More wonderful shots by club member Anne McDermaid.
A look back at summer
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Salamanders under threat
By guest author 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.
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.
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.
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.
President’s Message
Greetings to all,
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.
Best wishes,
Fiona Reid
The Significance of the Transit of Venus
By W.D. McIlveen
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.
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.
Great Egrets
By Don Scallen
Great egrets evoke notions of southern swamps – of alligators, bald cypress trees and Spanish moss. And yet, they are now common inhabitants of Ontario wetlands. At this time of year, post- nesting egrets are assembling at foraging sites, prior to their southward migration. Sandy Gillians and I counted about 50 egrets along the Beaver River near Kimberly recently. Other late summer roosts include Luther Marsh and Cootes Paradise.
Great egrets are a balm to disillusioned naturalists all too familiar with the loss and retreat of wildlife. They represent the promise of recovery. Once teetering on the brink of extinction, they were rescued by a remarkable conservation effort initiated by a small group of women in Boston.
Egrets were being slaughtered by the thousands in the 19th century America. Fashion mavens of the day advertised their status by adorning their heads with wildly extravagant hats, sprouting flowers and fruit. But more exotic accoutrements were desired.
Milliners obliged by affixing feathers, heads or the bodies of colourful birds to the hats they sold. Feathers of bluebirds, blue-jays, orioles and, of course, egrets were all commonly used. Stuffed warblers and hummingbirds peeked out blindly between the plumes. Even small stuffed mammals and reptiles clung to the hats of Patrician ladies as they sipped their afternoon tea.
Like today, most 19th century consumers thought little about the provenance of the products they bought. As now, purchases of clothing and accessories were motivated primarily by style and price. Sometimes though, uncomfortable truths rattle the public conscience: Think the Bangladeshi garment industry or the blood diamond trade.
The uncomfortable truth of bird slaughter for the millinery trade dawned on a group of well-connected Bostonian women in 1896 and the Audubon Society was born. They launched the first modern-style conservation campaign, successfully pressuring politicians to end to the killing.
The success of those early conservation pioneers is evident in the magnificent egrets that grace Southern Ontario in the 21st century.
Report on Evening Walks for 2014 – South Peel Naturalists And Halton North Peel Naturalists
By W. D. McIlveeen
During the summer of 2014 (May 26 to August 25), a total of 14 evening walks were organized for various areas of Halton and Peel Regions. The site locations are listed in the following table along with the names of the leaders and the numbers of participants on each walk. An attempt was made to alternate sites in the south and the north part of the area. Overall, there were five different leaders (Ray Blower, Kirsten Burling, W. McIlveen, Dawn Renfrew, and Leanne Wallis).
One of the walks was cancelled due to heavy rain which reduced the potential attendance and to eliminate any safety concerns that wet trails might cause. Excluding the cancelled walks, the numbers of participants (excluding the leaders) ranged from two to 9 with an average of six participants per walk. This is very close to the attendance in 2013. There was a small core group of participants that came out for most walks but there were also many walks where the participants were infrequent attendants. Two were not typical walks. The trip that took place on the weekend of August 9 and 10 went to two oak savannah sites in Windsor and to two sites at Point Pelee. At those locations, the participants were treated to fine weather and saw many rare species of plants and butterflies. The trip on August 18 met in Limehouse but the event actually happened in Glen Williams where we participated in the ‘Shadfly Festival’ and we got to see huge numbers of mayflies emerging from the river.
Overall, comments from people that did come out for the walks indicated that they found the trips to be interesting and enjoyable.
| 26-May-2014 | Conely Tract | Bill McIlveen | 6 people |
| 2-Jun-2014 | Indian Ridge Trail | Bill McIlveen | 6 people |
| 9-Jun-2014 | Jacquith property | Dawn Renfrew | 9 people |
| 16-Jun-2014 | Arbourview Woods | Bill McIlveen | 5 people |
| 23-Jun-2014 | Silver Creek at 8th Line | Leanne Wallis | rained out |
| 30-Jun-2014 | Iroquois Shoreline Park | Bill McIlveen | 5 people |
| 7-Jul-2014 | Limehouse Area | Dawn Renfrew | 4 people |
| 14-Jul-2014 | LaSalle Park | Bill McIlveen | 3 people |
| 21-Jul-2014 | Limehouse Area Springle | Dawn Renfrew | 6 people |
| 28-Jul-2014 | Beachway Park | Bill McIlveen | 10 people |
| 4-Aug-2014 | Limehouse Area | Ray Blower | 6 people |
| 9/10-Aug-2014 | Windsor Weekend | Bill McIlveen | 6 people |
| 18-Aug-2014 | Limehouse Area | Ray Blower | 6 people |
| 25-Aug-2014 | Rattray Marsh | Kirsten Burling | 8 people |
It is anticipated that evening walks will be continued in 2015. If possible, we will try to time one of the evenings in August to take place at the time of the Shadfly Festival. Consideration will also be given to having one evening walk coincide with a Chimney Swift count (e.g. Oakville).
Late spring birds by Anne McDermaid
Baltimore Oriole © Anne McDermaid
?female Blue-gray Gnatcatcher © Anne McDermaid
female Blue-gray Gnatcatcher © Anne McDermaid
Great Egret © Anne McDermaid
Black-crowned Night Heron © Anne McDermaid
Black-crowned Night Herons © Anne McDermaid
Great Blue Heron © Anne McDermaid
Yellow Warbler © Anne McDermaid
Bald Eagle © Anne McDermaid
Grebes © Anne McDermaid
Brown Thrasher © Anne McDermaid
Cedar Waxwing © Anne McDermaid
Protecting roadside turtle nests
The weather is warm, overcast, and humid – conditions that female snapping turtles in our region apparently consider ideal to unload their burden of eggs on the gravel shoulders of rural roads.
Snapping Turtle. Photo © Fiona Reid
Snapping Turtle. Photo © Fiona Reid
Snapping Turtle. Photo © Fiona Reid
Yesterday afternoon HNPNC President Fiona Reid spotted several egg-laying turtles during one short drive:
On my way home from dropping my son at school yesterday I found three snapping turtles laying eggs along the side of the road. One was at a fast and quite busy intersection. A worker from Halton Hills Hydro was about to pick her up and move her with a shovel but I asked him to leave her as she had not finished laying eggs. Very grumpily he agreed, saying it would be my fault if she got hit. Well, the best pond was right behind her and I thought she might well turn around. I went home, grabbed supplies (signs, boards, tape etc) and headed back. I found another three turtles, 6 total. One was not laying (may have already done so). They were spread over about 2 km, so I drove back and forth checking on each one. They all faced the road when laying, but each one turned and went back away from the road, although one walked a long way along the bank before going into the forest. Now they are all safely in the ponds and woods!
My conclusion is that it is better not to move an egg-laying turtle but to see where she heads after she is done.
Females don’t start breeding until they are 15-20 years old, so it’s no wonder the Snapping Turtle is listed as a special concern species both provincially and nationally.
Knowing that very few eggs survive intact to hatching, Fiona and I returned to the nest sites last evening to see what we could do to protect the eggs from scavengers.
We covered 5 nests with chicken wire and anchored them with rocks and dirt. Fiona has read that racoons hate mint, so we applied a liquid mixture of mint mixed with chili powder to two of the nests, and sprayed two more nests with Bitter Apple (a commercial products used to deter puppies from chewing). We sprayed both repellents on the fifth nest. We found four more nests and sprayed two of them but did not cover them with chicken wire; we left the last two completely unprotected as controls for our little study.
Fiona will continue to monitor the nests to see if our efforts pay off. Incubation time is heavily dependent on temperature, and in Halton Hills we are near the northern limit of their range so it may be another 90-120 days before the hatchlings emerge.
Real Estate Bird Boom
HNPNC members took the final meeting of the 2013-2014 season outdoors on Tuesday evening (June 10th) with a walk through Scotsdale Farm. While we were there we checked several of the nest boxes that we installed on May 19th.
To our delight we found that 50% of the nest boxes were occupied even though we put them up a bit late for the nesting season. Most of the occupants were Tree Swallows but one box appeared to have been claimed first by an Eastern Bluebird and then taken over by a House Wren.
Thanks again to Kim Dobson for making the boxes and overseeing the installation. Thanks also to the hardy members of the Halton/North Peel Naturalist Club and our guests from Friends of Scotsdale Farm, who braved hungry mosquitoes for a walk through this beautiful property on a lovely June evening.
Guided Monday evening walks will continue throughout the summer in partnership with the South Peel Naturalist Club. HNPNC’s next official meeting will be September 9th at Saint Alban’s in Glen Williams – mark your calendars!
May moth sightings by Fiona Reid
Lettered Sphinx (Deidamia inscriptans) © Fiona Reid
Intent zale (Zale intenta) © Fiona Reid
Straight-lined palgodis (Plagodis phlogosaria) © Fiona Reid
Lappet moth (Phyllodesma americana) © Fiona Reid
Dogwood thyratirid (Euthyatira pudens) © Fiona Reid
Comstock’s sallow (Feralia comstocki) © Fiona Reid
Clostera Apicalis © Fiona Reid
