A Fascination for Filberts

The flowers of late winter and early spring occupy places in our hearts well out of proportion to their size.

~Gertrude S. Wister

It is one of those plants I had seen a few times in the wild, but didn’t know much about, other than the nuts are quite tasty – small, but good. I am speaking of American hazelnut, Corylus americana, a native shrub of Eastern North America. There are a couple of patches of it along the Piedmont Nature Trail at work, so I have a chance now to watch it across the seasons. Even though it tends to form a dense clump of many-branched stems, it is easy to overlook. But, as with most plants, if you stop and look closely, it has some fascinating features.

American hazelnut male flower catkins - Corylus americana

Staminate flowers of American hazelnut (click photos to enlarge)

Male flowers (staminate) occur in the form of catkins. Immature male flowers appear on catkins in the fall and persist through the winter. A couple of weeks ago, I noticed they had elongated, and just last week, started to bloom.

American hazelnut female flower with finger for scale 1 - Corylu

The tiny female flowers are easy to miss (my fingertip for scale)

Last year was the first time I had tried to see the tiny pistillate (female) flowers, but I missed them. I have been checking one of the shrub clumps the past couple of weeks and, last Thursday, found a few of the bright red specks on the bare twigs. I think they are only open for a short period (though I will continue to check and confirm this) and are wind-pollinated.

American hazelnut female flower - Corylus americana

Small, but beautiful

You really have to be right next to the shrub in order to see them. If successfully pollinated, they begin to form one of the more unusual fruiting structures I have seen.

Hazelnut

Developing nuts have a green husk (photo from last July)

The genus name comes from the Greek word korylos, meaning a helmet, in reference to the husk on the nut.

American hazelnut

Mature nuts inside the husk (photo from October last year)

The nuts mature in fall and are an important food source for a variety of wildlife from chipmunks and squirrels to blue jays (and a tasty treat for humans as well). The other common name, filbert, may have a couple of origins according to resources I found online. Some speculate the name originated from “full beard,” which refers to the husk (or “beard”) that entirely covers the nut in some varieties. The German word for “full beard” is vollbart. Others believe the name was derived from St. Philibert, a French monk. The feast day honoring him is in late August, when the first filberts in England begin to ripen. A related species, Corylus avellana, is the official state nut of Oregon, which produces 99% of the U.S. crop of commercially raised hazelnuts.

 

Trending Now…Spring

No matter how long the winter, spring is sure to follow.

~Proverb from Guinea

It has been a busy couple of weeks, both at the office, and in the Garden outside. Temperatures have swung widely – 60+ degrees a couple of days ago, a nice fire in the fireplace last night, a pretty typical February in North Carolina. But the natural world has its own schedule, its own to-do list. It starts start slowly, and then erupts – it is the arrival of spring. One of the first signs is an auditory one. On one of the warm mornings last week, I noticed birds starting to sing (especially the Northern cardinals, Carolina wrens, and Eastern bluebirds).

Early saxifrage

Early saxifrage in bloom at the NC Botanical Garden (click photos to enlarge)

The first wildflowers of the season make a quieter appearance. Early saxifrage, Micranthes virginiensis, is easy to miss when walking the paths at the Garden, my mind full of things to check off my to-do list. Luckily, someone alerted me to the first flowers, but I still had to look hard to find them. The generic name means small flower. an appropriate name for a a plant with tiny white flowers less than 1/2 inch across. Ironically, the common name, saxifrage, bestows a more powerful status to these tiny plants. It means stone breaker. Many species of saxifrage are plants of rock outcrops, with the tiny plants often nestled in soil deposits of the cracks and crevices of boulders. People once believed these plants to be responsible for the splits in the rocks where they grew.

spotted salamander egg mass in turtle pond

The first spotted salamander egg masses of the season

Some early spring amphibians are also on the move as the days lengthen. The first spotted salamander egg masses appeared in the pools at the Garden and in my home woods last week. Not a huge run of salamanders as yet, but a sure sign that warmer weather is on the way.

Upland chorus frogs in amplexus

Upland chorus frogs in amplexus

While salamanders and saxifrage can appear without fanfare, the frogs of spring can’t be missed. Last week, we heard the first trills of our earliest frog breeder, the upland chorus frog. Instead of the vernal pool, their favorite dating hot spot last year, they were calling from the artificial “stream” at the back of the herb garden. This species is normally quite shy, and will quickly cease calling as you approach their breeding habitat, disappearing beneath the leaf litter or vegetation in the shallows. But at this location, the water is contained within concrete stream banks with little leaf debris, making it harder for these cryptic callers to vanish. You can usually locate one by a slight ripple in the water when they duck under the surface. Indeed, they all quit calling as I walked over, so I scanned the water’s edge, and found a pair in amplexus (the mating position of frogs and toads, in which the male clasps the female about the back and fertilizes the eggs externally as she deposits them). Unfortunately, I only had my macro lens with me, but I eased closer anyway, hoping to get at least one image. To my surprise, I was able to creep up, kneel down and get a close-up portrait without disturbing them The next evening I could hear more calling as I walked to my car. Then, two nights ago, the first spring peepers of the season were calling in the vernal pool in the woods next to the parking lot. It is coming…the eternal march of the seasons is quickening its pace. Get ready, the great greening of the landscape is not far off.

Special Place, Special Season

Yellowstone in the summer changed my life and teaching direction.  Revisiting in the winter was like going back to an old friend’s house when all the ‘guests’ have gone home and you get to sit in the den and have long quiet conversations with the residents.

~Mike Leonard, an educator that attended both a summer and a winter field experience in Yellowstone with the museum

I had hoped to go to Pungo yesterday, but the weather had other plans for me. A day trip with all day rain just didn’t seem the thing to do. So, I sat home, did chores, and wished I was someplace else – with Melissa. She is leading a museum trip to our other special place – Yellowstone. Winter is probably my favorite season out there – so quiet, a living Christmas card, and the wildlife spotting is much easier against the snow.  And so few people, relative to summer, it’s like having your own private park at times. She has sent a few notes about what they are seeing, and, today, the group heads to my favorite place – Lamar Valley. She said it has snowed every day. Not ideal conditions, since the landscape can seem so vast and sparkling when the sun is out, but not a bad way to spend your days – the softened sounds, the way the world seems to embrace you when it snows, everything (you, the wildlife, the scenery) all draped in a cloak of ever-changing white. And, she has discovered a new favorite thing – cross-country skiing. Guess I had better start getting in shape and practicing my balance for our next visit. As I sat reminiscing of past trips, I decided to share some images from our previous winter adventures to this special place in its special season.

Ice-covered tree in thermal basin

Sunlight catches a lone, ice-covered snag at Mammoth Terraces (click photos to enlarge)

sunrise through mist at Canary spring

Sunrise at Canary Springs at Mammoth Terraces

Grand Canyon of the Yellowstone

Grand Canyon of the Yellowstone

Lodgepole struggles

Struggling to stay above the snow

Patterns 2

A weathered tree trunk

Patterns 1

Edge of ice on the Yellowstone River

Melissa in deep snow at Canyon

Melissa in deep snow at Canyon on a previous trip

Hayden Valley scenic

Hayden Valley on a gray, snowy day

Hayden Valley

The majestic landscape of Hayden Valley

Coyote along Madison River

A coyote and shadow along the Madison River

Bison repetition

Bison patterns

Bull elk

Bull elk in Lamar Valley

Pine Marten in tree trunk

Pine Martin in Silver Gate

Moose valley

Moose in Silver Gate

Wolf pack in snow

The once-dominant Druid Peak pack in Lamar Valley

Bison plow

Bison snow plow

Magic mist YNP

A low fog hangs in Lamar Valley, highlighting a lone Cottonwood tree along the Lamar River.

Sunset

The incredible winter sky in Lamar Valley

 

Feeling Alive

Go where you feel most alive.

~Author unknown

I have been missing my usual winter routine of several trips down east. Schedules have been busy, and this thing called work has a way of occupying a lot of your time! So, last week we decided to make a day-trip to my favorite spots in North Carolina – Pocosin Lakes and Mattamuskeet National Wildlife Refuges. I wrote about one of the highlights in a previous blog – the epic battle between heron and fish. This post covers the rest of that amazing day, starting with a rendezvous with our friend in Raleigh at 6:45 a.m. (admittedly, a rather leisurely hour for such a trip).

Swans on ice

Tundra swans on ice (click photos to enlarge)

We arrived at the Pungo Unit a little after 9. The skies were gray, the wind whipping, temperatures below freezing – a Pungo kind of day. This is the reason I often tell people to dress as if “you will be the coldest you have ever been”. To our surprise, the only birds in the fields behind the maintenance compound were a ton of American robins. Friends had reported that large flock of snow geese had been feeding there in recent days, and it was the time of day when they are usually in the fields for breakfast. We drove on, spotting a couple of uncooperative river otter in a canal. Try as we might, we only managed quick glimpses before they totally disappeared. A quick stop at the blustery observation platform confirmed that the waterfowl know not to be out in the open on such a windy day. All we could see were some thin white lines of swans on the far shore where the forested shoreline provides them with some protection from the north wind.

sandhill cranes

Sandhill cranes on the refuge!

On to Marsh A, one of the managed wetland areas for waterfowl, and a favorite place of both swans and swan-watchers. Indeed, there were a few thousand tundra swans milling about, some, on the fringes of the flock, walking on ice. A quick glass of the area revealed a bonus – three sandhill cranes! They were reported earlier in the season, but we had missed them on the Christmas Bird Count. I have seen this species here sporadically over the years, usually just as a fly-over. but these three were hunkered down in the marsh, no doubt wondering why they had not opted for a warmer habitat. We then saw a giant flock of snow geese flying into the lake from the north. Had they been feeding in the fields along “Bear Road”? We drove over, hoping to see some stragglers and were greeted by a few hundred snow geese out in the corn. We encountered some other friends from Raleigh, shared a few stories, and then headed over to Mattamuskeet for the middle part of the day. We spent a lot of the time with the aforementioned heron, but also saw thousands of ducks (especially northern pintails), another disappearing otter, and a dancing night heron.

Black-crowned night heron shimmy

Night heron shimmy

Black-crowned night heron shimmy 1

Shaking it

An adult black-crowned night heron was on one of the usual pilings in the pool near the entrance to Mattamuskeet, so we stopped and walked over to admire. It was striking their usual stoic pose, when, all of a sudden, it went through a series of gyrations that would make any dance contestant proud. When it settled back down, it did a quick poop (lighten the load) and flew off.

After spending a couple of hours at Mattamuskeet, we headed back to Pungo for what we hoped would be a grand evening show. The walk down Bear Road quickly showed why I dubbed it thus years ago, before real road name signs went up – five bears came out across the field to feed. After watching them mill about and horse around (a couple of young ones were wrestling), we headed into the woods. Melissa and I both commented that there isn’t as much fresh bear sign in these woods this winter – there is some, but not the totally worn down “bear living rooms” we have seen in the past. Suddenly, our friend said, “Look, a tiny owl”!

Eastern screech owl out on branch

Eastern screech owl out on a limb

I had been checking out every snag as we walked, so I naturally looked at the dead top of the tree where she was pointing. I couldn’t see it. “Right there”, she exclaimed. I followed her outstretched hand, and, to my surprise, there is a screech owl sitting out in the open on a branch several feet away from the trunk. The little guy barely moved its head to watch us as we slowly maneuvered, trying not to scare it. The fading sunlight would move on and off the owl, highlighting its beautiful rufous plumage.

Screech owl in wood duck box close up

Gray morph Eastern screech owl from 2016

In a post from a very “owly” day a couple of years ago, I shared photos of another Eastern screech owl from the Pungo Unit. That one was a gray morph using a wood duck box as a nest site. Eastern screech owls come in two primary color morphs in our state – red (or rufous) and gray (there is a third, a brown morph, in the far south). That doesn’t mean they can change color (they remain whichever color they are their entire life), it simply means there are two primary colors seen in this species. It turns out that the red color morph is more common in southern parts of the range, while the gray is predominant in colder regions. Plumage color appears to be correlated with thermal adaptation. One ornithologist writing about the color morphs summarized findings that showed that gray birds survive colder temperatures better than red birds, which may account for their differential distribution.

Eastern Screech owl

That look that only a screech owl can give

After observing the owl (and it, half open-eyed, observing us) for several minutes, we walked on, hoping it would not fall prey to any of the numerous winged predators that hunt these woods (great horned owls, red-tailed hawks, Cooper’s hawks, etc.). About that time, flocks of snow geese started to fly overhead and began circling the fields along Bear Road. We  headed out into the open, hoping they would land. As we watched (and wondered about the energy budget of snow goose behavior), something else caught my eye down the road.

Black bear standing

This town isn’t big enough for the two of us

A medium-sized black bear came out into the road and started ambling our way. When I alerted the others, we undoubtedly moved a bit, and the bear stopped in its tracks. He looked our way, then stood up to check us out. A standing bear always reminds me of how much we have in common with bruins. This one also looked as if he was trying out for a role in Gunfight at the Pungo Corral. He dropped and cautiously went back into the woods.

Snow geese swirling above the field at sunset

Snow geese swirling over the corn at sunset

Our attention shifted back to the birds, which were now circling near us in dense, squawking clouds. I never tire of this visual spectacle and the incredible sounds that accompany it.

Buddy Bear

I just want to cross at my usual spot

For the next several minutes, we stood in awe of the scene before us – countless birds swirling nearby, swans flying over our heads back to the lake, and our bear friend tentatively trying to reach his canal crossover spot. The bear may be one I have seen over the past couple of years that we dubbed “buddy bear” (for his tolerance of humans). He kept coming out to the road, looking our way, then retreating back into the woods. He would then ease closer to us, come back out into the road, and repeat the sequence. All the while, thousands of birds circled out in front of us…which way to look? The bear ended up catching our attention again when he came out on the crossover path and headed down the canal bank. We all watched as he swam across, shook off, and scurried into the standing corn. What a privilege to be able to witness all this.

More snow geese arriving

Huge flock of snow geese flying into the field

We started to head back to the car and then saw wave after wave of snow geese flying in from the northeast to join the thousands already landing in the corn. This was like the scenes of a few years ago – thousands of snow geese in the fields along Bear Road at sunset, hundreds of ducks swooping in to join them, bears coming out from several directions, swans calling as they fly in from the north, deer coming out of the woods, and woodcock streaking out into the fields to feed. Then we heard the final actor in this grand play – the haunting call of a great horned owl.

Great horned owl at sunset

A great horned owl at sunset

Melissa soon spotted it in a tree not far from us. It flew to a branch out over Bear Road, silhouetted against the fading orange sky. What a great ending to an amazing day! This place is truly magical. It really is somewhere you go to feel alive, to recharge your spirit, and to rediscover a sense of awe and wonder about our world,  Thank you, U.S. Fish and Wildlife Service, for making this possible. We all need to support these public lands, especially now, so they remain available for us and these amazing natural spectacles.

Species observed at Pocosin Lakes (Pungo Unit) and Mattamuskeet National Wildlife Refuges 1/15/18:

Birds (61 species):

Double-crested Cormorant; Canada Goose; Snow Goose; Ross’s Goose; Tundra Swan; Mallard; Black Duck; Northern Shoveler; Northern Pintail; Ring-necked Duck; Wood Duck; Gadwall; Bufflehead; Ruddy Duck; Hooded Merganser; American Coot; Pied-billed Grebe; Great Blue Heron; Great Egret; Sandhill Crane; Black-crowned Night Heron; Turkey Vulture; Red-tailed Hawk; Bald Eagle; Northern Harrier; American Kestrel; Eastern Screech Owl; Great Horned Owl; Ring-billed Gull; Mourning Dove; Belted Kingfisher; Northern Flicker; Pileated Woodpecker; Red-bellied Woodpecker; Downy Woodpecker; Yellow-bellied Sapsucker; American Woodcock; Killdeer; American Crow; Eastern Phoebe; American Robin; Eastern Bluebird; Northern Mockingbird; Carolina Wren; Winter Wren; White-throated Sparrow; Swamp Sparrow; Savannah Sparrow; Song Sparrow; Tree Swallow; Red-winged Blackbird; Common Grackle; Brown-headed Cowbird; Northern Cardinal; Carolina Chickadee; Tufted Titmouse; European Starling; Orange-crowned Warbler; Yellow-rumped Warbler; Ruby-crowned Kinglet; Golden-crowned Kinglet

Mammals (7 species):

River Otter; Black Bear; Gray Squirrel; White-tailed Deer; Hispid Cotton Rat; Raccoon; Nutria

Winter in the Woods

There is nothing in the world more beautiful than the forest clothed to its very hollows in snow. It is the still ecstasy of nature, wherein every spray, every blade of grass, every spire of reed, every intricacy of twig, is clad with radiance.

~William Sharp

Road out front

Our road during the snow on Wednesday (click photos to enlarge)

The quiet beauty of a winter snow storm…this is one of the true blessings of living in the woods (and of loving cold weather, since you don’t mind getting out in it…in fact, you can’t wait!).

Under the branches close view

The view from beneath a snow-covered branch

I love the winter quiet of a snow storm…and the simple beauty it imparts on everything it touches. The patterns of branches, the trails of woodland creatures, the shapes of trees covered in white…all mesmerizing, magical. This snow lasted all day. Toward the end of the storm we went for a walk in the gray stillness of our woods, and felt lucky to live in such surroundings.

The house in snow

The house the morning after the storm

A brilliant blue sky greeted us the next morning, with a chilly 14 degrees on the thermometer. A walk in the woods seemed the thing to do (after filling the bird feeders, of course).

Road with diamond dust

The road out front with the air glistening with falling ice crystals

What had been a gray sky and a black and white landscape of patterns and shapes was now a glistening white, with the air full of tiny diamonds every time a breeze shook the snow-covered branches.

View through the woods to house

A view of the house through our woods

We walked the property boundary, taking in the scenes of a forest transformed by a sculptor working with powdery white clay.

Wind dust

Snow falling from limbs

Sunburst

Snow burst

The wind started blowing and the tree branches began to shake their white blankets, releasing a snow burst of crystals that sparkled as they fell.

Beech strains

A beech hunched over with its burden of snow

Our woods

Melissa walking through the winter wonderland

We ended the day with a perhaps too late attempt at sledding the big hill just down the road. The sun was already melting the lone tire track down to gravel, making for a few scrapes down the hill. Not as fast as previous snows, but still not bad.

Snow bear

Snow bear

This morning we went out and decided to make some wildlife in the yard. If only we had the time and could get to Pungo and see some real snow bears!

Crow pattern in snow

Snow crow in black and white

The real wildlife, especially the birds, have been very active since the storm. A group of American crows stopped by this morning, no doubt looking for some of the scattered seed. They are wary, so when I walked by the window they all took off, including the one that was brave enough to land in the yard. We checked out the track trail and tried to decipher what had happened. Look at it and decide for yourself before reading further to see if you agree with our conclusion.

I think the crow landed on the left side of the image, leaving a deep imprint of its body when it hit the snow (and a wing tip print on the far left). It then hopped up and turned to the right, leaving some wing tips seen at the top of the image. It took off from a position facing the right edge of the image, leaving two deep footprints and a sweep of its wings on both sides as it leapt off the snow. Let me know if you conclude something else.

 

 

 

Heron Dreams

Go confidently in the direction of your dreams. Live the life you have imagined.

~Henry David Thoreau

We all have dreams, some bigger than others. I dream of experiences, being in wild places, and seeing the spectacles that nature has to offer. I have often wondered if other species dream. Having had dogs much of my life, and watching them as they seem to chase something in their sleep with paws twitching and soft barks, I think they do dream. I’m not sure about other species – whether, for instance, herons dream, but we met one earlier this week that seemed to dream big…really big.

Great blue heron

A stately great blue heron at Mattamuskeet National Wildlife Refuge (click photos to enlarge)

We did a quick day trip on Monday down to Pocosin Lakes and Mattamuskeet National Wildlife Refuges. I just haven’t been able to get away as much as my soul needs, so a day-trip would have to do. A friend from work (who had never been) was able to travel with us so I was hoping for a good show for her sake. After a bitterly cold morning at Pungo (more on the Pungo portion of the trip in the next post), we headed over to Mattamuskeet mid-day to see what we could find. As is often the case, there was a stately great blue heron at the pool near the entrance along Wildlife Drive. But I noticed something different this time…

Great blue heron strikes

The heron strikes

There was something else on the island of grass…

The prize

The prize revealed

A huge fish! A mullet! Even though Mattamuskeet is a freshwater lake, this bird was on a canal outside the lake proper, one that connects via a long (~7 mile) system of canals out to Pamlico Sound, where striped mullet are very common. My apologies for posting so many images of this epic struggle, but I have always wanted to see a heron swallow a huge fish, and here it was, out in the open, a “dream” come true.

A beakfull

A lot to get your beak around

We watched as the bird tried to grab the still-flopping fish. It was a lot to get your beak around.

Getting a drink

The heron took frequent sips of water

The heron would work at grabbing the fish, then drop it, and almost every time dip the tip of its bill in the water. Was it taking a drink, removing slime, washing out a bad taste…who knows?

Stabbing the fish

A few sharp jabs with the beak eventually subdued the mullet

The heron used its stiletto beak in a series of quick jabs to try to subdue the mullet.

How do I get this thing off

Now…how do I get this thing off my beak?

It sometimes took a few shakes to get the fish off. After several bouts of spearing the fish, the mullet stopped moving.

Displacement behavior?

Displacement behavior?

Curiously, in between efforts to swallow the fish, the heron would every now and then grab some roots, sticks, and shoots of vegetation on the island. Is this some sort of displacement behavior? Taking out its frustrations on plants?

Almost there

A lot to lift

Not only was this fish a challenge in terms of its girth, it was a heavy lift for the heron. A typical adult great blue heron weighs about 5 pounds. Their upper bill is about 5+ inches in length. Looking at this photo, I estimate this fish to be about 14 inches in length (compare bill length to fish length). I found an online length-weight conversion estimator for fishes in Texas and used that to estimate the weight of this fish at about 1 pound – 1/5 the weight of the bird. So, that’s like me trying to gulp down a 40 pound hamburger!

eye to eye

Eye to eye

This photo “caught my eye”…the juxtaposition of the eye of the predator and the prey, now resigned to its fate. Our friend, Janna, suggested this caption…””that feeling you have when you realize who you have been trying to kiss”.

maybe if I wet it

Maybe if I get it wet…

We watched the struggle for about 20 minutes and reluctantly decided to head off to see some other areas of the refuge, wondering if the heron would ever be successful. We came back about an hour and a half later, and the heron was still at it. Another couple of photographers had stopped, but the heron was paying us no mind. It had eyes only for the mullet. While we were gone, the heron seemed to have figured out a better strategy for lifting the fish, and came oh-so-close to swallowing it a couple of times.

almost lost it

Almost lost it

But it almost lost it into the water at one point, managing a quick grab to pull it back onshore.

stand off

Pondering your dreams

The heron was starting to tire. It took longer breaks between feeding attempts. We watched another 20 minutes. The proud bird twice turned its back (maybe hoping we woudn’t see?) and caught tiny fish and gulped them down.

a quick snack

Settling for less, or just grabbing a quick snack?

It was getting late. The heron had been at this for at least two hours. We had spent almost 45 minutes watching the struggle, camera shutters firing away (I’m almost embarrassed to admit I took 892 photos of this battle), and there was no end in sight. It was time to leave and head for Pungo for what we hoped would be a great sunset show.

Really really big

Dream big

I hated to leave without knowing whether the heron realized its dream. But I guess I had achieved mine, even though I didn’t witness a successful end to the story. Perhaps the important thing, for both heron and human, is to dream in the first place.

All our dreams can come true, if we have the courage to pursue them.

~Walt Disney

 

It’s Nasty Out There

The simplicity of winter has a deep moral. The return of nature, after such a career of splendor and prodigality, to habits so simple and austere, is not lost either upon the head or the heart. It is the philosopher coming back from the banquet and the wine to a cup of water and a crust of bread.

~John Burroughs, 1866

After a strange couple of days of unseasonably warm temperatures, winter has returned. A reminder that I am one of those odd folk that enjoys cold weather. In fact, the colder the temperatures, the better. I remember fondly the coldest day I ever experienced – a frigid -33 degrees Fahrenheit morning in my favorite place, Yellowstone. But it was spectacular! The air was clear and crisp, no wind, and the world was twinkling with tiny crystals of ice, called diamond dust, suspended in the air. Magical, indeed. Back here in the Piedmont of North Carolina, we have had some unusually cold temperatures this winter, dipping down to 9 degrees a week or so ago, and supposedly headed that way again this week. It makes for very active bird feeding stations, brisk walks under clear blue skies, and a better-than-usual seat bu a roaring fire as you read a good book. It has also has an interesting impact on one of my favorite plants – rhododendron.

Rhododendron leaves at 32 degrees

Rhododendron leaves at 32 degrees (click photos to enlarge)

It turns out that rhododendron leaves can be used as a biological thermometer. This is a phenomenon that is well-known, though the cause is not so well understood. I have made a resolution to get outside at least once a day at work, an easy thing to convince myself to do since I work in such a beautiful setting. Our mountain habitat has several large rhododendron shrubs and I noticed the leaves had started to droop as the weather got colder. I remember seeing them tightly curled in the true mountains on a few freezing occasions, so, with the predicted cold spell last week, I decided to photograph the tip of a single rhododendron branch at different temperatures. The first photo shows the branch at 32 degrees, the temperature at which the leaves are known to start to droop.

Rhododendron leaves curled at 26 degrees 1

Rhododendron leaves at 26 degrees

As it got colder, the leaves drooped even more, and began to curl.

Rhododendron leaves at 15 degrees

Rhododendron leaves at 15 degrees

On the coldest morning we had recently, the leaves were tightly curled, resembling green cigars. This curling is called thermonasty. That’s right, thermonasty. This odd-sounding name comes from the two root words- thermo (temperature), and nastic, which are non-directional plant movements that occur in response to environmental stimuli, in this case, temperature. The nastic movements of rhododendron leaves follow a fairly predictable pattern – when temperatures fall below freezing, the leaves start to droop but remain flat. At 25 degrees F the leaves start to curl and by 20 degrees F they are as tightly curled as they can get. Many people believe the curling is to protect the leaves from desiccation by shielding the stomata (the openings in the bottom of the leaf which allow the leaf to “breathe” or transpire). But recent research shows that the stomata are already closed when it is cold, and one researcher suggests a different theory for the change in leaf position.

According to Dr. Erik Nilsen (Why Do Rhododendron Leaves Curl?), the stomata are always closed in cold weather — they have nothing to do with drooping or curling of the leaf. The drooping is more likely a way to protect from the thawing that can occur on a sunny winter day. When the leaf is held in its normal flat and horizontal position, it will absorb sunlight and heat up and thaw, then could refreeze at night. Experiments have shown that flat leaves thaw faster than curled leaves. This is because a curled leaf exposes far less surface area to the sun than does a flat one. By thawing more slowly, cured leaves are better able to avoid the damaging effects of daily freeze-thaw cycles which can rupture cell membranes and eventually kill the leaf. By drooping and curling the leaf may be protecting itself from too much sun — opposite of what you might think it would try to do.

Rhododendron leaves at 58 degrees

Rhododendron leaves at 58 degrees following the cold spell

My observations last week agree with the overall temperature response of these evergreen leaves. The thing I don’t yet have a good feel for is how quickly these changes occur. I need to watch the leaves this coming week to see how rapidly the rhodo-thermometer can track temperature changes. Always something to ponder and discover at the Garden.

Haw-inspiring Hike

One of the reasons there are so many terms for conditions of ice is that the mariners observing it were often trapped in it, and had nothing to do except look at it.

― Alec Wilkinson

I must give credit to our friend, Bill, for the title of this post (hope he doesn’t mind). He is a poet and a wordsmith and used this phrase in an email about a hike along the Haw River we took this past Sunday with his godsons, Turner and Charlie. We hiked along the Lower Haw State Natural Area from the Hwy 64 bridge over the Haw up to our neighborhood, a distance of a little over 2 miles. Temperatures were in the 20’s when we started, but mostly sunny, and the air was still. The river, always special, was especially beautiful, with a fringe of ice along her shores that often extended far across her rocky breadth.  From the outset, the river provided visual delights and mysteries.

Mystery trails on ice

Unusual “trail” on the river ice (click photos to enlarge)

Just a short way upriver from the bridge, we started seeing some winding “trails” on the ice, looking as if someone had pulled a tiny sled in an erratic route across semi-frozen ice.

Beaver trail through ice

An open channel helped solve the mystery

Just beyond those first mysterious ice trails, we saw a partially open channel that had a similar irregular path. This one led over to an island in the river where we could see evidence of beaver chewed sticks piled along the bank. Mystery solved! The initial trails were frozen over beaver channels.

beaver chew marks

Beaver teeth marks on a sycamore log

beaver chew

There is abundant beaver sign all along the trail

From that point on, we encountered many active beaver chewed trees, some quite large. Years ago, when I was doing programs for state parks, I remember reading some facts about beavers – the largest one ever trapped weighed about 105 pounds (although my current reference on mammals says the largest on record was 86 pounds – still a huge rodent).  Average weight for an adult beaver is around 50-60 pounds. I once saw a photo of the purported record tree felled by a beaver – a tulip polar a little over 5 feet in diameter! None of the trees along the trail approached that, although the busy beavers have been gnawing on some pretty large specimens. Beavers are somewhat generalist vegetative feeders in warm months, but this time of year they feed almost exclusively on the inner bark of tree trunks and branches. Other wildlife we saw included a variety of birds – great blue herons looking for open water along the river, and a variety of songbirds trying to find something to eat along the trail. American holly berries seemed a favorite and we saw several hermit thrushes and American robins feeding in some of the large trees. Mixed feeding flocks of other species including Carolina chickadees, tufted titmice, woodpeckers (red-bellied, downy, and pileated and a yellow-bellied sapsucker), some feisty yellow-rumped warblers, and a few ruby-crowned kinglets. A beautiful red-shouldered hawk, a blue jay, and some of its cousin American crows, rounded out our bird sightings.

river rock surrounded by ice

An exposed rock in a sea of ice

As I have said before, ice fascinates me. Life as we know it depends on the unusual characteristics of water and one of these is that, unlike most other chemical compounds, when it gets cold enough to turn into a solid, the solid floats (the solids sink in most cases).

 

crystals in ice

Needles of ice in a patch along the shoreline

I remember a discussion I had about ice with a museum co-worker back in 2006.  I was lucky enough to get chosen as part of an international science and education team to spend a month in the Arctic aboard a Russian ice-breaker (no collusion, I swear). She asked me if I thought I would get bored spending a whole month out on the ice, with nothing but an expanse of white to view. I had said no, and was justified when I realized the incredible variety of forms that ice can take – all beautiful. The ice along the Haw was no different, and showed us its many faces as we gazed upon it from the bank – all magical.

beech leaf on ice

Beech leaf frozen in the surface of thick ice

ice shelf

A small ice shelf next to a riffle area

ice shelf 1

Ice lace edging along the rocky shore next to flowing water

ice waves

Intricate patterns of ice on the surface of an eddy in the river

Frozen haw

The mix of ice and open water along the river

The weather is warming, and ice is melting, but memories of a cold hike along the Haw, with good companions, will stay with us for quite some time. I spoke to our group of my appreciation for those that fought to set this corridor aside, and to the dedicated folks, like those of the Haw River Assembly, that continue to work toward its preservation. Haw-inspiring indeed.

 

Cold Snap

Winter’s barren landscapes chide us to give our attention to the splendor of things nearby.  When the air is thick and the sky overcast, we need not travel so far to have high expectations, for in her nakedness she teaches us to be less distracted but instead to be more connected, more aware.

~Henry David Thoreau

Here in the Piedmont, we are accustomed to having our hopes for snow dashed at the last minute. Places an hour away usually get the white stuff and we get nothing, or just a couple of flakes. Last week was different. They had predicted a trace for our area, but we managed a full 2.5 inches! Not huge by any stretch, but this snow is “real snow” – dry powdery snow that you can sweep off the walkway instead of shovel. And it has been so cold (temperatures at night in the lower teens) that it is still white, a full four days after the snowfall. Unlike most of the people I know, I like cold weather. It is physically invigorating, gives more reason to chop wood for the fireplace, and, on a sunny day, brings a crispness to your surroundings that help you see and appreciate details in the landscape. I notice this about winter skies, and a winter walk in the woods is no different. Here are a few of those details from a hike in the neighborhood this week.

Leaves frozen in creek

Leaves frozen in creek water (click photos to enlarge)

I am fascinated by ice. We walked down to the neighborhood pond to check for ice, following the path of an intermittent stream that runs behind our house. Close to the pond, the creek has permanent water, and we had to look closely to see these leaves were actually suspended in extremely clear ice.

Hoar frost in mud

Needle ice along the muddy shore of the neighborhood pond

Walking along the creek bank at the pond was a noisy stroll, the soil crunching with every step.

Hoar frost columns on chunk of mud that dislodged while walking

Holding a chunk of needle ice in my gloved hand

I turned to look at a duck out on the pond (which was still mostly ice-free that day) and saw my path littered with chunks of ice crystals. This distinctive columnar shape is called needle ice (also known as frost pillars or frost columns). This occurs in porous soils where the ground temperature is above freezing and the air temperature is below. Water from the soil is pulled upward by capillary action. The ice columns tend to push away the soil at the surface and can make for a very noisy walk, with each step throwing chunks of connected ice columns, some a few inches in length.

Sycamore bark - young treeWhite Sycamore bark - young tree

Peely Sycamore bark - young tree

The many faces of young American sycamore trees near the pond

Along the back edge of the pond you walk through a grove of young American sycamores. The variety of bark textures and colors is amazing. Another advantage to the winter woods, a new appreciation for bark.

Tulip poplar in front yard

The large tulip poplar in the front yard

Back on our property (about a mile from the community pond), I pause to admire the unusual bark of a huge tulip poplar tree (Liriodendron tulipifera) in the front yard. This, and a couple of other smaller tulip poplars nearby, have strange bumps and twists in the bark that are particularly noticeable in the golden glow of late afternoon light in winter. I have asked several people, but no one seems to know for sure what causes this.

Tulip poplar in front yard looking up trunk

The unusual bark of our tulip poplar

mouse tracks in snow

Mouse tracks in the snow…

Mouse hole in snow

…disappear into a hole

Of course, tracks in the snow are one of the perks of a winter walk and the property is covered with distinctive shapes and patterns of hopping songbirds, bounding squirrels, a lone coyote trail, small groups of deer, and, surprisingly, only one white-footed mouse. Maybe they are laying low in these cold temperatures. This one trail led across a path and disappeared into a tiny hole under the snow next to a tree trunk.

South ridge at sunset

Our far ridge glowing in the setting sun

With sunset approaching, we decided to walk the path we have through our 14+ acres. It was so quiet in the woods with the sun glowing on the far ridge line of our property.

Large white oak

The largest tree on our property, a huge white oak, lost a large limb this winter

The far property boundary is marked by a nearby giant – a huge white oak that is the largest tree on our land. I like to think it is 250+ years old based on its huge size compared to other trees I had to cut after storm damage. One of those had 126 growth rings, and it was nowhere near the diameter of this behemoth. A huge limb broke out this winter, providing a sheltered hollow that I hope one day will be taken up by one of the resident owls. I can’t help but think that I am not the only creature in these woods fascinated by this giant.

Snow face on tree hollow

One more night of frigid temperatures

While many of my friends look like this old tree hollow when temperatures drop, I find it exhilarating and definitely worth the chill to explore the nearby woods. I encourage you to bundle up, and do the same.

Puffed Up

Nature now, like an athlete, begins to strip herself in earnest for her contest with her great antagonist Winter. In the bare trees and twigs what a display of muscle.

~Henry David Thoreau, 1858

It is not so much muscle I saw the other day on a walk in the Garden, but rather puffiness. I took the camera with me when I went out to feed the birds at our bird blind, then sat for a few minutes to see who was hungry. Turns out, they all were, and soon I was surrounded by a mixed flock, many that looked a bit rounder and more puffed up than usual.

tufted titmouse

A tufted titmouse seems to be wondering when this cold spell will end (click photos to enlarge)

The tufted titmouse above is a prime example. That bird even threw in a somewhat stern countenance as if totally unhappy about the current situation of very cold temperatures. The puffed up appearance is actually one of the more efficient ways that our winter birds manage to survive the bitter cold. Air trapped between its feathers is heated up by a bird’s body. Puffing up (raising their feathers) traps as much air as possible in their feathers. More trapped air means more warmth, with some sources stating the heat retention can increase by as much as 30% when all puffed up.

northern cardinal male

Northern cardinal moving in to feed

And, as any backyard bird watcher knows, bird activity at feeders greatly increases in cold or stormy weather. This week is no exception with many species (including a few, like Eastern bluebirds, that aren’t usually present at our feeders) spending more time at the feeding stations at work. Frequent feeding helps birds maintain their fat reserves which provide insulation and store extra energy used to increase body heat when necessary.

Northern mockingbird with berries

Northern mockingbird surrounded by its winter food supply

On my way out, to the blind, I saw the resident northern mockingbird in the usual spot – a large deciduous holly in the display garden of our courtyard. That bird has stationed itself in one of the two berry-covered hollies most days for the past few months. This is a common strategy for this species – guard your winter food supply from all those upstart berry thieves like bluebirds, robins, and cedar waxwings. As you can see, the strategy seems to be working. Other hollies in the garden are mostly stripped of the berries now.

red-shouldered hawk immature

Juvenile red-shouldered hawk wondering where all the frogs went

Back in the office, I glanced out to see an immature red-shouldered hawk looking intently in the grasses below for any sign of something edible. Since this species prefers a diet of reptiles and amphibians, these cold weeks must be stressful, especially for young and inexperienced birds. I am keeping an eye in hopes of seeing what they might add to their diet when times are tough.

hawk standing on one leg

Standing on one leg is another strategy for staying warm

A closer look at our hawk shows another strategy used by birds to stay warm in winter – standing one leg with the other one tucked up under a blanket of feathers. They will often then switch to give the other leg a turn. In this case, the placement of the foot looked a bit odd at first and resembled a knot coming out of its belly.

wooden owl

The only bird at the Garden that doesn’t seem to mind the cold

There are a couple of other ways birds strive to stay warm – they shiver, although they typically don’t shake like we do. These muscle contractions help maintain their body temperature around 105 degrees (average for most songbirds). If all these adaptations are pushed to the limit on days like we have had lately, then surviving the cold, dark, nights of winter must be extra tough. That’s why many songbirds flock together after dark. Some, like chickadees and kinglets, crowd together in tight groups in protected areas like brush piles, evergreens, or even nest boxes, which helps them to conserve and share body heat.

We can help our feathered friends that don’t migrate to warmer climes by doing a few things in our landscapes:

  • Plant native plants that provide cover and food. North Carolina Audubon has some great suggestions here.
  • Don’t tidy your wildflower beds until later in winter or early spring, leaving seed heads and structure for food and cover.
  • Provide winter water in the form of moving water, a bird bath heater, or regular re-filling with warm water in freezing weather.

Next time you head outside with your puffed up winter jacket, think of how the birds are managing to survive, and how what we do in our yards and gardens can help.