downy woodpeckers and black-capped chickadees are a few predators that hone in on the conspicuous galls for a protein-rich meal in winter. 

Once empty, galls become shelter for other insects, sometimes even nurseries for other insect eggs. Whether empty or occupied, galls provide visible sign into part of an insect’s life that often goes unseen. 

Note: Published in the Bonners Ferry Herald on Aug. 8, 2013.

Thursday, August 1, 2013

Bats only mammal capable of true flight


As twilight faded, all eyes watched the bat houses mounted on the side of the building. Slowly, the bats flew one by one from the bottom of the bat houses into the woods or swooped overhead searching for insects.

The night before, staff and volunteers at Kootenai National Wildlife Refuge counted nearly 1,100 bats emerging from the bat houses and eaves of the building. After a recent bat survey, biologists identified 11 of the 14 bat species that exist in Idaho at the Refuge. 

Nearly 1,100 bats live in these two bat houses at KNWR
The diversity of bats at the Refuge is most likely because of the variety of habitat in the Kootenai Valley, including different forest types, cliff faces, rock crevices and buildings. Each bat species seeks a specific type of habitat to roost and some roost in colonies while others roost individually. The maternity colonies of the little brown myotis can number up to 1,000 bats.

Over 20 million bats live in the Bracken Cave in Texas and eat over 250 tons of insects every night. Bats can eat about a third of their body weight each night. Pregnant and lactating females can eat up to their body weight every night. 
To consume the equivalent of a bat, a 150-pound person would have to eat 96 Big Mac’s every day.

The majority of bats in Idaho eat insects but other bat species around the world eat fruit, nectar, meat, fish and blood. 

Some bat species that fall from their roost cannot take flight off the ground
With insect populations beginning to decline in the fall, bats either hibernate or migrate for the winter. Two bat species found in Boundary County migrate south: the silver-haired bat and the hoary bat. The remaining bats in Boundary County hibernate in hibernaculum, either individually or in colonies. Disturbances can greatly decrease the chance of survival for the bats as they utilize precious energy bringing their body up to functional temperatures.

The migratory hoary bat is the largest bat in Idaho and in Boundary County at a weight comparable of 11.5 pennies. The smallest bat at the Refuge is the western small-footed myotis at a weight of 1.75 pennies. The largest bat species in the world is the large flying fox (Pteropus vampyrus), which has a wingspan of 78 inches. 

Bats are unique for their size. They are the slowest reproducing mammal on Earth for their size (think of how many young a mouse produces each year) and they have the longest life span for their size (average of 15 to 20 years). Bats don’t typically reproduce until their second or third year and usually produce one offspring each year.

The pups are extremely small when they are born but have strong legs and claws because they have to hang in the roost while the mother bat is gone. 
Bats that have fallen from their roost (once capable of flight) can sometimes fly from their position on the ground. Other species cannot take off from the ground and will crawl over to a tree or something they can climb in order to gain altitude to take off. If a pup falls from a roost and isn’t capable of flight, nature takes its course.

A bat biologist identifies a bat during research at Kootenai National Wildlife Refuge
Bats are the only mammal capable of true flight. Two thin layers of skin stretch over finger bones to create the wings. The feeling of the skin is likened to the skin on human eyelids. 

Being a nocturnal creature, the best time to see these unique mammals is when they take to the dimming sky at twilight to feed on insects.

Note: Published in Bonners Ferry Herald on August 1, 2013.