NatureWILD Magazine for Young Naturalists in British Columbia
Volume 14 Issue 4 2013
The Lonesome Spruce Tree
Spiders and Insects
Every Every Tree Tree Can Tell Tell A Story Story
www.ync.ca
SNOW
“Young Naturalists Observe and Conserve”
OUR CATS Indoors or Out? That’s the Question
Inside... 3 SNOW
4
Every Tree can Tell a Story
6 Spiders and Insects 8 The PORCUPINE 9 Aurora 10 Lonesome Spruce 12 OUR CATS 14 Ask Al
Hello,Young Naturalists! Do you have a cat? Is it an indoor or outdoor cat?
YNC Nature Champions
15 NatureWILD News 16 Fishyword Questions? Comments? Ian McKeachie, President info@ync.ca
In this issue of NatureWILD we ask a question “OUR CATS – Indoors or Out?” (see page 12). Do you agree with our answer to the question? E-mail me at info@ync.ca and tell me about your cat. If it is an indoor cat, share how you keep it happy and healthy. If it is an outdoor cat, how do you keep birds safe? I am waiting to hear from you!
Ian McKeachie President, YNC Chrissy the cat.
YNC is an exciting nature discovery and environmental action
program that invites young people ages 5-12 years to have fun discovering nearby nature on Explorer Days with local experts, learn about native wildlife and plants in NatureWILD Magazine and take part in environmental actions to protect their habitat with the Action Awards program. For more information: www.ync.ca.
Kristine Webber, Executive Director kristinewebber@ync.ca Tammy Keetch, Clubs Coordinator coordinator@ync.ca
Thank you to our sponsors and
supporters who share our vision that all children be connected with nature.
Rebecca Baker, Membership and Office Coordinator info@ync.ca NatureWILD Editorial Committee Content Editor: Daphne Solecki Production Editor: Monica Belko Editorial Assistant: Ruth Foster Contributor: Al Grass
NATURE
VANCOUVER
RR Donnelley
1620 Mt. Seymour Rd. North Vancouver, BC V7G 2R9
www.ync.ca 2
We acknowledge the financial assistance of the Province of British Columbia
ISSN: 1492-7241 NatureWILD is printed on SFI certified paper by Benwell Atkins an RR Donnelley Company,Vancouver.
C
SNOWE DW
It’s that time of year again - when the weather gets colder and you may see snowflakes falling (especially in the BC Interior). Celebrate the snowy season of winter by making your very own snowflakes... All you need is a: • square piece of white paper • pair of scissors (don’t be afraid to ask if you need help using the scissors and be careful, scissors can be sharp!)
1
Fold the paper diagonally to make a triangle.
2
Fold, along the dotted line as you see in the picture below. The corner of your paper triangle folds under.
C 3 4
Fold the other corner under as well. Using your scissors, cut out shapes like circles, ovals and squares into the sides of the folded paper. (Tip: try to make your cut-outs the same on both sides). The more cut outs you make, the more detailed your snowflake will be. When you have made your cut-outs - unfold the paperand enjoy your new snowflake!
N
SNOW FACT When snow crunches beneath your boots - that’s the sound of thousands of ice crystals being crushed!
H
TP I
SNOW FACT Ever noticed how quiet it is after a snowfall? Freshly fallen snow absorbs sound. The deeper the snow, the greater the effect.
F
K RG
SNOW FACT A snowy surface can reflect up to 95% of the sunlight shining on it. On bright days, remember to wear your sunglasses!
M
3
Every Tree Can Tell A Story Yes, it’s true – every tree can tell a story, the story of its own life. So how can we read that story? When a tree falls, if you cut straight through the trunk you can look inside the tree. A tree trunk is round so all the information comes in circles (rings) and each ring has a meaning. If you look across to the next page you can see how the tree grows and the names for the different rings. Every year of its life the tree grows a new ring. Wood that grows in the spring makes a light-coloured ring. In the summer (or dry season) trees don’t grow as much. Wood that grows in the summer makes a dark-coloured ring. (Trees generally don’t grow in autumn and winter.) SO - one light-coloured ring + one dark-coloured ring = 1 year. The growth rings are in the sapwood and the heartwood; the growth rings tell the story of the tree. They tell how old the tree is, what the weather was year by year, if there was a big storm, or a fire, or the tree was attacked by insects or disease. If you look carefully, you will see that the growth rings don’t all look the same. This is because in different years, different things happen to a tree.
4
Old-growth trees. Photo by Cacophony.
How many rings?
As there is one light/ dark growth ring for each year, count the rings to find out how old the tree is (counting the dark rings is easier).
Max is counting the growth rings on a slice of a cedar tree. Photo by Ruth Foster.
Thickness of rings
Look at how wide each ring is. In a good year, warm with enough rain for good growing, the ring is wider. In a bad year when it is cold or very dry, the tree did not grow very much and the ring is much thinner. Several thin rings together could mean that the tree was attacked by pests or disease and did not grow well until it recovered from the attack. Trees that live in harsh climates like the arctic or the desert can live a long time, but they grow very slowly. The growth rings are very thin and packed tight – really hard to count!
Shape
If rings start to become thinner on one side than the other it probably means the tree is leaning over to one side. High winds or a big storm can cause a tree to lean over.
Scars
A scar may show when a branch broke. A black burn mark on one of the rings shows there was a fire that year, but it did not kill the tree and the new rings gradually grew over the scar.
How a Tree Grows
A diagram of a core tree sample. By Thomas Steiner.
Pith
Heartwood
Bark
This is the outside layer of the trunk, branches and twigs of trees. The bark on the outside (outer bark) is actually dead wood; it is tough and hard and protects the tender wood inside (inner bark).
Cambium Sapwood
Sapwood
Sapwood is the youngest wood of the tree. This where the growth rings develop over the years, the inner layers of sapwood die and become heartwood.
Outer Bark
Inner Bark
Heartwood
The heartwood is dead sapwood in the center of the trunk. It is the hardest wood of the tree; it supports the tree and makes it strong. It is usually darker in colour than the sapwood.
Cambium
Pith
In young trees the pith has living cells. This changes as the tree gets older and the pith becomes hard.
The cambium is a very thin layer of tissue, sometimes only one cell thick. This is where new cells are made, so the tree grows bigger each year. The cambium produces a layer of phloem towards the outside (eventually becoming bark) and a layer of xylem on the inside (which becomes sapwood). Phloem (on the bark side) carries food down from the leaves. Xylem carries water and food up from the roots.
Dendrochronology
the science of tree-ring dating [from the Greek words - dendron (tree limb); khronos (time); logia (study)] Many scientists, who are interested in climate change, study tree rings to see what the climate was like thousands of years ago. The oldest tree we know of is Old Tjikko, a 9,550 year old Norway Spruce in Sweden, so you can see that scientists can look way, way back into the past. Luckily, these days a tree does not have to be cut down before it can tell its story. Scientists use a cylindrical steel tube to drill into the centre of a tree and extract a core only 5 millimetres in diameter (less than the thickness of a pencil). This doesn’t hurt the tree and can give the scientists all the information they need.
A crosssection or slice of a Douglas-fir tree with growth rings.
5
Spiders And Insects By Brian Herrin, with additional material contributed by Karen Needham.
How do these fragile little creatures get through the winter? Spiders and insects are what biologists call poikilotherms (so are other life-forms such as fish, snakes, frogs, toads). This means their inside body temperature always stays almost exactly the same as the outside air temperature. They can’t warm themselves up like mammals and birds do when they get cold.
Spiders A spider which lives inside a heated house doesn’t go anywhere! It stays where it is, hiding in a corner. Outdoor spiders have a harder time. In fact, most spiders can’t make it through the winter, but some species have special abilities. Ground and jumping spiders can curl up in a silk ‘sleeping bag’ they have woven, hidden under some leaves or bark or inside a hole. Some small spiders have special chemicals and proteins in their blood and body fluids that act as ‘antifreeze’ and keep their liquids from solidifying (which would kill them). This antifreeze only works for another 10 to 15 Celsius degrees colder, but that is enough in areas that do not get too cold in winter.
When the outside temperature drops to around 5 degrees Celsius, most spiders and insects stop moving. If the temperature keeps going down, they will eventually freeze and be killed by ice crystals that destroy their delicate body cells. So what can they do and where can they go to survive?
A Cellar Spider. Photo by Olaf Leillinger.
Most adult web-spinning spiders are built for warm weather so they must complete their entire cycle from egg to egg-laying adult in only seven or eight months. The females lay their eggs in the fall and wrap them up for winter in thick silk egg cases attached under a leaf or other bit of shelter to keep them safe. The egg cases need to be protected from icy blasts of cold air and from predators such as hungry little birds looking for food so they too can survive winter. When the adult spider has prepared all her egg cases, she will die but with luck her children will survive.
6
Snug inside the case, the eggs, which often have those anti-freeze chemicals in them, won’t hatch until early spring. After hatching, the spiderlings stay in the egg case until they make a hole big enough for them to all surge out. They will sit in the sun on the outside of the egg case for a day or two and then spread out, trailing thin gossamer webs. One after another they’ll balloon off on their silk strands and sail away to wherever the breeze may take them.
Insects
Like spiders, most insects that get through the winter will do so as eggs. They will survive if the egg cases have been laid in protected places such as under leaves or beneath the bark of trees. As with spiders, insect eggs have all the food and water they need to make it through the winter.
However, the insect life cycle is different from spiders as insects undergo metamorphosis. Some go through an incomplete metamorphosis (egg, larva, and adult). Many pond insects such as young dragonfly and damselfly nymphs, young water boatmen and many others, stay in the larval (or nymphal) stage for more than a year. They will find safety and warmth by burrowing in the mud on the pond’s bottom. They live on food reserves stored in their fat bodies. In severe winters, when the pond freezes right down to the bottom, the nymphs may freeze too – but they won’t die because they too have ‘anti-freeze’ in their blood. Other insects go through complete metamorphosis (egg, larva, pupa and adult). Some of these insects will also burrow to survive the winter. Beetle larvae hide deep in the trunks of trees or underground near tree roots. Bees and ants might spend the winter in a cosy nest that they have built in a rotting log or in the ground. Queen wasps bury themselves in an old tree stump. A few insects, like butterflies, may overwinter as pupae in a cocoon wrapped in a tough casing of raw silk. ***see Note So – tiny, weak and fragile as they seem - spiders and insects have many clever ways to live through frosty, windy weather. Nature has made sure that one way or another there will always be spiders and insects doing their good work.
A mayfly nymph.
A Common House Spider egg sac and recently hatched spiderlings. Photo by Richhoyer99.
***Note - If you find a cocoon, it is best to leave it where you find it because most insect pupae need a cold shock before they can finish developing into an adult. Just remember where you saw it and look for it again in the spring.
Brian Herrin is a teacher of children and adults, and loves all small creatures. He has written about springtails, mason bees, dust mites and many others for NatureWILD. Karen Needham is the Curator of the Spencer Entomological Museum, Department of Zoology, UBC. She has led many pond-dipping Explorer Days for YNC members.
A cocoon.
7
8
Source: BC Outdoors,Volume 31 – No.1, Jan-Feb 1975
Aurora Borealis (Northern Lights)
and Aurora Australis (Southern Lights)
Look up at the sky on a clear night. What do you see? A black blanket sparkling with stars – the Milky Way, the constellations and many many more.You may see the planets Jupiter, Saturn,Venus and Mars, and the moon too as it waxes and wanes. But if you were to go nearer to the North Pole or the South Pole you might also see planet Earth’s very own fireworks display – the aurorae. Earth’s fireworks display is quiet, not like our noisy fireworks, but if you are lucky enough to see a full show, it will be bigger and better than any other. The aurorae are created partly by the Sun, our life sustaining nuclear reactor, which is made of extremely hot gas of reacting atoms. It Aurora Borealis as seen from the ground. constantly belches this gas, carrying streams of high energy particles from its surface. This movement is called the Solar Wind and sometimes blows toward Earth. These energetic particles could be dangerous to us, but we are protected by an invisible shield around our planet called the magnetosphere. However, sometimes a few particles break free and head towards the atmosphere of our planet. That’s when the ‘fireworks’ really begin! Our Earth’s atmosphere is made of two main gases called oxygen and nitrogen. When the particles from the Sun collide with the molecules of these gases, they burst into colours that turn the dark sky into a beautiful light show – mostly every kind of green for oxygen and blue for nitrogen, but sometimes red. I wish we could show you these beautiful colours in NatureWILD, but as we can’t you will have to go and see the aurorae for yourself – the Aurora Borealis near the North Pole and the Aurora Australis near the South Pole. The white patches in this photo are an image of Aurora Australis lights captured by a NASA satellite. This image was then overlaid on a picture of the Earth.
To learn more check out this website http://en.wikipedia.org/wiki/Aurora_(astronomy)
9
The Lonesome Spruce Tree A read aloud story A young Mule Deer loved to wander the high hills and low valleys of Interior British Columbia. All summer, on top of the highest hills, he ate herbs like balsamroot, clover, wild strawberry and fireweed. In the lowest valleys he ate the grasses and the leaves of the trees and shrubs. When he was thirsty, he drank the water from rivers and streams. But halfway up, neither on the top of the hills nor at the bottom of the valley, stood a lonely old spruce tree. “What a scruffy looking thing!” said Young Deer. Its needles are tough and chewy and its horrible flaky bark tastes bitter. I can’t eat this! And if I can’t eat it, what good is it?” But the old spruce tree didn’t mind. “I am what I am,” it thought to itself, “and I’m very happy with that, thank you very much.” Every time Young Deer went from the hills to the low valleys or from the low valleys to the high hills, he ignored the old spruce tree. But the old spruce tree didn’t mind. “I am what I am,” it thought to itself, “and I’m very happy with that, thank you very much.” The Seasons Change Summer ended and autumn passed, the cold wind started to blow and snow began to fall.
10
Young Deer made up his mind to go down to the valley where it was warmer and safer. He was only half way down when the wind blew so hard and the snow fell so fast that it became a snowstorm. For every step he took the wind tried to blow Young Deer back. The snow swirled about him like a swarm of angry insects so that he couldn’t see where he was going.
“If I don’t get out of this storm I’ll freeze and perish!” he cried.
Then in the blustery blizzard he saw a shape. A tall raggedy shape, standing fast against the fury of the wind. It was the old spruce tree. Cold, wet and unhappy, Young Mule Deer crept under the branches of the old tree and curled up behind its thick wide trunk. There, where the wind couldn’t reach him and the snow couldn’t touch him, he settled down and waited for the storm to pass. The old spruce tree didn’t mind and it didn’t mind the weather, either. Snow slid off its shiny needles and fell away. Under its flaky bark, the strong trunk held firm against the wind. The old spruce was very happy with that, thank you very much. After the Blizzard By morning, the wind had died down and snow had stopped. Young Mule Deer stood up and stretched. “I’m glad you’re not like other trees,” he said “I’m glad your leaves are tough and hard. I’m glad your trunk is thick and strong, otherwise I would have perished. You are what you are and I’m very happy with that. Thank you very much.” Now, every time he went up to the high hills or down to the low valleys, he stopped for a while to rest in the shade of the old spruce tree. And the not-so-lonely old spruce tree didn’t mind at all.
From WILD TIMES, a publication of the Royal Society for the Protection of Birds, adapted with permission.
11
OUR CATS Indoors or Out? Big cats such as jaguars, cougars and bobcats are predators. They have to catch, kill and eat other animals in order to survive. Small cats – our pets –also have the instinct to catch and kill prey, but don’t need to. In fact a cat which is munching its kibbles may leave its food to pounce on and kill a mouse or bird, then abandon it to go back to the food in its bowl.
That’s the Question by Daphne Solecki
Quite often a pet cat will bring in the dead bird or mouse and lay the corpse at the feet of its owner. It does not often eat the prey but the ancient instinct to catch and kill is very strong. It is estimated that in Canada there are about 8.5 million pet cats which kill around 80 million birds per year. There are also up to 4 million feral cats (abandoned or lost cats that have gone wild) which kill another 116 million birds. (Environment Canada study, September 2013). On top of all those birds, they kill a huge number of small mammals like mice, voles and moles. Cats are non-native predators so our native birds and small mammals have not developed defences to escape them. In addition, when cats catch wild birds and mammals they take food away from native predators which do depend on this small prey to survive.
A cat in a birdfeeder.
Because it is we humans who own the cats we are the ones responsible for this killing of birds and small mammals.
Unfortunately, housecats are good at killing songbirds. Photo by Remi Jouan.
12
Cats are very acrobatic! They can easily get at birdfeeders hung high up in trees. Photo by Dwight Sipler.
Scenes of a cat hunting in the snow. Photo by Dwight Sipler.
What can we do? 1. Never abandon cats in the wild. People may think that the cats will be adopted by a kind farmer – not so! The cats will go wild (feral). If they avoid starving to death then, if they are not neutered, they will mate and raise family after family, all of which have to hunt for food. The whole balance of nature is upset by having so many non-native predators. Just as we get rid of non-native plants which are over-running native flora, so we must reduce the number of nonnative animals which are harming our native fauna. 2. Keep cats indoors. This is actually much safer for your pets and they will live longer, according to the SPCA. Outside they can be stolen, get chased by dogs, run over by cars, catch diseases, be poisoned, be exposed to fleas and ticks, get into fights with raccoons and skunks, and - worst of all – get eaten by coyotes. There is nothing a coyote likes better than a nice fat pussycat for dinner.
Making sure your indoor cat is happy.
A housecat watching a squirrel from inside. Photo by Airwolfhound.
1. Winter is a good time to get your cat used to staying indoors, because it will probably want to be indoors anyway. A young cat can grow up as an indoor cat and not miss the outdoors at all. 2. Cats need human company to be happy. They are likely to get more attention when they are inside, which will suit them just fine. 3. Provide your cat with: toys it can chase, boxes to climb into and a scratching post (teach the cat to use it). 4. Make sure it has plenty of exercise by rolling those toys around, bouncing them down the stairs, hiding them under the furniture. 5. Trim the cat’s claws every couple of weeks. 6. Train your cat to a harness and leash, and take it for walks. 7. Make sure the kitty litter is always fresh and clean. 8. Spritz a kitten with water to teach it to stay away from outside doors. 9. If all else fails, you can let your cat outside providing it is wearing a ‘cat bib’. The cat can run, jump, climb trees, eat, sleep, scratch and groom but it can’t catch birds. (Note: Cat bibs available at Widlife Rescue Association www.wildliferescue.ca)
You can get more tips at: www.keepanimalssafe.ca www.spca.bc.ca/pet-care www.abcbirds.org/cats/ References: Blancher, P. 2013. Estimated number of birds killed by house cats (Felis catus) in Canada. Avian Conservation and Ecology 8(2): 3. 2013 Environment Canada study – CBC report. September 30, 2013 American Bird Conservancy – Cats Indoors Campaign.
Did you know? Putting a bell on your cat doesn’t help. Wild animals don’t know that the sound of a bell means ‘danger’. Also, many cats learn to move carefully so the bell doesn’t ring.
13
Have a Nature Question?
Why do spiders and insects crawl upside down on the ceiling?
ASK AL
Al Grass has worked as a career park naturalist and ranger throughout BC. Now he is a well-known nature tour leader and photographer. Al especially likes birds, insects and spiders.
You are right - it is kind of odd to see insects and spiders crawling upside down on a ceiling. There are some spiders (like dome weavers) that sit in their webs upside down, but other spiders and insects (like flies) do it because they can! The legs (feet) of a spider have two or three claws A Zebra Spider (a type of jumping spider). depending on the group (Family). Not all spiders make webs (like wolf and jumping spiders). A spider often seen in house crawling on a window or on the ceiling upside down is the Zebra jumping spider. It’s helpful for the spider to be able to stalk its prey like a fly, which can also walk upside down. It’s kind of weird because we can’t do it, but for the spider it’s all in a day’s work.”
Does arthropods mean arachnid/ insects? Arthropods include more than insects and spiders. Arthropods have ‘jointed legs’; they include a wide variety of animals like crabs, millipedes, centipedes, scorpions, and mites. So yes insects and spiders are arthropods – along with other ‘jointed-leg’ creatures. Questions by Nico J. Bucher (Nelson, BC)
send me more Al says “Please ur question is questions. If yo ill win ureWILD you w chosen for Nat il! tebook and penc a Rite-in-Rain no ca c. tions to info@yn Send your ques ad Ro r 1620 Mount Seymou G 2R9 V7 BC r, ve North Vancou
YNC Nelson, YNC Victoria Home Learners, YNC
Eastern Fraser Valley and YNC Cowichan all took part in the Shoreline Clean up.
YNC
Jules Quesnel School YNC planted butterfly friendly plants in an unused flower bed at their school. YNC Eastern Fraser Valley
built and installed bat boxes.
YNC Cowichan Valley and YNC Cowichan Valley
14
Carlin School YNC studied turtles with biologists at White Lake and constructed Turtle Nest Protectors. Photo by Nicole Jeans-Williams.
Home Learners constructed bird feeders and boxes to take home and put up in their gardens.
Kamloops created bat boxes to take home and put in their gardens.
Many thanks to Shell Canada, to Habitat Conservation Trust Foundation and to the Greenest City Fund held at Vancouver Foundation for their financial support of YNC Nature Champions.
W r e I D u t a N NEWS L
Have any comments or questions? Email the YNC at info@ync.ca
YNC Eastern Fraser
Valley member John Hunter writes “I live on Sumas Mountain near Abbotsford. Sometimes in the night I hear howling and yipping outside. I think it is a coyote, because a wolf’s howl is longer and deeper. I also see coyote tracks at the end of our property. I have seen coyotes in the woods when I lived in Vancouver, but I have not seen them yet on our property.” John was so interested in coyotes he wrote and illustrated a long report.
Loys and Connor looking at a mushroom along the path.
A captured spider.
In October, YNC Comox Valley went on a Mushroom Walk in Nymph Falls, Courtenay, BC. Loys and Alison showed them how to identify mushrooms, how they reproduce, how fungi help plants communicate with one another, and many other fun facts.
Cowichan Valley Young Naturalists look, feel and touch sleeping bees during a recent bee talk.
Andaya Vincent tells about a YNC Vancouver spider hunt at Maplewood Flats with Al Grass. “Al told us a lot about spiders, such as - their legs are hairy to help the spiders hear (because they feel vibrations through the hairs). “I found that tickling an empty web with a piece of grass may bring the spider running out because it thinks a fly is stuck in the web. We saw some wolf spiders. Al told us that wolf spider females carry their babies on their backs. The babies fall off one by one, which spreads the babies around. We also found cross-spiders and a tiny zebra jumping spider, which was the same greeny-grey 15 colour as the lichen on the stump and was a bit stripey.”
Fishyword BC has many interesting fish species, not just within the ocean but in the lakes and rivers as well. Do your best to find these fish in this fishy-wordsearch...
ARTIC GRAYLING BROOK TROUT BURBOT CARP CUTTHROAT TROUT DOLLY VARDEN KOKANEE LAKE CHUB LAKE WHITEFISH
LONGNOSE SUCKER REDSIDE SHINER STEELHEAD STICKLEBACK WHITE STURGEON
Next time:
THE ALL-BIRD ISSUE
Return undeliverable Canadian addresses to YNC, 1620 Mt. Seymour Rd N.Vancouver, BC V7G 2R9
Canadian Publication Mail Sales Agreement 40038882
Have any comments or questions? Email the YNC at info@ync.ca