In contrast to the weather experienced for the 2013 Christmas Bird Count in the aftermath of the ice storm that year, the weather for the 24th annual Christmas Bird Count on December 27, 2014 was quite delightful. Although there was a very brief light shower around noon, the lack of snow made for excellent survey conditions. The temperatures that got to approximately 10C in the afternoon were probably the second highest in the 24 years that the survey has been undertaken. The survey had a new high total of 33 participants.
The results of the tally for Count Day and Count Week are summarized in the attached table. The number of species reported was 60 plus one hybrid, which exceeds the previous high of 57 species seen in 2003. Despite the large increase in numbers of Canada Geese (over half of the total), the total birds was 8413. The total of counted birds was lower than the long term average by more than 1300. Six species (Ruffed Grouse, Snowy Owl, Golden-crowned Kinglet, American Robin, White-throated Sparrow, and Pine Siskin) made the final list but were not tallied on Count Day.
Eight species were present in new high numbers. These included Trumpeter Swan (2), Northern Shoveler (7), Bufflehead (2), Common Goldeneye (22), Cooper’s Hawk (7), Eastern Screech Owl (6), Red-bellied Woodpecker (18), and Common Raven (4). Twenty-six species were present in numbers below average. The single Common Redpoll was the lowest count recorded to date when the species is actually present; however, this is a highly-eruptive species with numbers as high as 1670 in 1997 and present only about every other year.
The unusually warm conditions and lack of snow in combination with extra observers likely affected the overall results. The lack of snow would cause fewer birds to require food from feeders though most feeders observed were not filled. Despite the annual variability in numbers observed over the duration of the Halton Hills Count, we can conclude that numbers of Canada Geese, Common Raven and Red-bellied Woodpecker are increasing while the numbers of American Kestrel have declined.
Thanks to the following participants: Ray Blower, Alexis Buset, Mark Cranford, Melissa Creassey, Emily Dobson, Kim Dob-son, Ramona Dobson, Pam Forsythe, Ann Fraser, Sandy Gillians, Ian Jarvie, Aaron Keating, Dan MacNeal, Lou Marsh, Merle Marsh, Katie McDonnell, Bill McIlveen, Irene McIlveen, Matt Mills, Dan Pearson, Johanna Perz, Fiona Reid, Dawn Renfrew, Don Scallen, Adhara Collins Scholten, Yves Scholten, Dan Schuurman, Rick Stroud, Janice Sukhiana, Patrick Tuck, George Wilkes, Marge Wilkes, Dave Willams.
Many thanks once more to Larry May for arranging access to the Maple Lodge Farms property and to Fiona Reid for hosting the wrap-up session.
I’ve spent a lot of time recently at the Georgetown Hospital, visiting my mother who suffered a broken pelvis on December 1st. Looking out the windows of the various rooms she’s occupied, it occurred to me that a strategically placed bird feeder or two could be a pleasant diversion for bed-bound patients.
The hospital management heartily endorsed my proposal to install the feeders. I purchased two feeders along with poles and squirrel baffles from Wild Birds Unlimited in Guelph. Manager Richard Tofflemire generously offered a large discount on the total cost after I explained the project. He also provided two 20kg bags of seed and a carton of suet cakes at no cost.
Sandy Gillians and I erected the feeders just prior to Christmas. They now await discovery by the neighbourhood birds.
I’ll maintain the feeders throughout the winter and then likely remove them as the voracious grackles return in early spring. I’ll re-install them next fall. Both feeders are currently placed fairly close together in the hospital’s courtyard. One may eventually be relocated to another area of the hospital grounds.
Our club executive has agreed to help pay for these feeders, with money from membership fees. They are ours to celebrate.
The smooth gray bark of beech trees evokes elephant skin, making beech strikingly unique among the large trees of the forest. This smooth bark sometimes offers signs of mammals that have passed by: claw marks left by climbing bears, or declarations of love etched by romantic humans.
Beechnuts nourish wildlife. This bounty, properly referred to as “mast,” once fed legions of passenger pigeons. Where beech trees and black bears co-exist, the bears cling to the trunks and pull branches towards them to feast on the nuts, inadvertently tangling the branches to form structures fancifully referred to as “bear nests”.
Beech trees offer not only food, but also housing to wild creatures. Pileated wood-peckers chisel nesting holes into them. Other tenants, including flying squirrels, move in when the woodpeckers move out.
Woodlands in parts of southern Ontario were once referred to as maple-beech forests. Beech, like sugar maple – but unlike oak and pine – can grow in very shady conditions. This allowed beech, along with sugar maple, to dominate mature deciduous woodlands.
No more. Beech are being destroyed at heart-breaking speed by an introduced pathogen called beech bark disease.
The demise of beech goes largely unnoticed by people who don’t hike in the woods; this because beech trees seldom grow in the open. They require the shade, moisture and shelter of the forest’s embrace.
Beech trees also likely depend on soil-born forest fungi. Many trees, and other woodland plants, have a mutualistic, “you scratch my back, I’ll scratch yours”, relationship with fungi. The fungi take carbohydrates from tree roots and, in return, help the roots absorb water and minerals.
Regardless, the forest disposition of beech trees means you won’t see their bleached bones on the open landscape as you do elm trees. The glorious beech trees with the elephant-skin bark, die largely unmourned as they tilt towards the fate of the passenger pi-eons they once fed.
Bees and wasps like soft wood: drill holes of varying thicknesses in a 6 x 6 or larger log and hang this on an outer wall or barn
April
Salamander Season!
Join HNPNC on a salamander walk at Silver Creek to learn about these amazing animals
Hunt for frogs in local ponds
Head to Willow Park in Norval on a sunny day later in the month to look for emerging snakes around the rocks of the hibernacula or beside their small pond
Woodcocks may be back and on territory so go for a woodcock prowl at dusk
May
Help our Pollinators by going Native!
Join HNPNC in converting a stretch of the river bank by the St Alban’s church into a home for pollinators and a bank for nesting turtles
Help remove non-natives and plant natives
If you have a large lawn, why not convert a section into a native plant garden?
June
Dig it, Dig it Good!
Put in a pond in your back yard – nature will come to you (details coming in March newsletter)
No space? A dripping hose can attract birds, or a small fountain will lure in dragonflies
Turtles love ponds, and this month they will also be out looking for nest sites. Report your turtle sightings to the Toronto Zoo’s Turtle Tally Program
Do some pond-dipping to see the huge array of small creatures that live in a healthy pond
July
Out with the Invaders!
Now is the time to pull out dog-strangling vine and other invasive species before they set seed and spread further
Start a local initiative to remove Norway Maples and plant native trees
Talk to a neighbour about planting native trees and shrubs to provide food for declining birds (caterpillars far prefer native plants and they in turn feed birds)
August
Have a Wild Night out!
Join HNPNC on a moth night, or paint sticky goop (beer, banana and sugar) on trees near your own home to see what moths you can attract
Come on a Monday evening walk
Watch bats forage over water near the cottage
September
Help Migrants Journey in Safety
Put up weighted threads outside large windows to reduce reflection and bird collisions (check out www.flap.org/ for more information)
Keep cats inside when thrushes and warblers are passing through backyard habitats
Plant asters and other late-blooming natives for traveling Monarchs
October
Fall into Nature!
Take a trip with our club to see migrating hawks
Look for fall warblers and sparrows
Take a child for a walk in nature; it is a great time of year to see animals of all sizes on the move
November
Buy a new Field Guide and get on Track!
It’s slowing down out in the forest, so why not get some new nature books to study for next year and check off what you have seen to date
Get out after the first snowfall to look for animal tracks, and bring a book to identify them
December
Have an Eco-friendly Holiday!
Use recyclable wrapping (bags, newspaper, scraps of cloth)
Decorate the tree with popcorn and cranberries to put out for birds later
Minimize use of colored lights
Give nature-inspired gifts – for the friends who have everything, consider buying an acre of rainforest
Take part in the Christmas Bird Count and tell your friends all about it
I’m not sure I am still qualified to write this letter as I am now officially Past President. We are very happy to welcome newly elected secretary Emily Dobson to our board and thrilled to have had interest from new members in joining our executive (see below)! Many thanks to Anne Fraser for her work as past Secretary, and to Jeff Normandeau for his past work on the newsletter.
Executive 2014/15
President: Vacant
Past President: Fiona Reid
Vice-President: Don Scallen
Secretary: Emily Dobson
Treasurer: Janice Sukhiani
Roving: William McIlveen, Kevin Kerr, Nikki Pineau, Anne Fraser
Club membership fees are now due. If you haven’t already paid up, please bring your money to the next meeting or pay online at our website via PayPal. Your financial support is critical to our ability to provide great speakers, rent a meeting space, and cover our insurance costs. Thanks!
We have some great speakers and evening events to look forward to, including the Pot Luck Dinner in December, but we do need more volunteers to lead nature walks.
Today, November 1, we had our first snow of the year. Has winter already officially begun? Be sure to keep your feeders full and enjoy the winter birds.
All readers must surely have heard of the ongoing outbreak of the Ebola hemorrhagic fever that is occurring in several countries in West Africa. The disease is indeed a nasty one that starts with a fever, muscle pain, and headache followed by vomiting, diarrhea, and impaired kidney and liver function. Internal and external bleeding may also occur. The mortality rate of the current outbreak stands at about 70%. As of 14 October 2014, 9,216 suspected cases and 4,555 deaths had been reported. Given that the total population of the three main affected countries, Liberia, Sierra Leone, and Guinea, is over 22.1 million people, this translates to only 0.041% of the population infected. While this may seem to be a very small proportion, it must be realized that the number of people infected is continuing to increase.
Ebola hemorrhagic fever is caused by a virus. Among a large number of virus diseases affecting humans, there are some rather familiar types including AIDS, chickenpox, common cold, hepatitis, influenza, rabies, shingles, measles, SARS, West Nile fever, and yellow fever. Many of these have multiple strains. A virus is not a living organism though it does share some characteristics with pathogens of plants and animals. Instead, viruses are essentially sections of rogue DNA or RNA genetic material surrounded by a protein coating. They are capable of reproducing (increasing in number) by causing their host to make more copies of the virus, each one capable of causing the disease in the host.
All living species as well as viruses need to be able to reproduce themselves. If they don’t, then, over time, they will simply die out. If a species is to retain a stable population, then they need to replace themselves on a one for one basis. In the case of animals including humans, the female must, during her lifetime, produce two offspring (male and female on average) that live to reproduce themselves. Of course, not all offspring will survive to do so therefore the females must produce in excess of the minimum to compensate for the premature loss of the young. If she doesn’t, the species will die away. If she produces more than the number required to maintain the status quo, then the population will increase. This is simply a basic biological principle that often gets overlooked.
Figure 1. Examples of population growth curves for species reproducing at different rates.
In general, a reproducing population will increase at rates in excess of the minimum. The rate of increase is much like the way one must pay interest on the portion of an unpaid loan or receives interest (albeit very low these days) on a bank account. The longer that such an account exists, the greater will be the amount of accrued interest. The same thing applies in biological systems and the data can be plotted mathematically in graphs (Fig. 1). The rate of increase, ‘r’, can vary widely. A plant for example may produce just a few seeds or may produce thousands of seeds each year. The larger the number of seeds that are produced, the faster that an unchecked population can grow. When a population of some species is growing at a high rate (e.g. a rate higher than we humans wish it to be), we reach epidemic or invasive proportions.
Figure 2. Graph showing the ‘s-shaped’ pattern of colonization of a suitable habitat by an introduced organism.
In reality, a species will typically increase until there is no more space available or all of the resources are used up (Fig. 2). Dandelions, for example, will spread in a newly cultivated field until there is no more space left in which a seed can germinate and grow into a new plant. Disease organisms such as potato blight will spread through the crop until it has infected all of the available host foliage. The same principle applies to all organisms – fungal, bacterial, viral, insect, mammal, etc. Populations simply cannot increase forever. As well as exhausting all available resources or space or hosts, other factors will often have a bearing on the situation for they too will become hosts for a different type of organism. For example, an infestation of caterpillars on a crop will be subjected their own set of parasites and hyper parasites that keeps the population in check. And it is never in the long-term interest of a parasite to kill all of its hosts.
In reality, not every seed will germinate, or the conditions for growth are not suitable, or the plant or whatever organism is itself subject to its own parasite. In a balanced natural system, the growth of populations of all types of biological entities is constrained and the system functions as nature intended. The problem comes when a particular species does not have its inherent control systems. This is usually the case (initially) for a newly introduced species and it reaches undesirable numbers. This applies to plants, insects, fungi, bacteria, viruses, etc. But the net effect of all the factors that may come into play are keeping the ‘r’ rate lower.
Now, in relatively recent times, the computer programmers needed a word to apply to situations when malicious software was introduced into the electronic communications used by functioning computers. They latched on to the term ‘virus’ from the field of biology for they considered the desirable programs running on the computer to be ‘infected’ by the undesirable software. They could have just as easily used the term ‘fungal’ or ‘bacterial’ or even ‘epidemic’ to indicate the ability of the software to spread to other computers. The application of the term ‘viral’ still remains incorrect. Even more recently, people have used the term ‘viral’ to indicate the rapid spread of a photo, film clip, or some type of information among cell phone users and the like. The use of the word in this way is quite different from that where the malicious software is involved. It is even more distant from the true meaning of ‘viral’ and its use should be discouraged. Hopefully, time will cause the term to become obsolete in this manner of use and that its use will return to where it truly belongs – restricted to the world of virologists that are dealing with the spread of real issues including infectious diseases such as Ebola.
There are ten species of birds that commonly nest in suburban Georgetown: Mourning Dove, Black-capped Chickadee, House Wren, American Robin, European Starling, Northern Cardinal, House Finch, Chipping Sparrow, Common Grackle and Brown-headed Cowbird – a nest parasite.
One other, less common nesting species is the Chimney Swift, relying on the specialized nesting habitat of uncapped chimneys.
I have observed another three species nesting one time in suburban Georgetown: American Crow, Tree Swallow and Baltimore Oriole. Blue Jays and Red-winged Blackbirds are probably occasional nesters as well.
I can write about this with some authority, because I’ve been a resident of suburban Georgetown most of my life. I realize that homeowners fortunate enough to live along Silver Creek ravine may entertain other nesting species on their properties. Kerry Jarvis and Melitta Smole, former HNPNC members, attracted Great-crested Flycatchers and Screech Owls to bird boxes on their ravine lot for example. Downtown Georgetown, with its mature tree canopy, may also provide habitat for a few other species.
Regardless, town and city-scapes have a very low diversity of nesting birds. This contrasts with the higher diversity found in natural areas surrounding those urban centres. Consider the results of the second Atlas of the Breeding Birds of Ontario (2001-2005.) The atlas project divided Southern Ontario into “squares” measuring ten by ten kilometres. The “square” that held most of Georgetown also contains forest, wetland, fields and agricultural land. This “square” harboured 60 species of confirmed breeding birds, six times greater than the number nesting commonly in Georgetown’s urban area. Evidence gathered – primarily by club veteran Ray Blower – also identified 35 additional species as probable breeders and 17 as possible breeders.
Some specific comparisons of various categories of breeding birds between the atlas square and urban Georgetown are instructive.
Category
Number of breeding species in atlas square
Number of breeding species in Georgetown urban area
Warblers
8 confirmed, (8 others possible or probable)
0
Sparrows
5 confirmed, (5 others possible or probable)
1
Swallows
5 confirmed
1 rarely
Woodpeckers
5 confirmed
0
This low diversity of nesting birds in Georgetown applies almost certainly to other urban areas throughout the province. The urban landscape is simply not suitable for most birds. Birds avoid nesting in our towns and cities because of our roads and how we landscape our parks and yards. We remain wedded to our lawns. (I’m guilty – my front yard is still largely cropped grass.) Our yards lack the cover, the plant diversity, the water, the insects, which birds need to survive. As housing density increases, and it will, the situation will become even bleaker.
Some may invoke free-roaming cats to help explain the lack of bird diversity in urban areas. After all, studies have found that cats kill billions of birds (and small mammals) annually. While cats are almost certainly a major problem in rural areas where they can gain access to fields and woodlands, they shouldn’t be blamed for the low diversity of birds and mammals in urban settings. I suspect that if, miraculously, all of Georgetown’s cats were kept indoors starting today, the town’s diversity of birds would change little. The same ten species would continue their residence; the rest would continue to keep their distance.
Homeowners, both urban and rural, need to be more humble. It is disingenuous to condemn cat owners for letting their pets roam, while we habitually fire up the lawn mower for another diversity-reducing shearing of our grass. This applies to suburbia, but also to the ridiculous swaths of turf that surround rural estates. Yes cats are killers, but those that roam urban environments have little impact on an environment already severely compromised by us.
Yellow-Spotted Salamander. Photo by Matt Ellerbeck.
Although they are rarely given much thought, and often overlooked when they are, salamanders are in a terrible crisis. Around half of all the world’s salamander species are listed as threatened by the International Union for Conservation of Nature (IUCN). These species are all facing a high risk of extinction. A further 62 species have been designated as near-threatened with populations rapidly dwindling. This means they are quickly getting closer to threatened status and to the brink of extinction. Sadly for some salamanders it is already too late, as both the Yunnan Lake Newt (Cynops wolterstorffi) and Ainsworth’s Salamander (Plethodon ainsworthi) have already gone extinct.
Salamanders have been on the earth for over 160 million years, and the terrible state that they now find themselves in is due to the detrimental acts of humans. Even those species that are not experiencing population declines deserve attention and conservation to ensure that they remain healthy and stable.
Red Eft. Photo by Matt Ellerbeck.
One of the biggest issues affecting salamanders is the loss of their natural habitat. Many areas that were once suitable for salamanders to live in have now been destroyed for developmental construction and agriculture. Habitats of all kinds are being lost at an alarming rate. Wetlands are drained, forests are logged and cut down, and waterfronts are developed. Salamanders are literally losing their homes and they are losing them rapidly. The expansion of urban areas threatens the suitable habitats that still remain.
Where natural habitats do still exist, they are often fragmented or degraded. Fragmentation occurs when healthy areas of habitat are isolated from one another. These fragmented areas are known as habitat islands. Salamander populations are affected since gene flow between the populations is prevented. This increases the occurrence of inbreeding, which results in a decrease in genetic variability and the birthing of weaker individuals. Fragmented populations where inbreeding occurs often ends in a genetic bottleneck. This is an evolutionary event where a significant percentage of the population or species is killed or otherwise prevented from reproducing. Habitat fragmentation is also harmful because it often eliminates crucial requirements in the area which are critical to the survival of salamander populations. Such areas include spaces that can be utilized for thermoregulation, prey capture, breeding, and over-wintering. Without such habitat requirements populations dwindle.
Four-Toed Salamander. Photo by Matt Ellerbeck
Breeding sites, often in the forms of vernal pools are particularly important. The loss of such areas in the form of habitat destruction can negatively affect the entire population and its reproductive output. According to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), there is some evidence that certain salamander species have individuals that return to the pond in which they were born once they reach maturity. Therefore, destruction of a breeding pond may result in loss of the entire population returning to that site. Habitat complexity is also important as it offers shelter to salamanders from both predators and human persecution.
Degradation occurs when the natural habitat has been altered and degraded to such a degree that it is unlikely that any remaining salamanders species would be able to survive. Developments and agriculture near fragmented habitats put salamanders at serious risk. As amphibians, salamanders have extremely absorbent skins. Industrial contaminants, the introduction of sedimentation into waterways, sewage run off, pesticides, oils, and other chemicals and toxic substances from developmental construction sites and human settlements can all be absorbed by salamanders. This can quickly lead to deaths. They can also cause widespread horrific deformities to occur. A study conducted at Purdue University found that out of 2,000 adult and juvenile salamanders 8 percent had visible deformities.
Blue-Spotted Salamander. Photo by Matt Ellerbeck
According to Save The Frogs, Atrazine (perhaps the most commonly used herbicide on the planet, with some 33 million kg being used annually in the US alone) can reduce survivorship in salamanders. Many products are sold with the claim that they are eco-friendly. However, these should be viewed with caution. For example, according to N.C Partners in Amphibian and Reptile Conservation, Roundup and many other surfactant-loaded glyphosate formulations are not labeled for aquatic use. When these formulations are applied to upland sites according to label instructions, the risk to surfactant-sensitive species is considered low. While this may be the case for fish it does not necessarily apply to amphibians. Salamanders that breed in water also routinely use non-aquatic areas and could easily be exposed to glyphosate formulations that contain harmful surfactants through direct application and not just incidental drift.
Habitat destruction and degradation can also effect the availability of prey items, causing unnatural declines in appropriate food sources.
Habitats are often isolated and cut off from one another by the roads and highways that now run through them. Countless numbers of salamanders are killed on roads and highways every year when they are hit by vehicles. Salamanders that are migrating to breeding and egg-laying sites often must cross over roads to reach such areas. Here many of the mature members of the breeding population are killed. Removing members of the breeding populations greatly limits reproductive output, this makes it incredibly hard for salamander numbers to rebound.
Roads present an additional problem because they represent a form of habitat loss. The roads that run through natural areas also fragment the existing populations, drastically making them smaller in size. This limits the gene flow and genetic diversity between the isolated populations on either side and this greatly increases the chances of extirpation. When salamanders attempt to cross roads to travel between the populations, or to critical breeding/birthing sites it greatly increases their chances of being hit and killed by vehicles.
The Wetlands Ecology and Management (2005) population projections for spotted salamander (Ambystoma maculatum) life tables imply that an annual risk of road mortality for adults of greater then 10% can lead to local population extirpation. Unfortunately, it is estimated that mortality rates can often be as high as 50 to 100%, which means populations are at extreme risk of extirpation and extinction due to road mortality. Wyman (1991) reported average mortality rates of 50.3 to 100% for hundreds of salamanders attempting to cross a paved rural road in New York State, USA. Given that this figure pertains to a rural area from over a decade ago, it is fair to assume that even higher mortality rates occur as their has been in increase in cars and roads over the years. Reducing road mortality is paramount to preserving salamander species.
Being hit and killed by vehicles is not the only threat that roads create for salamanders. Chemical run-off from vehicles contaminate roadside ditches and pools. These sites are often utilized by salamanders for breeding and birthing. According to Steven P. Brady (2012) survival in roadside pools averaged just 56%, as compared to 87% in woodland pools. Thus, an average of 36% fewer individual embryos survived to hatching in roadside versus woodland pools.
Salamanders are also threatened when they are harvested from the wild. Salamanders are taken for food markets, for use in dissections, and for use as fishing bait.
There is much about salamanders that scientists do not know. Aspects of the biology, ecology, and lifestyles of many species is a mystery. This undoubtedly means human interference is negatively affecting salamanders in ways in which we don’t even know. The intricate relation between all species and the vital roles they play within eco-systems is also being altered. Such alterations can have serious consequences to not just salamanders, but many other animals as well (including humans).
Matt Ellerbeck is a Salamander Conservationist licensed with the Ontario Ministry of Natural Resources. He is also a partner of the Amphibian Survival Alliance (ASA), which is the world’s largest partnership for amphibian conservation.
Goodbye summer, hello fall. Come to think of it, where was summer this year?
Summer was not a wow for those of us who like it hot (tomato crops were poor, moth numbers down), but we are seeing some very pleasant weather now that September has arrived. The trees have at least been able to take up sufficient moisture to encourage new growth after the ravages of winter, and I expect the fall colours will be especially good this year.
We have a great line-up of talks coming up, so I hope to see everyone at these events.
About two years ago, there was an event that made a notable item in the news. This was the phenomenon where the planet Venus traces a course across the face of the sun. This happened on June 5, 2012. A similar transit took place on June 8, 2004. Transits of Venus are rare events, occurring in pairs about eight years apart but separated by periods of over a century. As notable as this recent event might have been, it was rather minor in significance by comparison with the attention paid in 1769 as described below.
Venus (small dark circle) entering face of sun, Acton Library, June 5, 2012. Photo made with hand-held digital camera and telescope. Photo by W.D. McIlveen.
During the 18th Century and onward, marine shipping around the world was increasing in importance, whether for commercial or military purposes. A critical part of this activity was the dependence upon the ability of ships to navigate the seas. At this time, ship captains could determine their latitude reasonably well based on the technology that existed at the time. The matter of knowing their longitude was an entirely different matter. By not knowing both the latitude and longitude, it was very difficult to know their true position and as a result, a great many ships were lost in various mishaps at sea.
In 1716, Edmund Halley realized that the problem of longitude could be resolved by understanding the direction, angular separation of planets and stars and the distance between them. A critical factor is knowing the distance of the earth from the sun. Halley realized that an ideal opportunity for making this distance measurement would occur by accurately observing the transit of Venus across the face of the sun and using this information in some complex mathematical calculations. He knew that the next such opportunities for making the needed observations would happen in 1761 and 1769. Although he never lived long enough to witness the results of the work carried out by astronomers making the measurements, he did set in motion an international process to collect the critical information.
Based on sea voyages to St. Helena and Barbados in 1764 and celestial observations made there, Nevil Maskelyne, Astronomer Royal of England, was able to produce a book of tables, The Nautical Almanac, in which the position of the moon for every noon and midnight was forecast for several years into the future. From these tables, navigators could estimate a longitude to a greater degree of accuracy than they could before that date. The required accuracy was still not sufficient and detailed observations on the next transit of Venus were needed.
Some early measurements of the transit of Venus were undertaken at Tobolsk, Siberia by Jean-Baptiste Chappe d’Auteroche on June, 6, 1761. Despite support from the empress, his trip from Paris to the viewing site was difficult to say the least, but he did manage to obtain the needed data.
Various competing but cooperative ventures were launched to observe the transit of Venus on June 3, 1769 at different points around the globe. A number of these failed completely because the skies were covered in cloud at the critical moment or because of travel logistics and political conditions. For example, Le Gentil from the French Academy of Science could not land at the intended outpost of Pondicherry in the Indian Ocean because the port had fallen into the hands of the British. He could not operate the telescope properly on the deck of a floating ship so his efforts produce nothing of consequence. Also, in 1769, the surveyors Charles Mason and Jeremiah Dixon (whose names live on in the form of the Mason-Dixon Line in the United States) were commissioned to set up an observatory at Bencoolen, Sumatra. A series of delays beyond their control caused them to shorten their trip so that they were only able reach Cape Town. They set up their observatory there but were able to collect only partial details due to clouds on the critical day.
Three teams of observers did collect the required data. One team consisted of Father Maximilian Hell and Joannes Sajnovics from Hungary. After a harrowing trip along the edge of fiords, stormy fall seas and spending the previous long dark winter on an island at Vardos off the north coast of Norway, they set up an observatory and made the needed observations. By comparison, Chappe was sent to collect the data San Jose del Cabo on the tip of Baja California. This required a trip on horseback across Mexico in the company of Spanish co-observers Vincente de Doz and Salvador de Medina followed by a boat trip across the Gulf of California. Chappe had the misfortune to arrive at his destination in the midst of a serious outbreak of typhus. Although he fell victim to the disease himself, sheer will power saw Chappe complete his task. He survived until August 1 when he too died. Fortunately, his assistant was able to bring the data back to Europe where the information could be utilized. Perhaps the most famous observer team that successfully collected transit information was that of Captain James Cook and his senior observer Charles Green. They made their way to the island of Tahiti in the Pacific Ocean after rounding Cape Horn. On that trip, the young botanist/naturalist Joseph Banks was a paying passenger. He was out to collect botanical and other natural history information along with his own team of servants and assistants. Fortunately for the expedition, Banks was more diplomatic than Cook and so he was able to retrieve the critical instruments stolen by the Tahitian natives who were enthralled by any metal objects. But Cook’s expedition experienced good weather for the observation date and they obtained all of the required data.
The data collected by all of the observers eventually was to pass through the clearing house set up under the auspices of the Royal Academy of Science in Paris. At the time, Jerome Lalande was in charge of processing the data. He was somewhat arbitrary in selecting the data that he accepted and rejected. This led to a public and heated spat with Father Hell. Lalande’s approach led to a measurement of the distance to the sun that was less accurate than some of the collected data would have indicated. Since then, more accurate measurements have been made using other techniques but the technology used in 1769 was the most advanced at that time.
The next pair of Venus transits will occur on 10–11 December 2117 and in December 2125. Not many people alive for the most recent transit will be alive to witness the next.
Reference Anderson, Mark, 2012. The Day the World Discovered the Sun. DaCapo Press, Philadelphia. 280 pp.
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
The unusually warm conditions and lack of snow in combination with extra observers likely affected the overall results. The lack of snow would cause fewer birds to require food from feeders though most feeders observed were not filled. Despite the annual variability in numbers observed over the duration of the Halton Hills Count, we can conclude that numbers of Canada Geese, Common Raven and Red-bellied Woodpecker are increasing while the numbers of American Kestrel have declined.
