by W.D. McIlveen – Halton/North Peel Naturalist Club
The 23nd annual Christmas Bird Count that took place on December 27, 2013 will be a most memorable one. The outstanding feature of the Count will be remembered not so much for the count results as for the weather that occurred a few days earlier. That weather included freezing rain that amounted to at least three cm of ice over all exposed surfaces. The consequence of the ice was extensive breakage of tree branches and electrical power outages that were still happening in parts of the survey area. Overall, there were 23 participants that took part in the field observations or checked their feeders.
Generally, the Count produced close to average results based on comparisons with previous counts in the case of numbers of species reported – 49 species on count day vs. 50 species for the long-term average. By contrast, the total numbers of birds seen was 5239 – slightly over half of the average of 9760. The results for the individual species are presented in the attached table. A new species for the Count was a Turkey Vulture that was reported to the OntBirds website. Only one species, the Red-bellied Woodpecker was present in record high numbers with 15 birds seen. Many species were reported at low numbers, both below average and at new lows. The new low numbers were noted with Mallards (26), Black-capped Chickadees (243), American Tree Sparrow (55), and Northern Cardinal (22). No Black Ducks were observed. Wild Turkey (50), Hairy Woodpecker (26), Blue Jay (171) and American Robin (95) were noted in above average numbers but not in record high numbers. The species that made it onto the Count Week list were Snowy Owl and Snow Bunting.
The impact of the ice storm that appeared to generally lower the observed bird populations cannot be assessed with any certainty. In part, the lower numbers of ducks and geese might also be correlated with early freeze-up of local water bodies. This would not explain the lower numbers of the more-terrestrial species. Only time will tell whether the decreased numbers are merely a blip or part of a long-term trend.
There is little doubt that the winter solstice of 2013 will be one to remember for a long time to come. The situation was certainly not unprecedented for some freezing rain occurs in most winters. And the amount of rain that fell was less than that that which happened in the great ice storm of 1998 in Ontario. Yet the extent of area that was impacted and the number of people affected in 2013 might well be much greater. More time will be required for a proper assessment of the effects to be completed but the following is a preliminary set of observations from our area.
Fig.1 – Map of precipitation pattern in Ontario for December 20, 2013 from CBC News
The storm was not a single event but two similar storms that followed the same track about two days apart. As it turns out, our area fell zone where the ambient temperatures were too low for the precipitation to fall as rain and too warm to fall as snow. As measured at the Pearson Airport, the amount of rain that fell on December 20 was 8.6 mm followed by 16.6 mm and 13.6 mm on the two days following respectively for a total of 38.8 mm. The distribution of the rainfall as shown in the attached map obtained from the CBC weather forecast indicates that the highest amount of rain was expected further west of Toronto so it would not be unreasonable to expect that we experienced well over 40mm. By comparison, the amount of rain reported during the 1998 storm was 85 mm in Ottawa, 73 mm in Kingston, 108 in Cornwall and 100 mm in Montreal.
Fig. 2. Woods with ice damage, Nassagaweya-Esquesing Line north of Sideroad 15
The net result was an accumulation of a thick layer of ice on all exposed surfaces. The thickness on tree branches was observed to be at least 30 mm on the upper side surfaces. Considering the possibility of dripping, three dimensional distribution and multiple of layers branches, it is conceivable that the true amount of rain here was perhaps double that measured at Toronto. It appeared that the amount of damage above the Niagara Escarpment was greater than that at lower elevations.
The ice that accumulated resulted in a huge weight stresses on the tree branches. Although many factors are involved, the stress resulted in a great amount of branch breakage. It was estimated that about a quarter of the tree canopy in Toronto was damaged by the ice. Falling branches caused extensive damage to power lines and many support poles were broken. It took up to ten days to get all power restored. Fallen branches also blocked sections of roadways.
Fig. 3. Ice damage to willows, Dublin Line.
There are additional factors to consider including species involved and branching patterns of individual trees but two patterns were evident in the breakage. Large branches that broke were often suffering from some previous damage or decay, especially when the branch crotches were narrow. The second thing was the there were huge numbers of smaller branches that were broken, usually in the upper crown. The branches affected exhibited a reasonable consistency in diameter where the break occurred. This was at branch diameters of 6 to 10 cm. It seems reasonable to conclude that the wood strength at diameters greater than this were able to support the load of ice. At lower diameters, the individual twigs were flexible enough to withstand the ice. But at the indicated diameters, the branches supported a certain combination of number of twigs of a particular length such that the critical load-bearing strength of the supporting branch was exceeded and so it broke. A very similar pattern was evident in Eastern Ontario following the storm of 1998. When trees did not break, the trunks bent under the load. In some cases, species such as poplars and birch bent to a high degree, sometimes involving trunk diameters that were well in excess of what one might expect as possible.
Despite the obvious damage, especially where entire trees had to be removed, the long-term impact likely to be limited. Broken branches will undoubtedly reduce the rate of growth of the trees for a short period of time. It is to be expected that broken branches will create potential infection courts for decay to become established. Studies of this kind were initiated following the storm of 1998 but the results of those studies have not been widely distributed. When one travels through eastern Ontario, it is becoming increasingly difficult to see broken branches as the branches lower on the trunk have grown and surpassed the point of the break.
While we cannot say with certainty that a similar storm will or will not occur again in the near future, the possibility for such a storm will always remain. While it may be counter intuitive that an ice storm resulted from global warming, that may in fact be the case. Global warming is expected to alter the frequency and severity of storms but storms can occur in all seasons. It will not be possible to attribute any individual storm to climate change. All we will be able to do is observe that more storms occur and deal with them as they arise.
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
The 22nd annual Christmas Bird Count took place on December 27, 2012. The fresh fall of snow overnight hindered or even prevented the participation of some count volunteers. Overall, there were 18 participants that took part in the field observations.
Generally, the Count produced close to average results based on comparisons with previous counts. The total number of species reported was 51 and the total number of birds was 10,082. The long-term averages for those are 49.9 and 9760 respectively. The results for the individual species are presented in the attached table. A new species for the Count was Cackling Goose seen in Count Week at Fairy Lake in Acton (See report in this issue of the newsletter). Also not previously reported was a Scaup sp. but this may not be entirely new as Lesser Scaup was recorded in 2011. New high counts were reported for Cooper’s Hawk (6), Merlin (2), Hairy Woodpecker (29), Bohemian Waxwing (180) , Dark-eyed Junco (693), and Northern Cardinal (101). Higher than average numbers of Canada Goose (3755), Mallard (682), Cedar Waxwing (159), American Tree Sparrow (591), and American Goldfinch (269) were recorded. Seventeen species had lower than average numbers and this offset the higher numbers mentioned above.
Thanks to the following participants: Ray Blower, Mark Cranford, Betty Ann Goldstein, Megan Kenzie, Lou Marsh, Meryl Marsh, Irene McIlveen, W.D. McIlveen, Fiona Reid, Dawn Renfrew, Teresa Rigg, Don Scallen, Dan Shuurman, Rick Stroud, David Sukhiani, Janice Sukhiani, Patrick Tuck, and Dave Williams.
Many thanks once more to Larry May for arranging access to the Maple Lodge Farms property and to the Halton Regional Police Service for use of the community boardroom for the wrap-up session.
On December 23, 2012, Bradley Bloemendal posted the sighting of at least three Cackling Geese at Fairy Lake in Acton was on the ONTBirds hotline. Next day, I went to check out the report. At that time, there was still a fairly large area of open water on the lake. I counted 330 Canada Geese, 32 Mallards, one American Black Duck, 6 Common Mergansers, and 8 Ring-billed Gulls. I could not distinguish any Cackling Geese among the birds there but they could easily have been present among the geese lined up on the ice off to the west side of the lake. Many had their heads tucked in and size differences were impossible to determine under those conditions. On December 26, I went back and found that much of the formerly-open water had frozen. The Canada Goose count was now down to 130 and those were present in the last open water close to the point in Prospect Park. Among them were four Cackling Geese. As can be seen in the accompanying photo, the Cackling Geese are much smaller than the regular Canada Geese and their bills are stubbier. Their presence was therefore confirmed for Count Week for the Halton Hills Christmas Bird Census that took place on December 27, 2012.
The taxonomy of birds that most people would recognize as Canada Geese has been in debate for many years. Splitting into various races was mentioned by Tavener over 90 years ago. Over the years, the number of recognized races or sub-species has stood at ten to twelve different forms. Distinction between these is blurred at best but size is one of the main features. There is much overlap and intergrading between the races as well as hybridization, not to mention size differences caused by diets and food supply, and thus distinction in the field is nearly impossible. It was no surprise though that American Ornithologist’s Union’s Committee on Classification and Nomenclature decided to split Canada Goose (Branta canadensis) into two species: Canada Goose (B. canadensis) and Cackling Goose (Branta hutchinsii). This became official in 2004 in the 45th supplement to the Check-list of North American Birds. Greater Canada Goose contains six subspecies, namely canadensis [Atlantic], interior [Interior], maxima [Giant], moffitti [Moffit’s], parvipes, fulva [Vancouver], and occidentalis [Dusky]. The smaller Cackling Goose (Branta hutchinsii) group includes the subspecies hutchinsii [Richardson’s], [Bering], leucopareia [Aleutian], taverneri [Taverner’s], and minima. The asiatica are already extinct.
Cackling Geese
The Cackling Goose was first recognized as a separate species when Sir John Richardson collected a specimen in 1822 north of Hudson’s Bay. He named it Branta hutchinsii after a man by the name of Hutchins who was employed by the Hudson Bay Company. For this reason, it is sometimes referred to as Hutchins’s Goose but now it is identified as the Richardson’s subspecies of Cackling Goose. The geese at Fairy Lake appear to be of this subspecies as their breasts are light coloured, unlike the Cackling Cackling Goose (minima) which usually has a much darker breast.
Nomenclature of Canada and Cackling Geese is far from settled and we can expect further changes. There has even been a recent proposal that the group be divided into six species with 200 subspecies. This classification would be quite unworkable for field biologists even though DNA analysis might justifiably distinguish that many true species. It is simply not feasible to recognize that number of subspecies without access to DNA laboratory testing. We are only now just learning to separate out the Cackling Geese. Let’s not go too far in the taxonomic splitting exercise. There is always a possibility that while there may be genuinely different genetic groups, the differences may not be enough to separate the species and in the end, we might still be looking at one large but diverse species of Canada Goose.
by W.D. McIlveen
Halton/North Peel Naturalist Club
Earlier this Spring on two successive days, I was driving along our gravel road and noticed a ‘dust devil’ at the same location each time. I am sure that everyone has seen such things at some point in their lives. Seeing one is not at all unusual but noting two in the manner that they occurred prompted me to prepare this little note.
The conditions that must exist to form the dust devils will likely occur many times but they remain invisible. We only see them when they cause fine dust, leaves, paper and similar light materials, rarely snow, to be swept up into a circular funnel. Without the telltale visual evidence, we pay no attention for we simply cannot detect them. Similarly, we seldom have the opportunity to photograph them. They typically only last a few seconds so unless we have a camera already at hand, we don’t get a fair chance to document their existence.
Dust devil photographed at Lake Bogoria, Kenya, 2001 (Photo by W.D. McIlveen)
In many respects, they are like miniature tornados with a spinning vortex. ‘Whirlwind’ is a fairly good description. They may be as small as meter wide and ten meters high to rare ones that might be ten times as wide and one hundred times as tall. The motion is nearly always upwards in the form of a swirling updraft under sunny conditions during fair weather. A basic requirement is that there are areas with a differential in heating of different air pockets. The devils form when hot air near the ground surface rises quickly through a small pocket of overlying cooler, low- pressure air. Under the right conditions, the air may begin to rotate. As the air rapidly rises, the column of hot air is stretched vertically, causing intensification of the spinning effect. A fully-formed dust devil is a funnel-like chimney through which hot air moves, both upwards and in a circle. Additional hot air rushes in toward the developing vortex to replace the air that is rising As the hot air rises, it cools, loses its buoyancy and eventually ceases to rise. As it rises, it displaces air which descends outside the core of the vortex. The spinning motion cause the dust devil to move forward. The upward speed of the air within the vortex has been reported to be at least 40 km/hr. On occasion, wind speed in the rotating air can reach as high as 120 km/hr.
Dust devils are most evident in flat terrain that lacks vegetation, or in fields, deserts, or tarmac. Such conditions favor the build-up of heat near the ground surface as well as the increase the chance that dust or sand may be swept up. Clear, or relatively clear, skies enable solar energy to easily reach the ground to warm the surface yet have cooler air above. Ambient wind needs to be very low or absent or else there would be too much mixing of the cooler upper air with the heated air at ground level. If two distinctly different air temperature regimes cannot be established, then a dust devil cannot form.
Somewhat similar vortices form in the center of large fires like forest fires where there is a rather obvious source of heated air and smoke. Vortices also occur in the lea of buildings that are exposed to winds, depending upon the size and shape of building and other characteristics of the surrounding environment. The latter are notably different in origin, arising from mostly lateral winds. The swirling motion can cause snow to form drifts and other debris to form circular piles on the downwind side of the structures. These materials fall to the ground in the centre of the vortex which lacks the air speed to keep the materials suspended.
Dust devils seldom cause significant damage or injury, simply because they are limited in size and do not last. On occasion, they might do limited damage if the particular conditions allow the wind speed to be unusually high. The wind movement could potentially move materials from one place to another and this may be undesirable from a human perspective. Dust might become entrained in the wind and this might be quite undesirable. They could cause the components of the dust or creatures nearthe ground surface (e.g. insects, plant pathogens, weed seeds) to become airborne and moved to new locations. Occasionally small rodents could be forcibly moved from one place to another. In general though, dust devils are mostly just fleeting visible indicators of the fact that our physical environment is constantly in flux.
by W.D. McIlveen
Halton/North Peel Naturalist Club
So far, the year 2012 has seen some disruptions in normal weather patterns. In March, we experienced some rather warm days that caused many wild flowers to appear early, foliage on trees and shrubs to emerge early, and for amphibians to start breeding early as well. This was followed by a relatively cool April. Then in June and July there were days with high temperatures and dry conditions. This report examines some of the impacts of those weather conditions on plants.
Temperature and water availability are two of the most important environmental factors that control the welfare of plants. When these are present at high or low values, then we can expect that certain stresses will start to occur or that the plants will perform at less than optimum growth rates. Not all plants will respond in exactly the same way for some are adapted for low temperatures while others prefer warmer temperatures for example.
The conditions that prevailed in the spring 2012 had major consequences for some crops, notably the McIntosh cultivar of apples. Specifically this was because of a frost or low temperature event at a critical time in flowering. As a consequence, the pollination rate was extremely low and little fruit was set. Other cultivars fared somewhat better. It is uncertain whether weather (i.e. frost) was the main factor but it was rather obvious that wild fruit loads on trees and shrubs through Northeastern Ontario were extremely poor and mostly zero by late this summer. A conversation with a wild blueberry seller confirmed that the blueberry harvest was extremely poor and pickers had a very difficult time finding enough fruit to collect and sell. Aside from the very high prices that could be commanded for the limited fruit that was available, it is easy to appreciate that wildlife such as birds and bears will have a difficult time finding food this year.
Figure 1. Ice and cold temperature injury to Alternate-leaved Dogwood, Acton, May 2, 2012
Locally, the effect of low temperatures in the early growing season did not appear to have significant impacts for native plants. Most native plants do retain some tolerance to short periods of low temperatures. Even at this, the young foliage on Alternate-leaved Dogwood showed a reddish-brown discoloration along the margins and between the veins. Reddish coloration often accompanies a physiological phosphorous deficiency that is induced by cold temperatures. This gradually disappeared as the growing season advanced. There was a small amount of acute necrosis of some Dogwood leaves but this only occurred where ice formed when rain runoff from the house roof froze on the foliage (Figure1).
Weather-stress conditions occurred later in the growing season in the form of drought. It was reported that the timing of the drought was particularly bad for corn producers. Although corn plants were widely seen to be suffering (leaves rolled up) in many parts of the Province, the plants remained alive for a long time. The yield though was impacted since the silks could not be pollinated during the critical short window when silks and pollen must come together. The overall effect was a low rate of pollination and this in turn will impact upon the amount of seed that gets set. The true impact can only be known after the harvest has been completed. It is expected that the price for corn for animal and human food will be quite high due to shortages in the crop through much of the corn-producing parts of North America.
Figure 2. Total monthly precipitation reported at Pearson Airport from March through July, 2012.Figure 3. Monthly precipitation reported at Pearson Airport from March through July, 2012 excluding the rain events on June 1 and July 31
The reported monthly totals of precipitation for the study period (March through July) may be a somewhat misleading. As shown in Figure 2, the monthly totals at Pearson Airport for March, April and May are not much more than half of the normal amounts for each month. The amount for June is very close to average while that for July is about 30% above average. But timing is everything. Of the total of the 76.4 mm for June, nearly half (37.4 mm) fell on the very first day of the month. In July, the largest rainfall that measured (38.8 mm) fell in a thunderstorm on the very last day of the month. There were a couple of light rains on July 22 and July 25 but these were not even seen in many parts of our area. This means that there was an extended time (over seven weeks from June 2 to July 21) where practically no rain fell at all. In combination with some days with rather high temperatures, most plants without an irrigation source would have been subjected to some very severe drought stress. Figure 3 shows the same data as Figure 2 but the amounts of rain that fell on June 1 and after July 22 have been excluded to provide a more realistic image of the conditions that plants would have experienced. Some native plants in our area did exhibit symptoms of weather (drought) stress. Such symptoms included drooping of the foliage and later, complete drying of the foliage. (Figs. 4 and 5).
The normal growth of plants includes uptake of water from the soil and transpiration of that water through the foliage. When there is an inadequate supply of water, the plant has several responses to help cope with the shortage. A prime reaction is to close the stomates to reduce the loss of water through the leaves. While water loss may be reduced by this action, it also reduces the amount of nutrients that can be absorbed from the soil and transported to the leaves. Closure of the stomates reduces the amount of carbon dioxide that can be taken up to become involved in the photosynthetic process. Reducedtranspiration means that the foliage does not get cooled through evaporation of the water. As a result, the leaf temperatures get raised above optimum and so the plant cannot grow at an optimal rate. Overall though, it is most desirable to the plant to conserve the water it has, rather than grow large. To compensate for the lack of water, many plants will shed their excess foliage. This effectively cuts down on the total leaf surface that is transpiring at any given time.
Figure 4. Temporary wilting of foliage of Green-headed Coneflower due to drought
Hormones produced in the roots trigger the mechanisms that lead to abscission of excess leaves, much like the normal fall of foliage each Autumn. Stressed trees for example might show a high proportion of yellowed foliage (often older leaves and leaves lower on the stem. Another clue to the drought stress is an excess of recently-fallen foliage on the ground much earlier than would normally take place. Sometimes, totally dried or dead foliage will be retained on the branches.
Figure 5. Foliar necrosis due to drought stress on Wild Raspberry, Acton, July 25, 2012
Late in August, large patches of totally brown, necrotic trees and shrubs were seen in the area south of Parry Sound. This area has rather shallow soil soil and therefore the water reserve in the soil is quite prone to drought stress but the degree of stress in the summer 2012 in that area is the most severe that the author has witnessed in over 35 years. Whether or not the affected vegetation was killed outright will become known in 2013; however, there is little doubt that there will at least be a notable impact on the affected sites for several years to come. Locally, the stress observed will not likely have an observable enduring impact on perennial species but cumulative stress from similar conditions in future years could produce notable effects, likely as smaller plants with less flowering, lower seed set, or greater incidence of insect and disease attacks.
by W.D. McIlveen
Halton/North Peel Naturalist Club
Particularly in Spring, a walk in the woods might turn up a very tiny grasshopper among the dead leaves. These are likely Pygmy Grasshoppers, not ‘baby grasshoppers’. They are also known as ‘grouse locusts’ or ‘grouse grasshoppers’ or in one case, a ‘frog groundhopper’. Pygmy Grasshoppers are members of the suborder Tetrigodea and most occur in the Family Tetrigidae. One exception is Tettigidea lateralis that occurs in the closely-allied Family Batrachideidae. The seven species that are known to occur in our area are listed in the following table and samples are illustrated in the attached pages.
These grasshoppers, as their name implies, are quite tiny with adults ranging from about 7 mm to only 14 mm (half inch) in length. Females are slightly larger than males. Because of their small size and generally cryptic coloration, they are easily overlooked. They can be of various colours, browns though gray and mottled, but never green. Their eyes are rather pronounced and the pronotum is often elongated along the back to cover the thorax. The antennae are short and they lack auditory and stridulatory organs. Wings may be long or short.
Although they can tolerate slightly drier sites, most prefer to live on the ground in damp, muddy situations, frequently close to water. They are reported to feed on vegetation debris and microscopic algae that accounts for their preference for moist habitats. Eggs are laid in soil or mud. Because they over-winter as adults, they are likely to be active shortly after the snow melts in the spring. Given the mild winter this year that gives prospects for an early start to the season, we could expect to see these little fellows out and about in the very near future.
by W.D. McIlveen
Halton/North Peel Naturalist Club
The impact of climate on the biota of an area can be manifested in a number of ways. One possible effect of global warming and climate change in general is that the growing season could be extended. We can measure temperature changes easily enough but the effect of the temperature changes may not be immediately apparent. In part, this is because the changes will be gradual and small but changes are obscured by annual and daily variations. One means of assessing the long-term influence of climate changes is to follow the phenological changes in the flora. This could include such things as documenting the dates of first flowers (anthesis) or bud breaks of tree leaves. In the present investigation, we have chosen to record the dates when open or viable flowers are still present on plants in the area late into the season. This can be taken as one measure of a late growing season. It is not possible to know the exact date when an individual flower is no longer viable. In reality, the probability that the late-flowering blooms could be fertilized and go on to produce seed is rather low; however, the monitoring of such flowers over a period of time should provide a measure of the change in growing season dates.
Each autumn from 2002 until 2011, members of the Halton/North Peel Naturalist Club have conducted a survey of the plants still in flower in the latter part of November. The exact dates of the survey are indicated in Table 1. The dates ranged between November 14 and November 26. The exact locations of the survey have changed somewhat each year; however, the Willow Park Ecology Centre and the Lucy Maude Montgomery Garden in Norval have been checked every year. In the earlier years, the woods near the Georgetown Fair Grounds were examined while more recently the survey route included the Dominion Seed House Park. As well, incidental observations of flowering plants in parts of Georgetown have been added to the list.
Table 1. Survey dates and number of plant species in flower in Halton Hills, 2002-2011
Species observed still flowering on the survey dates are included in Table 2. The number of species in flower observed has fluctuated from year to year (Figure 1) but there is general trend to larger numbers over time. In part, the trend might have been influenced by the choice of sites visited; however, other factors such as site management at Willow Park and natural succession of species within an area likely played a mitigating role as well. Overall, the survey documented as few as 11 species still in bloom in 2003 and as high as 41 in 2009.
The vast majority of the 108 species on the list (Table 2) are cultivated garden species along with several species generally regarded as introduced weeds. The cultivated garden species includes several that are native species that have been purposely planted. Only about 10% of the species on the list are ones that are both native and endemic to the area. Only two species, Canada Goldenrod (Solidago canadensis) and Common Dandelion (Taraxacum officinale) were found flowering every year. Other commonly encountered species (6 to 8 years each) were Yellow Chamomile (Anthemis tinctoria), Calendula (Calendula officinalis), Garden Chrysanthemum (Chrysanthemum hybrid sp.), Wormseed Mustard (Erysimum chieranthoides), Scentless Chamomile (Matricaria perforata), Canker Rose (Rosa canina), Common Groundsel (Senecio vulgaris), Tall White Aster (Symphyotrichum lanceolatum), and New England Aster (Symphyotrichum novae- angliae). Interestingly, all of the species on the most common list except for the Wormseed Mustard and the rose are members of the composite family.
Figure 1. Number of plant species observed flowering in late November surveys in Halton Hills, 2002- 2011
A survey of this type on its own cannot be expected to demonstrate that climate change is having a significant impact on the length of the growing season. In combination with many other surveys though, the data set will be more robust in demonstrating that a change is indeed occurring. This effort is a small contribution towards that end.
by W.D. McIlveen
Halton/North Peel Naturalist Club
The 21st annual Christmas Bird Count for Halton Hills was held on December 27, 2011. The weather that day was marked by a fairly constant snowfall that restricted viewing of birds and generally made for a dull day with temperatures just above the freezing mark.
The results for the 2011 Count are summarized in the attached table. For comparison, the average and high numbers recorded for the previous 20 years are also included in the table. The total number of species recorded for the day plus Count Week was 56 and that is just below the maximum count of 57 species. The species count was bolstered by five new species including Northern Shoveller, Ring-necked Duck, Lesser Scaup, and Red- breasted Merganser observed at the Maple Lodge farms sewage lagoons. The Mute Swan was seen at an estate on the 10th Line near Terra Cotta but although it was counted here, caution needs to be exercised in case it is really a captive bird. With the new additions, the cumulative number of species for the Count Area rises to 101. Two species (Great Blue Heron and Easter Screech Owl) were found in Count Week and not on Count Day. The total number of birds (10777) is somewhat higher than the long-term average count of 9744. Considering the weather, the day has to be viewed as very successful.
New high numbers of Common Goldeneye (18) and American Robin (266) were encountered and this might be attributable to conditions prevailing during or slightly before the count period for 2011. New high numbers of Red-bellied Woodpecker (11) are likely due to increases in the local resident population for the species is known to be increasing substantially across Southern Ontario. Both Green-winged Teal and Bufflehead with two birds each increased from the previous high count of only one. Black-capped Chickadee matched the previous high of 465 birds. Other species were present in numbers within previously established ranges for the respective species.
In total, 23 people participated in the count, either as observers or as feeder watchers. Thanks to the following participants: Anna Baranova, Judy Biggar, Brad Bloemendal, Ray Blower, Mark Cranford, Betty Ann Goldstein, Charles Hildebrandt, Larry Martyn, Diane McCurdy, Irene McIlveen, W.D. McIlveen, Michael Pearson, Fiona Reid, Valerie Rosenfield, Don Scallen, Dan Shuurman, Chris Street, Rick Stroud, Janice Sukhiani, Jake Veerman, George Wilkes, Marg Wilkes, and Dave Williams.
Many thanks to Larry May for arranging access to the Maple Lodge Farms property and to Halton Regional Police for use of the community boardroom for the wrap-up session.
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
