Tag Archives: scallen

author - Scallen, mammals

Groundhogs

Leave a comment
by Don Scallen, Vice-President

Our landscape is networked by roads – ribbons of death where myriad animals from butterflies to deer meet their demise. And though morbid, an objective look at this mortality can provide insight into changing animal populations.

In the 1960’s and 70’s groundhogs, aka woodchucks, were among the most frequent victims of vehicular faunacide. Their bodies littered roadsides as raccoon carcasses do today.

Groundhogs are now rare road-kill victims. No, they haven’t evolved the ability to look both ways before crossing. Rather, the lack of road killed groundhogs suggests that their population has fallen off an  ecological cliff.

When I was young, groundhogs – when not playing Russian roulette with cars – stood sentinel in meadows. Boys with 22’s shot them, with the approval of landowners who reviled groundhogs as varmints – diggers of holes that could snap the leg bones of cattle and horses.

I didn’t wield a rifle as a child, but I would sit patiently beside groundhog burrows, waiting for the myopic mammals to poke their heads above ground and sniff the air for predators.

I enjoyed these close interactions with groundhogs and imagined that First Nation’s hunters may have used this technique – crouching like polar bears at the breathing holes of seals – to capture the plump rodents.

So what happened to the groundhogs? Well, certainly their population has been reduced by the aforementioned road – kill, but it is likely no coincidence that the fall corresponded with a rise in coyote numbers.

In southern Ontario and throughout much of North America, coyotes have flourished in recent decades, assuming the role of top predator, filling the void left by the disappearance of wolves.

If a 12 year old boy can approach a groundhog near enough to see its whiskers twitch, consider how easy this would be for a coyote – with predictably unpleasant consequences for the groundhog.

Read more by Don Scallen at his blog, Notes from the Wild

amphibians, author - Scallen

Red-backed Salamander

Leave a comment
by Don Scallen, Vice-President
Red-Backed Salamander
Red-Backed Salamander

They weigh about as much as a paper clip. Dew worms dwarf them. They are, by weight, the smallest vertebrates in Ontario. But what they lack in size they more than make up in numbers. Red-backed salamanders are abundant, outnumbering all of the reptiles, rodents and birds that share their forest habitat. Densities of red-backed salamanders have been estimated as 500 to 9000 per hectare of woodland!

For several years I took part in a salamander monitoring project at Forks of the Credit Provincial Park. Boards were placed on the forest floor to provide cover for salamanders. Particularly bountiful monthly counts would yield upwards of 70 red-backed salamanders hiding under the boards.

Almost all amphibians need to lay eggs in water. Not so the red-backs. They have escaped the surly bonds of aquatic existence. Females lay small grape-like clusters of eggs, under stones or suspended in the cavities of rotting logs.

Freed from the necessity to remain close to ponds, red-backs can disperse to occupy the entirety of the available habitat in woodlands. Laying eggs sans aqua also allows their larvae to avoid becoming lunch for ravenous pond-dwelling predators like dragonfly nymphs and diving beetles.

Of interest as well is that red-backs are lungless, drawing oxygen through the skin. For this to work the skin must be moist, so during the day the salamanders stay out of sight under forest debris. In especially dry weather, and during the winter, they retreat underground.

Many populations of red-backed salamanders are now completely separated from each other. Creatures with legs smaller than carpet tacks cannot readily cross roads and farm fields. Isolation drives the creation of new species. In a few millennia or so, future herpetologists – reptile and amphibian biologists- may have their hands full, cataloguing a diversity of red-backed salamander descendants.

More of Don’s red-backed salamander photos

Read more by Don Scallen at his blog, Notes from the Wild

 

author - Scallen, insects/spiders

Monarch Butterfly- RIP 2026

2 Comments
by Don Scallen, Vice-President

The eastern migratory population of monarch butterflies is no more. Lepidopterists (butterfly and moth scientists) confirmed earlier this year, that the once familiar orange and black butterflies are essentially extinct. Their awe-inspiring north-south migrations, linking Mexico, the United States and Canada have ceased.

Most of us are old enough to remember when monarchs were a frequent sight in meadows and gardens. The monarchs’ demise was not unexpected. For decades, people in all three North American countries ratcheted up their assaults on these iconic insects. The monarchs’ overwintering sites in the oyamel fir forests of Trans-volcanic Mountains of central Mexico, while nominally protected, were steadily reduced in size by illegal logging.

Criminal gangs with the tacit assent of corrupt government officials plundered the forests under the cover of darkness.

At the same time, land use practices in North America conspired to reduce milkweed, the monarchs’ larval food plant. Round Up, a potent herbicide was sprayed on thousands of hectares of genetically altered “Round-up Ready” corn and soy, eliminating all of the milkweed in and around agricultural fields.

Homeowners throughout North America could have extended a helping hand by growing milkweed for monarch caterpillars and offering flowers with abundant nectar to the adults. Most people however, in thrall to their lawns, continued to primp and preen those biological wastelands at the expense of birds, butterflies and bugs.

The monarch is dead. No longer will it startle with its beauty. No longer will it inspire with its improbable journey from Canada to Mexico. And no longer will the imaginations of children be carried aloft on its gossamer wings.

Postscript:
In 2006 at a monarch overwintering roost in Mexico I met Lincoln Brower, a pre-eminent monarch butterfly researcher from the United States. He predicted that the eastern North American monarch – our monarch – had “about twenty years left”. I fervently hope he was wrong, but with populations this year at their lowest ebb ever, his dismal forecast may come true.

Read more by Don Scallen at his blog, Notes from the Wild

author - Scallen, insects/spiders

Mimicry

Leave a comment
by Don Scallen, Vice-President

People manage their appearance with clothing, jewelry and hair styles to present a particular image of themselves to the world.

Deception is often involved. A muscled, leather-clad, tattooed man may be a powderpuff, but his fearsome exterior projects a formidable – “don’t mess with me!” – presence.

Insects are masters of this bluff. There is a vast array of harmless flies and beetles for example, that have evolved to look like dangerous bees and wasps. This allows them to conduct their business with openness and swagger instead of cowering beneath a leaf or skulking in the undergrowth.

But, like everything in nature, mimicry is complex and nuanced. The viceroy butterfly famously mimics the poisonous monarch butterfly. For years it was assumed that the viceroy was free-loading on the monarch’s distasteful reputation, offering nothing in return.

As is often the case in science, this explanation proved too simple. Research revealed that the viceroy doesn’t taste good either, so the two unrelated species actually reinforce each other’s security.

Snowberry Clearwing Moth
Snowberry Clearwing Moth

The bumblebee serves as a common model for mimicry. The snowberry clearwing moth (left), unarmed and likely quite tasty, looks like a large bumblebee and no doubt gains some protection from this resemblance.

Some robber flies also look like bumblebees, but their motives extend beyond mere protection, to the sinister. Robber flies mimic the nectar sipping bumblebees to ambush their prey. They loiter around flowers, waiting for pollinators like bees, wasps and flies to sidle up to the floral bar for a drink.

Then they pounce. Imagine the surprise of the victim held firmly in the robber fly’s grasp: “But…but… you’re a bumblebee – you don’t eat meat – lemee go!”

Humans have come lately to the art of deceit. Insects have been practicing it for millions of years.

Read more by Don Scallen at his blog, Notes from the Wild

author - Scallen, birding

Hairys and Downys

Leave a comment
by Don Scallen, Vice-President
Downy Woodpecker - Illustration by Fiona Reid
Downy Woodpecker – Illustration by Fiona Reid

Hairy and Downy woodpeckers frequent backyard feeders at this time of year. Though different sizes – the hairy larger, the downy smaller – their colouration and patterning is well-nigh identical. The bills tell the tale. Hairy woodpeckers brandish large dagger- like beaks; the beaks of Downys are smaller and more chisel-like.

I’ve always assumed that downy and hairy woodpeckers were about as closely related as two species could be – that sometime in the relatively recent past, their lineages diverged from a common ancestor.

This happens when a species of animal or plant becomes geographically isolated through some mechanism, such as an ice age. Each group then proceeds on its own evolutionary trajectory to become a different species.

Interestingly, gene sequencing has proven that this process is not responsible for the similarity between downy and hairy woodpeckers. It turns out that they aren’t closely related at all. They are both, most assuredly, woodpeckers, but they peck on separate branches in the woodpecker evolutionary tree.

One startling theory suggests that mimicry – like the mimicry that explains the similarity between monarch butterflies and viceroy butterflies – is at work. Just as viceroys benefit from their resemblance to toxic monarchs, downy woodpeckers may benefit from looking like hairy woodpeckers.

To explain how, a study in 2012 proposed that the look-alike downys are able to claim space and resources because hairy woodpeckers mistake them for other hairys. The reasoning continues that since hairy woodpeckers know that fighting each other is potentially dangerous – recall the dagger beak — they leave the similar looking downys alone as well.

I don’t think the last words have been written on this topic. For me the idea that downy and hairy woodpeckers developed their striking similarity as a result of mimicry strains credulity, but then the natural world is nothing if not astonishing.

Read more by Don Scallen at his blog, Notes from the Wild

author - Scallen, environment

Death of a tree

Leave a comment

Two weeks ago one of my favourite trees was felled by a bulldozer. This tree, on Creditview Rd. in Brampton, was graced with the lovely arching form that only mature elms exhibit.

Before Dutch elm disease ravaged the land this beauty was common. The few remaining mature elms are rare treasures.

The lure of this elm was so powerful that I would include Creditview Road on my route to work simply to see it in the morning. The green and gold cropland surrounding it provided a lovely foil for its iconic form.

The cropland is no more. The soil that gave life to the wheat, the corn and the soybeans has been scraped bare by earth moving equipment. Denuded and sterilized, the land waits sullenly for the homes and strip malls that characterize the inexorable expansion of Brampton.

I knew the destruction of this landscape was imminent. New development announces itself with cheery signs and property stakes. But I harboured hope for the elm. Fencing had been placed around it. I thought – naively it turned out – that “my” elm would be saved.

The elm now lies ingloriously in the mud, its roots ripped from the desolate earth.

I realize that thousands of trees are felled every day in this province to feed various appetites. I realize as well that landowners have certain broad rights to do as they wish with the property they own.

But, perhaps it is time to try to enshrine some protection for trees of character – trees that rate highly for certain features including size, rarity, cultural importance and the admittedly subjective quality of beauty.

The elm will continue to influence the route I take to work. I’ll now avoid the place where it once stood.

by Don Scallen
Vice-President, Halton/North Peel Naturalist Club

author - Scallen, birding

Bobolinks and Forks of the Credit Provincial Park

In mid-July I watched a flock of bobolinks at Forks of the Credit Provincial Park. They were gathering prior to their incredible 10 000 km journey back to the pampas of Argentina.

Male Bobolink
Male Bobolink

The bobolinks of Forks of the Credit Provincial Park are good news for a species in sharp decline in Ontario and beyond.

Breeding Bird Survey data indicate an alarming 52% drop in Ontario’s bobolink population over the last fifteen years. In part this is because of their penchant for nesting in hayfields – hayfields that are often cut in June when bobolink young are still in their nests.

At the Forks bobolinks needn’t worry about whirring blades. But alas, even here, the future of bobolinks may be in jeopardy.

Forks of the Credit Provincial Park is gradually returning to its primeval state – forest. Ash, maple and choke cherry are reclaiming the meadowlands cleared by intrepid farmers long ago. Left alone, trees will prevail and the bobolinks will be gone.

Bobolinks though, are only one patch in the quilt of the glorious grassland ecosystem that exists at the Forks. Many other birds such as meadowlarks and a wealth of sparrow species including savannah, grasshopper and clay-colored will disappear as the trees return. And the extensive milkweed stands will vanish along with their famous patron, the monarch butterfly.

Forks of the Credit in Fall (photo by Fiona A. Reid)
Forks of the Credit in Fall (photo by Fiona A. Reid)

Park officials here (and I’m sure in other jurisdictions in Eastern North America) face difficult choices in the management of former agricultural lands in their care.

Should they honour the natural inclination of the land and allow trees to return along with the birds, animals and wildflowers that depend on them? Or should they intervene and kill the trees to save grassland and the myriad species it supports?

We need to start a conversation about the future of the grasslands at the Forks and elsewhere.

This story appeared originally in Notes from the Wild at inthehills.ca/blogs

by Don Scallen
Vice-President, Halton/North Peel Naturalist Club