Well, our January thaw is over. The north wind is hissing through the white pines again and yesterday’s mushy soils have congealed to fossilize all us critter’s footprints together until spring. It’s a good day to go for a brisk walk and check out how well the habitat is holding up. At my place, a couple of pines in the household windbreak have died and there is a noticeable leak there today. The message from the wind is that it’s time to plant more trees. Also, the big old hollow oak “bee tree” in the woodlot went down last summer in a storm. It’s keeping our house warm right now. Looking up from the stump there is a large blue hole in the canopy. By this time next year, the ground below will be a matching circle of weeds, and in a few years, brambles, where the summer sun can penetrate. Eventually, a tree will poke up through and shade them all out again, completing they cycle, and in the meantime songbirds will have enjoyed the weed seeds and bramble berries before relinquishing the cafeteria to squirrels, chippys, and jays. However, our little woodlot only has a few oaks left after a century of mismanagement, so next spring I’ll nudge “eventually” in their favor by planting a seedling in the gap and putting up a little chicken wire sleeve to keep the bunnies at bay, plus a big sidewalk mesh cylinder to restrain the deer.
And what species of oak should it be? The two great oak families each play the habitat game by their own rules. The white oak members (which in our area includes bur, white, post, chestnut, chinquapin, and swamp white) are more reproductively precocious. Their acorns mature in one growing season, are relatively sweet, and start growing a root almost as soon as they hit the ground. If you dig one up after a squirrel has buried it, you might find that the cotyledon has been bit through to keep the embryo tree from growing and consuming its stored food. The red oaks are more conservative and in our area include northern red, black, pin, scarlet, blackjack, and shingle. Their acorns take two seasons to mature and have a high tannin content, which makes them initially bitter and unpalatable to wildlife, prevents spoilage, and helps get them through the winter to begin growing the following spring. Repeated thawing and freezing breaks down the tannins and by late winter the acorns are tolerably edible and become important survival food for everything from woodpeckers to turkeys, at a time when most of the tasty food is gone.
Although the two oak families have diverged and are going their different ways, they are geologically young and within each family there is still a lot of natural cross-breeding going on, as they sort out appropriate adaptions for different niches. Many individuals are obviously hybrids, so don’t get discouraged if you have difficulty with identification.
Our woodlot is short on white oak, so my gap replacement will be from that family. A couple centuries from now, may it get blown down in a summer storm, open a gap for songbirds, and heat someone’s home. But the habitat needs around your place may be different.
Are too many mice chewing up your plantings and moving in with you in late autumn? Maybe you need more of those secretive small owls in your neighborhood. For little guys like the screech, saw-whet, and short-eared owls, there is no finer winter shelter than a dense thicket of arbor vitae or red cedar. Just wander out there on a bitter blustery January day, pay attention, and the winter wind will advise. If it’s too cold and drafty for you, it’s too cold and drafty for them. You’ll quickly learn that a single row of conifers is not very useful as winter cover. However, a little grove of only a dozen evergreens, if growing far enough apart that they can keep needles on their lower branches, can form a cozy shelter. If you cannot find that kind of shelter, where you can take off your mittens and retie your boot laces in comfort, then you need to plant some. Waddyamean your yard is too small? Share a thicket with a neighbor and straddle the property line. Split a 4-way back corner with 3 neighbors and it’s only 3 or 4 trees per lot. How about that odd corner with nothing but a garbage dumpster behind the apartment house up the street? Or maybe on the edge of the stormwater basin over on the next block?
Now is the time the nursery catalogs roll in, often with a good selection of conifers. And seedling native red cedar are available for the asking on many county properties, see my blog for details about this species: Red Cedar: Our Only Local Native Conifer, and the Birds Love It.
This blog first appeared in WINGS, the former environmental journal of the Johnson County Songbird Project. Reprinted with permission from Jim Walters.