mammals – Page 17

Make a list, check it twice

For Christmas, I got a number of books, one of which was Julie Zickefoose‘s new book, Letters From Eden. I read it in just a couple of sittings, and enjoyed every page (some day I wanna be just like Julie!). Another one I got was Good Birders Don’t Wear White. It’s a collection of “essays” by some of the country’s best-known and leading birders and naturalists. There are some good stories and advice in it, but one of them that I thought was a particularly good suggestion was submitted by Julie as well. It’s titled, “Write it down: making a calendar”.

A bunny in my mom’s garden – photo credit my mom

Many naturalists, and birders especially, are great at keeping track of what they see. Usually, however, it’s in the form of lists. Here I have my backyard list. There is my year list. This one’s my life list. Lists are great because it’s a record of what’s been seen. The more specific the list, the more useful it can be later (for instance, a list for your backyard is more useful than a list for a state or province because it’s more specific to a certain spot; not everything on your state list will be encountered in a given spot in the state). The best lists are those that are accompanied by extra information. Rather than simply being a list of names, more details are attached to each name. For instance, recording the date you first saw a particular species in your backyard, or the location that you saw a certain species in your state.

This is the basis to Julie’s suggestion. Keep a calendar of your observations. When you see the first robin of spring, write it down. When the first green frog starts to trill in the swamp, make a note. Record notable observations you have, such as a bluebird feeding babies, or a fox trotting across your backyard. If you do this over the course of a few years you start to get a very precise picture of the timing of nature. You have a great reference to refer to when you want to know when something happens, or where, or even if. There are some great online tools for tracking bird observations, the best perhaps being eBird.com (or eBird.ca for Canadians).

The Tommy Thompson Park Bird Research Station, which I currently volunteer for, has essentially created such a calendar through careful records of observations every day for five years. It’s really interesting to compare arrival dates for species to previous earliest (or latest) dates, or to look at frequency (you actually have numbers to back yourself up when you make the statement, “this is the most bluebirds I’ve ever seen in a spring!”)

My mom has lamented recently that she wishes she’d kept a journal or record of her observations. My parents have lived at the same home in the southern Ontario countryside for nearly 30 years. By now my mom has a pretty good idea of when the Red-winged Blackbirds arrive, or when the spring peepers start to sing. But it’s still a general idea when, and there’s no record of whether it’s the same as it was 30 years ago. My parents are planning on moving and were thinking to leave some nature notes, including a species list, for the new owners. Such a calendar would have been a great introduction to the home.

Look at that great bill! And those out-of-this-world eyes!

I myself have kept a very casual personal journal on some of my birding observations over recent years, going back to 2004. It’s been helpful to refer to for some things, when I saw a certain bird, or took a particular trip. This week, I looked back through it for the date the American Woodcock arrive here. I had been thinking that they should be showing up soon. I had the notion in my head that they start their dusk display flights at the end of February.

Well, I browsed through all my late-February entries, and saw no mention of it. I tried early March in case I’d written it down late. Still nothing. Finally, it twigged that I was a month early, they won’t return till late March. Sure enough, there were the entries, at the end of March.

How disappointing. But at least it saves me from trudging out through the snow at dusk this week looking for birds that aren’t there yet.

(For those who were curious, that leading photo is from a point count survey I did one spring for the bird research station. I had forgotten my pen and notepad, but handily found a bit of charred wood to make notes with; the list washed away in the next rain. Hopefully you’ll have paper available when making your lists.)

The bad lands of South Dakota

Yesterday we got another dump of snow, a good six inches worth, which piled on top of the foot we got last week, which was on the foot from the week before, with very little melting in between. It’s a shame that I’m not more into winter sports, because it seems the conditions out there at the moment are perfect for just about any of them. However, given that my pastime is hiking, and hiking in knee-deep snow is not only a lot of work but also results in very wet feet, it doesn’t work as well for me. I should learn to snowshoe, but haven’t.

So for those of you who need a short break from all the snow, like I do, I offer some sweltering hot South Dakota grasslands in the summer. I was sorting out some of the pictures last night, and thinking fondly of the warm temperatures. These were taken last July, during a cross-country car trip (final destination was a fall employment contract in British Columbia). I tried to pace myself so that I could make some stops along the way and do some birding, and the formations of the badlands combined with the birdlife made it a target destination.

When I first got there it was overcast and lightly raining, and I was a little disappointed at the muted colours and potential for low bird activity. Little did I know how preferable this was to the clear sky! I had put on jeans and a long-sleeved shirt when I first arrived, but within half an hour of the sun coming out I’d stripped off as much clothing as was socially acceptable and lathered myself up with sunscreen.

The formations are caused by erosion of soft sediment and volcanic ash over the course of millions of years. The landscape has gone through many changes, starting out as a large sea some 75 million years ago, becoming lush, wet floodplains about 40 through 25 million years ago, and then undergoing regional uplifting some 5 million years ago that began the erosion resulting in the formations seen today. Because of the area’s wet history, many well-preserved fossils can be found in the layers, often exposed by erosion (I didn’t see any while I was there, but I was focussed more on the wildlife). I took so many photos of these cool formations, but they’re a little like mountains – when you look back at the photos, they all sort of look the same, even though each one seemed marvelous and new when you took the picture.

I loved the colours in these formations, called the Yellow Mounds. It was only in a very small area of rock where these rainbow walls could be found, so I have to assume there was some local event here when the sediment was laid down that created these unique hues (or, alternatively, where the unique hues were exposed by erosion). The Badlands National Park visitors guide indicates they were caused by the uplifting of the area exposing the ocean mud to the air where it became yellow (through oxidation? does that suggest high sulfur content?). Lots of great information about the geology of the park can be found in their guide (in pdf form at the above link).

Spotted Towhee, Badlands National Park, SD

This was one of the first birds I came across in the park, in a small sheltered area with a good stand of juniper trees. It’s a Spotted Towhee, previously considered the same species as the Eastern Towhee (no spots) that we have here at home. He was singing from the trees while I was there, but staying mostly hidden.

Western Meadowlark, Badlands National Park, SD

At my next stop this young Western Meadowlark had obviously gotten quite used to the bustling parking lot; he walked back and forth along the edge and under the cars looking for bugs, paying little attention to the people. He got so close at a couple points that I could no longer focus on him with my telephoto lens (which has a close-focus of 1.5m). Look at him strutting…

Lark Sparrow, Badlands National Park, SD

I tried starting down one of the trails to get away from the crowded lookout spots, but the beating sun (which came out just after I made my first stop at the towhee) turned me back quickly – I just didn’t have enough water to make it very far. However, in the short area I did traverse, I found this Lark Sparrow, evidently quite upset with me being in the area. I love the Prickly Pear cactus. :)

Lark Sparrows, Badlands National Park, SD

A short search of possible hiding places turned up this little fledgling huddled at the base of a small shrub. Although it had left the nest, it was only a day or two out of the nest, as it didn’t flush when I peeked in at it.

Just down the road a bit was this Lark Sparrow family. The youngster (on the right, taking off after its parent) was considerably older than the one I found in the bush. Considering that these were the first Lark Sparrows I’d ever seen, I felt fortunate to have come across multiple whole families of them.

Meadowlarks were the bird of the day. They were at virtually every stop. While I struggled to turn up a Rock Wren or a Lark Bunting, meadowlarks were a dime a dozen.

Upland Sandpiper, Badlands National Park, SD

I had really been hoping to see an Upland Sandpiper while there, but departed the park gates without having seen one. Then, not 100 metres outside the park, I spotted this guy perched on a fencepost at the side of the road.

Mammals weren’t very apparent, but there were a couple colonies of prairie dogs who all very obligingly posed for pictures near the side of the road (the road seemed to bisect the colony; I wasn’t sure what this did for roadkill statistics, but didn’t figure it could be good. However, there was no evidence that it was a problem, either).

Black-tailed Jackrabbit, Badlands National Park, SD

And finally, I startled this jackrabbit from underneath the boardwalk where he was trying to keep cool. He paused after going out about 50 metres into the grass to look back at me, before taking off and disappearing from view. Even though it was just a quick view, I was excited to see him. Check out those ears! Their giant ears are used for keeping cool in the scorching prairie heat, through heat loss over the broad, exposed surface area.

Well, that’s it for South Dakota. We’ll be back to the regularly scheduled Ontario winter tomorrow!

The February freeze

It was minus frigid today. The thermometer showed a high of -8 oC (18 oF) in the afternoon, and a brisk wind dropped it to the teens. Actually, that’s not terribly cold; yesterday it was -17 oC (0 oF), with a wind chill of -29 oC (-20 oF). I had the pleasure of walking home from the subway in that, and the bits of my face that were exposed, my cheekbones and the bridge of my nose, were aching by the time I got inside. The ten minute walk probably only took me seven because I was hurrying so much! The good news was that my new down jacket performed fabulously in its first serious field test. Average temperatures for this time of year run about -1 oC according to weather.ca, so we’re in a bit of a cold snap.

Today, back out in the country at my parents’, I couldn’t help but think of all the little critters who didn’t have the ability to hide indoors beside the wood stove. Those juncos looked a little cold out there. They turned down my offer to come in, though. A lot of animals suffer through conditions that would freeze us solid quickly. All those poor male Emperor Penguins incubating their eggs in the Antarctic winter (seen March of the Penguins?) comes to mind. More locally, the chickadees and sparrows in the backyard often make it through long stretches of sub-freezing temperatures and deep snow.

One of the keys to their survival is their full-body down jackets (or, in the case of mammals, fur coats) that keep them well-insulated. I reflected, as I was hurrying down the street yesterday, that if I had a down jacket for my legs and face I’d be in pretty good shape, since my torso was quite comfy. Part of that was the fact that I was being quite active and producing a lot of heat. This is also a key for birds; they keep relatively active during the day, and the heat they produce then gets trapped under the layers of down. On the above feather, the fluffy bit at the bottom creates many tiny air pockets that trap warm air against the body (this is the bit they stuff in your down jacket or duvet, though less expensive ones include the whole feather), while the smooth upper part streamlines the bird’s body to optimize aerodynamics. Mammals have a similar system of hairs that creates the same effect. Both birds and mammals have the ability, through itty-bitty muscles at the base of the feather/hair, to raise the insulative layer to create a wider air pocket and trap more heat when it’s colder (this is what goosebumps are… we don’t have enough hair for it to do much, though).

But what about those tiny bare feet? Standing on the snow in the winter it would be hard to keep any warmth in them at all. And think of the ducks swimming on the near-freezing water. Well, as the junco above is demonstrating, often birds will tuck one foot up into their breast feathers if they’re resting (I’ve even seen some birds continue to forage for a time, hopping on one foot, while the other’s tucked up). Ducks, gulls and other waterbirds do this frequently, landbirds are less often observed doing it (mostly because they don’t loaf as much as gulls do!).

In addition to that, they’ve evolved an ingenious circulatory system to their legs, called countercurrent circulation. The arteries in their legs line up right next to the veins, so that the blood being pumped down into the legs through the arteries transfers its heat to the blood coming back up from the feet in the veins. This cools the blood down before reaching the feet to minimize heat loss to the environment, and warms it back up before it reenters the body. There’s actually very little tissue in a bird’s foot, it’s mostly tendons, so it doesn’t have the same heat requirements that muscle or organs do (in fact, it can approach freezing with no serious consequences). Mammals have a similar system in their legs, although they have more muscle tissue, so also use a layer of fur for insulation.

Speaking of mammals… look who was out today! I have seen the Red Squirrel more this winter than I can recall in previous years. I have a feeling it’s in part because he’s set up shop in the attic of the house, I think in the area over the room with the wood stove. Judging by the size of the icicles hanging off the eaves there, the attic is probably pretty warm, and I imagine he doesn’t have to work too hard to conserve heat. Plus, with the feeders right there and handy for him, once his cache ran low he didn’t have to go too far for more food. I may have seen more of him this winter than the Gray Squirrels – unusual.

“Oh my GOSH it’s cold!”

Snowstorm, the day after

I took a break this afternoon to wander outside and enjoy the snow of yesterday. It had stopped snowing last night, and the day dawned clear, with a gorgeous blue sky and brilliant sunshine. These are the sorts of days that I love about winter. That, sitting by the fire, and fat softly-falling snowflakes. I could do without the slushy, slippery roads, the freezing rain, the bitterly cold winds (although these are all easier to take while sitting by the fire). The bright white snow and blue sky wonderfully set off the green conifers and red dogwood.

The snow in the front yard was clean and pristine, stretching out beneath the big trees. I can’t bring myself to walk through it, it doesn’t seem right to spoil something so clean and fresh and full of promise. I’ll leave that to the squirrels and rabbits, and I skirt around.

The smooth white of the unbroken snow makes a great canvas, catching the shadows of the big maple above. It seems somewhat abstract, like something that should be hanging in a museum somewhere. Nature is a great artist.

One downside to all this snow is the necessity of clearing it from the driveway so people can come and go. Here a snowball has rolled down off the giant snowbanks created by the plow (they were at least up to my waist in front of the house, and can be larger along the drive). My parents have an old 1945 Ford tractor that my dad has managed to keep running all these years and has hooked a plow to, used primarily in the winter for clearing snow. It’s been a faithful machine, and, given the length of the driveway (see the second photo), let’s hope it continues to be!

All this deep snow can be a challenge to ground-foragers such as the juncos and tree sparrows. At these times feeders become an invaluable resource that allows more birds to survive the harsh weather than might be able to without a supplemental food source. My mom tries her best to keep the feeders stocked through the winter, though wading through knee-deep snow can be a challenge. Certainly appreciated by the birds!

I wasn’t the only one out enjoying the fresh snow. The two younger horses were having a grand old time frolicking in the white stuff, throwing up plumes of it as they raced through. After a few laps around the field they pulled up near the gate where I stood, their bellies caked with snow, their nostrils wide as they panted deeply. But their eyes sparkled with energy and enjoyment.

Mine too.

Tunnels in the snow

There was a period before Christmas where we had a lot of snow accumulation on the ground. Some rain over the holidays, followed up by this warm stretch, melted off most of it, and the receding snow can reveal some interesting things that take place under the snow layers, where we can’t see them. One that many homeowners are probably familiar with are these strange half-tunnels carved into grassy lawns. Only an inch or two wide, they can carve intricate networks or simple purposeful trails into the grass and soil which many people find unsightly and can often be difficult to fill in again.

Meadow Vole (Gillian Bowser, NPS Photo)

The culprit, at least here in the east, is the common and widespread Meadow Vole. It’s the only species of vole that occurs in eastern North America, but it’s also found as far west as Alaska. It doesn’t usually come into homes, so like most rodents, it’s rarely seen itself. However, it leaves ample evidence of its presence. The trails in the lawn are a network of pathways that the vole uses to travel between its burrow, where it sleeps and stores food, and the food itself.

In the winter the voles travel under the snow, rather than over it, for three reasons. The first is to avoid predation. It’s much easier for an owl or a fox looking for a meal to track a rodent running across the snow than it is to find something underneath the snow (although these predators are adept at doing that as well!). Also, given the excellent insulative properties of snow, it’s much warmer underneath it all than above it, where the little vole would be exposed to wind and cold. This makes it much easier for the vole to remain active during the winter.

And thirdly, it provides much easier access to its food sources. In the winter, voles will eat seeds and grasses, which are usually found close to the ground, as well as roots and the bark of young saplings. If you have birdfeeders out you might chance to spot one munching on fallen seed when snow cover is low, but more likely the evidence of feeding you’re likely to come across is finding a sapling stripped of bark around its base. Munching by voles can be differentiated from that of rabbits (who will also chew the bark from saplings) in that rabbits won’t usually chew all the way to the ground, and the pattern of gnawing by voles isn’t uniform. I didn’t notice any such saplings around these particular trails. Once the snow melts, you can also often see little piles of grass clippings within the trails, where the vole has snipped the grass off at the base, pulled it down, snipped off some more, etc, until it can reach the seed heads.

This long trail was crossing a narrow stretch of lawn between two naturalized patches (a group of sumacs to a couple of wild apple trees). I’m not sure if the voles are actively foraging for roots or seeds when making these trails, or if they’re directionally challenged (or perhaps just sleepy?), but it seemed like a very curvy trail for just going from one place to another. Perhaps it’s a mechanism to throw off predators listening to rodents running under the snow cover?

Surprisingly, there weren’t very many trails on the lawn, just these couple. In the winter, voles often nest communally in groups of anywhere from two to a number of generations . Female voles breed for the first time when about half grown, at about 25 days. They breed nearly continuously, mating again immediately after giving birth to a litter, and can have three to six litters (depending on latitude and food resources) of four to seven young in a year, which would quickly become quite a large group! Most individuals live less than a year, however. I suppose larger groups would be likely to make a broader network of trails, and a pair would probably just have a handful of well-used trails. A colony of voles can occupy a territory of up to 100 feet in diameter.

Voles aren’t uniformly appreciated by everyone, and particularly in urban settings, the damage to lawns can result in an unsightly mess. There are lots of vole-control solutions to be found by a quick Google search, but my recommendation is just to not have a lawn – plant a garden, it’s more useful to wildlife and prettier anyway! :)