Turquoise tree frog on a turquoise chair

George Sirk: Frog Stories 

Cortes Island naturalist George Sirk knows a lot about frogs.  

GS: “A lot of people know me because of my interest in birds, which is really an addiction, isn’t it?  I’m just hopeless when it comes to birds.  I’m just totally into them. They’re so fascinating.  I came from Venezuela when I was 10. My parents immigrated to Vancouver and I couldn’t speak English. I could speak Spanish and I knew a little Estonian and I could understand German because my parents argued in German.”  

“So there I was in Vancouver, a little weird guy 10-years-old, and I met some other weird young people too, what we would call nerds.” 

“They were into frogs. Jim Palmer was one,  Lowell Orchid, that’s another.  Jim just passed away actually in December, but Lowell’s still with us all here. We used to collect frogs  very close to Kits Beach, the Lacarno beach area. It used to be a military base at one time.  So there used to be a lot of empty properties,  fields and it  got very wet in the wintertime. The tree frogs would all go in there and have a great time.” 

Image credit: George Sirk in Lancaster Sound, Nunavut,working with Cruise North Expeditions – submitted photo

“We used to get the tree frog eggs, take them home, have our aquariums and feed them algae when they turned into tad poles and then they would turn into little frogs. If you could get the adult frogs, that would be an even better pet. They’re very good eaters, you give them little flies and all kinds of things. We would raise the tadpoles and then release all the teeny, teeny tiny frogs, three eights of an inch long. Just barely the width of  your small fingernail. That was great fun.” 

“I’ve done it for our children and our grandchildren, as they grow up. You get a gallon jar, a few eggs, make sure there’s algae in there and watch them grow. You’re actually improving their chance of survival, because they don’t have the predators in your gallon jar. There’s nothing more fun than letting them go, especially with kids.”

“Kim, my wife, did that in the elementary school next to the University of Victoria. She raised the little tadpoles to little tiny, tiny mature frogs. The kids could watch the frogs for two months in the classroom. We went across the street into the pond area of the university,  with the school kids and let them all go into the grass. So they were just beside themselves that these little frogs were all hopping away into nature.” 

“We used to collect salamanders too. It became  a great hobby, going to different places, catching salamanders and bringing them home. Don’t ever keep newts by the way. They are the worst pet in the world. They will not eat. They will refuse to eat. They need a very specialized little mini-pond as an aquarium. Clouded salamanders or wandering salamanders, they’re great eaters, but you always have to make sure that you’re letting them go after you’ve had them for a little while.”

 “I just felt totally in love with different frogs. Vancouver used to have ditches, so you’d had green frogs and bullfrogs. They were all introduced, so we would catch them and keep them as well.” 

“So, bringing it to Cortes, we have two species of frog here. We’ve got the red-legged frog, the tree frog and one toad – bufo boreas,  the northwestern toad, but I won’t talk too much about the toad. That’s another show. Something has happened to the toad population on Cortes as it’s plummeted. They’re virtually gone from Cortes, but not the tree frogs.” 

“Now they’ve changed the name of the frog to chorus frog, and I just hate it when scientists start meddling with names that have been around for a long time. Somebody gets a PhD and once again, they change the name. I still call them tree frogs because they don’t chorus all the time and they actually do climb trees.”  

“Most people  in your listening area have heard them when they’re in the forest.  They’re never on the ground. They are maybe on a bush, maybe a few feet off the ground, but often they’re up in the trees going ‘reeak, reaak.’ Every warm day in the wintertime – which we get, sometimes, we’ll get over five degrees Celsius and a bit of sun like today- you can hear them calling.”  

“They spend  most of their lives up in the trees,  hunting little flies, spiders and everything. Then in the spring, which is just imminent, March 21st or so,  they’ll be coming down to the ponds. We’re very familiar with the different ponds on Cortes.” 

“They’re so busy croaking away. It’s a sound that’s really missing from the urban areas down south, Victoria and Vancouver. The chance of you finding a frog croaking somewhere is really, really hard.” 

“They have a lot of predators. Ducks, for instance, are just wicked because they’ll eat all the tadpoles. If they do lay their eggs in a pond where there are ducks, big ponds like Kw’as pond, the ducks will gobble them up and  they disappear.”

“So they tend to be in more shallow ponds like Jack Perry’s pond where people like to go skating, which is only about a foot deep. Not much for ducks to eat there. Not much vegetation, but perfect for frogs. By the time August comes along, that pond is dry and if there’s been a lot of tadpoles, the ground is actually covered in little tiny frogs all hopping off into the forest. It takes them about three years to mature.”

“Red-legged frogs, on the other hand, will live up to 15 years. They take three years to mature.  It lives in the forest , usually near streams.  Their tadpoles are twice as big as the tree frogs tadpoles and they sometimes take two years to become a little frog, go through metamorphosis.”

“They get to be about three or four inches long, and brown and red legs.  They just scour  the forest floor for anything that moves. They’re quite the animal.” 

“So two basic species living in two different habitats. One basically up in the trees and the other one right in the forest litter.”

The frogs are all, ‘raaa,’ ‘raaa,’ ‘raaa,’ and  you put a couple hundred of those together all at once, like if you drive by the motel here on Cortes in late March or early April, there’s that pond there. It’s deafening. If you go by there about 6 in the evening, it’s just unbelievable.” 

“Lots of cattails in there and lots of bullrushes, so it’s not very easy for the ducks to work their way in there and get it all the tadpoles.” 

“So it’s a very successful breeding site. [Tree frogs] lay about 150 eggs in a cluster.  The red legged frog though, in the ponds, small rivers or creeks in the forest, will actually lay up to 750 eggs in one mass. You need to have a lot of offspring because not many of them are going to survive. All you need is two to survive from the original two. It’s a tough life for the little tadpoles.” 

“The tadpoles will feed on algae that’s in the ponds, the detritus, the bottom muck underneath the pond. They’ll go sift through there and see what other bits of protein they can find.” 

“Then first come out the back legs, then come the front legs, and then the tail shrinks. It’s withdrawn into the body, as all the energy that’s in the little tail is used up to make the bones and make the rest of the body. They’ve been growing this nice tail at the back, and then they absorb the tail and get all those nutrients. They have legs and they can get out.” 

“It’s quite an interesting group of animals, the amphibians. They never became like reptiles, which are dry skinned and lay eggs in holes. Snakes can be  viviparous, they can have live young, like the garter snake. Amphibians have a stage in the water. Newts lay eggs in the water and they have a larva, which is ferocious and will eat the tadpole eggs too.  Then it’ll go through metamorphosis and become an adult. That’s the big difference between amphibians and lizards, the stage in the water.”

“If people want to help frogs, they can collect the tadpoles.  Use a little cup or something like that. Get yourself a big gallon jar. Get some plants from the pond. Don’t put too many tadpoles in there, maybe 10, maybe 20 tadpoles. Or you can get the eggs if you want and watch them hatch. It’s great for kids,  maybe you have a small aquarium. Don’t get too many because they’ll crowd each other out.”

“Out of those 10 or 20 tadpoles, eventually, if you are lucky, you’ll end up with maybe 2 or 5 little tiny frogs.” 

“If you live in a dry area and you don’t have a pond near you, why don’t you consider getting a local backhoe. There’s lots of them around.  Dig an area in your backyard and put a pond liner in it,  that plastic material, make sure it’s sloped. Put your different plants from different areas around Cortes in there, so they’ll start growing. Those frogs will find that pond of yours, and it’ll be just wonderful.  Every spring you’ll have them all croaking away.”

You know the Bee Islets, in the mouth of the Gorge. If people don’t know,  these are two large rocks the size of a very large house or a community hall. They are next to one another. There’s a pond, up there on those rocks. It’s just basically a depression and there’s tree frogs in there, surrounded by salt water. It’s the craziest place  to hear them.” 

“{Tree frogs] basically live on the west coast of North America and they were introduced to the Charlottes, or now we call it Haida Gwaii.”

“I was actually up there in 1972.  I spent the winter there, and a kid from the high school brought tree frogs to the Charlottes and let them go. They colonized the islands. From one teenager. Oops, but there we go – we’re helping the frogs. Apparently the red-legged frog was also introduced to Haida Gwaii.”

CC: Would you call them invasive to Haida Gwaii? 

GS: “Yeah, I suppose you could say because they never could make it over to Haida Gwaii. It’s 50 miles of open ocean on Hecate Strait, a long ways for a little frog to ride on a log, for instance. They never made it to there.  There’s lots of species that actually never made it to Haida Gwaii because it is so isolated. So you could say yes, it’s an invasive species.”

“Is it detrimental to Haida Gwaii that there’s frogs there now? Oh, I don’t know. No more detrimental than it is here.  Unless you can’t stand the sound of ‘raaaa, raaa, raaaa.’” 

CC: So they’re native here? 

GS:  “They would’ve gotten here on driftwood, let’s say.  It’s not very far to the nearest island. The closest one is only about  a mile of open water. So logs can get here. It’s been 10,000 years since the ice started to leave here. There’s been lots of time for the amphibians to get here, as well as lizards too, but the frogs never made it to Mitlenatch Island, sitting out in the middle of the Salish Sea. It’s eight miles from Vancouver Island and about five from Cortes.” 

“Aren’t all species invasive?  We all came from that primeval slime, and something slurped out of the slime and found terrafirma.”

“The thing that I found really neat about the tree frogs is their color. I decided to look into the details of why they have this green color. A part of their skin has Chromatophores and Chromatophores use the crystals inside it to bend the light to look green. They absorb all the other wavelengths coming at the frog, but they reflect back the light that they don’t want – the green. You could say it’s everything but green.” 

“I’m sitting here at my place, and we have all these green trees out there. Why are they green? The reason is the same as in the frogs, the trees don’t want that wavelength. It’s not the energy form that they want. They want the red wavelengths. They want the hotter wavelengths so they can go through their process of breaking down carbon dioxide into carbon.  So they dump the green, because green is useless to them. It’s too cold and that’s why the world is green.”

“In the case of the frogs, a tree frog, green happens to be a very good color to dump because then they can be camouflaged in the tree. So evolution has favored the frogs that are nice and green.”

“One day about four years ago, out on our porch here, I had these turquoise plastic lawn chairs. You get them at Canadian Tire. They’re turquoise and it was covered with  a tarp or something. I was protecting it. It was spring and when I lifted the tarp up to get the chairs back into motion, there was a tree frog sitting on the arm of the chair and it was lilac color. It was imitating the turquoise chair to its best ability. Have you ever seen a lilac tree frog? I’ve never seen one since and I was shocked because I didn’t realize that they could change so much. Of course squid and octopus are famous for changing their colors, but here, this one tree frog was lilac color, and I’ll send it to you and you can post it on your website (at the top of the page) and people can see it on the turquoise chair. It’s definitely a lilac colored frog. So they have the ability to change their chromatophores to the color  that’s in their surroundings.” 

“Another wonderful adaptation doesn’t live here. It’s further north. It’s the wood frog, people can google that one.  It’s interesting because it goes above the Arctic Circle and you’ve got eight months of freezing out there. The wood frog actually freezes solid, it can’t get away from that deep cold that’s there. It can try to burrow down a bit into the moss or whatever, but the moss still gets cold and the frog will freeze solid. It has the ability to get the water out of its cells, because of course our cells that make up our bodies have got lots of water in them.  They move the water out of the cells and live basically on the glycerides behind the sugars. They also make a lot of extra urea and urea is like antifreeze to them. Inside their bodies, they have a lot of urea and it doesn’t matter that they freeze solid because the cells don’t burst. That’s the problem with freezing. With frostbite in humans, for instance, the cells burst and then of course the skin dies from the cold, but not so in the wood frog.”

“Apparently when they’ve been picked up accidentally, they’ll actually shatter. They break because they’re frozen solid.  Then for the four months of summertime which is short up there, they are as active as could be. The advantage of freezing solid is they thaw very quickly and can become active very quickly, even if there’s still snow on the ground.”

“I wonder how our tree frogs manage here.  I’m only guessing that they just move down the trunks of trees and get into the leaf litter, when we hit  -5°C. As soon as it warms up a little bit, I guess they just walk up the trees and get back into the leaves  of our forest.”

“Next time people are wandering around and hear ‘raaa, raaa,’ they’ll know there is a tree frog up in a tree and soon they’ll be in the ponds.” 

“I have to tell you one last story.  About  20 years ago I was at Jack Perry’s Pond  here at Sutil Point, with my friend Tim Janz. He’s a Canadian composer and  had a band (with his wife Elisa) called Prairie Ceilidh. Tim is very much into sound.  He’s a professor in Calgary as well.”

“We were  down at Jack Perry’s bond and he was quite interested in all the frogs, making all the croaking sounds. We snuck up on the frogs, thinking we can get right up. It’s darkish, and they stopped making the noise. It became really quiet.”  

“Tim told me that he had just been to Salt Spring Island and he decided to start yelling at the frogs and doing a ‘human pretend that he was a frog.’ Only he wasn’t croaking, he was just yelling nice and loud.  He told me that the frogs all started to sing.” 

“That’s what we did at Jack Perry’s Pond. We started yelling and all of a sudden all the frogs around us started croaking. We were surrounded  by all these croaking frogs and we just kept yelling. So people could try that little trick. Don’t sneak up on them, come in there yelling away and they’ll join you. Is that funny?” 

CC:  How did you become a naturalist? Is it a career? 

“Yes, it is a career and I started, like I said, from  first collecting frogs when I was 10 years old and bird watching when I was 14. At 19, I got my first job at Parks Branch. I worked at Mitlenatch in 1969 and 1971, and I worked for the parks for six years. I learned from wonderful naturalists how to be a naturalist guide.”

“From there I ended up working in Costa Rica and then Belize.  I’ve worked for major tour companies up in Alaska, Baja (California) and just recently I was in Churchill, Manitoba. I spent 11 seasons in the high Arctic working as a naturalist guide.” 

“So yes, it is a career. I’ve learned on my own through books, I didn’t go to university. There is actually no course in university for how to be a naturalist guide. There is one in Costa Rica, but not here. We don’t have that career path. You have to get a degree in biology or whatever.” 

“I’ve always worked part-time, maybe a few months in Belize  or Costa Rica. It helps to supplement my retirement pension,  still working in naturalism . Of course I volunteer too here on Cortes with FOCI, Friends of Cortes Island or the museum. I do bird walks and I love sharing the information that actually I have learned from other wonderful, great naturalists that are out there.

Top image credit: The Lilac Tree Frog!, Cortes Island (with some alterations to fit a square photo into a rectangular space) – submitted photo

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One thought on “George Sirk: Frog Stories ”

  1. George, I want to correct something you said about newts. I studied Taricha granulosa and Taricha torosa for my masters degree, before switching to hummingbirds for my PhD. Newts do eat and are interesting to watch, so they are delightful pets. And they go absolutely nuts over scissored pieces of live earthworm dropped near them. If you want to discuss this, I am lee@leegass.com.

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