The snow and ice of winter can be enough to keep the boldest naturalist indoors and watching David Attenborough documentaries with a mug of hot chocolate in hand — but bundle up, because there’s still a lot to take in outside. Here are some ideas to get you started.
Whatever you end up observing, consider documenting it with volunteer science tools such as eBird and iNaturalist. This is a great way to keep track of your finds while making the data available for scientists and conservation agencies.
When the Temperatures Drop, the Action Picks Up Overhead
You’re probably used to seeing a flock of pigeons take off in a clapping whoosh of wingbeats and sweep through the sky in a flock that surges one way and then another until they settle on a power line or the edge of a building. Keep an eye on those flocks this winter, and you might spot a slightly larger bird with a longer tail tracking the pigeons and doing its best to catch one for a meal.
Cooper’s Hawks — along with Sharp-shinned Hawks, their smaller but outwardly similar relatives — breed in small numbers in Philadelphia, but winter brings their country cousins into the city. Here they hunt our abundant sparrows, starlings, pigeons and other native birds such as mourning doves.
Both of these species of hawk are agile flyers adapted to chasing birds through thickets and around tree trunks. In the city, those skills take them in blazing pursuits around building corners and even under parked cars to flush out their prey.
Both can also be seen resting on tree branches. Compared to our abundant Red-tailed Hawks, Cooper’s Hawks have a slender build and a longer tail. Immature birds are brown with a light-colored breast patterned with black spots (but without the Red-tail’s distinctive band across the belly). Adult Cooper’s and Sharp-shinned Hawks have breasts marked by short orange streaks, as well as a gray back and cap.
Leaves make it easy to identify trees, but you can still figure out what’s growing on your block or in the forest based on their distinctive bark, branch patterns, the scars left where leaves had grown on twigs and the buds waiting to unfurl into new leaves in the spring. Tree guidebooks always include features to help you identify trees in winter. After a little while, naming trees with no leaves will become second nature. A local arboretum, with so many labeled trees, is a great place to practice. Start on the side without the label and pop around to check your identifications.
Stump Yourself? Look for Beavers
The famously busy beavers of Philadelphia leave behind extensive evidence of their work as they cut down trees and shrubs for food and building materials. Winter, with no leaves in the way, is the perfect time to walk along our creeks, rivers and marshes to search for the stumps left behind by beavers as well as trees whose inner bark they are eating or cutting down.
Although they can make life difficult for landscapers and park managers, our urban beavers are a conservation success story. They were wiped out in our region by the mid-1600s due to the trade in their pelts (the original commodity that brought European colonists to the land of the Lenape), but reintroduction efforts in the mid-1900s succeeded wildly, resulting in our booming beaver population.
While humans tend to use blades or chainsaws to cut straight through a tree or the stems of a shrub, beavers go one bite at a time, leaving a pile of woodchips on the ground. They’ll work through a larger trunk in what looks like an hourglass pattern, leaving a pointed stump once the tree falls. They can take out smaller stems of shrubs in one bite, leaving behind an angled surface with a point.
Stumps that beavers leave behind often resprout, so when you see trees like cherries, maples or willows growing as a cluster of small stems near the water, check the middle of the cluster for the original trunk still showing the telltale evidence of beaver chomping.
Beavers living in large waterways often burrow into the banks instead of building lodges, and they don’t always build dams. But once you get the hang of it, you’ll start spotting beaver signs (evidence of an animal’s activities) along waterways throughout the city.
Tracks in the Snow
Get outside as soon as the flakes stop falling. We have the option to stay inside, but plenty of animals don’t have a choice but to get out and make a living. The prints they leave in the snow can tell you a lot about who is living where and what their habits are.
On your block you can pick out tracks of dogs and cats (and, of course, humans). Start at tree trunks and the bases of utility poles for the tracks of squirrels, bounding so that they land with their back paws in front of their front paws. Sparrows, starlings, pigeons and other birds leave tracks as they forage for seeds and our crumbs. Observe how birds hop (like sparrows) or walk one step at a time (like a pigeon). Can you tell which tracks came from which birds?
If you can get into a wooded park, you can see how the forest comes alive (or came alive the night before) with the tracks of foxes, raccoons, deer, opossums and white-tailed deer. Be sure to get your eyes close to the ground. Voles, shrews and white-footed mice leave tiny prints as they move between the surface and their subnivean (under the snow) tunnels.
Tracks can tell amazing stories. Rodent tracks along walls can show you where rats and mice leave their burrows and forage for food. Fox prints in a park could lead you to a hole in the snow, where the predator jammed its snout down to catch a rodent it could hear running through its subnivean tunnels.
Go On a Basement Safari
If you can’t make it outside and still need a nature fix, head to the basement with a flashlight. Long-legged cellar spiders, house centipedes and other arthropods adapted to caves make themselves at home in our basements, where their slow metabolisms fit the quiet and cool conditions.
Try not to freak out. These are harmless critters, and they can be a great introduction to nature exploration and entomology for the whole family.
Don’t have a basement? Check window sills and underneath furniture and appliances such as refrigerators for spider webs and the tiny arachnids trapping bugs in your apartment.
Remember, you don’t have to venture out into the cold alone. Consult your local nature center or park group for their schedule of walks, and check the calendars of our many birding groups and Audubon chapters for a walk near you. You’ll learn from the experts and be able to practice new skills until the spring thaw.
Bernard Brown is a nature writer at Grid magazine and author of Exploring Philly Nature: A Guide for All Four Seasons.