Maples catch fire,
red sparks against cool mornings—
autumn is begun.
Peterborough Examiner – September 19, 2025 – by Drew Monkman
For me, fall always feels like a fresh start – the true New Year. I find myself energized by the cooler air, the change of colour in the leaves and even the shorter days. I also take a certain comfort in the return of predictable schedules. This year, the change of season couldn’t have come soon enough. This past summer’s severe drought and intense heat – 18 days above 30 C – just about did me in.
Although we experienced a rather abrupt transition to autumnal temperatures this year, the Weather Network is calling for an extended stretch of consistent mild weather from now through to November. Autumns in the Kawarthas have trended much warmer in recent years.
As I do at the beginning of each season, I want to look ahead this week to some of the events in nature that are typical of fall. If you need help identifying some of the species mentioned below, be sure to use the free Merlin app for bird identification -including bird vocalizations – and the Seek and iNaturalist apps for everything else. Seek is the more beginner-friendly sister app to iNaturalist.
A more detailed account of what’s happening each month can be found in my book “Nature’s Year in Central and Eastern Ontario” and on my website at https://www.drewmonkman.com/. Click on Almanacs.
September
- In response to the severe summer drought, many sugar maples are changing colour much earlier than usual. The stress of drought pushes trees to shut down growth sooner, breaking down green chlorophyll and revealing red, yellow and orange pigments. In some cases, stress even boosts anthocyanin production, intensifying reds, but if conditions are too harsh, leaves may simply turn brown and drop early.
- Monarch butterflies are migrating. These butterflies will travel an astonishing 4,500 kilometres to the mountains of central Mexico. To mark this remarkable phenomenon, The Monarch Ultra is hosting Peterborough’s third annual Monarch Butterfly Festival on September 20 from 10 am to 2 pm at Millennium Park. It is a family-friendly event that combines nature, community, and fitness. Highlights include a 10 km and 1 km race, educational activities, and celebrations of the monarch’s incredible migration. For more information, go to https://www.themonarchultra.com/peterborough.html
- Fall songbird migration is well underway. Watch for warblers, vireos and other songbirds in trees and shrubs along forest edges and rail trails. Quite often, they are in mixed flocks with chickadees.
- Fall webworm activity is conspicuous. Watch for the large silk webs spun by the larvae that encompass the tips of tree branches.
- If you see goldfinches or cardinals looking ragged, patchy or even “bald” in late summer, this is perfectly normal — it’s molt season and many birds are replacing worn feathers.
- In damp, sunny areas, the orange, red-spotted flowers of jewelweed (touch-me-not) catch the eye. Look for a fat seed pod, pinch it, and feel it explode between your fingers, scattering seeds up to a metre away.
- When walking in the woods on a warm day, listen for the high-pitched calls of lone spring peepers. Light conditions similar to spring may inspire these vocalizations known as the “fall echo”.
- One of the most common and iconic sounds of September is the squawking of blue jays as they move about in small flocks.
- Be sure to put your bird feeders up by late September. Purple finches often show up in our yards at this time.
- Take time to appreciate and identify the wide variety of fall asters.
- The fall equinox occurs on September 22, marking the beginning of autumn. The Sun rises approximately due east and sets due west.
October
- Large numbers of migrating turkey vultures are often seen in early October as they soar southward to overwintering sites in the southern US and both Central and South America.
- White pines are shedding some of their needles. Notice how about a third of the needles furthest from the branch tips are now yellow-brown.
- On October 9, Dr. Erica Nol will speak to the Peterborough Field Naturalists on studies of how farming, logging, trails, development, and climate change affect songbirds in southern Ontario. The event takes place at the Camp Kawartha Environment Centre from 7 to 9 pm. For more information, go to: https://peterboroughnature.org/about/
- Red and sugar maples – two stalwarts of fall foliage – usually reach peak colour around Thanksgiving Weekend.
- The first “winter finches” like common redpolls and pine siskins sometimes show up in mid- through late fall. To learn which birds to expect this year, Google “winter finch forecast 2025-2026.” It should be available by late September.
- This is a great month to see fungi such as pear-shaped puffballs (Apioperdon pyriforme), turkey tail (Trametes versicolor) and orange jelly (Dacrymyces chrysospermus). All can be found on dead logs and stumps.
- A tide of yellow spreads across the landscape in mid- through late October. It comes courtesy of aspens, balsam poplar, silver maple, white birch and, at month’s end, tamarack.
- In the weeks leading up to the November rut, the antlers of white-tailed deer harden and the velvet skin covering them dries up. Bucks proceed to rub it off by scraping their antlers against small trees. Watch for portions of bark that have been removed.
November
- Late October through November is the best time to see migrating diving ducks such as goldeneyes, buffleheads, scaups, ring-necked ducks, redheads and mergansers. All of these species stop over on our larger lakes. Some of the best viewing is at Pengelly Landing on Rice Lake and at the Lakefield Sewage Lagoons on County Road 33.
- Non-native trees and shrubs like lilac and buckthorn, along with our native oaks, tamaracks, and silver maples are about the only species that still retain foliage in early November.
- Beavers are active all day long cutting and storing large piles of branches – their winter food – on pond bottoms near the lodge. The piles are usually visible.
- Standard Time returns on Sunday, November 2 at 2:00 am. We turn our clocks back one hour.
- This is a great time of year to focus on evergreen plants of the forest floor and rock outcrops. Look for mosses, liverworts, wood ferns, and club-mosses.
December
- Every year, small numbers of glaucous, Iceland, lesser black-backed and great black-backed gulls show up on Little Lake this month.
- Ball-like swellings known as galls are easy to see on the stems of goldenrods. If you open the gall with a knife, you will find the small, white larva of the goldenrod gall fly inside.
- Ducks that linger here all winter usually include common goldeneye and both common and hooded mergansers. Some trumpeter swans remain, as well, especially on Lake Katchewanooka.
- Cooper’s hawks are quite common in the city during the fall and winter months. They often prey on mourning doves at feeders. Most years you can also see one or two peregrine falcons perched on the river side of the Quaker Oats plant in Peterborough.
- The Peterborough Christmas Bird Count will likely be held on December 20. Anyone interested in participating should contact Martin Parker at mparker19@cogeco.ca
