As I was returning home yesterday, on a beautiful, warm, sunny afternoon, I turned onto our road to spot a turtle shuffling off the edge into the grasses. Though it wasn’t necessary for me to hop out to move him, I hopped out anyway, with my camera. The warm sun had kicked his metabolism into high gear, and he had no intentions of just pulling into his shell and waiting for me to finish playing with him. He dug his claws in and motored away from me. Even when I picked him up and moved him back to the open road to try for a photo, he was too quick to get anything but his backside as he turned away from me and ran off again. When I picked him up to hold him for the camera, he looked boldly right at me. I’m calling it a him, but I admit that none of the photos I took clearly show the characteristics that would separate a him from a her: presence or absence of a notch in the back of the shell, and the position of the cloaca underneath the tail. A notched shell and the cloaca partway down the tail would make this a him. It’s still a tad early for females to be out looking for nest sites, but if this was a male then he might be on the hunt for females to mate with; I’m not sure what the “gestation” time is for a turtle. Raven found a Painted Turtle at the lake house last year, and I wrote more about it, including other notes on behaviour and physical characteristics, in this post.
Today’s blog post is courtesy of Dan. He was out this past weekend, taking advantage of the gorgeous weather to do some site scouting and other tasks related to his Frontenac Bird Studies projects. On this particular outing he was down at the now-retired third MAPS station, Hemlock Lake, which was north on the road where we used to live. Upon departing the site he discovered a turtle at the side of the road, and stopped to move it out of harm’s way. Judging from the nicks to its shell, it’s already been a little beat up. I wonder how much is just from scraping against rocks wherever it hibernated.
The bright yellow throat makes the identification easy: it’s a Blanding’s Turtle, Emydoidea blandingii. Although it’s not a rare species here in southern Ontario, it’s certainly uncommon. It’s also classified as Threatened, both provincially and nationally, as its populations are in decline. A large part of this is habitat loss, but also road mortality. Blanding’s Turtles are highly mobile, by turtle standards, with the potential to travel as much as 7 km (4.3 mi) in search of food or a mate. One can imagine that such a journey would take them across many roads.
Compounding the problem is that they don’t reach reproductive age until they’re 14 to 20 years old, or even as old as 25 years, and even once they start laying eggs, the small clutch size of only about 8 eggs, plus predation from raccoons, skunks and others, means only a small number of laid eggs ever make it to hatching (and an even smaller portion of those reach adulthood). In ordinary circumstances, once it’s made it through the perilous first few years, a Blanding’s Turtle may live to reach 80 years old. This should be lots of time for at least one of its babies to reach sexual maturity, thus replacing itself and maintain a stable population. However, early mortality may mean the adults are killed before this can happen.
Last summer, on my way back from running a few errands in town, I found a Blanding’s Turtle crossing our road. Naturally, I didn’t have my camera with me. I picked it up and moved it off the road, toward a wet bit there, and hoped it got where it was going. I was a bit surprised to find it in our area, but only because I tend to think of it as being a more southern species and we’re pushing the edge of the Shield here. Turns out it’s actually found quite a fair way north in the province. The above map is borrowed from the Ontario Herpetofaunal Summary Atlas, on the Ontario Ministry of Natural Resources’ website. Away from the shores of the Great Lakes, there seem to be definite areas of higher density – and the edge of the Shield, that transitional zone between St. Lawrence Lowland forest and Southern Shield which is sometimes labeled “The Land Between”, seems to be one of them. I’m not sure why this should be, but perhaps it relates to the area being rocky enough to be mostly undeveloped for farmland, but still containing many wetlands and water bodies.
Like the terrestrial Box Turtle, the Blanding’s has the ability to close up its shell by way of a hinged portion of its plastron (the belly of the shell), although it doesn’t close as tightly as the Box Turtle can. Wikipedia suggests that the species is fairly timid, but the ones I’ve encountered have all seemed just as bold as the Painted Turtles; I’ve never seen a Blanding’s close its shell right up (but then, my sample size is quite small).
I was a little surprised to hear Dan had encountered one so early; I only saw my first turtle (a Painted) this weekend at my parents’. However, they start emerging in early April and mate from mid-April to early May, so I’ll have to be on the lookout for them.
Yesterday I highlighted what my favourite posts of the last year were, choosing one per month (and leaving out many that were probably just as worthy as a result). As a related idea, last year I also summarized what the most popular posts of the year were, and I thought I’d also do that again this year. WordPress keeps tabs not only on how many visitors your site gets, but also which pages they’re visiting. By far and away the page that gets the most visits is my home page, with the blog stats returning 33,333 hits in the last 365 days, as of this evening. My “About Me” page also gets quite a few. But what about the others? What are people looking for?
Well, most people are looking to find more about milk snakes. Although I don’t typically rank very high on the Google web searches, my photos can often be found on the first handful of pages of results for relevant search terms. I think this is how most people searching for milk snakes, or even just “snake”, arrive here. In a search for “eastern milk snake”, the above photo even makes the first page, and I suppose is different enough to catch people’s interest. A grand total of 7,861 people dropped by to check out the milk snake post.
Compared to the milk snake, all of the rest of my posts have a rather paltry visit count. The next closest, if you can still even call it close, is my grapevine beetle post. The above photo comes up on the first page of image results for “grapevine beetle”, and probably accounts for much of the traffic. There aren’t very many images on that first page that offer a sense of scale, so perhaps that’s why this one is interesting. Over the last year, this post got 2,139 people visiting.
Ranked number three, with just 1,509 hits, is my post on poison ivy. Given just how many pages there are out there about the subject, it’s surprising that it gets even that much regular traffic. It doesn’t come up on the first few pages of Google results.
Coming in fourth is my post on White Pines, the Tree of Great Peace. It collected 1,298 page views over the last year. It’s likewise a commonly discussed subject, so visitors must be coming by way of more detailed searches.
I’m a little surprised that my fifth-ranked post, about house centipedes, isn’t higher on the list considering how creepy most people find them. On the other hand, so many people find them creepy, there’s lots of web content about them. It had 1,292 hits.
Number six is about water bugs – a handful of species of invertebrates that I found in some pond water samples. Although the post mentions a number of species, I suspect many, if not most, of the 1,264 visitors were searching for info on blackfly larvae, the corresponding photo of which, above, comes up on the first page of Google image search results for the subject.
The seventh post, I’m delighted to say, is about a few colourful moths. Yay moths! I would hazard a guess that the particular moth most of the visitors were interested in was the Isabella Tiger Moth, above, which is the adult form of our very familiar Woolly Bear caterpillar. The above photo is the very first image returned for the Google image search “Wooly bear caterpillar moth” (number two if you spell woolly with two L’s). It’s had 1,235 visitors over the last year.
Some 1,185 people have come by to check out my post on flamingos. The post was titled “pink flamingos for the yard” and I’ve noticed a number of search terms on my stats pages indicating people looking for plastic lawn flamingos. These ones probably weren’t what they were looking for; they were captive birds kept by a neighbour down the road from my parents’ old house who bred them and sold them to zoological institutions.
I noticed that as soon as my post on snapping turtle eggs went up last June that it started getting a lot of hits. In just half a year it’s accumulated 1,149 page views. It’s a shame that the eggs I found had been depredated already, but hopefully the post at least offered some useful information.
And rounding out my top ten, the only other one with more than a thousand hits (1,007 total), was my post on giant water bugs. This one got picked up on a web forum – for video game animation or something weird like that – which still brings me periodic hits. The popularity, I think, is partly due to the post’s title, “monster bug”. One of the photos comes up on the second page of Google image results for that term.
It’s interesting to note that only two of these ten posts are actually from 2009: the white pine and the snapping turtle. All the rest are from 2008.
Last week a new blog carnival was announced on the Nature Blog Network. Though there are carnivals dedicated to everything from birds to trees to deserts, reptiles and amphibians (collectively herpetiles, shortened to herps) had been overlooked. This new carnival, called House of Herps, was organized and brought to fruition through the efforts of Amber of Birder’s Lounge and Jason of Xenogere. The first carnival will be hosted at the official House of Herps homepage, but subsequent editions will be roaming, hosted at a different blog each month. The deadline for submissions for the first issue is December 15 (which is tomorrow as of when I’m typing this).
It hasn’t been warm enough for herps to be active about here since early November, so I have no recent herp encounters that I might share. Instead, I thumbed through my photo archives to see what I might be able to find. I recalled a few snakes in the summer that I took photos of but never got around to posting (there’s always lots of those). As I was looking for them, though, I stumbled across these photos, taken September 17, back when the trees were still mostly covered in green leaves, and snow was but some vague idea in the future.
They’re photos of a shed snakeskin. I found this skin threaded through the long grasses beside our front steps. You can actually tell the species of snake that shed the skin from the pattern of its scales, if the skin is sufficiently intact, but we have few enough snake species up here that just its size told me it was from a Garter Snake. Don’t ask me how you’d check the scales; I don’t find too many shed skins, so I’ve never bothered looking up how to identify the species.
Snakes are somewhat unusual in the vertebrate world in that periodically they’ll shed their entire skin. How often they do so depends on a few factors, including age of the snake, the snake’s metabolism, the particular species of snake. Young snakes, in their first year or two of life, may moult as often as once a month, or perhaps as few times as every three months. Older snakes might moult once or twice a year.
Whether the moulting allows for the snake to continue growing, in the way that an insect shedding its exoskeleton allows it to grow, is still disputed. At the very least, though, the moult allows the snake to replace damaged scales, and also to shed itself of ectoparasites such as mites. Mammals and birds are constantly shedding damaged or dead skin cells (eg. dandruff), but reptiles must periodically moult their skin to refresh it. This regular “renewal” is thought to be the reason the snake appears on the well-known symbol of medicine (the Rod of Asclepius).
I like how in the above photo you can still see the grooves of the keel along each dorsal (back) scale.
This is the head end, but the skin from the head is actually tucked inside the tube. A snake’s scales are made of a hard substance secreted from the epidermis: keratin, the same stuff that forms our fingernails. Just as our fingernails are firmly attached to the skin underneath, so too are the snake’s scales. When it comes time to moult, the snake forms a layer of specialized cells in between the scales and the epidermis. At the same time, it begins forming a new layer of scales underneath the old ones and the new specialized cells.
Once the new scales are ready to show off to the world, the specialized cells between the two layers of scales liquifies, essentially freeing the old skin from its bonds. The snake will rub its chin and nose against a rock or something else hard and abrasive to break the edge of the old scale layer. It then either finds a tight spot or something rough to rub up against, and uses that to grip the old skin as it wriggles out. Often the old skin will just peel back off the snake like rolling a tube sock off your foot, with the result that the shed skin is actually inside-out. Check out the second image again. The keels of the scales actually face into the tube, not out from.
Keratin, when formed thinly enough and softened with moisture, is actually fairly pliable and transparent. Think of your fingernails (if you ever let them grow long enough :) after a shower or washing the dishes. While the skin and scales are attached to the snake’s body they are kept hydrated, so they offer a softer protection than, say, the armour of a pangolin. They’re easily punctured by teeth or talon, and mostly serve as protection to the snake from pokey things in its environment such as twigs or rocks.
See how each belly scale has a bit of a backward-facing lip on it? Those help provide grip to the snake as it’s sliding across the ground, since the rest of the scale is very smooth and designed to reduce friction.
I carefully turned the snake’s head out so I could see it, but of course because the whole skin was inside out, the two jaws were reversed, with the lower jaw appearing to be above the upper one. Check out the pigment in the scales here. The eyes are actually covered by very thin, very transparent scales as well. Snakes have no eyelids, and so never blink; they rely on these thin scales to protect their eyes from damage. (For those movie trivia buffs, the snake at the zoo in the first Harry Potter movie blinks at Harry, something an actual snake is incapable of doing.)
As the outer skin is separated from the new inner skin, it will begin to dry out and lose its lustre, even before it’s actually shed, giving the snake a slightly unhealthy look. Just prior to a snake starting its moult, its eyes go cloudy blue-white, and its vision is very limited. During this period it will often stop eating and find itself a safe place to hole up until it can see again. Although the websites I checked didn’t specifically say so, I think the cloudiness is caused by the liquification of that middle layer of cells; once the outer skin has been severed and the liquified cells either reabsorbed or whatever it is that happens to them, the eyes will clear up again.
The whole process takes about two weeks. Now imagine doing that twice a year. Aren’t you glad you’ve got dandruff instead?
I missed Miscellany last week; I didn’t have very many photos, and the ones I had were part of series that I wanted to post more than one image from. With the passing of summer, nature is slowing down outside. There aren’t as many bugs about, the wildflowers are largely finished. Most of our summer birds have headed south, leaving just the winter feeder visitors behind. My walks through the woods are getting quieter, and I have to make more effort to notice interesting things; they aren’t as abundant or obvious as they were.
I love playing with milkweed seeds. I have a hard time passing by open pods when I’m out walking. I like the way the seeds all grow in such careful organization, smoothly layered upon each other like scales. I’ll often pull out puffs and cast them to the wind, just for the joy of it. Last week I pulled out a full, un-fluffed bunch of seeds from a recently-opened pod, such as the one shown here. I peeled off the seeds, slowly, enjoying the silkiness of the down. When I got to the end, I was left holding a fascinating structure. It was papery, with paper-thin divisions running along its length. the down of the seeds was tucked neatly into these creases, securing it until the wind became strong enough to tease it from the pod (or a person pulls them out and tosses them into the air). Presumably this is an adaptation to make sure that there is sufficient wind to carry the seed away from the mother plant when the seed falls off, and not just fall straight down.
If the structure has a formal name (undoubtedly it does), I don’t know what it is, as I wasn’t able to turn up the answer with a web search. I did, however, find out that they make excellent fire-starting material because they’re so papery. Of course, so do dried leaves, which also happen to be abundant at the same time of year…
I found this pair hanging out on a milkweed pod last week. The upper one I’ve already mentioned once this fall; it’s a Small Milkweed Bug, a species that feeds on the seeds of milkweed plants. The smaller one below is a nymph of the same species. In most true bugs (that is, the group of insects that have a piercing tube-like structure for mouthparts and wings that are solid for only half their lenth and membranous the rest, leading to the group’s name Hemiptera – hemi/half, pteron/winged) the nymphs resemble wingless adults in shape but are usually differently, and often more brightly, patterned than the adults. This is a later instar of the nymph; younger nymphs are nearly all red-orange.
Speaking of bugs, I have been inundated with Giant Water Bugs this evening. After a spell of cold, near- or below-freezing nights, we’ve had two in a row that have been fairly warm, up near or slightly above 10 C (50 F). Last night I didn’t realize it was so warm until well after midnight, but tonight I was prepared, and set out my moth trap for a try at late-season moths. I plugged it in just before dusk, and then forgot about it. After dinner, I put Raven on her tie-out when she asked to be let out, and went back into the house. A few minutes later she started barking in alarm. I stepped outside and could hear something rustling in the leaves at the front of the house – clearly what had gotten Raven worked up. I grabbed my shoes and went around to investigate, and it was immediately obvious what she was hearing. There were dozens of these guys, on the porch, in the garden, in the lawn, and yes, rustling around in the thick bed of leaves under the trees in front of the house. Where the heck are they all coming from? I did finally walk through the forest that borders our meadows on the west, where I’d also heard spring peepers calling a few weeks ago, but couldn’t see anything near the edge that was very wet, or even perhaps a springtime vernal pool. I’m hoping not too many of these things actually go into the trap.
Another sighting of puzzling origin is this guy. I’d stepped outside this afternoon to dump the compost while I could see what I was doing (I’d created a large pile last night when I prepared and froze a batch of carrots from our garden), and right beside the porch steps was this little snake. Only 6 or 7 inches (15-17 cm) long, it was in the rocky, mostly empty soil bed beside the walkway. I quickly put down the compost and hurried back inside for my camera. At the time I just assumed it was a young milk snake. I took a few photos, then picked him up and move him away from the house. Sitting down to blog this evening, I had another look at him. Eastern Milk Snakes usually have a pale Y-shaped mark at the back of their head and this one didn’t have that. I wasn’t sure if that was because it was a juvenile, or because it wasn’t a milk snake. Some poking around suggests the answer is the latter. I believe this is actually a young Northern Water Snake, Nerodia sipedon. Although adults tend to remain closely associated with water, juveniles seem to often stray across land, perhaps as they disperse looking for new water to colonize. The solid bands in the front half, turning into a checkered pattern in the back half of the body, seem to be characteristic of the species.
I found this caterpillar clinging to the inside of the porch screen last week. I’m not quite sure how it got in, but it was a very chilly day, and it wasn’t up to going anywhere further. I took a few photos, and then put it outside where it could hopefully find a more appropriate place to hole up. I believe it’s the caterpillar of a Hitched Arches, Melanchra adjuncta, a species of moth. I’d encountered the adults at the lake house last August (2008), and then again in May (this year). I caught one again this summer, after moving to this house. The species is found across much of North America, and flies for much of the year, May through September. Presumably they overwinter as caterpillars or pupae, thus delaying their appearance in spring.
We’ve had a couple of hard frosts now, and even the frost-hardy plants have wilted away. The grapevines are nearly bare of leaves, exposing the clusters of dark blue Concord grapes, and the mass of woody stems twining and crawling and sprawling across the side of the shed. As I was standing looking at the vines, thinking I should collect up some of the remaining grapes and freeze them to make pie with this winter, I noticed a clump of twigs tucked into the back of the tangles. Looking closer, it turned out to be a nest. It was quite large, appropriate for something robin-sized. It had probably finished up and fledged its young before Dan and I moved in in July, assuming it was even from this year. Determining the identity of the builders of nests can be difficult, with the exception of a few distinctive species (such as robins, or swallows). I’m not sure what species this one belonged to, although if I had to hazard a guess I might say Brown Thrasher, which build chunky, twiggy nests, usually on the ground but also sometimes tucked into thick shrubs or vines.
Nearly all of our leaves have fallen now, and they form a thick bed across the lawn under the trees. I was tempted to rake them up today, if only because it was such a nice warm afternoon and it would be a reason to be outside. I didn’t, however, instead tossing the ball with Raven and Dan. Here Dan’s commanding Raven to “Drop it!”, which she does, though generally only after a good bit of bounding about in circles playing keep-away. She tosses up sprays of leaves like she’s running through water. A few more weeks and we’ll be feeling less inclined to stand still and toss a ball around outside.
Day 5 on the Kolibri Expeditions’ Manu bloggers’ tour takes us to Cocha Blanco (roughly translated to “White Lake”), an old oxbow lake that is now home to waterlilies, sunken logs, fish – and a family of Giant Otters. The largest species of otter, and by extension the largest species of mustelid (weasel family), it lives up to its name with males reaching 5-6 feet (1.5-1.8 m) in length. In some areas, and historically, it was also known by the name of “River Wolf”, for its huge size and carnivorous habits. Like other otters, they’re highly social, living in family groups and vocalizing frequently. Unfortunately, it is now endangered, primarily to habitat loss, with nearly 80% of its original South American range now unsuitable. Because their occurrence tends to be so patchy, population estimates are hard to make, but are thought to be less than 5000 individuals. Suriname and the Guianas are the otter’s stronghold, with a scattering across the rest of northern South America. The promotion of responsible ecotourism can lead to habitat conservation efforts that will help this species and others. Back in January Julie Zickefoose did a great post (one of a few) about Giant Otters she saw in Guyana, which made me keen to experience these creatures.
I’m going to Peru with Kolibri Expeditions as part of their blogger promotional series. Want to come? I’d love to have you along! My departure leaves November 13, 2010 and returns the 21st, well before the US Thanksgiving. You can get more information about the trip, including itinerary and, of course, cost, at this page. Don’t forget that if you’re also a blogger you get $100 off. In addition to having a great time, meeting some great bloggers, and seeing some fabulous birds, you’ll also be supporting the local communities as they work toward developing a sustainable ecotourism industry for their area. It’s a win-win!