2011-2012: Trends in Fauna & Flora
“Avoiding Attack: Design and Deception in Nature” presented by Tom Sherratt, Carleton University
Creatures evolved to survive in the natural world: a report of the October 2011 lecture, written by Joel Byrne
The lights go down, the shuffling and conversations stop and I hear myself whispering: “This is going to be another great talk.” And so it was as the Mississippi Valley Field Naturalists (MVFN) public lecture series continued October 20th with the presentation, “Avoiding Attack: Design and Deception in Nature.”
The guest speaker, Dr. Tom Sherratt from Carleton University’s Biology Department, would be comfortable being described as an ‘evolutionary biologist’, in that his “primary interest is in how natural selection has acted, and continues to act to produce organismal traits.” His research interests, both theoretical and experimental, are in evolutionary ecology. He quickly outlined the solutions animals have evolved to avoid being attacked by predators in the natural world.
The first of these, and most obvious, is to avoid detection. Fortunately for potential prey animals there are a good number of ways to disguise themselves. Crypsis, or matching your background, sure challenges a predator. So does masquerading. The science behind this was explained using the Winnie the Pooh and the honey tree story (in which Pooh tries to fool the bees by pretending to be a little black rain cloud). Disruptive patterns break up your shape. Disruptive colouration can also do the trick. Dr. Sherratt’s lab researchers went out looking for Yellow-Banded Underwing Moths and Carpet Moths on trees to see if the way they rested on the bark, vertically, horizontally, or somewhere in between reduced their rate of being attacked. They discovered that the best way to survive if you’re an Underwing is to hang on vertically and head down and this is what they do. Orienting yourself with the bark worked better for Carpet Moths. Just remember—camouflage is good; without it, you’d better find another strategy.
Develop a defense and advertise it! That is use ‘warning colours’, develop spines, get a stinger, or develop a toxin. A classic example is the poison arrow frog with its toxicity and very bright warning colours, raising the big question, why do warning signals tend to be conspicuous? And, Dr. Sherratt asked, “Do invertebrate predators pay attention to warning signals?” To answer this the lab researchers tempted dragonflies with wasps, hover flies, bees and flies attached to sticks. The dragonflies attacked one and all, not paying attention to black and yellow markings or any other warning signs. Instead they seemed to be very size-selective about their potential prey, choosing the smaller flies and bees.
But what if you, the prey, have no defenses from predators? This brings up the third solution that Dr. Sherratt illustrated with more fascinating images: Look like something defended. In other words be a mimic. If you’re an edible species, ‘the mimic’, evolve to resemble an inedible one, ‘the model’. Thus the prey species gains a degree of protection from predators by resembling an unpalatable or otherwise defended species. This is Batesian mimicry, named after Bates a contemporary of Charles Darwin. Consider hover flies, of which there are many species. They so resemble bumble bees and wasps that they have played a key role in debate about ‘perfection’ in mimicry. Another kind of mimicry, Műllerian mimicry, named after Műller, also a contemporary of Darwin, occurs when ‘an unpalatable or venomous species resembles another of the same.’ Sound familiar? These two kinds of mimicry (Batesian and Műllerian) were brought to our attention to illustrate that distinctions between different kinds of mimicry might not be that clear cut. There can be overlap, grey areas, mistakes can be made, and myths can grow. A case in point is the Viceroy Butterfly’s resemblance to the Monarch Butterfly. This was thought to be a great example of Batesian mimicry— the Viceroy a tasty (to birds) species resembling an unpalatable monarch and thus avoiding attack. But it has been discovered that the viceroy is toxic but still more edible than the monarch to some birds, Blue Jays and Red-winged Black birds, for example. Thus the viceroy butterfly is now generally classed as a Műllerian mimic of the monarch. Since both monarchs and viceroys get eaten it seems to be to their mutual benefit to stay toxic, resemble each other, and share the burden of teaching predators to not eat too much of either one. If this is too complicated a solution, a prey species can, like members of one fly family, adapt to look like wasps and pretend to actually sting would-be predators. Other kinds of mimicry were discussed including sexual mimicry accompanied by more illuminating images.
“Consider hoverflies . . .” said Dr. Sherratt during his natural history lecture. They so resemble bumble bees and wasps that they have played a key role in debate about ‘perfection’ in mimicry. This photo shows, not a wasp, but a hoverfly of the family Syrphidae. MVFN file photo courtesy Dr. Henri Goulet
Dr. Sherratt wound up his talk with a quiz. He showed an image of wasp mimics, eighteen insects of various taxa all on one page, and asked which ones were wasps. Some of the look-a-likes were bees, some flies and so on, but picking out the wasps was tough. There were only four in the whole bunch. No one guessed correctly but one or two in the audience were close. Very humbling. After the talk, Dr. Sherratt fielded questions from the crowd. There were lots of good questions—a sure sign that the talk was well received. I found a great source of further insight into these questions and more, in a book entitled Avoiding Attack-The Evolutionary Ecology of Crypsis, Warning Signals and Mimicry co-authored by our speaker Thomas Sherratt, Graeme Ruxton and Michael Speed. Dr. Sherratt asked some of the Big Questions in evolution in his talk which only wetted our appetites for more big questions. Fortunately we can get some relief from this hunger in another of his books Big Questions in Ecology and Evolution co-authored with David Wilkinson.
E.T. Seton, in his book Two Little Savages, wrote a one-sentence preface as follows: “Because I have known the torment of thirst I would dig a well where others may drink.” He was referring to his “torment of thirst” for knowledge of the natural world. Tom Sherratt gave us a hearty drink from his well. Go on-line for Dr. Sherratt’s lab, website and email. One of Dr. Sherratt’s doctoral candidates, one Tom Hossie, has a caterpillar of the day blog about caterpillars & their eyespots. One actually appears to wink!
Evolutionary Biologist Tom Sherratt (right) receives enthusiastic thanks from MVFN President Joyce Clinton at the conclusion of his MVFN talk on design and deception in nature. Photo by Pauline Donaldson
“Citizen Science Networks: Linking Nature Observation with Conservation” presented by Marlene Doyle, Environment Canada
Becoming a citizen scientist . . . or how to help monitor ‘what’s up world?’: A report written by Dr. Jim Bendell
When most of us stop and ask ourselves what we value most in life, we likely admit it is not a thing or things at all, but ourselves and other people. Next would be the natural environment, which, after all, we depend upon for at least food, water, clothing, and shelter. What can we do to understand more about our natural environment and how to protect and sustain it? Marlene Doyle of Environment Canada told us what we can do during her presentation: “Citizen Science Networks: Linking Nature Observation with Conservation”.
At her lecture to the Mississippi Valley Field Naturalists (MVFN) in Almonte, Ms. Doyle invited the audience to “Join the ranks of Darwin and the Compte de Buffon” . . . that is to become citizen scientists!!! Ms. Doyle has worked for many years in enlisting people of all ages to monitor plants and animals and their habitats as coordinator of our national Nature Watch program. Ms. Doyle holds a Master’s degree from the University of Waterloo and is currently Canadian representative on the Circumpolar Biodiversity Monitoring Program’s Terrestrial Export Monitoring Group, or, “What’s Up? in the lands of the North?” Monitoring means observing and noting, something we do every day. Ms. Doyle gave us lots of ideas for what we can do to find out “what’s up world?” by monitoring the health and diversity of our natural world as citizen scientists.
Everyone can take part and the requirements are simply interest, time, and wanting to help. Along the way you will learn new things, including how top professionals think and work. You will also see for yourself what people are or are not saying and writing about important issues. You will connect to nature and the community. You will certainly make new friends, have fun, and perhaps begin a successful career. The major reward is caring for Canada and the world by recognizing real environmental problems and doing something about them. The concerns are many and the need for help is unlimited. An important issue is climate change, which is real but what can be done about it? We are losing species of animals and habitats, making the world a poorer place, at never so fast a rate. Locally, and in a life time; tree swallows, nighthawks, whip-poor-wills, little brown bats and other birds and mammals have been significantly reduced. Might this signal greater losses for the future and eventually impact negatively on our own way of life? But why the losses and is there anything that can be done about them?
A start in solving these problems is to monitor aspects of the environment by sight, sound, odour, or feel. As a citizen scientist, you will work with an experienced leader and follow set procedures. The more who are working together to the same end the more powerful will be the result. While amateurs are the main workforce, professionals in organizations, schools, universities and government typically provide information, participate, and publish the results. Observations and actions by citizen scientists may be out-of-doors, or in a laboratory or library. Work as much as you wish, alone or in a group. The longer observations can be made the better. Some monitoring projects extend over many years. For example, you might go out and tag a clump of wildflowers on your property, and then follow PlantWatch monitoring directions for information which should be collected in the spring, file a report and repeat this again with the same plants each year. Or, you might join an MVFN Christmas bird count. You might participate in a marsh monitoring program or a Lakes Loon Survey next summer at your home or cottage. Always there is help at hand for advice and direction.
Often people hesitate to participate in an activity because they think it is of little value or beyond their abilities. In fact, thousands of people are actively caring for our environment simply by reporting observations. And their findings have been used by many professionals and others to write reports on research and management in authoritative journals and books. Numerous tests show inexperienced volunteers, with training, make accurate observations and determinations to provide trustworthy results. In fact, says Ms. Doyle, the quality of data is more likely affected by survey design or quality of communication than by the expertise of the person or group who collected the data. Not only is citizen science data reliable but it complements professional monitoring, it is relevant, local, timely, unique, and it is relatively low-cost to collect. Remember, you are not alone and can easily join many other interesting and committed people. Contact local and global leaders in the care of our environment. A main doorway in joining a quest of interest is through the speaker; Marlene Doyle at 613-949-7754 (and more on how to reach her later). She welcomes your call.
There are at least 283 projects powered by ordinary citizens across Canada. A classic example is the Christmas Bird Count, started more than 100 years ago, which now includes 50,000 observers reporting from 2000 locations throughout the United States, Canada, and beyond. The findings, which are solely based on citizen scientist reports, have helped elucidate the requirements of birds and clearly show changes in the abundance and distribution of species. For example, the counts tracked the spread of an introduced European Starling over the northern states and Canada and the disappearance of the similar Japanese Starling introduced to British Columbia. The Japanese form apparently cannot hatch its eggs under as cool conditions as the European bird and the abundance of both may be linked to climate change. Other projects range from counting Monarch Butterflies (an at risk species) to searching old logs and journals for information on past environments.
Data gathered by citizen scientists are credible, unique and useful for furthering our understanding of the natural world. In this photo, ‘citizen scientists’ join amateur naturalists and professional scientists taking a biological inventory of a Mississippi Mills property during MVFN’s 2009 Bioblitz. Photo Pauline Donaldson
Ms. Doyle, through Nature Watch Canada, coordinates the input of four large inventories. They are: Plant Watch, Frog Watch, Ice Watch, and Worm Watch. Observations on plants include invasive species and dates of flowering. The kinds and abundance of worms reveal the health of soil. Frogs and the formation of ice are sensitive indicators of many factors in aquatic ecosystems, including temperature.
Interested in more information? In Lanark Highlands, Carleton Place and Mississippi Mills talk to Cliff and Lynda Bennett at 613-256-5013, ; or Cathy Keddy at 613-257-3089, Then some relevant organizations, in no particular order, are: Environment Canada (NatureWatch, www.naturewatch.ca, Ms. Marlene Doyle, 613-949-7754, , see above); Natural Heritage Information Centre, Peterborough (705-755-2159, ); Toronto Zoo (361A Old Finch Ave., Scarborough, ON M1B 5K7, www.torontozoo.com); Ontario Nature (336 Adelaide Street West, Suite 201, Toronto, ON, M5V 1R9, www.ontarionature.org ; Royal Botanical Gardens (Ontario Plantwatch Coordinator, Natalie Iwanycki, ); Bird Studies Canada ( P.O. Box 160, Port Rowan, ON, N0E 1M0); Canadian Wildlife Service (Ontario Region, 49 Camelot Dr. Nepean, ON K1A 0H3); and Canadian Amphibian and Reptile Conservation Network (Chairperson, Christine Bishop, 4553-46B Street, Delta, B.C. V4K 2N2, ). Cornell University also keeps a directory of projects undertaken by volunteers at http://www.birds.cornell.edu/citscitoolkit/projects/find.
Another way to join the ranks of Darwin and become a citizen scientist is to participate in one of the many annual Audubon Christmas bird counts across North America. Two local counts include the Lanark Highlands and the Carleton Place Christmas Bird Counts (for further info visit mvfn.ca). Birder Cliff Bennett records data during the count-in held after local count-teams return from a 2006 MVFN CBC. Photo MVFN archive.
Citizen science in action in the Mississippi River watershed: from August 5-7, 2006, nearly one hundred citizen scientists (MVFN members and others), set out in canoes, row boats and motor boats to take the watersheds’ temperature. The goal was to collect data and engage citizens in considering local implications of future climate change Shown is Howard Robinson, water-sampler in hand, ready to survey Palmerston Lake. Photo Mary Robinson
Avoiding attack: Design and Deception in Nature at next MVFN lecture
by Cathy Keddy
The Mississippi Valley Field Naturalists’ (MVFN) public lecture series, Trends in Fauna and Flora, continues October 20 with the second presentation, “Avoiding Attack: Design and Deception in Nature” with guest speaker Dr. Tom Sherratt from Carleton University. You do not need to be an expert to enjoy these presentations—just possess a curiosity or appreciation for wild nature. Cottagers, hunters, fishermen, canoeists, hikers, campers, artists and seasoned field naturalists alike will find something to interest them as we explore what lives in Lanark County and how best to protect it for future generations. Refreshments are offered at each lecture.
Dr. Sherratt will talk about crypsis (camouflage), warning signals and mimicry in nature—a diverse array of mechanisms that many organisms have evolved to avoid attacks from predators. He has studied these interesting and effective survival strategies in many different species including birds, butterflies, fungi, and dragonflies, and has also published a book on the subject.
Do you remember learning about peppered moths in England in connection with the Industrial Revolution and how the dark form of the moth became more abundant than the peppered (black and white) form because it could hide on soot-covered tree trunks? Well, this is only part of the cryptic story for these moths…It turns out that the peppered form is hidden from birds (which can see ultraviolet light) when resting on crustose lichens (both moth and lichen reflect UV light), but not when resting on foliose lichens (these lichens do not reflect UV light but the moth does). To us however, being unable to detect UV light, the moths appear camouflaged on both lichen types!
Mimicry in nature seems unlimited. Flies pretending they are bees—done so well, even professional entomologists may file specimens in the wrong drawer. Or consider sexual mimicry in damselflies—30-90% of females (in some species) want the males to think they too are males to avoid harassment. There are moth larvae that look like twigs and moths that look like leaves. Some moths even look like bird droppings. An example is the aptly named ‘bird-dropping moth.’ Mimicry comes in many forms including shape, odour, taste, sex, sound, movement, or colour. All reflect the ability of predators to perceive and prey to deceive.
Why are warning signal colours in nature (in our eyes) yellow and black? Why not red and blue? Why don’t more prey species sport these colours? Rather than wonder why a particular organism does not seem to be wearing warning colours, or does not appear to be cryptic or be using mimicry, we should consider first what sorts of predators the organism is at most risk from, and then think about that predator’s sense perceptions. Also remember… our appreciation of predator-prey communication is hampered by our own limited sensory perceptions of nature.
In the fascinating natural world, just as in our society, there is likely far more deception than we realize. Dr. Sherratt will tell us more at his MVFN presentation “Avoiding Attack: Design and Deception in Nature,” at 7:30 pm, Thursday, October 20, 2011 at the Almonte United Church, 106 Elgin St., Almonte. All are welcome ($5 fee for non-members). For further information please contact MVFN’s Program Chair Cathy Keddy at 613-257-3089.
Mississippi Valley Field Naturalists
September 2, 2011
Citizen Science—Joining the Ranks of Darwin and the Comte de Buffon
by Cathy Keddy, MVFN Program Chair
The Mississippi Valley Field Naturalists’ (MVFN) public lecture series on natural history and biology is set to begin September 15th. Attendance records were broken at the lecture series last year. Talks this year will once again be held at the Almonte United Church, and are open to the public as well as MVFN members. You do not need to be an expert to enjoy the presentations—just possess a curiosity or appreciation for wild nature. Cottagers, hunters, fishermen, canoeists, hikers, campers, artists and seasoned field naturalists alike should find something to interest them as the series explores what lives in Lanark County and how best to protect it for future generations. Refreshments are offered at each lecture.
The lecture series theme this season will be Trends in Fauna and Flora. Lectures will include a wide range of topics such as citizen science, ‘deceit’ in nature, flying squirrel battles, plants invading in our county, and tuning up for spring birds.
The first lecture, “Citizen Science Networks: Linking Nature Observation with Conservation,” will be presented by Marlene Doyle, Science Officer with Environment Canada. Marlene has worked for many years with citizen science approaches to ecosystem monitoring, assessment and reporting. Doyle is currently coordinator of the national NatureWatch program and is the Canadian representative on the Circumpolar Biodiversity Monitoring Program Terrestrial Expert Monitoring Group.
Citizen scientist networks are groups of volunteers who collect natural heritage information which is shared with those involved in decisions impacting the environment. For volunteers, it’s as easy as using your eyes and ears to track changes in nature. Citizen scientists have the rare opportunity to participate in cutting-edge biological research, to help with monitoring and protecting ecosystems, and to gain insight into ways scientists unravel the mysteries of the natural world. Thanks to the observations of citizens, scientists understand environmental changes better. As a citizen scientist, you join the ranks of famous citizen scientists such as Charles Darwin and George-Louis Leclerc, Comte de Buffon.
Many will be familiar with the Christmas Bird Count surveys that are carried out in our region each winter. That is citizen science. In fact, the National Audubon Society initiated this survey over 100 years ago to make use of and organize bird sightings of amateur naturalists. Originally comprised of 27 volunteers at 25 locations, this citizen science network is now continent-wide with more than 50,000 volunteers reporting from over 2,000 locations. Such information obtained over the long term and based on consistent methods is highly reliable and of great value to scientists for assessing species trends and conservation needs.
A more recent citizen science network, set up in 2008, addresses the decline in honey bee and native bee populations. Volunteers have been enlisted all over the world to observe bees on their Lemon Queen sunflowers (recently, also wild plants). Sunflowers are relatively easy to grow and a great resource for bees. It has been discovered that on average the flowers are visited by pollinating bees every 2.6 minutes. This means your garden is doing better than average if you see more than 3 bees every 15 minutes. If you observe fewer bees in that time then your garden has poor pollinator service. Over time, your observations and those of others helps build up an accurate picture of global trends in bee populations and their effects on the vital pollination of garden plants, crops, and wild plants.
If the birds and the bees are not your forté, perhaps you have an interest in catching scuttle flies to assist scientists with genetic research, or in monitoring monarch caterpillar distribution. Or perhaps you could get involved in Project Budburst that tracks the timing of leafing, flowering and fruiting of plants, or bat monitoring, or Icewatch, or the Lost Ladybug Project, or Firefly Watch, or the Garlic Mustard Field Survey… Even on a rainy day, you could contribute to a better understanding of the natural world from the comfort of an armchair by sifting through the pages of a ship captains’ data logs from a voyage made during the 1780s to 1830s to find historic weather data, or by examining star brightness charts to detect changes, or simply by letting your computer detect strong-motion seismic events. As you have probably gathered, fantastic opportunities to contribute as a citizen scientist abound!
There is no need to be bored—after retirement or at any time—become a citizen scientist! There is a worthwhile project for you and likely a new group of friends. Talk to Marlene Doyle about opportunities for participating in citizen science work to support conservation at her MVFN presentation “Citizen Science Networks: Linking Nature Observation with Conservation,” at 7:30 pm Thursday, September 15 at the Almonte United Church, 106 Elgin St., Almonte. All are welcome ($5 fee for non-members). For further information please contact MVFN’s Program Chair Cathy Keddy at 613-257-3089.
How long ago did ancient ‘beavers’ start ‘engineering’ Earths landscape?
-lecture report by Pauline Donaldson for an unpublished 2011 Whip-poor-will
More than 50 members of MVFN and the public were treated to a fascinating story packed with modern science details and enthusiastically told at our March lecture. Speaker Dr. Natalia Rybczynski, Canadian Museum of Nature paleobiologist, came to talk about our national animal, the beaver. When and why did this unique creature evolve? “How did evolution come up with this?” These are interesting questions from the perspective of the structure of our environment. How long have beavers been around cutting down trees and most significantly, re-engineering the very landscape they inhabit with their incredible dams?
Natalia explained that our Canadian beaver Castor canadensis and European beavers (Castor fiber) are the only surviving members of a diverse group of 18 genera of beaver ancestors which died out millions of years ago. These include ones with skulls much larger and much smaller than Castor ranging from the ‘infamous’ very large Castoroides, to the non-swimming burrowing beavers which dug with their teeth (forming, for the fossil record, mysterious, grooved tunnel structures known as devils corkscrews whose origins were earlier attributed to worms or thought to be channels from plant roots), to Agnotocastor which had a rather ‘boring’ rat-like tail.
To find out how long ago ‘beavers’ have been engineering the landscape, Dr. Rybczynski considered what features make a beaver the engineer it is. Swimming ability, wood-cutting talents and, of course, the ability to build dams; but how far back in the fossil record can one find evidence of these features, and which of Castors ancient relatives possessed them? As a paleobiologist Natalia studies the fossil record to better understand animals that live and that once lived. A key site Rybczynski and colleagues visit several times a year is ‘Beaver Pond’ on Ellesmere Island, an Early Pilocene peat deposit rich in fossils of bear, beaver and beaver-cut wood from a time when that arctic area enjoyed a lush, greener, warm period.
Fossil evidence suggests that beginning ~ 23 million years ago some of Castor’s ancestors could swim. Modern-day beaver are the most swimming adapted of rodents: closed ears, webbed feet, a streamlined body, and, last but not least, the characteristic flattened tail, an improvement which seems to have come about ~ 5-10 million years ago, and which is unique to Castor. This amazing tail (as we saw clearly in an underwater video clip) is not just a rudder for steering but, as the flapping rate showed, clearly contributes to the animal’s powerful underwater propulsion. The familiar flattened part is only part of the tail; there is a furry, muscular part closer to the body.
The next feature to consider is wood cutting. Once one knows how a beaver’s teeth cut wood, one can predict which of beavers ancestors had teeth that might work the same way. So, Dr. Rybczynski went undercover with some zoo beavers and made a movie of them cutting wood. They use their lower teeth only, and, turning their heads, they use only one lower tooth at a time! The cutting produces a characteristic gnawing pattern on two pieces of wood, an ‘A’ and a ‘B’ piece. Castor uses about 60% of the cutting edge of its incisor for cutting. At the Ellesmere Island site fossil evidence of beaver ancestor Dipoides was discovered with what could be wood-cutting teeth, although it likely used only 45% of its incisor surface. It was exciting to learn that there was fossilized Dipoides-cut wood to match. No fossil cut wood has yet been found to match the dentition of the mighty Castoroides ohioensis (shown in this early painting by O.M. Highley). When asked about the likelihood of it ever being found, Dr. Rybczynski says, yes, she thinks it will eventually be found.
So 23 million years ago there were creatures which could swim and cut wood. Perhaps this means our planets landscape has been engineered by beaver-like creatures for 23 million years. The final piece of the puzzle will, of course, be to determine when dam building actually began. The hope now is to find a fossil of an ancient beaver dam. Dr. Rybczynski speculates that ‘Beaver Pond’ on Ellesmere Island may actually be one. However, they will need to do more research to look at the sequence of deposition of materials there before they can be sure.