When the feeders are stocked we expect the usual residents – Blue Jays, Cardinals, Mourning Doves, House Finches and Chickadees. However, in some years various finches invade from the North. Find out why these seed eating birds are here (or not!).

About ten species of finch in Ontario undergo so-called “irruptions”. In some winters they arrive from Northern Ontario and Quebec in spectacular numbers and in other years they are nearly absent. Around Kitchener these birds include:

• Pine Grosbeak
• Red Crossbill
• White-winged crossbill
• Common Redpoll
• Hoary Redpoll
• Pine Siskin

Why do these finches come south only in some years? Mostly, it depends on how much seed they have in the North. If the trees whose seeds they eat have fruited well, then they will probably winter where they bred in the boreal forest. If these birds are short of food they come south – because the cone crop has failed or the bird population is high, or both.

Each species uses particular tree seeds, so failure of one kind of tree to set seed affects some birds more than others:

• Pine Grosbeaks like Mountain Ash
• Red Crossbills eat Red and White Pine and Eastern Hemlock seed
• White winged crossbills use Black Spruce and Hemlock, never pines 

So…. provide a variety of seed at your feeder to cater to several types of bird and thus to enjoy diversity in your visitors.

Links:

About irruptive finches

Also, try “Googling” “winter finch forecast Ontario Pittaway Iron” (The exact URL changes annually).

Attracting birds to your winter feeder

For identifying birds online, try All About Birds.

And check out Bird Studies Canada‘s site for a national perspective on bird conservation.

With the spring thaw, the ground here is often left crisscrossed with tiny animal runways and dotted with grass nests. These have been the homes of voles that are a feast for local owls. Learn more here!

Mice and voles are different. Mice eat seeds but have a varied diet. Voles, in contrast, are grass eaters, but they can switch to seeds, roots and fruits in winter. And do they eat! By winter’s end grasslands like this are often networked with the feeding tunnels of a growing vole population. Voles thrive under the snow. It shelters them from harsh weather and from predators like owls and foxes.

Voles reproduce quickly, even under the snow. The meadow vole (Microtus pennsylvanicus) has up to 17 litters a year, each of 4-8 young.

Before the snow melts to expose these rodents, owls are already building their nests and then carefully brooding their eggs – often in the cold of February! Young owls hatch just as the snow is melting, and exposing the voles. Hungry owlets can eat as many voles as their busy parents can fetch! Look out for Great horned owls and barred owls here. The picture is of a Short-eared Owl that usually lives in open fields.

Links:

The meadow vole

The Great Horned Owl

The Barred owl

Purple Loosestrife is attractive but this non-native herb has invaded many North American wetlands with destructive effects on native plants. Biological control is now keeping it in check.

Purple Loosestrife is native to Europe and North Africa where it is found in wetlands, on shores and in ditches. Its pretty flowers made Purple Loosestrife a hit with gardeners and it has been widely cultivated. This plant was introduced to North America where it is not native. Purple Loosestrife soon spread to wetlands here and it grew much better than at home. It clogged waterways and crowded out native cattails. It even impacted wildfowl and amphibians. The situation was worsened because plant nurseries continued to sell Loosestrife, thus spreading it further.

Purple Loosestrife is a model for biological control of invasives. This plant arrived in North America without some of the insects that eat it at home. Several of these have now been deliberately introduced here as a control measure. Two leaf-eating beetles (Galerucella) and three seed-eating Weevils are helping to control purple loosestrife.

Please don’t buy purple loosestrife plants and don’t plant them in your garden!

Interesting Links:

Purple Loosestrife

Biological control of Purple Loosestrife

Biological Control

This typical grassy field is being invaded! Aspen are taking over. Read more about this quiet invasion here.

First there is bare ground, then come grasses.Then golden rods and other broad-leaved plants find their way into the grassland next. They pave the way for woody plant invaders, represented here by Red Osier Dogwood shrubs and the Aspen Poplar tree. Both are colonising through seedlings and by suckers sprouting up in the grass. You can recognise the young aspen trees by their bright yellow fall foliage.

When there is a disturbance in the forest more sunlight and warmth reach the ground. This stimulates aspen tree roots to sprout and start a new grove of trees.

Eventually other trees like sugar maple will replace the relatively short-lived aspens. You can see a grove of sugar maple trees further north on this trail.

Ecologists call this replacement of one plant community by another “succession”.

Aspen trees are a hugely important tree in North America, both as wildlife habitat, and as a species used for making newspaper and cardboard.

Learn more about Aspens here:

About aspen

Aspen identification

Succession, a neat song for kids of all ages