Audubon Guides

A Murder in the Everglades

April 15th, 2013

A Murder in the Everglades by Jungle Pete

I awoke Monday morning before the sun had risen and before the light could burn off the fog of a dream that would remain with me even until today. It wasn’t one of those dreams where you’re about to die but wake up just in time.  In this dream, I was informed I was dead, how I died and how the world had proceeded in my absence. It was upsetting to say the least.

As I headed for my commute across the Everglades I decided to cheer myself up by navigating towards one of my favorite places in the vast wilderness of South Florida. At the southern tip of the peninsula, at the southernmost frontier of the continental United States is a little place called Flamingo in Everglades National Park. The park has three main entrances: the Gulf Coast Visitor Center in Everglades City, Shark Valley Visitor Center in the heart of the Everglades and the Ernest P. Coe Visitor Center just west of Florida City. From Ernest P. Coe (named for the spiritual father of the ENP), a 38-mile road winds its way through pine rocklands and sawgrass prairies, ever-so-slightly sloping into the mangroves and out to Florida Bay.

Out here the cell service grasps for devices just out of reach. Out here I am one of a handful of humans in a four million acre wilderness. I am content.

I am treated to the site of Anhingas feeding white-feathered chicks, camouflaged by the fecal-stained, white-washed tree islands and guarded by alligators basking in the last of the dry season watering holes. As I make my way south, the road sweeps back and forth through dwarf cypress prairies, like a school of mullet chased by dolphin. Crows hop away from bits of carrion pulverized by passing cars.

I stop for a moment to take advantage of one of several spur trails. A crow hops over and is joined by a second. I retrieve my camera for the walk and suddenly there are four crows watching me, speaking to me with a nasally “gonk”. I photograph them and wonder to myself how many crows make up a murder.

 

Crows © Jungle Pete

Crows © Jungle Pete

After my walk I head south once again on what seems like an endless road. Crow after crow hops to the side of the road as I drive along. And then one doesn’t. One crow maintains its position just on my side of the yellow line, watching me approach, looking as if it’s timing its move. It doesn’t, I slow dramatically and finally the bird takes flight. A light thud grazes the upper windshield and black feathers puff like a dandelion in the wind. I circle back, park and dart for the bird lying on its back on the side of the road. I get only a few feet from the car before I am mobbed by seven crows. I retrieve a hat for my protection and on my second attempt to check on the injured bird the crows are huddled like football players around their fallen mate. When a Turkey Vultures glides over the tree line and towards the injured crow the distracted mob of crows takes off and drives the carrion eater away, enabling me access to the bird. As I return to my car with crow in hand, the mob returns with more birds, perched above me, making a ruckus unlike I’ve heard from birds before. They are yelling and they are not happy.

Was the bird just stunned? Does she have internal injuries? (For some reason I sense she’s a female). Can I get her to an animal rehabilitator? Will they care for a crow as much as I do now? As I head to Flamingo the mob of crows follows me for a distance and seems to gather members as they go. I stop. They stop. I go. They go. It’s unsettling. The crow under my shirt on the passenger seat makes a soft “gagonk” and an “awww”. I peak under to see if she is ready to fly. She’s struggling and with one last “caw” she goes limp.

Crows © Jungle Pete

Crows © Jungle Pete

There are many cultures that believe that crows are messengers from the spiritual world. Any spiritual connection I have is with the natural world so it’s difficult for me to untether this moment from my unnerving dream. Was this a message and what did it mean? Is it possible that the intelligent crow that normally moves out of harm’s way made a mistake as I had? In the end I find myself struggling to find the meaning in death and in this case one that I caused. And now I can’t help noticing crows wherever I go.

Want to take a tour of the Everglades with Jungle Pete?  Visit his website for more information: www.ecosafari.com

Posted in Entries by Jungle Pete | No Comments »

The Birds of Hawaii

April 11th, 2013
Nene

Nene © Arthur Morris/VIREO

The Birds of Hawaii by Gene Walz

Hawaii is not the place to go if you’re intent on adding to your Life-Bird list. There just aren’t that many unique native birds left on the islands.

Since “civilization” reached Hawaii about 200 years ago, over 30 native bird species have gone extinct.  Recent evidence seems to suggest that more species were killed off by the original islanders; bird plumage played a huge role in their costumes and decoration.

When I was in Maui in January, I did see about three dozen species of birds. But most of them I could have or had seen elsewhere. Cardinals, skylarks, mannikins, white-eyes, the usual Euro-trash, some common shorebirds and waterbirds from the Americas, and others.

There was even a colony of Peach-faced Lovebirds thriving in south Kihei – so new that they aren’t yet in the bird guides for the island.

I take delight in finding and identifying all kinds of birds. But it’s actually disheartening to see non-tropical birds on tropical islands. Especially if they are contributing to the demise of the native birds, the endemics.

One of the last places to see Maui endemics is in Hosmer’s Grove, a canyon near the top of the extinct volcano Haleakala on the east side of the island.

I went there twice and managed to get long, satisfying views of the Apapane, Amakihi, Alauahio, I’iwi — all bright, active, wonderful bird finds. But I missed the Maui Parrotbill and Crested Honeycreeper, two high-priority target-birds that are rapidly disappearing on the island. A huge disappointment.

Nearby I found several NeNe (Hawaiian Goose), and in the shallows at Kealia Ponds I easily spotted Hawaiian Coots, Hawaiian Ducks, and many Hawaiian Stilts.

I went to Maui for the whale-watching, the seafood and fresh fruit, the beaches, and the warmth. It would have been great had I been able to tick all the bird species I targeted. I guess I’ll have to go back. Damn!

Tags: , , , , ,
Posted in Entries by Gene Walz | No Comments »

Javelinas

March 25th, 2013
Collard Peccary

Collard Peccary © G. C. Kelley

Javelinas by Gene Walz

Big Bend National Park is a magnificent place – a desert full of mountains of every size, shape and color. If it were closer to civilization, it would be much more popular. But you have to drive through the rest of Texas to reach it. Not many people want to. So, it’s one of the least frequented of the national parks.

That’s great! The fewer the people, the more natural the experience.

I went camping there with my dog Buddy in February without knowing a single thing about the place. Buddy and I both wished we’d done some preliminary research.

For instance: it gets bloody cold in the west Texas desert! Usually around freezing or below at night (once it went down to 14 Fahrenheit), and “the wild Texas winds” that Marty Robbins sang about can make it feel colder.

For instance number two: the west Texas desert is full of too many spiky, thorny, prickly things that stick in a dog’s paws and fur. That makes it a bad place for dogs. I had to inspect and groom Buddy daily; invariably prickly things came off of him and stuck to me.

Also: several wild things that like to mess with dogs. We kept seeing notices about mountain lions, bears and javelinas. The signs warned that dogs must be kept on short leashes and never left alone because of them. That made it tough on both of us.

We never did see bears or mountain lions. (We heard wolves and coyotes.) But javelinas were our constant companions.

Javelinas (aka, Collared Peccary – Pecari tajacu) don’t look particularly dangerous.

They’re less than two feet tall and look like black, furry pigs with skinny legs and big heads. I heard a dunderhead call them “cute” and approach them for a photo. Bad idea! They have sharp tusks and bad tempers. They can gore and gut a dog in seconds. Probably a tourist too.

Collard Peccary hoof prints © NatureShare

Collard Peccary hoof prints © NatureShare

In Big Bend, Texas and nearby they are habituated to tourists. They hang around campsites and slake their thirsts in easily accessible areas of the Rio Grande (actually Rio Puny!).

Another example of wild things adapting. They hardly seem wild!

Tags: , , , ,
Posted in Entries by Gene Walz | No Comments »

Reenergizing the Red-tailed Hawk

March 20th, 2013

Reenergizing the Red-tailed Hawk by Josh Haas

Red-tailed Hawk

Red-tailed Hawk © Josh Haas / Glances at Nature

I’m betting the last time you saw a Red-tailed Hawk, you didn’t give the bird a second look. When birding and creating lists for the day, there are species that tend to get boring. As one of the most prevalent hawks in North America, the Red-tailed Hawk fits this category for many birders. But I’ve found the bird is worth a closer look.

Red-tailed Hawk

Red-tailed Hawk – midwest © Crossley ID Guide: Raptors

This raptor is a dynamic hunter that tends to go after small mammals, amphibians, reptiles and more. It’s opportunistic nature is one reason the bird is so pervasive and, hence, boring to birders. One type of prey missing from the list is small perching birds. And while it’s true they’re not necessarily built for hunting this type of prey, once while hawk watching at the Whitefish Point Bird Observatory I saw an individual display the power and versatility needed for the task. Flying at tree-top level with a strong steady wing-flap, the bird suddenly fanned its tail in such a way so as to flip sideways and nab an unsuspecting Northern Flicker off a dead tree. My binoculars came down, a smile came over my face, and for me the Red-tailed Hawk became a little more exciting. More recently, during a Detroit River Hawkwatch count, I saw a beautiful Northern Harrier circling above the count site when a Red-tailed Hawk unexpectedly stooped into view in pursuit of the Harrier. Enthusiasm soared among the onlookers as the Red-tailed Hawk continued after the Harrier. The aerial battle demonstrated to all who had seen it that this large-bodied Buteo could not only keep up with other agile raptors but maneuver like a Merlin as it dipped and raced around the skies. Yet another experience where for me, the Red-tailed Hawk became a little more exciting.

Red-tailed Hawk

Red-tailed Hawk Range Map © NatureShare

These are just two quick examples of how the Red-tailed Hawk is more than a modest soaring bird living around our highway systems. The large hawk is nothing short of amazing. With its large powerful feet, snappy wing flap, and keen hunting techniques, this adaptable bird can adjust easily to many habitats and situations. My hope is the next time you find yourself viewing a Red-tailed Hawk through your binocs, you’ll linger a bit longer. It might just do something for which the bird becomes a little more exciting.

Red-tailed Hawk

Red-tailed Hawk © Dave Haas / Glances at Nature

To see more of Josh’s work, get tips on photography, or to sign up for workshops and trips please visit www.glancesatnature.com.

Blog tour logoThe Crossley ID Guide: Raptors by Richard Crossley, Jerry Liguori, and Brian Sullivan will be available April 2013.  The book covers thirty-four of North America’s diurnal raptor species (all species except owls), 101 stunning color plates–including thirty-five double-page layouts, species information and more!  Be sure to enter to win the ultimate Crossley ID Guide Sweepstakes to win some cool prizes including the Audubon Birds app!

Tags: , , , , , , ,
Posted in Entries by Josh Haas | No Comments »

Getting Ready for Spring: Horned Larks

March 18th, 2013

Horned Lark adult male, Eastern © Arthur Morris/VIREO

Horned Lark adult male, Eastern © Arthur Morris/VIREO

Getting Ready for Spring: Horned Larks by Gene Walz

A winter tradition here in Manitoba that I missed this year usually involves jumping in the car on a clear, snow-free day in early February (on or near an accompanying friend’s birthday) and heading out to find Horned Larks. I spent this winter in a warmer, mostly snow-free zone. So the larks weren’t the first returning birds of the year for me. Bald Eagles beat them.

Horned Lark

Horned Lark adult male, Northern © Glenn Bartley/VIREO

I’ve never considered Horned Larks the true harbingers of spring. They don’t qualify because every year I hear reports of Horned Larks that over-winter here. And the migrating larks usually come back to Manitoba far ahead of the official arrival of spring on March 21, and well before the snow melts (the actual arrival of spring sometime in April). But I like to celebrate their hardy appearance.

Horned Lark

Horned Lark adult male, Interior West © Rob Curtis/VIREO

Any bird that sticks around from November to March or comes back here in the dead of winter has got to be special, deserves a salute, a toot of the horn, especially a bird so delicate.

Twenty-one subspecies of the Horned Lark can be found in North America (another 19 around the world). Subspecies associated with Manitoba, the Canadian Prairies, and the Great Plains include Eremophila.aalpestris enthymia, E.a. leucolaema, and E.a. praticola.

Dusty brownish-grey above and white below, they are best distinguished by the black, yellow and white markings on their heads and necks (black “horns” aren’t often visible) and their white outer tail-feathers.

Horned Lark

Horned Lark adult male, Interior West © Greg Lasley/VIREO

They prefer open areas with short, sparse vegetation — croplands, fencerows, road rights-of-way, pastures, and recently cut hayfields. The gravel mile-roads in farm country southwest of Winnipeg are the best place to find them.  They flit along the road edges, folding their wings after each beat and never flying very high or far from the car.

Because they are grassland birds, their numbers are diminishing. I’d hate to see them disappear completely. They cheer me up considerably in February when I usually need it most.

Horned Lark

Horned Lark adult, Pacific © Alan David Walther/VIREO

Tags: , , , , ,
Posted in Entries by Gene Walz | No Comments »

Throwback Thursday: Winter Sparrows

February 21st, 2013

Throwback Thursday: Winter Sparrows by Drew Weber Originally Posted 2/16/12

As I related in my last post on ducks, the winter months can appear to be a slow period for birding. However, in addition to ducks, there is another group of birds that is more diverse and easy to observe in the winter compared to the summer: the sparrows.

Sparrows have always had the bad rap of looking the same and being difficult to identify. They are often lumped into a group of birds called the “lbj’s” or “little brown jobbies”: birds that all look the same and aren’t worth the time it takes to identify them. To these folks I say: nonsense! With some patience, sparrow identification is pretty straightforward with most species having obvious features that can be used for identification.

Song Sparrow

Song Sparrow © Drew Weber

Across much of North America, the Song Sparrow is the default sparrow. It is worth the time to really get to know the field marks of Song Sparrows. It has smudgy red-brown streaks on its chest and a spot in the center of its chest.

White-throated Sparrow birds

White-throated Sparrow © Drew Weber

During the winter months, one of the most common sparrows is the White-throated Sparrow. Aptly named, the White-throated Sparrow has a bright white patch on its throat, as well as white stripes on its head that turn bright yellow near the beak. These are one of the most common feeder birds in many areas, especially when snow has covered up their more natural food sources.

White-crowned Sparrow

White-crowned Sparrow © Drew Weber

A close relative, the White-crowned Sparrow, has bold black and white barring on its head. White-crowned Sparrows are less common at feeders, often tending to hang around overgrown hedgerows along fields. Depending on the habitat around your yard, you may be lucky enough to host these large sparrows.

Dark-eyed Junco

Dark-eyed Junco © Drew Weber

Another easy to identify winter sparrow is the boldly patterned Dark-eyed Junco. Dark above and white below, the little twittering noises of these birds as they scavenge for seeds under my feeder always makes me happy. Juncos vary widely in their plumage across their range and it can be fun to scan through the flocks, looking for a ‘pink-sided’ junco.

American Tree Sparrow

American Tree Sparrow © Drew Weber

The most northern of the winter sparrows is the American Tree Sparrow. With its red cap, it is superficially similar to the Chipping Sparrow, a summertime resident. However, the bi-colored bill and spot on the breast separate it from Chipping Sparrow.

These are the most common sparrows you will encounter during the winter in the northeast. Most of them have pretty distinctive features, so the next time you see a sparrow hopping under the feeder or in the shrubs, take the time to identify it and add it to the list of birds that you can quickly recognize.

Tags: , , , , ,
Posted in Drew Weber | 1 Comment »

Photo Essay: Nightscapes

February 11th, 2013

Photo Essay by Josh Haas: Nightscapes

 

Sedona Nightscape, Trails of Light

Sedona Nightscape, Trails of Light

Sedona Nightscape:

This very special image took hundreds of miles in travel, days of scouting, hours throughout the night shooting, and hours of post-processing. This makes it an ‘earned’ image in my book. It’s a classic long exposure but instead of just leaving the shutter open for 30 minutes, I created this using multiple stacked exposures instead. This was because the town of Sedona was close enough that in a super long exposure, the light pollution would’ve ruined the image. The first shot was taken about 45 minutes after sunset when there was still enough ambient light to illuminate the rocky ridge in the foreground. After that, I had to leave my gear in place and wait a couple hours until it was dark enough to begin taking the 30 second exposures one after another. I did this for another 90 minutes until I was sure I had a sizable group of images without plane lights and other problems to create a nice star trail image. Finally, the shooting was complete. On the plane ride home at an altitude of 30,000 feet, several interested people on the flight watched as the final image was created. A night image was my goal weeks before heading to Arizona for this trip and I’m excited to say we made it happen.

 

Camera Body & Lens- Canon 1D Mark III, 24-70mm f2.8 lens

Aperture- f2.8

Shutter Speed- Multiple 30sec exposures, stacked

ISO- 250

 

Lightning with a Purple Hue

Lightning with a Purple Hue

 

Lightning with a Purple Hue:

After years of waiting for the perfect storm to photograph, it was finally here. The storm has to be just right to make lightning photography work and this one was perfect. Using an intervalometer, I set up underneath my deck and began shooting. After setting my exposure settings, focus and composition the intervalometer took over to kick off the exposures one after another while I retreated inside where it was safe. This was a great compromise that made my wife happy. =) Safety has to be number one in storm photography and this device sure makes it safe. While inside, I waited until the rain was close enough that it would compromise any good images and then retrieved my gear. After loading the 100+ images, I had one that turned out great (and this one is it!) The purple sky, tree line and lighting all work together to make this a nice image.

 

Camera Body & Lens- Canon Rebel T2i, Tamron 28-75mm f2.8 lens

Aperture- f6.3

Shutter Speed- 20sec

ISO- 100

 

Lake Superior Lightning

Lake Superior Lightning

 

Lake Superior Lightning:

A more recent image, this was taken on the south shores of Lake Superior in Michigan’s Upper Peninsula. After a day of shooting waterfalls the lighting was drab that evening so I figured my shooting was done for the day. It was about that time I began to hear distant thunder and decided to make the trek out to the beach to see what was happening. As a distant storm approached I set up and waited. The evening light dwindled and the storm approached; a hole in the clouds opened up at the perfect time show-casing an orange sky lit by the fading sun. The lighting popped and all I needed was a rock star of a lightning bolt to finish off the scape. Just before the rain began my wishes paid off and I got my lightning. To create this image I set my aperture, ISO and then used 6 second exposures over and over until the right lightning appeared in the sky (notice my stopped down aperture of f13 to keep too much light from hitting the sensor). As the sky becomes darker, this technique gets easier as you can use longer exposures but because I was shooting before dark, I had to stop down my aperture and could only use 6 second exposures without blowing out the images.

 

Camera Body & Lens- Canon 5D Mark II, Canon 24-70mm f2.8 lens

Aperture- f13

Shutter Speed- 6sec

ISO- 200

 

 

Star-filled Night with Space Station

Star-filled Night with Space Station

Star-filled Night with Space Station:

This image is the result of a family member contacting me about some action I might be interested in. The International Space Station was set to pass by our night sky that night. At the time, I was still living in the city where light pollution would ruin the image so I grabbed my gear and headed out in the country in search of a spot. I ended up on a golf course and struggled to find a decent spot with enough time to get set up in time. I was able to make it work and record the image with the International Space Station streaking across the sky. For all of you photographers out there, it pays to spread the word and build a base of people that can give you tips on where possible action may be. I’ve captured several images this way and had I not been tipped off, the images would not exist today.

 

Camera Body & Lens- Canon 1D Mark II, Tamron 28-75mm f2.8 lens

Aperture- f2.8

Shutter Speed- 30sec

ISO- 100

To see more of Josh’s work, get tips on photography, or to sign up for workshops and trips please visit www.glancesatnature.com.

www.NatureShare.com

Tags: , , , , , ,
Posted in Entries by Josh Haas | No Comments »

A Family Trip with an Unexpected Find

February 4th, 2013

A Family Trip with an Unexpected Find by Josh Haas

While in Lafayette, IN for what would be our last Christmas gathering, I awoke well before sunrise to the sound of a baby playing in her crib.  Being up early has its advantages and like many mornings, I jumped on my iPhone for things like the daily weather, news, and of course a gander through the Audubon Field Guide to North American Birds app.  Using the “Find Birds with eBird” feature, I scanned the list and one bird jumped out very quickly.  A Varied Thrush had been seen the day prior no more than 12 miles from where I was staying.  This bird should be in California, let alone Indiana so it was worth the effort.  If you haven’t checked out this great feature in the app, it’s worth your time.  It’s quick and much better than some of the other apps that feature eBird searching.

Cooper's Hawk, Adult © Josh Haas

Cooper’s Hawk, Adult © Josh Haas

Unfortunately, after two morning attempts for this western thrush, I never did see it but I did get a nice opportunity with an adult Cooper’s Hawk before meeting a nice birder who mentioned having Saw-whet Owls roosting on his property.  That obviously perked some interest!  I jumped at the invitation and soon found myself riding in a gator across his property 6 miles away after a different bird.  Boy it would’ve paid to be prepared for the 12 degree temps but who would’ve known a family Christmas could turn into a birding adventure.  I suppose in our family, it’s very likely!

Sure enough, as we approached a small Cedar grove, we slowed and eventually stopped.  Looking into the woods, one can’t help but notice the many yellow ribbons hanging on trees marking where birds were or are roosting.  The gentleman does surveys daily to gather data about the individuals.   Amazing commitment…

Northern Saw-whet Owl © Josh Haas

Northern Saw-whet Owl © Josh Haas

All in all, he showed me three individual Saw-whet Owls.  One was even awake and willing to be photographed.  Oh man was I one happy Daddy!  This property was amazing and he told stories of the many species of Owls, Raptors and Passerines that fledged over the years from the 200 acre parcel.  This is another example of a great find and a genuine birder willing to share his great spot.

To see more of Josh’s work, get tips on photography, or to sign up for workshops and trips please visit www.glancesatnature.com.

Tags: , , , , , ,
Posted in Entries by Josh Haas | No Comments »

2013 BIGBY – Big Green Year

January 31st, 2013

2013 BIGBY – Big Green Year by Josh Haas

Big Green Year

Birding by Bike © Josh Haas

For 2013 I’ve decided to blend my passion of birding and cycling into a one-year event.  Some of you may know what a Big Year is (seeing as many bird species in a calendar year, within specified boundaries) but I’m taking it one step further.  I’m doing a BIg Green Big Year (BIGBY).  My boundaries are anywhere within Barry County, MI and my goal will be to see as many bird species as possible by bike.  My ride of choice is shown below.

Josh and the BIGBY Bike

Josh with his BIGBY Bike © Glances at Nature

This cyclocross bike is perfect for the job with slightly wider/knobby tires for back roads.  While perfect on gravel, it still has a road feel for when I need to cover some serious mileage quickly, while on pavement.  I’ve outfitted the bike with lights for night riding after nocturnals, a rack for carrying my scope and a unique bag on the front to carry my binocs for quick use.  I do want to say a big thanks to our favorite optics folks at Eagle Optics who helped me choose an inexpensive binoc for this rough-road journey and also a big thanks to Mike at Team Active Cycling and Fitness for yet another great bike!

My plan the first couple months is to concentrate on winter species until the ice thaws and the first spring migrants begin showing up.  As spring thrusts upon us, longer rides will ensue and I will be after the mass of migrants moving through.  Barry County breeders will be the focus in summer, fall will bring another mad dash for any missed migrants and the last couple months of 2013 will be dedicated to any winter species still missing.

Red-headed Woodpecker & Trumpeter Swan

Red-headed Woodpecker & Trumpeter Swan © Josh Haas

We’re through the first month of 2013 and I’ve accomplished six rides thus far with a total of 42 species and 95 miles ridden.. The first ride brought species such as Snow Bunting, Bald Eagle, and Horned Lark. The second ride yielded a Red-headed Woodpecker, a few late ducks and an Eastern Meadowlark still lingering. The third ride was short but I was able to snag a Wild Turkey. During my fourth ride, I was able to track down Trumpeter Swans and a Rough-legged Hawk. While my fifth and sixth rides didn’t yield many, important species such as Red-breasted Nuthatch and Red-shouldered Hawk were added to the list.  These are just the highlights of each ride.  There are still winter specialties to get so stay tuned!  Please visit http://www.glancesatnature.com/blog to see the latest tally and full list all year long.

To see more of Josh’s work, get tips on photography, or to sign up for workshops and trips please visit www.glancesatnature.com.

Tags: , , , , , ,
Posted in Entries by Josh Haas | No Comments »

Nature Stories: Snowflake

January 3rd, 2013
Snowfall in Vermont 12/27/12

Snowfall in Vermont 12/27/12

Anyone who has looked closely at a snowflake under a magnifying glass, or even with their naked eye, has an appreciation for the intricacy and delicacy of these frozen ice crystals that descend from the sky.  Exactly how do they form and why do they assume the shapes that they do?

Snowflake © Kenneth G. Libbrecht

Snowflake © Kenneth G. Libbrecht

According to physicist Kenneth Lebbrecht, in his book The Snowflake: Winter’s Secret Beauty, snowflakes and snow crystals are made of ice. As its name implies, a snow crystal consists of a single crystal of ice.  Snowflake is a general term that includes all shapes and combinations of snow crystals.  A snowflake can be a single snow crystal, or a conglomerate of crystals.

A snow crystal is not a frozen raindrop.  When raindrops freeze, they are referred to as sleet; the individual particles of ice lack the intricate patterns of snowflakes.  Rather, snow crystals form when water vapor in the clouds condenses directly into ice. As more vapor condenses, the ice crystal grows and develops, creating elaborate patterns.

Snowflake © Kenneth G. Libbrecht

Snowflake © Kenneth G. Libbrecht

There is a sequence of events in the formation of a snow crystal.  Evaporation from the ocean, lakes and streams, as well as the transpiration of plants and the expiration of animals puts a large amount of water vapor into the air.  When a mass of air cools, the water vapor it contains condenses out of it.  In summer, when this occurs next to the ground, we refer to the condensed water droplets as dew. When the air high above the ground is cooled, the water vapor condenses onto particles of dust, forming clouds full of water droplets.  In winter, the individual water droplets start to freeze around 14 degrees Fahrenheit. They don’t all freeze at once; gradually the water droplets surrounding the particles of ice evaporate into water vapor which then condenses onto the ice crystals, growing snow crystals.

w050207a094

Snowflake © Kenneth G. Libbrecht

Many snow crystals begin as hexagonal prisms – flakes with smooth facets, or sides, arranged in a hexagonal shape.  “Branches” then sprout at each of the six corners of this hexagonal crystal and as the surrounding water vapor condenses on them, they grow. Because the entire crystal passes through the same climatic conditions, the branches tend to grow in a similar pattern at a similar rate, creating the six-pointed star-shaped crystal, or stellar dendrite, that we are familiar with.  Many shapes, including columns, plates and needles, are formed.  Humidity, and particularly, temperature, affects the pattern of growth.  Snow crystals tend to form simpler shapes when the humidity is low, and more complex shapes at higher humidities. Even so, the majority of snowflakes are not symmetrical.  Within a given cloud, different snowflakes are blown in different directions, encountering different temperatures, which results in slightly different shapes.  Thus, no two snowflakes are identical.

Snowfall © Mary Holland

Snowfall © Mary Holland

Tags: , , , , , , ,
Posted in NatureShare | No Comments »

« Older Entries
Newer Entries »