winter | Sheldrake Environmental Center

Lunch Break at Sheldrake

Wednesday, January 8, 2020

New year, new program! Take a mid-week break at Sheldrake to de-hibernate and recharge your battery outdoors. Each Wednesday, we’ll venture into the woods together for a 45-minute nature diversion, embracing the chill or a little snow. Dressed for the elements, we can savor the season and observe its effects on the natural world. Optionally, stick around after to join us for a brown-bag lunch (B.Y.O.), either outdoors if the weather permits or indoors if not. Need to get back to work, your kids, your to-dos? We’re keeping our forest time to under an hour.

Dates: Wednesdays, January 8-Wednesday, February 12 (6 sessions)

Time: 12:15-1:00 pm (optional brown-bag lunch follows)

Cost: Members: $60 for the full series; non-members: $80 for the full series. Drop-in rate: $15/session (cash at the door). Please check here for any cancellation notices before heading over.

Target Age: Adults

Photo courtesy of Jim Sutherland.

Baby, it’s cold outside

Thursday, February 23, 2017

Last week the winds howled and temperatures fell below freezing. Trees and branches cracked and sprawled across the ground. Leaving my house, I pulled my coat tight, drew my hat over my face, and in my fuzzy boots scuttled the 15 feet to my car. I blew a gust of frozen breath in the safety of the front seat. Then I looked out and saw a dark eyed junco, a tiny songbird pictured above, sitting on a branch, calm as can be.

How can a wee bird weighing no more than three pennies spend 24/7 in such cold temperatures without freezing to death?

Down, down, down

That jacket or blanket that you may have for extra cold days is stuffed with down for a reason. Unlike the long flight feathers on a bird’s wings and tail, the down feathers are short and can be fluffed up. This fluff creates air pockets that trap the warmth escaping from the bird’s body. The specialized down feathers can keep a bird’s body temperature at 104 degrees even in freezing weather!

Birds also undergo a fall molt in which they grow up to fifty percent the number of feathers on their body for greater insulation. That fluff is what makes these tiny birds look round as tennis balls in winter.

Have you ever seen birds poking their beak into the base of their tail, then rubbing their beak all over their bodies? They are collecting oil from the uropygial gland and spreading the oil over their feathers. Not only does the oil keep feathers preened and clean, but it also adds a weatherproofing layer that keeps them from getting wet. Can you even imagine the misery of having wet feathers in winter?

Wait, what about my feet?

No matter how warmly I dress, my feet and hands are usually the first thing to freeze in winter. So how do those featherless, little reptilian bird feet stay warm in winter?

For one thing, those sinewy feet have very few nerves, which reduces the cold that the birds feel through their feet. The scales are specialized to minimize heat loss. Birds also take turns lifting one foot and tucking it into their feathers to warm it up, or crouching down over their feet to warm them.

But they have another brilliant adaptation as well: rete mirabile, which is Latin for “wonderful net.” In the rete mirabile, arteries that carry warm blood away from the heart intersect with veins that carry cold blood from the feet. A heat exchange occurs, and the blood from the feet warms before reaching the bird’s heart.

And then there is shivering

Birds are warm blooded creatures and, through a high metabolism, maintain a body temperature at about 105 degrees Fahrenheit. How challenging it must be to keep such a high body temperature in extremely cold weather! When all else fails, birds will start shivering their powerful chest muscles. The pumping of their strong flight muscles sends blood and heat surging through the body. But this relief comes at a cost. Half the calories that a bird needs to survive a wintry day could be depleted in the act of shivering. A chickadee, for example, requires the equivalent of 65 sunflower seeds to survive a cold winter day. Food to replace those lost calories is scarce in winter. Most insects and trees are dormant.

Birds are highly resourceful creatures, and they have adapted to find sustenance in seemingly barren environments. They have exceptional eyesight, and can tease out tiny cracks in tree bark serving as insect hideaways. As gardeners, we can help them by not removing our dead plantings in the fall. Those browned flower heads can contain seeds and insects that sustain birds through the winter (see Hidden Provisions blog entry). And if you are feeling extra generous, you can fill a feeder with sunflower seeds or suet, and enjoy the feeding frenzy that ensues.

cardinal — Cardinal waiting for his turn at bird feeder

cardinal1 — “What are you waiting for?,” this female cardinal must be thinking.

cardinal2 — Joining the junco and sparrow for a sunflower seed snack.

Hidden Provisions

Thursday, November 3, 2016

Svetlana Wasserman

As November blows in, the bright colors of summer are a distant memory and the reds and golds of fall have dimmed. Plant life has faded to a grayish brown. An annual rite begins as gardeners start clearing out their dried plant matter in preparation for winter. But maybe it is time to reconsider.

The flower petals may have dropped, but they have left behind something precious. Recall those sticky pads emerging from the center of the flower, the stigma? When pollen lands on the stigma it travels down the style into the ovary, connects with an egg, begins fertilization and produces seeds for the next generation. The flower parts have been replaced by seedheads.

The seeds inside are an invaluable food source for myriad creatures trying their darndest to survive the deprivations of winter. Take for example the black capped chickadee. These little marvels, whose cheery “chick-a-dee-dee-dee” trills are our yearly soundtrack, are so small, you could mail two of them for the price of a first class stamp. The chickadees’ primary method of staying warm through winter is shivering. Shivering their chest muscles surges heat through their little bodies. Shivering is expensive, however, from a calorie standpoint. To stay alive on a winter day, chickadees must eat the calorie equivalent of about 150 sunflower seeds–250 if temperatures drop below zero degrees! In warmer months the chickadees feed on insects, but in winter, bugs are dormant, the birds’ caloric requirements are higher, and daylight hours for foraging are fewer. For the chickadees and many other birds, finding enough seeds to eat is the difference between life and death.

chickadee — Chickadee feeding on the seeds of a dead flower. Photo Credit: National Geographic

Many of our beloved perennials offer up plentiful seeds for birds. The coneflower (Echinacea), for example, is a popular garden staple. It is a powerhouse for nurturing wildlife. Bees and butterflies flock to it in summer. But its usefulness is not limited to summer. Goldfinches and other birds need its seeds to get through winter.

Not only can birds find nutritious seeds in dead flowerheads, but they can find insects too. Many beneficial insects such as caterpillars, moths, and ladybugs overwinter in the stalks of dead plants. They provide a calorie rich meal to the birds who find them, and those that are not eaten have important pollinating work to do in the spring.

Many gardeners plant Joe Pye Weed, pictured below, because of the abundant pollinators it attracts in the warmer months. But cutting it down in winter removes an important food source when it is desperately needed. As a bonus, the tall browned stalks lend an austere beauty to winter gardens.

joe-pye-weed-spring — Joe Pye Weed flowers in spring. Photo Credit: Prairie Moon Nursery

joe-pye-weed-seed — The seeds of the Joe Pye Weed use the “fluff and fly” method to travel on breezes. The thin stalk is the seed. Photo Credit: Svetlana Wasserman

Milkweed, the primary food source for our beloved Monarch butterflies, releases its seeds on long silky parachute threads. Leaving the stalk standing in winter provides a haven for insect larva and a food supply for birds.

img_20161007_114238621 — Milkweed seeds about to set sail on a breeze. Photo Courtesy: Mary Ellen Kelly

This fall consider holding off on the conventional wisdom of deadheading and removing spent flower stalks. Seed-eating birds such as juncos, goldfinches and others will thank you. The pollinators and other beneficial insects wintering in the dried plants will reward you in the spring. And there’s something to be said for the stark sculptural beauty of the seed head in winter.