J.R.R. Tolkien provided the ideal words to describe the in-between season in which we’re suspended right now: “… a morning of pale Spring still clinging to Winter’s chill.” Spring is officially here with the Spring Equinox, but mornings in the prairies and forests of the township can still feel as though we’re caught in the last weak grip of winter.
So this week, I thought I’d be on the lookout for sure signs of spring’s arrival and naturally, once I started looking, they were everywhere!
Birds Herald Longer Days with Song and Some Fancy Posturing
Arriving at Draper Twin Lake Park one cold, gray Sunday, my husband and I heard a very loud, clear rendition of the entire spring song of a Northern Cardinal (Cardinalis cardinalis). (Cardinals have a lot of calls. Listen to the second call listed at this Cornell link – that’s the one we heard.) This fellow seemed confident that he could woo the ladies and establish his territory at the same time with his full-throated singing! Look at that beak!
Male American Goldfinches (Spinus tristis) at our feeder are changing out of their modest winter attire into their breeding feathers. In a month or so, they’ll be bright yellow in the hope of interesting a female with an eye for color. Here’s a male on the bottom right perch of our thistle feeder who started changing his wardrobe in March. Perhaps the female on the bottom left perch will be interested? (The other birds are Pine Siskins (Spinus pinus) who will migrate north before long.)
The buzzing trill of the Red-winged Blackbird (Agelaiusphoeniceus), which is accompanied by raising his red shoulder patches, is a common and beloved sign of spring here in Michigan. But last week I saw a male who was taking display to a whole new level. While calling, he also began awkwardly dancing along a branch, keeping his scarlet “epaulets” raised, occasionally fanning his tail, all in the interest of establishing a territory and showing off for some lucky female. What a guy! (Click through the slide show below to see the progression of his dance!)
Other birds establish dominance over other males with creative use of their necks! Below two newly arrived Common Grackles (Quiscalusquiscula) appear to be trying to “out-snoot” each other with their beaks tilted skyward! I think the one on the right is probably the winner here, don’t you? Or else the one the left is an uninterested female. It’s hard to tell.
Mark, a birding friend, told me that the Common Goldeneye (Bucephala clangula) at Stoney Creek Metropark were doing their dramatic neck displays as well. According to Cornell Lab’s All About Birds website, Goldeneyes spend December to April in courtship groups where they form mating pairs by performing a lot of energetic neck movements. The male bends his neck backwards until his head lays on his back and then he snaps it forward, splashing water with his feet at the same time! The female responds by lowering her head and swinging it forward. Pretty dramatic courtship! I wasn’t able to get to the Metropark this week, but a kindly photographer from iNaturalist, who goes by Mike B, allowed us the use of this photo of a male taken near Chicago. These diving ducks are headed to their breeding grounds in northern Canada and Alaska, just south of the Arctic.
Flocks of Birds – Large Ones and Small Ones – Fly Overhead and Forage in Our Parks
The birding group had an exciting Wednesday at Charles Ilsley Park when two huge flocks of Tundra Swans (Cygnus columbianus) flew overhead! Cornell says that these huge, all white swans with black beaks spent the winter on the Atlantic coast and are now headed to the Arctic tundra to build their nests and breed. Aren’t we lucky to be on their flyway?
Another birding friend, Mike Kent, took the photo below, because, wouldn’t you know, that was the day I decided to leave my camera at home!!! Look carefully at Mike’s photo because he caught a fascinating detail. We saw one lone Canada Goose (Brantacanadensis) traveling along with this huge flock of swans! You can just see its dark body in the upper left of the photo, third bird down. Hope this adventurous goose doesn’t plan to go all the way to the Arctic with its new-found friends!
That Wednesday was great for seeing big birds at Ilsley Park. Mike also caught for us a nice photo of a family of Sandhill Cranes (Antigone canadensis) who settled at the bottom of a slope to rest and feed. The larger, darker birds to the right are probably the adults, while the two smaller gray ones on the left are probably last year’s young ones.
At Bear Creek Nature Park, smaller flocks were chatting in trees and foraging along the paths. A noisy group of American Robins (Turdus migratorius) were snatching berries from a tree infested with invasive Oriental Bittersweet (Celastrus orbiculatus). Some robins overwinter here and some migrate to southern Ohio and Kentucky. Some move back and forth all winter long. Though these non-native berries attract them during the winter, they unfortunately don’t provide much nutrition for the birds since thawing and freezing makes them very sugary. So migrating, in their case, might be a better choice!
On a path from the playground to the Walnut Lane at Bear Creek Nature Park, I saw my first flock of Song Sparrows (Melospiza melodia). I love to listen to these tuneful birds in the spring, but have never before seen a flock of them in one area, as I did this week. They were “chicken-scratching” by scooting backwards with their feet in a ferocious attempt to get at some food beneath the surface -probably small seeds or insect eggs. The flock was so busy that the ground along the trail looked torn as they scraped their way down to the frozen surface, looking for food.
Buds are Swelling from Bare Branches – a Welcome Sign of Spring’s Arrival
Every year as spring approaches, I watch the Silver Maple (Acersaccharinum) to the right of the deck at Bear Creek’s Center Pond. It’s always one of the first trees to signal spring for me, its robust, red buds hanging gracefully from drooping branches over the water.
A small Shagbark Hickory (Carya ovata) near the pond has just barely thrust its leaf bud from the woody protection it had during the winter (left). In May, it will be a huge glorious bud (center), and in June, the green leaves will unfold into the sunlight (right). (Click photos to enlarge; hover cursor for captions.)
Yes, It’s Muddy…but It’s S’posed to Be, Right?
It’s the end of March. Most of the ice on the surface is gone (at least for the moment!), but the ground is still frozen beneath. So rain and melting snow have nowhere to go. That makes for muddy shoes, smeared pant legs and cars decorated in various shades of brown. But hey, those signs announce that full-fledged, glorious spring is almost here! Birds are beginning to sing, dance, do a bit of neck gymnastics, don spring colors and wing their way north overhead in huge numbers. And trees are slowly waking from their roots, sending sugary sap up through their vascular systems, ripening their leaves for another summer of sun-gathering. All of nature, including us humans, have survived a very challenging, deep-freeze winter. Now’s the time to celebrate just being alive on a mudluscious walk in the pale sunshine of an early spring morning.
Like many of you, I suspect, I have always had great admiration and even a special affection for trees. As a child in a sometimes chaotic family, I found peace and solace sitting high in a hundred year old sugar maple on Lake George Road with my book and a snack. But more recently, writing this blog has brought me time and again to startling new revelations about these giants of the plant world. So I thought in these lingering winter-ish days of early spring, we might take a few minutes to marvel at trees – and plants in general.
Cool Things about Trees that I’ve Explored Before
In February of 2017, I shared what I’d learned about the recent scientific work that shows how endless miles of mycorrhizal fungi create a “wood-wide web” beneath forests. Trees benefit from allowing these underground thread-like fungi to pierce or wrap around their roots because the fungi provide them with more nutrients and water than is available through their roots. In fact, the web created by these fungi can reach a soil area up to 700 times larger than a plant’s roots can reach on their own – a huge benefit! Trees in turn feed these fungi the sugars created by photosynthesis that the fungi need to grow – symbiotic teamwork that benefits both species. Check out this short video for a visual representation of how this relationship takes place. Trees also use this web to feed other trees, including, it is now reported, their own saplings and other trees.
In March of 2017, I explored the many similarities between humans and trees. For example, I marveled that oak, hickory and other trees in a forest somehow coordinate their production of nuts by periodically but irregularly creating huge amounts of them. We call these abundant years “mast years.” One of the hypotheses on mast years is that predators like deer, blue jays, squirrels and such can only eat and store so many nuts in any season. So during mast years when trees produce an abundance, many more nuts are left to start young trees either through being left behind or being “planted” and forgotten by the animals that store them. Tree teamwork! Scientists have several hypotheses about this phenomenon, but have not yet reached a consensus on why and how mast years occur.
Some New Insights on the Ancient History of Trees
Just lately, though, I’ve been exploring some other remarkable aspects of trees, their fungal partners beneath the soil and their relationship with us, the human population. I began by thinking about the evolution of plants in general. According to Scientific American, “The world’s lush profusion of photosynthesizers …owe their existence to a tiny alga eons ago that swallowed a cyanobacteria and turned it into an internal solar power plant.” Voilà, about one billion years ago, algae on the ocean surface could use sunlight and nutrients from the water to grow through photosynthesis. And in the process, they released unneeded oxygen, though not yet enough to change the earth’s atmosphere significantly. Oxygen was still a rare commodity. (Click on photos to enlarge; hover cursor for captions.)
According to Wikipedia’s Evolutionary History of Plants, the first land plants may have evolved about 850 million years ago at the edge of those ancient bodies of water. These early mat-forming plants had no vascular system or roots so it was impossible for them to find a reliable source of water and nutrients on land which was still solid rock. Soil, after all, was created later by decaying plants. So they were either restricted to moist settings as mosses are today, until they developed a waterproof outer layer (or “cuticle”) and other adaptations that allowed them to survive until water was available again.
According to Plantae, a website founded by the American Society of Plant Biologists, primitive forms of those mycorrhizal fungi may have helped out by attaching themselves to plants and bringing them the inorganic nutrients and water they needed to photosynthesize in their rocky new environment. So the relationship between plants of all kinds and these weblike fungi goes back hundreds of millions of years! Perhaps our very existence, then, is owed to mycorrhizal fungi! Hooray for those ancient mushrooms!
The highly toxic mushrooms on the left below are the reproductive fruiting bodies of Deadly Webcap (Cortinarius rubellus), one of the thousands of species of mycorrhizal fungi worldwide, some toxic and some not. On the right, is a photo of one of the fungi from the genus Cortinarius with structural filaments, or hyphae, beginning to grow out from the roots of a beech or oak to seek out nutrients. [The Deadly Webcap photo was shared by iNaturalist photographer, Andrea Aiardi. The photo on the right of the mycorrhizal association between plants roots and fungal hyphae was taken through a microscope and kindly provided by Dr. David Burke of Holden Arboretum in Kirtland, Ohio and is posted with his permission.]
Ancient Plants Living and Dying Made Life Possible for Oxygen-dependent Creatures like Us!
During warm periods, newly developed roots allowed prehistoric plants to take in water and nutrients from the earth, while newly evolved leaves took in carbon dioxide from the air through their stomata, the little mouth-like holes in leaves.
Through photosynthesis, plants converted light energy to chemical energy stored in sugars. They used the sugars to grow larger and reproduce. Oxygen is the other byproduct of photosynthesis, so as leafy trees got larger, they began putting greater amounts of oxygen into the atmosphere and removing larger amounts of carbon. Eons of land-based plant material changed the earth’s atmosphere, making life possible for the oxygen-breathing creatures that evolved millions of years later – including us, of course!
Thank goodness for that algae and cyanobacteria combo a billion years ago! Because of photosynthesis and the new abundance of oxygen in the atmosphere, organisms like mammals and birds with fast metabolisms evolved. A rich diversity of oxygen-loving organisms occupied the earth for millions of years before humans and their predecessors came on the scene.
Trees Still Supporting Life on Earth – including Ours!
The trees we know, love and rely on today – oaks, maples, walnuts and such – first appeared on earth about 65 to 144 million years ago. They blanketed the earth long before modern humans arrived about 30-50,000 years ago. Their leaves, like the ancestral leaves of early plants and trees, are still supplied with chloroplasts stocked with chlorophyll and other light-absorbing pigments from those ancient cyanobacteria; in fact they turn the leaves green by absorbing reds and blues while reflecting the green part of the spectrum. So trees are still busy storing carbon and sugars while releasing the very oxygen we need to survive.
I learned from a National Geographic article that during northern hemisphere winters, carbon dioxide builds up in the atmosphere. Once deciduous trees drop their leaves, they temporarily cease their photosynthesis. Check out the fascinating month-by-month NASA video down the page in this article to see the red areas of carbon dioxide in the northern hemisphere during the winter months, December through March. When springs arrives, leaves sprout and a huge number of trees in the northern hemisphere go back to absorbing carbon dioxide through photosynthesis. Watch the months June through September on the NASA video and see what I mean!
Sadly, trees can’t remove enough carbon dioxide from earth’s atmosphere these days due to human use of fossil fuels, which is releasing huge amounts of stored, compressed carbon from the remains of ancient living organisms, including trees.
Trees as “Kin” We Count on for Survival
In Shakespeare’s Troilus and Cressida, Ulysses tells Achilles, “One touch of Nature makes the whole world kin.” Though Shakespeare meant something quite different, the line occurred to me as I came to a deeper understanding of our intimate, essential connection to trees and other plants as well as our fellow humans. We share the double helix of DNA, after all, with all living organisms – plants as well as animals.
And though it’s the small number of genes that are unique to humans that make us what we are, genome experts say we share a large portion of our DNA with plants. So in a way, trees and plants truly are our “kin!”
What we don’t share is the ability of plants to turn sunlight into sugars, fiber, fruits, nuts, vegetables, grains, etc. Every single thing that we eat to stay alive comes originally from plants (although algae and some other organisms also photosynthesize). Even the meat in our diet comes from animals who survive by eating plants or by eating other animals that eat plants. We depend on plants to feed us and we depend on them for the very oxygen we breathe. Up until the 20th century, trees and other plants could also effectively use or store all the carbon dioxide we and our activities exhaled into the earth’s atmosphere. They still contribute to that process.
Respecting Our Elders…
We can’t survive without plants. Yet they survived for millions of years without us. So that encourages me to think that caring for nature isn’t just a matter of loving and enjoying nature or being a good-hearted steward of our “natural resources.” It’s really a matter of enlightened self-interest for our species. Caring for and respecting our “kin” in the natural world that support us and nurture us is simply a matter of our survival, as well as a joyful activity.
I’m willing to admit that winter walks are a bit more demanding for me. Though I love being out in the open with red cheeks and the glitter of sunlight on snow, breaking through an icy snow crust with every step can be a bit arduous. And as a writer who loves taking photos, well, wildlife is simply a bit more scarce and plant life is a lot less colorful. So the blog creates an interesting challenge. Luckily, I’m all for a good challenge! So this week, in a way, I’m writing about what I didn’t see in February at Charles Ilsley Park. Bear with me…
One February morning, I pursued the paw prints of an unseen coyote who had left a trail in the ice-encrusted snow on the previous moonlit night. And I spent part of an afternoon just noticing the brown and gray architecture of the dry seed heads of some favorite summer wildflowers, now ghosts of their colorful summer selves. Their pleasing shapes provided some inspiration about the native garden I’m dreaming about for next summer. But I’ll start this blog with the handful of birds that I did see, that kept me company on frigid days, just to remind myself that I had sturdy companions on the grayest and coldest days of the year.
Who’s That Twittering in the Tall Grass?
One late afternoon as I approached the Eastern Prairie at Ilsley, I heard the cheerful “chatting” (see first “call” heading at this link) of a small group of winter visitors from the Arctic, American Tree Sparrows (Spizelloides arborea). One of them paused long enough for a good look at its two-tone bill. This little bird had puffed up its down jacket to deal with a frigid morning!
Two days later, the birding group heard more “chatting.” We spotted a large flock of Tree Sparrows flowing like a river from the trees, down into the tall prairie grass. These social flocks keep in contact with short calls back and forth – “I’m here! I’m over here!” – as they forage. I managed to catch a group of them in a vine-laden bush at the edge of prairie.
It was wonderful to watch so many migratory birds feeding enthusiastically on the native seeds of our restored prairie. We were curious to see which plants they were enjoying. That morning they were finding bent Black-eyed Susan stems (Rudbeckia hirta) and plucking out the seeds. Here’s the bent stem at almost ground level, the seeds on the snow and the area trampled by the flock’s small feet.
Actually, this large flock of birds had a few fellow travelers. Dark-eyed Juncos (Junco hyemalis) and American Goldfinches (Spinus tristis) joined the Tree Sparrows’ feast. Larger flocks increase the odds that birds can survive against predators in winter, when birds show up well against the snow. They also mean more eyes spotting good food. (Click on photos to enlarge; hover cursor for captions.)
On a Sunday walk in the Western Prairie at Charles Ilsley Park, my husband and I spotted Eastern Bluebirds (Sialia sialis) diving in and out of the grass. Finally, a pair of them settled on some brush and fallen logs along the tree line. The male ignored me completely while he preened vigorously. Since bluebirds often use the abandoned nests of woodpeckers in the winter, I wondered if he’d picked up some mites from an old nest, poor fellow. I managed to get one quick shot when he rested for just a moment.
The female nearby was keeping an eye on me and as I approached she sent the male a little “chit-chit-chit” call (second “call” heading at this link) that warns of ground predators – me, in this case! Then they both flew off again.
At the far edge of the western prairie, we heard the “ank-ank-ank” call of the White Breasted Nuthatch (Sitta carolinensis). (Under “Eastern calls” at this link.) It was hopping quickly from branch to dead branch above our heads, searching out anything it could eat , like frozen insect eggs or caterpillars.
Now, About Those Tracks Here, There and Everywhere…
As I started out one Thursday morning, I was presented with some pretty impressive tracks. I recognized them immediately, because one of them was mine! The last four birders on the Wednesday morning bird walk had trekked along chatting as we went back to our cars. As a former bookseller, I had to smile remembering Pooh and Piglet tracking a “heffalump” around a bush, which of course turned out to be their own footprints, too. A fun beginning to my search for animal tracks.
I left the trail and headed diagonally across the field following a nice straight line of canine prints – and readers of my previous winter blogs probably know what that means – a Coyote! Coyotes (Canis latrans) trot along at night making a straight trail of prints. Being wild animals, coyotes want to use as little energy as necessary between meals, so they never run around in the snow like dogs do. They place their back feet inside the print of their front feet to use less energy and move directly where they want to go.
Because a crust covered the snow after freezing rain, it was clear that this coyote had to break through the snow with each step, leaving a pointed top to the track it left behind.
I followed the prints as it became apparent that this coyote was headed for the farthest west section of the park, where Stewardship Manager Ben VanderWeide had hired a forestry mower to remove invasive shrubs and create a path to the nearby subdivision for residents’ use. Two trees nicely frame the opening to this newly renovated area.
This western section with its rolling, glacial landscape, wetlands and wooded areas is very different from the open prairies of Ilsley. It seems our coyote thought this might be a better place to rest on an icy, windy night. Coyotes are not really nocturnal animals, but they have learned that night is a good time to hunt and not be bothered by humans and their activities. So I imagine this coyote had been out hunting mice on the prairie and was heading back to the woods to get out of the wind.
After passing into the western area, the coyote turned sharply south into the woods. So I followed its tracks, imagining it trotting between the trees, slipping in and out of the shadows made by the full moon the night before.
It’s easy to see that among the glacially-formed slopes of this rolling landscape, a coyote would be out of the sharp wind that blew across the prairie. The landscape in this area of the park is suddenly so different, as the slopes rise and then descend to one wetland after another. I kept following the coyote deeper into the woods as the line of prints flowed over the slopes.
At last the coyote’s tracks came down to a small pond where they seemed to end in a flattened area under some vines and branches at the right which would have provided a bit of cover.
Beyond that pond was another lovely little pond covered in snow and embraced by the hills around it – but not a track in sight.
I lost the coyote’s trail after that and wandered up to Ben’s path again. I stopped to admire a very tall, wonderfully straight native Tulip Tree (Liriodendron tulipfera) with its closely furrowed bark.
Its yellow blossoms were now dried but still quivering in the wind at the very top of the tree. Ben pointed it out on an earlier walk and told us he thought our area is at the northern edge of this lovely tree’s range. It’s the first wild tulip tree I’ve ever seen.
Nearby stood a tall Silver Maple (Acer saccharinum), its red buds just waiting to expand and bring us one of the first really vivid colors of early spring.
As I left the western wooded area and headed back onto the western prairie, I came across a flattened place in the trail that looked like a major crossroads for critters. The tracks around it were hard to read . I thought I recognized squirrel and possible rabbit tracks, but I have no idea who was there and what was going on, really. Since there are coyote tracks above this flattened area, I wondered if one slept here; as top predators, they do sleep in the open at times. Its warmth would have melted the snow and allowed smaller creatures to get to the ground underneath the crusted surface once the coyote left the scene. Just a guess.
One possible hint was a hole in the snow nearby where a squirrel may have tried to dig up a nut in the frozen soil. Or perhaps our coyote dug up a Meadow Mouse (Microtus pennsylvanicus) before heading off to sleep? I’m not sure because the tracks around it were not fresh; they had been trampled, rained on and frozen.
The coyote tracks did lead away from area toward the private property on the west side of the park.
If the open hole was that of a captured mouse, the birders saw evidence that some mice are luckier than others. Here are some mouse tracks that we spotted near the edge of the western prairie. It looks like this mouse made it safely under the snow’s insulation – safe from the icy wind and out of sight. I love the “stitching” look of mouse tracks in the snow.
On the last leg of my tracking trip to the park, as I approached the central section from the north, I saw one of the spring-fed ponds covered with lots of tracks, making neat, straight lines across the snow-covered surface. What was going on? And then it occurred to me. These were stewardship tracks! Ben had told us at the end of the bird walk that he’d brought a native wetland seed mix to spread on the ponds before it rained later that day. He and Stewardship Specialist Alyssa Radzwion put the seed right on the frozen surface. Native seeds needs to be exposed to the cold before they will germinate properly. Once warm weather comes, the seeds will drop down into the shallow water or moist edge habitat and with luck, begin bringing some color and native plant life to these special areas of the park.
The Ghosts of Summers Past Provide Inspiration for Spring
I’ve begun learning to recognize and appreciate the winter forms of some favorite wildflowers. Their subtle shades of brown or gray as well as their patterns and geometry have started me wondering if I could create a native garden next summer that the birds and I could enjoy all year ’round. It’s clear that birds need the seeds that cling to native plants despite snow and wind. And I could appreciate the architecture of winter plants. So which shapes provide what landscapers like to call “visual interest” and also provide winter food for wildlife?
Perhaps some of you remember how beautiful the Eastern Prairie looked when filled with Black-eyed Susans (Rudbeckia hirta) in the summer. This hardy native has always had a special place in my life. When I was a teenager, the first song I ever wrote included the “wide-eyed stare” of this sunny flower. So it definitely needs to be in my garden. I’m taken with its winter fringed cap in winter and would be happy to let it hang out in my garden.
Black-eyed Susans in bloom
Black-eyed Susan in winter – a lovely cone of seeds for the birds
Mixed in with these bright yellow beauties were the lavender fireworks of Bee-balm (Monarda fistulosa) and they create appealing geometry in a winter landscape.
For contrast, I’d need some white in my summer garden – and maybe good old Yarrow (Achillea millefolium) would be a possibility – if I could keep it from spreading too much. I like its chocolate brown against the white snow.
I love how Yellow Coneflowers (Ratibida pinnata) sway in a summer breeze so I hope they’ll be included somehow too. The plump, oblong seed heads obviously provide forage for the birds and silvery, pointed spears would be a graceful accent in a winter garden.
I may plant Asters in our field rather than in the garden. They grow in such profusion! I’m not sure which of the many Asters is represented in the winter photo below because so many kinds of asters bloom in late summer and fall! They are such a boon to all kinds of butterflies and bees who can feed on them before winter arrives. Here’s just a sampling. (Use pause button for captions.)
Brown-eyed Susans (Rudbeckia triloba), which also bloom late in late summer and fall, might be another good choice for the field, since they grow so tall (compared to Black-eyed Susans) and have a branching form with multiple blooms at the same time.
Well, that’s a start. I want to search out some other favorites, like Foxglove Beard-tongue (Penstemon digitalis) and see what it looks like after bloom – though I doubt I can resist it for the garden. That little Field Sparrow (Spizella pusilla) makes me impatient for spring!
See? Wasn’t that a clever way to get to get some color into an early March blog, when everything is still brown, gray and white? I knew you’d appreciate it…
Finding Delight in a Late Winter Walk
It takes a bit more effort to get out on a frosty morning. There’s all that layered clothing and boots and gloves and scarves. And the early March landscape is getting just a bit tiresome — too much brown and white out our windows. But once I’m out the door and into the landscape, nature offers me a few treats to keep me coming back. Tracking a coyote’s tracks to a secluded pond in the woods feels like a little adventure. The friendly chatting of winter birds keeps me company and the sight of bluebirds in the stark landscape nourishes my color-starved eyes. And how lucky that noticing the winter geometry of last summer’s blooms sets me off dreaming about a new native garden! So all that makes crunching step-by-step through the snow crust worth the effort when the thermometer encourages me to stay home.
Footnote: My sources for information, besides Oakland Township’s Stewardship Manager Ben VanderWeide, are as follows: Allaboutbirds.org, the website of the Cornell Lab of Ornithology at Cornell University; Wikipedia; A Field Guide to Nature in Winter by Donald Stokes, and Trees of Michigan Field Guide by Stan Tekiela.
I’m guessing lots of us who love nature have wondered the same thing in the last few weeks. “As the temperature drops below zero, how do those small birds with bare feet survive out there?”
Well, it turns out that although our avian winter neighbors share a similar technique for keeping their feet from freezing, their strategies for dealing with cold, snowy days can differ.
First Rule: Use Those Feathers!
We humans love down jackets on cold winter days and snuggle beneath down comforters on winter nights. Well, birds like the female Northern Cardinal (Cardinalis cardinalis) above, or the Tufted Titmouse (Baeolophus bicolor) pictured at the top of the blog, use the same technique. When birds fluff up their feathers in the cold, they trap a layer of air between the feathers. Their body temperature – in small birds more than 100˚ F – warms the air layer just as it does in our jackets. According to Peter Marra, head of the Smithsonian Migratory Bird Center at the National Zoo, “Birds’ feathers provide remarkable insulation against the cold, and the oil that coats feathers also provides waterproofing, which is important since the only thing worse than being cold, is being cold and wet.” Here are a few of birds making the most of their feathers on a recent cold morning. (Click on photos to enlarge; hover cursor for captions.)
What About Those Bare Feet, Though?
Last summer I caught this American Goldfinch (Spinus tristis) staring at its feet in a tree near Lost Lake. I laughed to think that perhaps it was worrying about how they’d feel on a snowy day! Birds really do have very cold feet in the winter. According to scientist and professor Bernd Heinrich on the Cornell website, the feet of chickadees stay just above freezing even while their body temperatures are very high. Presumably, they don’t feel it much. Their feet are mostly tendons and bones with very few muscles or nerves. If you look at those three birds with feather puffed that are pictured above, you can see they’ve hunched over their feet, covering them with their body feathers. Or sometimes birds simply tuck one leg at a time against their breast. Also, the arteries and veins in birds’ feet are close together. As Heinrich explains it, a bird’s feet are provided with continuous blood flow which keeps them from freezing. Since the arteries pass close to the veins in a bird’s legs, the cooled blood from the feet gets warmed on the way back to the heart to keep the bird’s body warm. And the warm blood from the heart is cooled down as it moves out to the legs, reducing heat loss. Pretty efficient system!
Second Rule: Eat as Much as Possible!
On cold days, small birds really need to stuff themselves every few minutes to keep warm. When you see a White-breasted Nuthatch (Sitta carolinensis) or Black-capped Chickadee (Poecile atricapillus) dashing from your feeder to nearby trees, it’s eating some seeds and storing others in the trees’ bark. Amazingly, the brains of Chickadees expand in the fall to improve their memory so that they can later find those seeds or nuts. According to Cornell’s Birdsleuth website, “neurons are added to the Chickadee’s hippocampus in the fall, increasing its volume by about 30%.” As a result, Chickadees can remember up to a thousand places in which they’ve tucked their winter provisions! (I’m sure I’ve mentioned this before in the blog, but it’s so amazing that it bears repeating!)
But What Do They Eat in Winter?
Mourning Doves (Zenaida macroura) and American Goldfinches can be gluttonous at feeders during the winter because they are vegetarians; no insects or caterpillars for them! On most winter days, they can find seeds or fruits, but your feeder helps to supplement the wild supply. Mourning Doves can eat 12-20% of their body weight per day! They store seed in their crops, a muscular pouch near the throat, and digest it later to help keep themselves warm at night.
I’ve seen Cedar Waxwings (Bombycillia cedrorum) eating frozen vine fruits or leaf buds that overwinter on the branches of trees.
But many local birds, including Waxwings, are omnivores who can eat a wide range of foods. The Tufted Titmouse, White-Breasted Nuthatch, Chickadees and all kinds of Woodpeckers (family Picidae) spend winter days probing loose bark or hopping along branches looking for frozen dinners; insects, insect eggs, pupae or perhaps a frozen caterpillar will do just fine as sources of protein on a cold day.
AmericanCrows (Corvus brachyrhynchos), being bigger birds, will eat almost anything to “stoke their furnaces” during the winter. In our area, the carcasses of White-Tailed Deer (Odocoileus virginianus) provide lots of good protein. And if a crow finds one, it notifies its family and friends to join the feast. (No fair being squeamish. We all have to eat!)
Where Do Birds Spend Cold Winter Nights?
According to the Smithsonian’s Peter Marra, “Many small birds, like Black-Capped Chickadees, Eastern Bluebirds, and House Wrens, will gather in large groups at night and crowd together in a small, tight space to share body heat.” Sharing body heat keeps down fat loss during the night to preserve energy for the next day’s foraging. In his article for Cornell’s All About Birds, Bernd Heinrich describes finding a group of tiny Golden- Crowned Kinglets (Regulus satrapa) huddled in a circle on the branch of a pine tree, beaks in, tails out, sharing their body heat on a winter night. These tiny birds, which overwinter in our area, are about half the weight of a Chickadee! This lovely winter photo of a Golden-crowned Kinglet was taken by a photographer named cedimaria at the website inaturalist.org.
Bernd Heinrich reports in his essay collection, Winter’s World, that woodpeckers provide some cozy winter housing for other birds as well as themselves. Every spring, woodpeckers make a fresh hole for raising their young, but they tend to use them for only one year. So small birds can often find an abandoned woodpecker hole to get out of the wind and snow on a winter night. In the autumn, Dr. Heinrich has also spotted both Downy Woodpeckers (Dryobates pubescens) and Hairy Woodpeckers (Dryobates villosus) constructing special overnight shelters just for winter use. I spotted a Downy doing just that in Gallagher Creek Park one November day. Note the flying wood chips!
Special Winter Strategies Can Be Helpful…
Even though Chickadees can excavate their own holes, in extreme cold they require a few extra tricks at night. According to the Audubon society, these little birds can lower their body temperature at night by as much as 22 degrees, minimizing the difference between their body temperature and the bitterly cold air. They also keep warmer by shivering, which activates opposing muscle groups and produces heat. Luckily, they can even shiver while sleeping, which is something I can’t quite imagine doing! And of course once settled, like many birds, they can tuck their beaks and feet into their feathers to preserve heat as well.
Though they don’t appear in our parks these days, Ruffed Grouse (Bonasa umbellus) survive days of light fluffy snow in a surprising way. They burrow into the snow, creating a long tunnel with a chamber on the end. These one-day burrows not only provide insulation, according to Bernd Heinrich, but they also provide protection from predators. Large dark birds are very visible against the snow! (This photo was generously shared at iNaturalist.org by photographer Brian Murphy.)
Thank Goodness for Our Adaptable Winter Birds!
Aren’t you glad that some birds stay with us all winter? And that some actually arrive for an extended stay just as the snow begins to fall? The constant flutter of a busy Chickadee, the “yank yank” call of a Nuthatch as it circles a branch or the friendly chirping of a flock of foraging Tree Sparrows in dry grass are so companionable on gray winter days. And what could be more heartening on a frigid morning than the sight of scarlet Northern Cardinals or azure Blue Jays in a snowy bush? I’m so thankful that some birds have figured out how to survive the cold along with us. By taking shelter, shivering, eating heartily, and snuggling into down comforters very much like we do, they keep us company as we make our way towards spring.
Footnote: My sources for information, besides Oakland Township’s Stewardship Manager Ben VanderWeide, are as follows: Allaboutbirds.org, the website of the Cornell Lab of Ornithology at Cornell University; Wikipedia; A Field Guide to Nature in Winter by Donald Stokes, Winter World by Bernd Heinrich, A Naturalist at Large by Bernd Heinrich and others as cited in the text.
Meet the New Zealand Mud Snail (Potamopyrgus antipodarum), a very problematic, tiny snail (up to only 1/8th of an inch!) which is one of the latest invasive species to begin changing the Great Lakes ecosystem.
At a recent Oakland Township Stewardship Presentation, Emily Bovee and Kennedy Phillips of the Aquatic Ecology Lab at Oakland University shared their extensive knowledge and research on this hitchhiking snail that’s begun infesting Michigan rivers and lakes. The program was quite an education! Here’s a brief overview of some of the information they presented.
Please note that the photos in this blog were generously shared by photographers from iNaturalist.org and by the researchers at Oakland University. Names and permissions are listed in the captions on their photos.
Michigan’s Problem with Invasive Species
Our state is surrounded by the Great Lakes, which hold 20% of the world’s freshwater. Unfortunately, it is also now home to 180 non-native species. How do these species get here?
Waterway connections, e.g., the Sea Lamprey arrived through the St. Lawrence Seaway.
Released pets and aquarium water.
Aquaculture – the movement of fish or eggs from commercial fisheries may have brought the mud snail originally. The transport of exotic water plants can do it, too.
Ballast water in ships can harbor them. For example, the invasive Zebra Mussel (Dreissena polymorpha) arrived this way and perhaps the New Zealand Mud Snail as well.
Boats, other watercraft and recreational activity can spread the unwelcome New Zealand Mud Snail from river to river, river to lake.
The problem with invasive species is that, once established, they alter the very environment in which our native creatures have lived for thousands of years. Often, for instance, they eat the food on which on our native species depend. By doing that, they can cause local extinctions and generally make the ecosystem less healthy, less able to adapt. Some, like the Quagga (Dreissena bugensis) and Zebra Mussels contribute to the creation of toxic dead zones caused by huge algae blooms that use up all the available oxygen in the water. What a mess!
Now We’re Dealing with the New Zealand Mud Snail
This very tiny menace is called a “mud snail” because it hides buried in the mud during the day and emerges at night to feed. It feeds on algae, decomposing leaves, or wood that falls into the water. As a result, mud snails live in areas where the current slows and plant material is deposited. That, of course, is also a place where anglers frequently find the fish they are seeking!
Mud Snails Reproduce by Cloning Like Crazy!
Although New Zealand Mud Snails are both male and female in their native range, the ones here in North America are all females – and they can clone like crazy! In fact, DNA analysis indicates that the millions of mud snails already in the U.S. originated from as few as three females! These snails produce live young about every 2-4 months and can produce over 200 hundred in one year, and each of those can produce 200 more – and well, you see the problem. The Oakland University researchers have found colonies of 30,000 in a square meter (about 10 square feet) in the Au Sable River, Michigan’s internationally known trout stream. In the western United States, where the snails have existed since 1987, researchers find 500,000 in a square meter!
Tough Competitors Who Can Survive Almost Anything!
These are tough little females! New Zealand Mud Snails are fresh water snails, but can tolerate salty water, and survive excessive heat and winter ice. They thrive in disturbed areas and survive floods better than other snails by burrowing into the mud. They attach themselves quickly to boats, anchors, waders, and fishing equipment for transportation to other lakes – as well using pets and wildlife like the legs of wading birds. Mud snails can live out of water for up to two weeks by closing their shells. And they can even survive traveling through the innards of fish or birds and make it out alive 50-80% of the time! We are talking about a tough competitor here in our waterways!
And Mud Snails Can Be Devastating
There’s evidence that trout in the Au Sable River eat New Zealand Mud Snails, but they can’t get much nourishment from them. Their shells are too hard for most fish to crush or digest. Hence the nutrients in them don’t nourish fish like native snails or other macroinvertebrates in a river would. And to add more injury, these snails eat the very organic matter on which our native species depend, the species which efficiently nourish fish and other creatures. New Zealand Mud Snails, for example, eat the most tender parts of algae, but leave the less palatable parts for other aquatic creatures. Thanks a lot!
What to Do? Practical Steps to Prevent Hitchhikers
Sadly, as is often the case with invasive species, there is no hope of ever eliminating these minute snails. They have no natural predators in North America. And if we tried to physically remove them but missed even one, we’d have hundreds of thousands again in a matter of years as the creatures clone and clone again.
So the goal now is to all pull together and STOP THEIR SPREAD! Here’s where you come in. The Oakland University researchers made these recommendations:
Clean, Drain and Dry All Boats, Watercraft and their Trailers – You’ll need to drain them for 24 hours before you go to another water system. Drain your live well, your bilge and dry your motor. Remember! These snails are tiny and easily missed! Look carefully!
Clean Your Waders, Nets, etc. Go away from the water’s edge (near your car for instance) and spray your gear liberally with Formula 409, which right now is the only substance found to kill 100 % of these little critters. Don’t get any 409 in the water system! The surfactant that makes it work on the snails is lethal to many creatures. Be sure to brush/scour the soles of your boots or waders. Rinse the equipment with water, dry them, and wait 24 hours before going into another stream. Again, remember to check carefully for these tiny snails!
Educate Others about These Procedures – Spread the word to other people in your life who fish. These snails prefer rivers where sunlight can reach the mud and grow algae. But they have been found in lakes as well, since rivers, of course, empty into lakes. Anglers can’t protect our waterways if they don’t really understand the dangers associated with these snails.
Volunteer to Help – You can provide a water sample from a river in which you fish and submit it easily to the Aquatic Ecology Lab. Find out how by emailing Emily Bovee, one of the researchers from O. (See the researchers’ emails below.) A DNA test can discover whether mud snails are present in the waterways where you fish or boat. That helps researchers know where to do their work and allows conservationists to offer information on local signage and to strategically locate cleaning kiosks for fishing gear.
It’s Not Fun to Think about Invasive Species…but We Really Need To Do It.
I will readily admit that learning about invasive species is not as uplifting as learning about the restoration of forests, prairies and native species in general. Non-native species often end up dominating the landscape and thereby diminishing the rich diversity of our natural areas. And often the story of invasives does not have a clear ending, much less a happy one. For though we can work at controlling them, in many cases, we will never be entirely rid of them.
It seems that our best hope is to get educated about invasive species and then pass on that understanding to others in the hope that we can dramatically limit the damage that they do. We can participate in citizen science projects. We can choose to be informed and careful about inadvertently spreading invasive plants, fungi or creatures when we garden, fish, hike or choose our pets. We can plant and nurture native flowers, grasses and trees. Seems do-able, doesn’t it? In fact, we’re already doing it here in Oakland Township through our stewardship program. And really, it seems like the least we can do to honor the diverse beauty and generosity of the natural areas which have supported us for thousands of years.
Need More Information?
To participate in DNA water sampling, contact the research team at Oakland University’s Aquatic Ecology Lab by contacting Oakland University researcher Emily Bovee at this email address: firstname.lastname@example.org.
As well as attending the excellent workshop, I found these two websites very useful.
A US Fish and Wildlife Page on New Zealand Mud Snails in the Columbia River