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.
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.
On my way home from our last meeting, with coyotes in mind, I was on the lookout for mammals and eyeshine in my car headlights. In the ten-minute drive, I spotted six domestic cats in fields and along the roadsides. These were the only mammals I saw that night.
So, what impact do our cats have on wildlife if they are allowed to roam free? A recent study in the USA (based on a systematic review and quantitative mortality estimates) found that free-ranging domestic cats kill 1.4 to 3.7 billion birds and 6.9 to 20.7 billion mammals annually (Loss et al., 2013). This means that free-ranging cats are the single greatest source of human-caused mortality for wild birds and mammals. The authors found that feral (including barn) cats caused more damage than owned pets, but many dearly-loved felines spend time in the great outdoors happily hunting. Native species make up the majority of birds and mammals killed by cats, only a few non- native birds are impacted. Free-ranging cats on islands have caused or contributed to 33 recent extinctions, as recorded by the IUCN.
Of course, the cats that do not impact wild populations of songbirds and small mammals are the ones that are kept indoors! Indoor cats are safe from predators such as coyotes and owls. They are less likely to get fleas or other parasites, and they can live a long and happy life without decimating our fragile fauna. Or, take them out on a leash! The photo below by club member Jeff Normandeau shows how content cats can be on a leash.
Cats are funny, smart, loveable, affectionate, and they are cold-blooded killers. They are not native to North America. Unlike most carnivores, they hunt by day or by night. If roving gangs of children were killing thousands of songbirds, would we not hold their parents accountable? Why then do we not hold pet owners accountable for the actions of their pets?
Please, keep your cats indoors and get them spayed. They will live longer and so will your neighborhood birds and small mammals.
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.
Ontario is home to five species of rabbits and hares. These include the Arctic Hare (Lepus arcticus), White-tailed Jack Rabbit (Lepus townsendii), Snowshoe Hare (Lepus americanus), Eastern Cottontail (Sylvilagus floridanus), and the main subject of this report, the European Hare (Lepus europaeus). The first two species do not extend into our area at all. Arctic Hare barely get into the most northern parts of the province while the White-tailed Jack Rabbit is included on the basis of a few records from the Rainy River District. The Snowshoe Hare is our most widespread species in Ontario but we are situated at the southern edge of its range so we do not often encounter it unless we travel a short distance further north. In our area, the species that we are most likely to encounter is the Eastern Cottontail. Their populations go through a cycle of abundance and scarcity. It was seldom if ever encountered by European settlers until the mid-1800s and is regarded by some as a species that has expanded its range into Ontario. Skeletal remains found in a First Nations village in Oxford County prove that the species was here long before the supposed arrival in Ontario in 1868 [MacCrimmon, 1977]. There is little doubt though that after its recent arrival, their populations have dramatically increased as the species spread across all of southern Ontario [Dobbyn, 1994] (Map 1). As well as the five wild species noted above, from time to time, the Domestic Rabbit (Oryctolagus cuniculus), escapes from captivity or is purposely released by owners that no longer wish to keep them as pets. These animals do not persist in the wild for any significant period after they are released.
Map 1. Distribution of European Hare in Southern Ontario (Dobbyn, 1994)
The story of the European Hare is quite well documented [MacCrimmon, 1977]. They were introduced to Ontario just over one hundred years ago although some of that species was introduced some years earlier in the eastern United States. In 1912, Otto Herold, the manager of Bow Park Farm located near Brantford imported seven female and two male hares from Germany. Inevitably, they soon escaped. Their numbers increased and they soon spread in all directions from the Bow Park Farm. It expanded its range to cover most of the area south of the Canadian Shield [Dobbyn, 1994]. The peak populations in Ontario appear to have been reached by about 1950. Later attempts to introduce the species to Thunder Bay and Cochrane areas as a new game species were not successful as the hares could not tolerate the conditions in the north.
In 1921, Howitt [1925] reported quite successful hunting of Jack Rabbits in Beverly Township in Wentworth County about 15 km southeast of Cambridge which was then named Galt. This was only nine years after the Hares had been released.
While the hunting community was happy to have a new game animal, farmers trying to grow grain (e.g. winter wheat,) alfalfa, clover, or orchard crops had to contend with a new pest that damaged their crops, especially during the winter. Wild plants were also consumed by these relatively large animals.
As a youngster growing up on a farm on Mississauga Road, it was fairly commonplace to see these animals in the fields. We viewed these animals, usually referred to as Jack Rabbits, as a normal part of the local fauna and we were generally oblivious to the fact that they were not native. Species such as Groundhogs because of their burrowing and Starlings because they were ‘dirty birds’ were a much greater concern. As well, foxes that occasionally took a turkey from the field were a particular nuisance.
Map 2. Location of European Hare sightings in the GTA since 1987
In 1985, we returned from the North to live in this area. A few years later, I began to include mammal sightings in my records and included observations of the European Hares. While the annual numbers of observations were never large, I had records of the species from 1987 to 1998. The records from the GTA are summarized below and the locations are shown in Map 2. Many of the records were made during travel from Acton to Toronto along the Go Train routes. Since 1998, I have not seen the species. The realization that it had been several years since the last observation prompted this report. While there may be other reasons for the disappearance, it would seem that decline in Hares coincided with the increased populations of Coyotes. A parallel decline in numbers of Groundhogs has also occurred in the same general time period. By contrast, Cottontail populations have continued to go through a cyclical pattern.
The local Conservation Authorities (C.V.C, and Conservation Halton) were consulted to determine what records they had in their databases for European Hares. Most of their records were actually ones that I had contributed. The only recent record for the species was a sighting of a Hare at the Frank Tract in Nassagaweya Township by Bob Curry on June 3, 2003. That makes it ten years since we have had a report of the species for our area.
Acknowledgements
Many thanks are extended to Jacqueline Kiers (C.V.C.) and Brenda van Ryswyk (Conservation Halton) for reviewing their agency records of European Hare.
References Cited
Dobbyn, J. 1994. Atlas of the Mammals of Ontario. Federation of Ontario Naturalists, Don Mills, Ontario. 118 pp.
Howitt, H. 1925. Another Invasion of Canada. Can. Field-Nat. 39: 158-160. MacCrimmon, H.R. 1977. Animals, Man and Change. Alien and Extinct Wildlife of Ontario. McClelland and Stewart Ltd. Toronto. 160 pp.
by W.D. McIlveen
Halton/North Peel Naturalist Club
Where there are abundant sources of food, as is the case well illustrated above, there will be predators. I was amazed when I walked in the woods at night, searching for elusive winter moths, to see spiders on the snow surface at intervals of just a few feet. This was on a mild night (relatively speaking) and their sub-nivean burrows may have been flooded with snow melt.
I discovered that these animals are active all winter, mostly below the snow but also on the surface, and their major food is the snow flea. These spiders seem to have big “boxing gloves” that I thought might help them dig, but they are actually the male’s enlarged palpal tips used for copulation.
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
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.
This winter brought Tundra Swans very close to us, just south of Georgetown during April. The agricultural fields southeast of Mountainview and 10th Side Road also hosted Canada Geese, Caspian Tern, and nearby Ring necked Duck, Lesser Scaup, Bufflehead, Ruddy Duck, Coot, Mallard, Redhead, and 7 Hooded Mergansers were seen on one visit by Dave Williams. Who needs Lake Ontario when the birds will come to us!
Late in winter almost every year if one is out and about in the woods, we will encounter an interesting group of tiny organisms on the surface of the snow. These are Snow Fleas (Hypogastrura nivicola). Snow Fleas, a species of Springtail, are very small insect-like creatures that are totally unrelated to true fleas that prey on dogs, cats, humans and other mammals. In fact they are no longer even considered to be insects. At one time, the group called Collembola were considered to be a primitive type of insect. Now, due to recent studies, they, along with two other groups, the Protura and the Diplura (two-pronged bristletails), have each been moved to their own Class equal in status to the insects. Collectively, these four groups make up the Subclass Hexapoda or ‘six-legged’ arthropods.
There are many species of Collembola. They are quite small, about one millimetre in length and most live in the soil where they are seldom encountered, at least knowingly by humans. They can be extremely numerous with populations reaching 250,000,00 per acre. They mostly feed on organic detritus, breaking down leaf litter and the like and aiding in the recycling of nutrients for plants.
Figure 2. Masses of Snow Fleas floating on water, Acton, April 30, 2013
The Snow Fleas represent the one Collembolan species that we do see fairly often. They appear in large numbers, and because their dark colour contrasts with the white snow surface, we take note. They tend to aggregate in small depressions such as old footprints in the snow. The depressions likely offer a microhabitat that is just a little warmer, is protected from the wind, and the snow is likely to be saturated with liquid water. In any case, the Snow Fleas appear in large numbers and look much like dust particles. If one looks closely, you can see them jumping about on the surface of the snow.
Figure 3. Close-up of Snow Fleas in Figure 2
These photos were taken on April 30, 2013 at a small vernal pool along the Guelph Hiking Trail south of Acton. The masses of Springtails floating on the water looked a lot like globs of oil. It is uncertain if these animals were at the end of their days or if they had trouble breaking free from the surface tension of the water. Some of them were certainly still alive and were jumping about. Nevertheless, the photographs give some idea of the abundance of the creatures.
Although they have legs to help them move about, Springtails are also equipped with an unusual abdominal appendage called the furcula. This structure is what gives the group its name. It folds beneath the body with the loose end tucked into a receptacle also under the body. The furcula is held under tension and when needed, the tension reaches a level that the end slips out of the receptacle. The furcula snaps against the substrate and this throws the Springtail into the air to escape.
Snow Fleas are able to live quite comfortably in the snow and survive low temperatures owing to a special glycine-rich protein that acts as a form of antifreeze. In addition to the important role in recycling nutrients noted above, Springtails have been reported to provide a valuable ecological service by moving spores of mycorrhizal fungi and destroying spores of plant pathogens. Certain species have been blamed for damaging alfalfa crops. They have also been put to use as indicators of soil contamination owing to their sensitivity to certain chemicals in the soil.
by W.D. McIlveen
Halton/North Peel Naturalist Club
serving Brampton, Georgetown, Milton, Acton & surrounding areas
Meetings are held at St Alban the Martyr Anglican Church
537 Main St,.
Glen Williams
On L7G 3T1
