What a puzzling week, eh? Was it spring or late winter? The buds on the Silver Maple (Acer saccharinum) near the Center Pond seemed as confused as the rest of us. They began to emerge as the sun warmed the cold air. I was concerned about the effect of icy nights later in the week. Alas, a twisted ankle meant I couldn’t get back to the pond to check on them. But maples seem to survive unpredictable Michigan winters, so we’ll hope it pauses and waits for a few weeks. On a long walk one sunny, snowy day, I crossed the late night/early morning path of a rabbit and went on to enjoy the antics of the “usual suspects” of a late winter day at Bear Creek: a Bluebird pair, a Chickadee pursued by a stalking Titmouse, and a Red-bellied Woodpecker busily poking at bark, looking for beetles. On a sunny, mud-slushy short walk with my somewhat tenuous ankle, I came across Goldenrod duplexes and while watching squirrels, decided I’d share some new info I read about these mischievous mammals.
Bird Antics from the “Usual Suspects”
Our Eastern Bluebird couple (Sialia sialis) seems to be sticking around despite fluctuating temperatures. A hardy pair of Bluebirds! This week I again spotted the female fluttering among the fruits of invasive Asian Bittersweet (Celastrus orbiculatus) – the vine that chokes our trees!
She will undoubtedly disperse the seeds in them in short order since birds have very quick metabolisms, if you know what I mean…
I wish she’d eat the Staghorn Sumac fruit(Rhus typhina) on the Western Slope! They’re native plants and are supposed to be on a Bluebird’s winter menu!
Her male partner sat stolidly on a nearby branch, keeping an eye out for any competitors.
On the trail that leads north from the playground, a Tufted Titmouse (Baeolophus bicolor) stalked a Black-capped Chickadee (Poecile atricapillus), apparently trying to see where it was caching its seeds in the tree bark. No matter where the Chickadee hopped or flew, the Titmouse was right behind. Here’s the Titmouse with its crest raised. It does that when excited, in this case perhaps perturbed by my camera, or as this article suggests, by trying to snitch some seed from the Chickadee’s hiding place!
The Chickadee looked pretty annoyed when it finally paused for a moment! Was it that annoying Titmouse or my camera? Or was it just its natural expression? Who knows?
High in the trees, a Red-bellied Woodpecker (Melanerpes carolinus) made its wet “Kwirr” call as it hopped about a tree trunk, getting snow on its beak as it searched for bark beetles or other small creatures.
As I approached the top of the Western Slope that, a Blue Jay (Cyanocitta cristata) high in a distant tree spotted me and shouted its warning call, “Jay, jay, jay!!!!”, announcing my presence to all the other birds. Here’s one in an invasive Autumn Olive bush (Elaeagnus umbellata) later that day.
Signs of Other Creatures: Tracks and the Duplexes
Behind the Center Pond, my husband and I crossed the tracks of an Eastern Cottontail ((Sylvilagus floridanus) emerging from under a bush next to the trail. Though you can see a rabbit almost any time of day, these tracks were likely made between dusk and dawn because rabbits generally feed at night. In winter, their diet is mostly bark, buds and the twigs of woody plants. Cottontails don’t usually live underground. Though they use holes for raising young, the rest of the time, they huddle in piles of vines and brush. They will sometimes use a groundhog’s den temporarily during heavy snow – like this Wednesday’s snowstorm!
Along the path that runs just to the west of the Playground Pond, toward the benches at the top of the hill, the Canada Goldenrods (Solidago canadensis) bulge with ball galls, the round, woody little dwellings that house the Goldenrod Gall Fly’s larva (Eurosta solidagnis) for the winter. (See the blog from January 21 for more info.) Lots of them will successfully hatch out in the spring, but it looks like this one won’t. Instead it probably provided much-needed protein on a cold day – perhaps for a persistent Chickadee who had to chip away for a while to get to the larva inside.
Nearby, I found a whole patch of Gall Fly duplexes! The holes in these galls are the neat little ones usually made by a Downy Woodpecker (Picoides pubescens). They are experts at drilling holes to find food, after all. Goldenrod Gall Flies must be a great source of sustenance for birds in the winter!
Squirrels in the Winter
This month the Seven Ponds Nature Center in Dryden had an informative newsletter piece about squirrels, written by Lois Rheaume, a naturalist on staff there. Having read it, I decided that I needed to read more about them. Bear Creek, of course, is full of squirrels, three different species that seem like four!
From top to bottom below: the American Red Squirrel (Tamiasciurus hudsonicus), the Fox Squirrel (Sciurus niger), and the Gray Squirrel (Sciurus carolinensis) which comes in two basic colors, gray or black – and variations of those. (No, they are not a cross with a Fox Squirrel; that’s genetically impossible.)
According to Ms. Rheaume, Fox and Red Squirrels were most common in our area when the land was heavily farmed. Red Squirrels and Fox Squirrels spend more time on the ground so open farm lands suit them. Gray Squirrels spend more time up in trees, so as trees have taken over open fields and have matured in suburban neighborhoods, more Gray Squirrels have moved in. Squirrels can move easily up and down trees because their back feet can rotate 180°!
Fox and Gray Squirrels bury nuts underground. Using excellent spatial memory and a keen sense of smell, they find about 95% of them. (The forgotten ones help trees to sprout in our forests.) The Red Squirrel, who grows a rusty strip of fur down its spine for the winter, makes a cache on top of the ground.
Ms. Rheaume’s piece informed me that squirrels assess acorns by rotating them quickly under their sensitive noses with their front paws. They tend to eat White Oak acorns (Quercus alba) right away because they have thinner shells and sprout more quickly. They’re also less nutritious for them. Squirrels are more likely to store Red Oak acorns (Quercus rubra) which contain higher amounts of tannin to preserve them and because they contain more fat and nutrition for winter months. Amazing what creatures know.
Some folks may not know that squirrels build nests in trees, nests that can be mistaken for those of hawks, for instance. Squirrels prefer a tree hole on a cold, snowy night but they are frequently unavailable. They build nests, called “dreys” in the fork of a tree or where a sturdy limb meets the trunk. These dreys can be used for young in the summer but they can also come in handy on cold days.
Dreys end up being a foot or more in diameter and start out with a platform of small branches with green leaves attached. Squirrels gnaw off these branches before autumn, so that the leaves don’t fall, but stay on for the winter. Ms. Rheaume saw one dislodged by a storm. It contained “a fluffy layer of leaves and sticks on the outside with the next ‘wall’ lined with several layers of oak leaves, making a virtual waterproof barrier for the soft grasses, shredded bark, and lichens which make up the soft bed in the center.” According to Wikipedia, dreys have one or two “entrance/exit holes…usually close to the bottom and oriented toward the trunk which keeps the rain out.” Sounds reasonably cozy on a cold night, doesn’t it?
It seems that the coming week will be as topsy-turvy as the last one – a huge snowstorm followed by a warm weekend. The dry stalks of last year’s plants, like the Queen Anne’s Lace (Daucus carota) above, are succumbing to the weight of snow, wind and cold. But through it all, the creatures of Bear Creek find ways to keep warm, find food and keep us company as the days get noticeably longer. I heard a report of a Sandhill Crane (Grus canadensis) arriving this week. We have lots of Red-winged Blackbirds (Agelaius phoeniceus) in our yard and we saw an obese Raccoon (Procyon lotor) taking a hibernation break and stuffing itself beneath our bird feeder. Perhaps these springtime creatures were fooled by strangely warm winter days or perhaps they know something else we don’t! Time will tell.
Footnote: My sources for information are as follows: Ritland, D. B., & Brower, L. P. (1991); Stokes Nature Guides: A Guide to Bird Behavior Volumes 1-3, Allaboutbirds.org, the website of the Cornell Ornithology Lab at Cornell University; Wikipedia; http://www.butterfliesandmoths.org; Herbarium of the University of Michigan at michiganflora.net; various Michigan Field Guides by Stan Tekiela; Butterflies of Michigan Field Guide by Jaret C. Daniels; University of Wisconsin's Bug Lady at www4.uwm.edu/fieldstation/naturalhistory/bugoftheweek/ for insect info; http://www.migrationresearch.org/mbo/id/rbgr.html for migration info; invaluable wildflower identification from local expert, Maryann Whitman; experienced birder Ruth Glass, bird walk leader at Stoney Creek Metro Park for bird identification; Birds of North America Online; Audubon.org; Nature in Winter by Donald Stokes, Trees in My Forest by Bernd Heinrich, Winter World by Bernd Heinrich, Savannah River Ecology Lab (Univ of Georgia); Tortoise Trust website www.tortoisetrust.org; An Orchard Invisible: A Natural History of Seeds by Jonathan Silvertown; The Ecology of Plants by Gurevitch, Scheiner and Fox; other sites as cited in the text.