Often the trees are from the North American boreal forest - a swath across 1.4 billion acres of Canada and Alaska.
It constitutes a vast nursery for between 30 and 40 percent of North Americans land birds, shorebirds, and waterfowl - many of which spend the winter in this region, eating out of our feeders.
Of course, the boreal forest is being logged. Millions of acres are clear-cut each year, according to the Boreal Songbird Initiative, a nonprofit advocacy group.
The last few years have seen significant changes. Environmentalists and the paper industry have declared a truce and are figuring out how to protect both the forest and the forest products industry, said Jeffrey Wells, the Initiative's senior scientist.
But, bottom line, "Trees are still being cut," he said.
Fortunately, there are alternatives - paper products made from recycled paper.
Environmentalists often mention New Jersey-based Marcal, whose Small Steps line is made of 100 percent recycled paper - junk mail, old magazines, office paper waste.
Papers like this used to be specialty items. Recently, they've become common in grocery stores.
By choosing them, you'll keep the market pressure on paper product companies.
"We're hoping that continued recognition of the connections between the birds and the products" keeps up the momentum, Wells said.
On to the land of coffee, the southern end of many birds' geographical range.
With each sip of your morning brew, you can choose to help - or to hinder - the Baltimore orioles and many other species that winter in Central and South America.
You want coffee grown in the shade - the traditional, synergistic way that benefits all kinds of life. Shaded coffee farms have teeming populations of insects, orchids, frogs - and birds, more than 150 species, say biologists for the Smithsonian National Zoological Park.
But now, coffee production is dominated by rows of plants in cleared, sunny fields that require dosing with pesticides, herbicides, and fertilizers. Nix the shade, researchers have found, and the number of bird species drops by 97 percent.
The connections between here and there are incredibly strong. Bridget Stutchbury, a conservation professor at York University in Toronto, has banded wood thrushes - an iconic Pennsylvania species - near Erie.
They wound up at a shade coffee plantation and research site, El Jaguar, in Nicaragua, where forest losses pretty much match losses in the wood thrush population. A wood thrush banded there was recovered later outside Philadelphia.
Farmers are feeling financial pressure to clear their shade farms. Buying shade-grown coffee "removes the pressure," said Stutchbury.
With increasing awareness, more shade-grown coffees are available. Yes, they cost more. You can get a pound of Maxwell House for less than $6, and most specialty coffees cost more than double that.
But if we've already proved - in the amount we spend on backyard bird-feeding - that birds have value, many people can probably chip in a little more for better coffee.
(And many say that, because shade-grown coffee ripens more slowly, the flavor is better.)
Packages have an array of logos to help you choose.
The Smithsonian Migratory Bird Center certification is considered the gold standard. Those coffees are not widely available except online. Interest is growing, however, and outlets are increasing.
A West Chester roaster, Golden Valley Farms, offers several Smithsonian-certified coffees from Peru, Guatemala, and Nicaragua.
Expanding the online presence, crews took Golden Valley coffees to farmer's markets in this region last summer, and had a good response, said owner John Sacharok. Now, they're also available at Whole Foods in Devon and Glen Mills.
Much more widely available - including at my local grocery, albeit on the bottom shelf - are Rainforest Alliance certified coffees. The certification isn't as rigorous, but it's a big step up from sun-grown coffee.
Wells likes to set this scene when he gives talks: You're in your kitchen in the morning, looking out the window, smiling at the birds on the feeder.
You're also wiping up a spill on the counter. Or taking another sip of coffee.
"Are you thinking about where that paper towel came from?" he asks. "Are you thinking about where the coffee came from? Is it affecting the birds you're watching?"
The answer is yes.
"GreenSpace" appears every other week, alternating with Art Carey's "Well Being" column. Contact Sandy Bauers at 215-854-5147 or firstname.lastname@example.org, or follow on Twitter @sbauers. Visit her blog at www.philly.com/greenspace.