Nov 092017

Late fall is a great time to get to know these enigmatic structures

I’ve always loved November. Maybe it’s the change of pace and the sense of nature slowing down. Yet, we do notice changes. As deciduous trees shed their leaves, our eyes are drawn to the conifers like at no other time of year. They stand out in all their green splendor and beautiful shapes. And, if you look closely, you’ll notice something special this year: they are laden with a huge crop of cones.

You’ve probably held them, maybe used them to make a holiday wreath, but how many of us really know what cones are? The short answer is that cones – named after their shape – are the reproductive parts of an ancient branch of plants known as gymnosperms. Conifers form the largest group of living gymnosperms, but gingko trees also belong to this class of plants. About 300 million years ago, the gymnosperms became the dominant trees on the planet. They continued their dominance throughout the Triassic and Jurassic periods – the age of the dinosaurs. Their cones were even a favourite food of species like duckbill dinosaurs. The gymnosperms reigned supreme until the rise of the angiosperms – the flowering plants – during the Cretaceous period.

The arrival of gymnosperms was revolutionary, because it heralded the advent of the seed. This was as profound an evolutionary event as the development of the shelled egg in reptiles. Just as the egg allowed reptiles to become the first truly terrestrial vertebrates – and break nearly all aquatic ties – the evolution of the seed meant that plants no longer had to grow in moist environments like their fern and moss ancestors did. They could therefore colonize upland habitats. The gymnosperms protected their embryos from drying out by encasing them in a tough waterproof seed coat.

A closer look

All conifers produce cones. In fact, this is where the name “conifer” comes from. It is not accurate to call these trees evergreens, because some species, the tamarack for example, actually shed all of their needles in the fall, just like a maple or an oak. And not all cones are pine cones. This term only describes the cones of the pine tree. The cones of the other conifers should be named according to their parent tree.

Gymnosperms are different from angiosperms in that they lack true flowers. There are no petals, stamens, pistils or ovaries. In fact, the word gymnosperm actually means “naked seed”, because the seeds are not enclosed in an ovary. They simply develop from an ovule (egg) located on the inner surface of each of scales. Flowers, on the other hand, are produced by angiosperms, which include everything from oaks and maples to grasses and daisies. Angiosperm seeds develop when a pollen grain adheres to the stigma at the top of the pistil, travels down through the style and fertilizes an ovule located in the ovary. When you eat an apple and spit out the seeds, you are eating the enlarged ovary.

Male vs. female

As is the case with many flowers, cones can be either male or female. Both usually occur on the same tree. Junipers are an exception, having separate male and female trees. Let’s look at the female cone first. These are the typical hard, brown, woody cones. They consist of a central stalk surrounded by stiff, overlapping scales, reminiscent of wooden shingles. The ovules, which when pollinated become seeds, are located at the base on the inner surface of the scale. If you pry open the scales of a mature cone before it falls from the tree, you can often see the seeds inside. In white pine and balsam fir, the female cones are located high up in the tree at the tips of the branches. In most other species, they are found lower down, as well.

The male cones, also known as pollen cones, are much smaller (often only a centimetre or two in size) and far less conspicuous structures. Usually located on the lower branches, they are most often brown or reddish and resemble little spikes or buttons. They have a central axis, which bears pollen-producing structures. You’ve probably brushed up against them, causing a smoke-like cloud of pollen. Soon after the pollen is released, the male cones whither and drop from the tree. You will often see piles of male cones under pine trees in early summer.


Each conifer species follows its own reproduction timetable. In the case of the white pine, Ontario’s provincial tree, clusters of male cones first appear in the spring at the base of new twig growth. A few weeks later, the soft, green and purplish female cones emerge. At the time of pollination, they are about two centimetres long. Towards the middle of June, the male cones release their pollen grains. The grains are so well adapted to wind pollination that they actually contain two air bubbles. Only an infinitesimally small amount of pollen ever makes it to the female cones, however. Most of it simply descends from the sky turning cottage decks, shorelines and puddles a lemon yellow.

At the same time as the pollen is released, the female cones become receptive to receiving the airborne sex cells. The tiny cone scales open slightly  and a small amount of fluid is secreted which serves to “trap” the pollen and draw it in towards the two ovules at the base of each scale.

Having secured pollen, the scales begin to thicken and to press tightly together. The cone continues to grow, hardens and turns from green to brown. Strangely enough, the actual fertilization of the ovules by the pollen only occurs 13 months later. It then takes an additional 13 months or so for the seeds to mature. In late summer, the scales dry out, flex backwards and open up one final time. This allows the seeds inside to simply escape to the wind. Each seed has a tiny wing, which helps it to float on the air, travelling up to 200 metres from the parent tree. In all, the process of reproduction will have taken over two years. The cones themselves drop off the tree during the late fall or winter, a few months after seed release. You can find them on the ground right now under almost any white pine.

Cone and seed development in all of the other conifers requires less than one year. In the case of white spruce and eastern hemlock, for example, the cones open and shed their seeds during their first fall or winter. The seeds often litter the snow. Spruce cones drop from the trees during this same period, but the cones of the hemlock remain on the branches until spring. White cedar cones also open in the fall and shed their seeds over several months.

With balsam fir – the best choice for a Christmas tree – the process is quite different. The scales themselves drop off the cone while it is still on the tree, thus liberating the seeds to the wind. All that is left is the bare, stick-like core of the cone. It can remain on the tree for several years. Balsam fir cones grow in dense groups near the top of the tree and stand straight up like candles.

In some conifers like junipers and yews, the scales on the female cone swell up and fuse together after pollination. This leads to the formation of a small, soft, fleshy cone, which superficially looks like a berry. You may have noticed the huge number of blue, berry-like cones on junipers (e.g., eastern red cedar) this year. Each contains one to four brownish seeds. Red cedar “berries” are very popular with birds like waxwings and robins.


Cones are a testament to the wonder of evolution. The arrangement of the spirals of scales, for example, is anything but random. They follow nature’s numbering system, known as the Fibonacci pattern. It goes like this: 1, 2, 3, 5, 8, 13, 21, 34… (each subsequent number being the sum of the two preceding ones). If you look closely at a pine cone, you’ll see a double set of spirals, each going in a different direction. When these spirals are counted, the two sets are found to be adjacent Fibonacci numbers. For example, you might see eight spiraling counterclockwise and 13 spiraling clockwise. Larger or smaller cones can have different pairs of numbers. No, trees are not mathematicians. This arrangement is simply the best use of space, so it has been favoured by evolution.


For a great holiday activity, you might want to try making a cone wreath. Going out to gather the cones themselves is half the fun. Try to find cones from different species. You’ll also need to make a cardboard base. The base can be cut into any shape you like – maybe a snowflake. Paint the cardboard or glue on a piece of felt. Then, using a glue gun, attach the cones to the base. If you spray the cones with water several hours before you begin, the scales will usually close and be easier to work with. Glue on the larger cones first, and then fill in the remaining spaces with the smaller ones. You can also add accents such as acorns and sumac berries. After the cones have fully dried and the scales reopened, spray the wreath with a clear lacquer. Handled with care, it will last for years and be a beautiful holiday reminder of the fascinating biology of cones.


Oct 192017

Bird numbers and diversity at feeders at feeders depends on wild seed abundance

If you’ve been paying attention to coniferous trees this fall, you’ve probably noticed the abundance of cones on many species. Cedars and spruce, for example, have produced an especially heavy crop. The quantity of seed on sugar maples, too, is of epic proportions, most likely in response to last summer’s drought. In fact, the maples put so much energy into manufacturing seeds that the leaves on many trees never grew to their normal size.

The relative abundance of seed has a ripple effect on other species, as well. For instance, it goes a long way to telling us what birds are most likely to keep us company in the coming months. Anyone who feeds or watches birds knows that the relative abundance and diversity of species varies widely from one winter to the next. Last year, for example, thousands of robins overwintered in the Kawarthas. This was largely due to an abundance of wild grape. American goldfinches and purple finches were also very common. Other species, such as pine siskins, were almost completely absent.

The fluctuation in winter bird abundance is most noticeable in a group known as winter or northern finches. The term is used to describe highly nomadic species like redpolls, siskins, purple finches and pine grosbeaks, all of which belong to the Fringillidae family. Some winters, they don’t show up at all, while other years there are so many that they empty your feeder in only a day or two.

Northern finches move south – or sometimes east or west – in late fall when there is a shortage of seeds in their breeding range, which extends across Canada’s boreal forest. Seeds come in many forms. These include berries (e.g., mountain-ash), catkins (e.g., birch) and cones (e.g., spruce). In the case of cones, the seeds are located under the scales. The key seeds affecting finch movements are those of white and yellow birches, alders, American mountain-ashes, pines and spruces. If seed crops are good in the boreal forest, the birds usually stay put. If food is lacking, they will sometimes fly thousands of kilometres to find it. Whether they actually choose to spend the winter in central Ontario and the Kawarthas depends mainly on the abundance of seed crops here.

Since the fall of 1999, Ron Pittaway of the Ontario Field Ornithologists has prepared an annual forecast of what winter finch species are most likely to make an appearance in southern and central Ontario during the coming fall and winter. The forecast is based on information he collects on the relative abundance of seed crops in the boreal forest. According to Pittaway, cone crops across northeastern North America are of bumper proportions this year – maybe the best in a decade or more. Given the amount of food available, this should be a banner winter to see cone-loving species such as pine siskins and both white-winged and red crossbills. The big question, however, is whether these birds will concentrate in only some areas or be spread out across the entire northeast.

Finch forecasts

1. Pine Siskins – Siskins should be common in the Kawarthas this winter, drawn here primarily by the abundant cone crops on spruce. They will almost certainly turn up at nyger seed feeders, as well.

2. Common Redpoll – Redpolls, too, are likely to put in an appearance. The birch and alder seed crops on which they depend are below average in northern Ontario, so they won’t be hanging around. However, this southbound movement may be slowed or stopped as soon as they discover adequate food supplies. If redpolls do make it to the Kawarthas, good local birch seed crops and an abundance of weedy fields should keep them here. You can also expect them at your nyger seed feeder. If a flock of redpolls graces your backyard, watch for small numbers of hoary redpolls. They tend to be larger, paler and smaller-billed than common redpolls.

3. Crossbills – Thanks to the crossed tips of the upper and lower mandibles of their bill,   crossbills are able to specialize in removing seeds from beneath the scales of conifer cones. Red crossbills prefer pine cones, while white-winged crossbills are attracted mostly to spruce, tamarack and hemlock. There should be a good showing of red crossbills in central Ontario in the coming weeks and months. In fact, many will probably take time to breed, despite the snow and cold. Both species of crossbills are able to nest at any time of the year if food is abundant. Watch for streaked juvenile birds.

Red crossbills are of particular interest to scientists who study evolution. Research suggests that there are nine or ten discrete populations, each of which specializes in a different conifer species. They do not interbreed and may represent different species. Careful examination shows differences in body size and in the length of the bill tip (degree of “crossing”). Most types are impossible to identify, however, without analyzing recordings of their flight calls. Matt Young, a researcher at the Cornell Lab of Ornithology in Ithaca, New York, is studying red crossbills and needs your help. He is asking people to use their smartphone to record the birds’ flight calls and to send him the recordings at He will then identify which of the populations the birds belong to and let you know.

White-winged crossbills move east and west like a pendulum across North America, searching for bumper cone crops. Large numbers have already arrived in parts of the northeast, where they’ve been gorging on spruce seeds. There’s a good possibility that they will also turn up in the Kawarthas, too, and probably right here in Peterborough. Watch and listen for their loud trilling songs given from tree tops and during circular, slow-flapping display flights. Algonquin Park, however, is usually the best place to see these birds. Both red and white-winged are often observed right on Highway 60, where they glean grit and salt from winter road maintenance operations. Unfortunately, crossbills rarely come to feeders.

4. Pine Grosbeak – Most pine grosbeaks will probably stay put this winter, since the mountain-ash berry crop is abundant across the north. A few might get south to Algonquin Park, but they are unlikely to turn up in the Kawarthas. When they do make an incursion into central Ontario, they usually found feeding on European mountain-ash and ornamental crabapples. Considered the most beautiful of the boreal finches, pine grosbeaks can be surprisingly tame.

5. Evening Grosbeak – Most evening grosbeaks are expected to remain in the north this winter. However, you can usually see grosbeaks by checking out the feeders at the Visitor Centre in Algonquin Park. In 2016, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) declared the evening grosbeak as a species of Special Concern due to worrisome population declines.

6. Purple finch – Most purple finches will stay north this winter, thanks to the heavy seed crops on conifers and mountain-ashes. They usually appear at my feeder in early fall, but this year I’ve haven’t seen any. An easy way to tell purple finches from look-alike house finches is by checking the tip of the tail; the former has a distinctly notched or slightly forked tail, whereas the house finch’s tail is squared off. Both species prefer black oil sunflower seeds at feeders.

Non-finch species

1. Blue Jay – Thanks to a good crop of acorns, beechnuts and hazelnuts, large numbers of blue jays will probably remain in the Kawarthas this fall and winter. I am already noticing above-average numbers.

2. Red-breasted nuthatch: Like many of the finches, this species depends primarily on conifer seeds. Pittaway is therefore predicting large numbers in central Ontario this winter. This was certainly the case on Thanksgiving weekend at Big Gull Lake, south of Bon Echo Provincial Park. Red-breasted nuthatches were by far the most common bird.

3. Bohemian waxwing: Most bohemians should stay in the north, because of the large berry crop on American mountain-ash. That being said, we almost always see at least a few flocks of this species in the Kawarthas every winter. This may be partly due to the local abundance of European buckthorn, a non-native shrub that produces a large berry crop every year. Bohemian waxwings are also attracted to European mountain-ash and ornamental crabapples.

4. American robins:  Although not part of Pittaway’s forecast, I suspect that robin numbers will be low this winter, given the poor crop of wild grape. Last year, thousands of robins overwintered here and gorged themselves primarily on abundant wild grapes.

The best way to stay on top of bird movements across Ontario is to subscribe to Ontbirds. You will receive a daily digest of sightings. Sign up at To follow what’s happening locally, I recommend using eBird. When you go to the website, click on “Explore Data” and then “Explore a Region”. Type in “Peterborough, Ontario”. Choose “Current Year” and then click on “Set”. You will see an up-to-date list of all species seen in the area. By clicking on “Species Name”, the birds will appear in the same order as in your field guide. By clicking on the date, you will see where the bird was seen, along with other species observed at the same location.

Project FeederWatch

If you feed birds, you can support research and conservation by taking part in Project FeederWatch. Simply count the kinds and numbers of birds at your feeder, and then submit your observations. This information helps scientists study winter bird populations. To register, go to or call Bird Studies Canada at 1-888-448-2473.





Oct 022017

I live in Northumberland County – Baltimore to be exact, 10 km north of Cobourg near the Balls Mills conservation area. We are surrounded by forest. Our own property is 3 acres of forest that backs on to Baltimore creek. Beyond that is a mix of forest, marsh and farm land. Anyway, Since July I have noticed that there are no more Red Squirrels around! There used to always be 3 or 4 hanging around, getting into my feeders and making a racket! It’s so quiet without them that it’s bothering me now. I’ve had one Gray Squirrel (black colour morph) come by a few times, and they are actually rare to see in this forest environment normally. What could account for their sudden disappearance? We’ve lived here 5 years now, and they’ve always been around. I’m assuming a predator of some kind might be present, but I expected the space to be re-populated rather quickly. I have a game camera set up on, and I’ve caught everything you can name – coyote, fox, raccoon, deer, etc. I even caught a blurry image of what I believe to be a Fisher.  In past years they would be busy gathering all the cones from the conifers, but this year the cones are all still there and it’s a bumper crop! Anyway, I was wondering if you might provide some insight or opinion?

Pierre Gilbert, Baltimore, ON

Note: Since Pierre wrote this (August 29), one Red Squirrel is now present. It may be that a predator such as a Barred Owl is responsible for the drop in squirrel numbers. That being said, small mammals like Red Squirrels and Eastern Cottontails go through population cycles in which abundance can vary dramatically. These are poorly understood as to cause.

Pierre also reports (October 1) that the usual forest birds that visit his feeders have completely disappeared. “Where I used to fill up the feeders daily and weekly, they now sit almost full for weeks on end. Usually in abundance, I almost never see chickadees (although I hear them around) or nuthatches. Could it be that there is such a good crop of natural food that they are simply not bothering with the feeders? The only frequent visitors I have are several woodpeckers (both small and large) that visit my suet feeder. Other then that, I’ve had almost no traffic.”

Red Squirrel – Terry Carpenter