Posts Tagged ‘Vermont’

Throw Back Thursday: Abscission and Marcescence in the Woods

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Wednesday, October 10th, 2012

Throw Back Thursday: Abscission and Marcescence in the Woods by Kent McFarland

Originally Posted 11/9/2009

While on a recent hike in the hills of Vermont, I noticed that some trees had lost their leaves while others still had golden brown leaves all over them. It seemed that all of the Red Oak and the American Beech trees still had a nearly full canopy, while the Sugar Maple along the old woods road were completely naked.

trees woods

Foliage © Kent McFarland

I snapped a photo of it so I could do a bit of research at home. It turns out that Oak and Beech trees have marcescent leaves. Marcescence is when a plant part dies but is not shed. In the photograph you can see that the Sugar Maple trees in the foreground along the old carriage road have completely shed their leaves, while the Beech trees on the hillside are still fully loaded.

A tree is full of vascular cells that transport water and sap from root to leaf. As the amount of sunlight decreases in autumn, the veins that transport sap into and out of the leaves slowly close. A layer of cells, called the abscission layer, develops at the stem base. The leaf falls off when this layer is completely formed.

Oak (Quercus), Beech (Fagus) and Hornbeam (Carpinus) are an exception. The separation layer doesn’t fully allow the leaves to detach. That’s why most of their dead leaves remain on the tree through winter until the wind rips them away. But one has to wonder what advantage this would have for the trees. It may be that it deters foraging of young buds and branches by deer. If there are a lot of dead leaves on the ends, it may not be as palatable. It may aid in protecting the tree from water or temperature stress during the winter. Or, perhaps it is a left over ghost from the past that is now neutral, neither hindering nor helping the species prosper. Whatever the reason, in late fall you can easily see the forest for the oak and beech trees.

Dawn Chorus: Nature’s Best Bird Songs

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Friday, August 10th, 2012

Wood Thrush © Brian E. Small/Vireo

 

Dawn Chorus: Nature’s Best Bird Songs by Meg Lowman

As I come over the hill, I hear the wood thrush singing his evening lay. This is the only bird whose note affects me like music, affects the flow and tenor of my thoughts, my fancy and imagination. It lifts and exhilarates me … It is a medicative draught to my soul. It is an elixir to my eyes and a fountain of youth to all my senses…

Henry David Thoreau, Journal, 1853

The time was 4:24 a.m. I sat upright in bed, awakened by an inspirational choir that just burst into sound. Vacationing in the woods of northern Vermont, I took a June sojourn back to my childhood forests of New England. Sleeping until noon is an obvious privilege of vacation, but late sleepers in the short Northern summer miss one of the best musical events of the year.

The American Robin was the first songster on nature’s program. Opening up the dawn chorus with a melodious, cheerful message, it announced to the forest denizens that sunrise was imminent. Soon, that dawn harbinger was joined by other robins, a trio in full song. As if not to be outdone, the White-throated Sparrows trilled, “Oh sweet Canada, Canada.” Almost 150 years after Thoreau described New England songbirds, their melodies have remained remarkably true over time.

White-throated Sparrow birds

White-throated Sparrow, adult (bright) © Robert Royse/VIREO

Within 10 minutes of the robin’s wake-up song, the entire hillside was in full symphony – Red-eyed Vireo, House Wren, bluebird, goldfinch, Ovenbird, Song Sparrow, Eastern Wood-Peewee. I was awestruck and wide awake – no going back to bed now. By 5 a.m., all musicians were in full song. Suddenly the forest quieted for a brief lull. One soloist took center stage. Its flutelike song and resplendent trills filled every hollow of the forest, sending chills down my spine. Thoreau was correct in saying that the Wood Thrush “is an elixir to my eyes and a fountain of youth to all my senses.”

Eastern Wood-Pewee birds

Eastern Wood-Pewee, adult © Brian E. Small/VIREO

In North Carolina, the dawn chorus in downtown Raleigh is very different. Robins provide the wake-up call (often a predawn solo!), following soon after by Carolina Wrens, cardinals, mockingbirds. As an urban dweller, I rejoice to have feathered residents announcing the day.

Carolina Wren birds

Carolina Wren, adult © Glenn Bartley/VIREO

After hearing the Wood and Hermit Thrushes in the spruce boughs of Vermont, my annual pilgrimage back to childhood is complete. Like an opera buff, I am willing to travel great distances to hear my favorite singers. By midmorning, the forest is relatively quiet. Having faithfully announced the new day, my feathered musical troupe moves from song to other activities – nest-building, tending to their young, foraging for food and defending territories. There is something inspirational, almost celestial, about the dawn chorus. Birds seem to celebrate each new day with great optimism, but after a stunning performance, they move on to the business of survival.

Margaret D. Lowman, Ph.D.

About Margaret D. Lowman, Ph.D.: As Director of North Carolina’s new Nature Research Center (NRC), Meg Lowman oversees all aspects of this cutting-edge research center including staff supervision, research laboratories, technology, fund-raising, strategic planning, and integration with existing Museum programs.

 

American Tree Sparrow

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Thursday, March 22nd, 2012

American Tree Sparrow by Lisa Densmore

Location: Burlington, Vermont

It was the second night this winter that I spent at my cousin’s house. This time I was prepared. On my first visit, a month ago, I didn’t bring my “wildlife lens”, a 500 mm Sigma zoom that lets me fill the camera frame with a small songbird without spooking it. I missed the chance to photograph a number of vireos, chickadees and juncos that gathered around their backyard bird feeder. I didn’t know they had one.

This time, I watched and watched, but only one chickadee flitted to the feeder, snatching a few seeds. Not a vireo or a junco in sight! I was about to give up when a small flock of American Tree Sparrows (Spizella arborea) stopped by for breakfast. These chubby, long-tailed sparrows busily flew from a tree branch to the feeder to the ground then back to a tree branch. They foraged voraciously as they need to eat 30% of their body weight per day to stay alive. If they are forced to fast only one day, their body temperature drops too low, and they likely won’t make it to the next morning.

Despite their names, American Tree Sparrows, spend a lot more time on the ground or perched on low shrubs and weeds than in trees. During the summer, they forage and nest on the ground in the Krummolz (scrubby stunted trees) or just above tree line.
It’s been a mild winter in New England with only intermittent snow. I wondered if these twittering seed-eaters were already winging their way back to the Canadian tundra where they breed. Winter is the only time you can see Tree Sparrows in the Lower 48.

American Tree Sparrow, adult © Brian E. Small/VIREO

The American Tree Sparrow is a cute little thing, with a rust-colored cap on top of its head, matching stripe off the corner of its eye, and white and black bars on its wings. Its bi-colored bill is black on top and yellow below. It has a curious dark smudge in the middle of its buff breast as if it bumped its pudgy belly on a patch of soot.
As winter wanes, I’m excited to stake out my bird feeders when I get home to see if any migrating birds drop on their way north. Anything stop by your feeder lately?

www.DensmoreDesigns.com

Thunder Pumpers – The American Bittern

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Monday, March 19th, 2012

American Bittern by Jungle Pete

Stick your head in an aquarium and say “glunk-ga-glunk” repeatedly. This was the best description I could offer to a friend who was trying to help me identify the other worldly noise I was hearing coming from just outside my home in Londonderry, VT back in 2002. I had never heard such a sound and if pressed to jump to conclusions I was leaning between a pump going bad or an ET. With flashlight in hand, I circled the house and checked for mechanical malfunctions. I found nothing, but in the distance I could hear the “glunk-ga-glunk” again, far from the house, through a stand of Eastern Hemlock and down towards the edge of Lowell Lake. You’ve seen this movie right? I had to know what it was. In the remaining illumination of twilight, I crept closer to the noise and as I approached the marsh I noticed something standing in the water and waving back in forth like a drunkard on a sailing ship. I flashed the light on it and it flew. Based on the heron-like shape, I believed it was an American Bittern (Botaurus lentiginosus). Upon returning to the station I looked up their call and sure enough, my spooky mystery noise had been solved.

The name bittern comes from the Latin butire meaning “to cry”. The genus name Botaurus is Latin for “cry of the bull” and they are also known as Thunder Pumpers for their habit of swaying back and forth as they generate the incredible booming sound. The call can be heard for miles but in my case a quarter mile was enough to raise my curiosity.

American Bittern © Brad Bolduan/VIREO

I didn’t see another bittern until returning to the swamps of South Florida. Even here, the solitary marsh hunter is rarely spotted. As relatives of the herons, they have a similar body shape and a stout, sharp beak that is used for spearing frogs, fish and aquatic invertebrates. When approached they have a unique behavior of “hiding” by extending their neck and beak straight up and playing the part of tall thin aquatic plants. The brown and white streaked upper body parts also help camouflage the bittern. If that isn’t enough they’ll silently sway in the breeze with the vegetation – quite a contrast for a bird that generates such a racket.

A Fisher Finds Its Match

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Friday, December 2nd, 2011

Fisher

There is perhaps no animal that has as much mystique in northern New England as the Fisher. And wrapped up in its mysterious natural history are plenty of tales. Take the blood-curdling scream of the fisher at night. Actually, they are a nearly silent predator, most of those night noises are fox or owls. Or how about the colloquial name: fisher-cat, when they are neither a cat nor do they eat fish. European settlers named them for their superficial resemblance to the European polecat, also referred to as fichet or fitche.

So I wasn’t surprised to learn something new about Fishers when my friend Deb Williams at the Aloha Foundation’s Ohana Family Camp on Lake Fairlee, Vermont contacted me about a strange Fisher finding. She found the desiccated body of a Fisher under a cabin they were rebuilding. But what was amazing about this poor fellow were the quills. Its face and body was full of Porcupine quills. I’d always heard Fishers were specialists at eating Porcupines, but here was one that clearly died after a massive misstep.

I thought Fishers were experts at eating Porcupines, so I turned to my colleague Steve Faccio, a biologist at the Vermont Center for Ecostudies who studied Fishers during their reintroduction to Connecticut years ago. “This drives home a common misconception about the fisher-porcupine relationship,” says Steve. “Fishers are not porky ‘specialists’, but will take them on occasion, usually when they’ve been unsuccessful at killing other prey.

It turns out that although mostly carnivorous, Fishers will generally eat whatever comes along or is available. They can travel 60 miles on some hunting forays. Their main prey include carrion of all sorts, snowshoe hare, mice, voles, shrews, squirrels, birds, amphibians, insects, and even fruits and nuts. I once tracked a Fisher in deep snow with Steve for miles only to find in the end that it settled for dinning on frozen apples off an old tree. One summer I even found Fisher scat filled with Hermit Thrush egg shells.

But when they have to, Fishers do indeed feed on Porcupines, which are covered in dangerous quills. Well, not totally covered. If you ever come across a porky you will notice that it always tries to expose its hind end and tail while hiding its face. Move to the front of it and it will turn around to show you the business end, raising its quills and swinging its armed tail back and forth. But its face has a gap in the armor and is exploited by Fishers. They attack Porcupines with swift and repeated bites to the quill-free face and head. Once it has killed it, the Fisher turns it over and devours it from the stomach side where there are also no quills.

“Attacking one is a gamble that takes a lot of energy, but has a big payoff if they are successful, although the risk is high and potentially fatal,” notes Steve. And Deb’s find gives us proof positive of that.

Photograph courtesy of Deb Williams.

Washed Away – The Sculpin

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Tuesday, September 6th, 2011

On Sunday, August 28th, the Weather Channel reported the last bands of rain and wind had passed through New York City. Hurricane Irene was dubbed a meteorological flop. From the often storm battered coast of Florida, I found it hard to believe that this storm had let so many off the hook.

I checked my facebook page to see how friends and family in Vermont were doing. Photo after photo, along with unbelievable videos of catastrophic flooding proved that A) forecasters and news outlets were quick to dismiss the consequences of heavy rain in a landlocked, mountainous state and B) Vermont is in fact part of the United States. They even have maps to prove it.

My friend Chris Saylor, the ranger at Camp Plymouth State Park in Ludlow, Vermont uploaded some stunning photos and videos of the park as the rampaging Buffalo Brook stormed through it. Turbulent mud and boulders had ripped through roads and taken out bridges leaving behind an unfathomable landscape of debris and muck. In all of the destruction, one little curiosity caught Chris’ attention. Buffalo Brook is known for gold panners who occasionally find flakes and nuggets. Chris found something else bright and shiny. He sent me a photo and asked “what’s this?” In his hand was a now deceased Sculpin (Cottus sp.) that had been washed away from its stony brook hideaway into an open field.

Vermont is home to the Mottled Sculpin (Cottus bairdi) and the Slimy Sculpin (Cottus cognatus). Both thrive in the pebble and stone filled streams and creeks that were severely impacted by the hurricane. These slow-flowing, well-oxygenated waterways are breeding grounds for aquatic invertebrate larvae which sculpin feed on. Although the cryptic coloration of the sculpin aid them in blending in to their aquatic surroundings, they are preyed upon by trout who share the same habitat.

It’s hard to say how Hurricane Irene impacted the wildlife of Vermont’s brooks, streams and rivers. It is clear how it has affected the Vermonters. Despite over 200 road closures, 30 bridge washouts and hundreds of houses destroyed across the state, the people of Vermont are picking up the pieces, digging themselves out and standing tall in the face of adversity. Their positive spirit can not be washed away.

To help Vermonters in need please visit the Vermont Food Bank and offer what you can.

Photos provided by Chris Saylor.

Painful Memories–The Porcupine, Part I

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Monday, August 8th, 2011


Pain can be defined as both physical suffering from bodily harm, as well as mental or emotional stress. The venomous bite of a rattlesnake is painful and destructive to body tissue and potentially fatal. The spray of a defensive skunk smells terribly and burns even worse. The bite of a grosbeak on the face is not surprisingly, horrible, as I can attest to.

Emotional pain is a feeling of distress or grief. Losing a loved one, falling overboard on a lake full of alligators or simply missing the amazing photograph of a black bear because you’re camera battery died. Clearly there are varying levels of pain, all of which tell the brain to stop doing whatever brought it about in the first place.

It was a grotesquely hot summer day in Vermont. The car thermometer read 101 Fahrenheit. It’s hard to believe I left Florida to vacation in this. As we snaked our way through the mountainous roads near Plymouth we spotted something moving slowly across the road. It was a dark object about the size of a basketball and looked as if someone had it on a string and was pulling it across the road. As we approached, it became clear that this was the slow, ambling gait of a porcupine.

I followed the porcupine into the woods were he paused and watched me. This unexpectedly beautiful animal is armed with roughly 30,000 modified hairs or quills, which are loosely attached to the skin. They can’t shoot them but the porcupine knows that if I get too close he can slap me with his tail and dozens to hundreds of those quills will become lodged in my skin. Each quill has a nearly imperceptible barb on the tip, making extraction difficult and painful.

If you look closely under the porcupine’s chin in the photo you’ll notice a curved white quill. It’s in backwards and I can only assume it came to be there after relations with another porcupine.

Leaving nothing to chance, this porcupine scaled a tree to escape the threat of my camera. I’m well aware of the pain this animal can cause and not wishing to cause him undue emotional stress, I leave the quilled rodent to his business.

Woven of Mushrooms

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Friday, August 5th, 2011


Crawling on my hands and knees through the thick, stunted forest near treeline, a subalpine forest formation called krummholz, I stumbled upon some fine, black hairs wrapped around a dead Balsam Fir branch just above the mossy understory. I immediately recognized them. I had seen them woven into the lining of songbird nests I was studying. And remarkably at the very end of a few of these hairs was a tiny mushroom cap not much larger than the head of a pushpin.

George Wallace, born and raised in Vermont and later a great ornithologist, studied the life-history of Bicknell’s Thrush in the 1930s on Mount Mansfield, Vermont, not far from where I found these mushrooms. Wallace described in great detail the nests he had found, but he was unable to identify the inner lining of “fine, black rootlets” and commented that “they are unquestionably rootlets of some sort… resembling horsehair, but where the birds get them is a mystery.” I had a hunch I had solved that mystery.

I collected a sample as I lay hunched under the crooked trees. Later, when the birds were done breeding, I collected a few of the nests. Nearly all of them had copious amounts of the black, rootlet lining, which was a perfect match for my sample. But not one appeared to have a mushroom cap. I found the tiny mushrooms in the forest after a rainy period. Perhaps they needed moisture. I placed one of the nests in a plastic container with just a bit of water sprinkled on the bottom. Within just a few days some of the rootlets appeared to spring upward with caps on them. But what kind of mushroom grows in such a strange manner?

Samples of the hair-like structures and caps were sent to a North American expert, Dr. Dennis Desjardin, Director of H. D. Thiers Herbarium at San Francisco State University, for identification. The hair-like structures were identified as rhizomorphs of the Horsehair Fungus (Marasmius androsaceus). It’s considered common in North America, and can be found across the boreal zone and south along the Rockies, the Coastal Mountains and the Appalachians. It belongs to a group of closely related species, all of which produce numerous rhizomorphs.

The thread-like rhizomorphs are made up of parallel hyphae, branched tubular filaments that make up the body of a typical fungus, and absorb and transfer nutrients. Horsehair Fungus is saprotrophic, an organism that lives and feeds on dead organic material, and is found on dead needles, leaves and twigs and parasitic on some ericaceous plants in wet, boggy habitats. They penetrate solid materials such as dead wood and use acids and enzymes to digest it.

The use of rhizomorphs as nesting material, especially by tropical bird species, has been found to be widespread but poorly documented. It had not been reported for any birds breeding in North America prior to my discovery. From Bicknell’s Thrush to Yellow-bellied Flycatchers, we’ve found that most subalpine songbirds in the Northeast use these mushrooms in nest construction, but why?

A number of Marasmius species have been shown to produce antibiotic agents that inhibit the growth of Staphylococcus. However, Marasmius androsaceus, was practically inactive upon Staphylococcus cultures when tested years ago. While it is possible that this fungus may be an effective agent against nest pathogens and parasites of subalpine birds in the Northeast, this is not known. Bernd Freymann from the University of Groningen in the Netherlands examined the physical properties of Marasmius rhizomorphs used by Streak-backed Orioles in Central America. The rhizomorphs had significantly higher tensile strength and absorbed less water than alternative available fibers in the area. Alternatively, they may simply provide the best of most easily obtainable material in the subalpine forest for lining nests.

Whether the birds are shaman selecting a fungus for medicinal properties, engineers selecting the best construction materials, or just grabbing what is handy; I marvel at the intricate relationships of nature all woven in the lining of a nest.

Of Common and Latin Names

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Wednesday, July 20th, 2011

As Green Mountain Digital’s in-house naturalist/scientist, I spend an awful lot of time naming things… I am forever keeping up with changes in the Latin (otherwise known as scientific) names of various organisms, and trying to determine which common (or English) names are most widely used – birds have standardized English names, but nothing else does (I can think of one mammal, Puma concolor, with at least 8 common names in reasonably wide use).
The genius of Linnaeus’s system of Latin names is that they uniquely identify every species, whether it be animal, plant, fungus or more unusual still. When a new species is found, the name it is assigned fits it in with its closest relatives. While it may seem intimidating, the system is not, in fact, all that difficult to understand. It is based on levels, all nested within one another. Perhaps the easiest way to explain it is to trace us through our family tree…

Kingdom – Anamalia – animals (anything composed of multiple cells that actively seeks food, as opposed to obtaining nutrients from the sun or from decay). This is a huge group, which we share with everything from lobsters to sea anemones, mosquitoes to octopi

Phylum – Chordata (has a notochord or spinal cord) and subphylum Vertebrata (has a backbone) – Everything from fish to fowl, this group contains most things that people immediately think of as “animals” (fish, amphibians, reptiles, birds, mammals). There are a few odd creatures (sea squirts and relatives) that are chordates, but not vertebrates, but, for the most part, you can think of these creatures as things with backbones, most of which have recognizable faces.

Class: Mammalia (nurses its young, has hair – even the apparently hairless whales have a little bit of hair, especially when young). All the mammals from whales to wombats. Many of these creatures are as familiar as dogs or cats, while others are as exotic as anteaters or armadillos, but they’re all clearly more closely related to us than any fish, bird, reptile or amphibian.

Order: Primates (monkeys, apes and people, along with a few more primitive groups like lemurs). These animals all clearly look and act fairly human – they have hands, they tend to live in bands or groups, and most of them communicate in sophisticated ways.

Family: Hominidae (the great apes, including people). Now, we are in the group of our closest relatives – these are all large, highly intelligent, tailless apes that share almost all of their DNA. They all take care of their young for years, while teaching them complex skills they’ll need to know to live in a complex society. Next time you’re at the zoo, watch a gorilla or a chimp, and try to understand their facial expressions and gestures. It’s not hard – their gestures are ours…

Genus Homo (people) and species Homo sapiens (modern humans). No other member of our genus survives, but, from what we know from fossils, our extinct relatives at the genus level were pretty much human.

The levels of names speak directly to levels of evolutionary relatedness. Two organisms that share a genus are more closely related than two that share a family, and so on through the higher levels. For any given species, it shared a common ancestor more recently with other species it shares more of its names with. As an example, the common ancestor of humans and chimpanzees lived about 6 million years ago, while the common ancestor of all mammals probably lived closer to ~100 million years ago.
To avoid a seven-name tongue twister, scientists generally refer to species by the last two levels of their name (if you’re reading this, you’re a member of Homo sapiens). Each genus name is unique throughout life – our genus Homo in the primates is the only genus named Homo allowed to exist anywhere, and because of this, a two-part name uniquely identifies a single species. The higher five levels put the species in context in the evolutionary tree.
The English (or other non-Latin) names are given by people who are not scientists (again, with the exception of birds, where various scientific societies including the American Ornithologists’ Union have standardized names in a variety of languages), and have one advantage, and several disadvantages, compared to the Latin names. The advantage is that the common names may be easier to remember, not being in Latin. The most important disadvantage is that a common name may not always refer to the same thing. Perhaps the worst example is “dolphin”, which refers to a large number of closely related mammals, but also to one fish that has nothing to do with the mammals, and what is called an “elk,” in Europe is a “moose” in North America (despite the fact that there are also “elk” in North America, which are different. Common names are also often not specific (“skunk” and “squirrel” both refer to a range of species) and there are very often multiple common names for the same species, even one language (to say nothing of the range of common names for the same creature in different languages). Because of all of these disadvantages, common names also don’t tell us anything about evolution – a “dolphin” (mammal) is very closely related to a “killer whale”, which is a large dolphin, and only loosely a whale, but neither one is related in any meaningful way to a “dolphin” (fish). There is very little porpoise in trying to sort these critters out by common name (it’s much easier to remember that the dolphinish mammals are all in the same family, the Delphinidae)
Next time, I’ll delve further into how scientific names came to be, the rules for their assignment, and what happens when a bunch of taxonomists (practitioners of the specific branch of science that deals with the naming and classification of living things) get into an intellectual boxing match.

Birding Tip Series #8: Sort the Oddity from the Flock

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Friday, June 3rd, 2011

Sort the oddity from the flock. Uncommon or out-of range birds will often join a flock of common, but closely related species. Large, mixed-species flocks of waterfowl, gulls or shorebirds are good places to look . Here in Vermont, winter aggregations of birds by the edge of ice on Lake Champlain often contain a rarity or two. Several years ago, I was sorting through a raft of ducks that included quite a few Common Goldeneye (expected on the lake in the winter), but, upon closer inspection, one of the “Common Goldeneye” proved to be a severely out-of-range Barrow’s Goldeneye. Looking at eBird data for Vermont, that’s how Barrow’s is reported – one or a few at a time, in winter, probably mixed in with a flock of other ducks. In a similar situation, an aggregation of a few hundred (mostly ring-billed) gulls on the lake proved to contain single individuals of both Glaucous and Iceland Gulls – both rare in Vermont.

Another trick is to watch eBird, birding lists and other sources for reports of a species you’d like to see – even if it’s nowhere near you. Some species appear out of their accustomed range in irruptions, significant numbers of birds that leave their accustomed range in the same year, probably for reasons of weather or prey density. Both Snowy and Great Gray Owls are known for this behavior. Snowy Owls are rare most places south of the US-Canadian border, except in the far upper Midwest. However, in an irruptive year, numerous birds can be seen as far south as Pennsylvania, and isolated specimens are found even farther south. If you hear of Snowy Owls south of their usual haunts in some places, it’s a fair chance that an irruption is going on, and one may show up closer to you.