In the fall, leaves will fall from multiflora rose, making it easier to spot this invasive plant. Steve Miller/Associated Press

Time to cut back invasives

One of my favorite things about gardening and yard work in the fall is that I get to be lazy. As I’ve written about here in the past, and many people ask about at this time of year, a good motto to adopt in the fall is “leave the leaves.”

Let your yard get a bit wild as winter sets in. Those leaves will provide very important shelter for a number of species, especially insects, and ultimately will put nutrients back into the soil as the leaves decompose. So you get a healthier yard all around. That said, this is also a good time to go on the offensive and identify invasive species that should be removed from your yard.

By “invasive” species, we are talking about the plants that are non-native to Maine and present a threat to our wildlife and habitats. There are many plants – possibly a lot of the flowers and other ornamental things you’ve planted in your yard – that are not native, but there is a growing list (100-plus species) of plants that will outcompete natives and actually be detrimental to the landscape. Battling invasives is often a never-ending task, but with dedicated effort – especially at the right times of the year – we can give our native plants a fighting chance.

Fall is a good time to tackle invasives for a few reasons. First, depending on your efforts earlier in the year, most species are going to be at their greatest abundance. In spring, I find it easy to overlook a fresh shoot of some invasive vine, but in fall many will be grown enough to be easier to find, assuming you haven’t already been lopping them back in the summer. In that same regard many species are going to be easier to identify in the fall thanks to diagnostic features such as fruit or color of their leaves. For example, I find the leaves of Japanese barberry (Berberis thunbergii) much easier to spot in the fall as they turn a vivid red; they were camouflaged among all the greens in the summer. The leaves falling off multiflora rose (Rosa multiflora) help me detect their unique fruit (rose hips) and often bicolored stems that could have been easier to overlook the last few months.

Speaking of distinctive fruit, an important part of cutting back invasives in the fall is to remove those seed-bearing fruits from the landscape. Many birds will be feeding on these and inadvertently spreading the seeds as they move around Maine (and beyond). Leave behind those lovely clumps of winterberries, but keep your eyes peeled and be ready to cut back the orange husked red fruit from Japanese knotweed that is popping open.

Cut back as much of the invasive plants as you can. In fall, as in the spring, we have the advantage of a typically wetter soil, which can be helpful for digging and pulling up complete root systems. Keep that leaf blower in the shed but grab the pruners! One extra leaf and one less invasive at a time – these are the steps we need to take to help Maine’s wildlife in our yards.

Hearing birds at night

The woods have gotten very quiet as the breeding season has wrapped up for many of our birds and even insects. As I wrote in my last column, you can hear quite a few young birds learning their songs right now, but Peter Larson of East Boothbay wrote in to ask about some bird noises he was hearing at night, wondering what’s the deal with that?

First, I should mention that Peter was specifically asking about noises he was hearing from songbirds, but it is worth noting that some of our nocturnal birds are becoming quite vocal. I heard my local great horned owl for the first time in many months just last week, giving his loud “Who’s awake? Me too!” vocalization, an early call for a mate (that went unanswered that evening) or a proclamation to other owls that this territory is taken.

The other common calls you may hear at night right now are from migrating birds. Unlike the typically complex songs we expect from birds, the call notes of high-flying migrants are short chips and buzzes. You might think at first that these sounds are coming from insects, but the speed of the sounds and where they are coming from – up high in the sky – are a giveaway. These are officially known as nocturnal flight calls, or NFCs. Birders often sit out in the evenings and listen to migrating birds, who sometimes pass overhead by the thousands in a single night, and try to tell some of these notes apart. Perhaps my favorite is the NFC of a Swainson’s thrush, which sounds almost identical to the call of a spring peeper. Don’t be fooled – it’ll be coming from hundreds of feet overhead.

A few birds do sing at night, though it will be a rare treat to hear one this late in the year. One of the coolest sounds, in my opinion, is the nocturnal song of the ovenbird, a warbler that migrates to Maine to nest in the summer (and most have left the state for warmer climates by now). Their usual song is a rolling, and increasing in volume: “teacher – teaCHER – TEACHER – TEACHER!” But at night you can hear a more complex version that’s almost twice in length and sounds like 10 times the effort.

Another famous night singer is the unpaired male northern mockingbirds. You’ve maybe heard these noisy males singing through the night, in an effort to lure females from their neighbor’s territory. It can sound pretty obnoxious at times but is perhaps better than blasting “In Your Eyes” from a boombox…

As the fall progresses we won’t be hearing any of those songsters, but perhaps we’ll have a few more good evenings for picking out NFCs. You may even get lucky and hear an early owl, so get out there before it gets too cold to enjoy those nocturnal noises.

Have you got a nature question of your own? Email questions to ask@maineaudubon.org and visit www.maineaudubon.org to learn more about backyard birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug leads free bird walks on Thursday mornings, 7 to 9 am, at the Gilsland Farm Audubon Sanctuary in Falmouth.