Flight of the Bumblebee

Bumblebee pollinating fireweed by Heather HinamIt’s been a long, long, long winter here in the north woods. Then, suddenly, it was summer. The browns and greys of last year’s decay vanished nearly overnight, replaced by the verdant greens of new growth. Flowers are coming up everywhere and the air is alive with insects. That last part doesn’t get most people up here all that excited. A large proportion of those insects at the moment are mosquitoes. However, trundling along through the clouds of bloodsuckers are the pollinators.

One of my favourite groups of the myriad species that call this region home are the bumblebees (Bombus sp.), the flying teddy bears of the insect world.  While most members of the Order Hymenoptera, like wasps and hornets, tend to send people running in the other direction, bumblebees hold a special place in the hearts of even the most nature deprived. Their brightly-coloured, fat, fuzzy bodies, topped with almost comically small wings, coupled with their almost roly-poly nature makes even the most hardened insect-hater melt a little bit on the inside.

Unlike honeybees, bumblebees are native to North American. There are a few dozen species that have fit into just about every niche across the continent, making up what may be the most important assemblage of pollinators we have.  What makes them so efficient at the job is their hairy bodies. Bumblebees feed on nectar and that is usually stored near the centre of the flower. As the bumblebee noses its way deeper into the blossom, the pollen-laden stamens brush against the insect’s body, transferring its important cargo to be transported to the next blossom.

While they do collect that nectar, bumblebees are not honey producers. Unlike the species we’re mostly familiar with, bumblebees are only semi-colonial, setting up small nests that only last for one year. It all starts once the frost is out of the ground. Queen bumblebees overwinter by themselves in the leaf litter or underground. Once she wakes up, her first order of business is finding food. With the late winter we had this year, she likely would’ve had a harder time than usual.

Once she’s managed to restore her energy levels, the queen will set up shop in a quiet, dry place like a woodpile, old rodent hole, tree cavity or even a nestbox. There, she will lay her first clutch of eggs, which she’s incubates in the most adorable fashion by sitting on top of them and ‘shivering’. To feed herself and her young larvae once they hatch, the queen gathers nectar that she stores in her nest in little wax pots.

That first generation of bees are all worker females, who quickly take over the foraging duties, bringing home more nectar and fashioning more wax pots, upon which the queen lays her subsequent eggs. Workers also take on guard and cleaning duties while the queen remains in the nest, taking a well-deserved rest and generally ruling the roost.

As the long days of summer begin to wane, the queen plans her insurance policy for the following year, laying eggs that hatch out both males and new queens. Both of these cohorts leave the nest and somehow find each other in the big, bright world outside of the colony.

Once mated, those new queens head off to find a place to hunker down for the winter while the home there were born from fades away.  It’s a system that’s worked for thousands of years, ensuring the proper functioning of pretty much every ecosystem in North America. Unfortunately, now, it’s in trouble. Like most pollinators, bumblebees are facing hits from all directions. Losing both nest and food sources to habitat loss from large-scale agriculture, timber harvest and urbanization, they are also having to contend with pesticide usage turning the plants they depend on into death traps.

However, if we, as a populace, make a conscious effort to change the way we do things, curtailing bee decline is not an insurmountable problem and every individual counts. By planting bee-friendly species in your yard that come from growers you know don’t use pesticides, you’re creating a haven for these beleaguered bugs. Talk to your greenhouse owners, talk to your representatives. There’s more and more data showing that certain types of chemicals are the problem and need to be taken off the shelves and out of our food production. We’ve done it before with DDT. We can do it again.If we don’t, the world as we know it will cease to function. It’s as simple as that.

For those of you who are a little less insect-inclined, it’s also good to remember that bumblebees are nothing to be afraid of. While they can sting, they’re pretty mellow individuals and if you take precautions like not wearing strong perfumes and running around barefoot, you’ll have no trouble co-existing peacefully with these fuzzy, buzzing, beautiful and essential bugs.

 

 

 

Under Pressure

Pressure ridge on Lake Winnipeg by Heather Hinam

With the ‘polar vortex’ that held much of North America in its frigid grip last week, it was interesting for this ‘girl of the north’ listen to southerners goggle about phenomena that I’ve been experiencing for most of my life.

I found one event, in particular, rather interesting. Last week, the media and thus a large portion of the population, was introduced to the concept of ‘frost quakes’. Torontonians were rattled out of their beds by thunderous booms that shook parts of the city at random intervals. Soon the headlines were reading that it was so cold in Canada, the ground was cracking.

Lake Winnipeg Cliffs

Large crevasse in the rock, likely split apart by frost action

Having spent a number of winters on the shores of Lake Winnipeg, where  temperatures regularly dip below -30C, I’ve seen first-hand the power of ice and its ability to snap rock in two. Ice expands and contracts with temperature fluctuations. It also becomes less flexible as it becomes colder. Water that finds its way into fissures in the rock or soil can push so hard went it freezes – especially if the temperature drops quickly – that the substrate buckles under the pressure. Here, along the lake, the limestone cliffs are full of cracks forced open by winter’s icy push. Still, these earth-shattering events are extremely rare. You don’t usually see new cracks on a yearly basis.

However, there is another type of frost quake, or ice quake, as I prefer to call them that happens considerably more often. Based on where the events were reported last week along Lake Ontario, I’m willing to bet that it was this type of cryoseism  that residents heard for the most part. While the ground doesn’t crack very often, the ice on the lake does. On large lakes, like Lake Winnipeg or Ontario, a sudden snap of the ice can sound like a cannon shot, nearly knocking you off your feet and rattling windows in their panes. While it’s still not something you experience everyday, such quakes happen on Lake Winnipeg fairly regularly.

That’s because this 23,750 sq km lake freezes completely to a depth of at least a metre every year. That much surface area can’t solidify into one piece. So it freezes into floes that knit together much like the tectonic plates of the earth did when the crust first formed. Like the earth’s crust, the lake’s surface is full of fault lines, or pressure ridges.  These giant cracks can run for kilometres along the lake and usually form in about the same place every year.  Some ridges, known as stamukhi, are grounded along the shoreline, where ice that is held fast to the shore meets the free-flowing ice of deeper waters, while others run along over top of varying depths.

Even frozen, the lake is very much alive and pressure ridges are the sites where this is most noticeable. It’s along these lines that the ice floes move, sliding along, away from and into each other. A particularly violent collision is like a mini mountain building event and along with an ice quake, you will also see a ridge of ice has been pushed sometimes more than 2 meters into the air.  More often, however, the two floes simply press against each other, expanding and contracting like long, drawn-out breaths as the temperatures wax and wane. Eventually, the pressure overtakes the compressive strength of the ice and the ridge snaps in a startling bang that is often followed by the gentle whale-like ‘whoom’ sounds of the pressure waves dissipating through the rest of the ice.

As fascinating as they are, pressure ridges are also dangerous places to be. The ice floes can slide away from each other just as quickly as they can come together and loose plates of ice can trick the unwary into thinking they are still on solid ground. A number of commercial ice fishermen have been lost through shifting ridges over the last century on the lake.

Unless you live along a lake that freezes regularly, Ice quakes are truly something few people get to experience. So, I’m glad that our recent continental cold snap gave more people the chance to learn a bit more about this fascinating phenomena and remember just how powerful nature can be.

Jumpin Jack Flash

White-tailed Deer Flagging by Heather Hinam

If you’ve ever spent any time in North American forests east of The Rockies, you’ve seen it, a sudden flash of white, that snags your attention before disappearing into a tangle of vegetation.

White-tailed deer  (Odocoileus virginianus) are very aptly named.  The bright, snowy fur on the underside of their tail is impossible to miss, especially because they often wave it in the air as they bound away from you.

This behaviour is called ‘flagging’ and it’s an instinct that kicks in only hours after birth.  To a human observer, its purpose is a little hard to understand. Why would an animal that is otherwise very well camouflaged wave a big flag at a predator that essentially shouts “I’m over here!”.  Because it seems so counter-intuitive, flagging has been the focus of a number of studies, but researchers still have yet to come to a consensus in regards to why they do it and who are they doing it for: their fellow deer or whatever is trying to make them dinner.

Some biologists believe that by flagging, their tails at the approach of a predator, deer are signalling each other and maintaining the cohesion of the group while at the same time confusing their stalker by making it hard to pick out an individual in the group.

The problem with that assessment, however, is that deer will flag when they’re by themselves or when others in their group can’t see them. I’ve seen it many times as I’ve approached them. You know you’ve taken a step too far when the tail goes up, even if the deer doesn’t immediately run away.

The consensus now is that this flashy signal is for the predator, not other deer. But, why wave a white flag when you could be better off blending into the background? Deer flag most often when they’re out in the open and when you are still a good ways off. It’s essentially their way of telling the predator (or you) that they’ve spotted the danger and are prepared to outrun it.

The hard part is figuring out how predators respond to such a signal. Humans and domestic dogs don’t understand the language and are poor models of how a coyote or wolf might behave. No one has managed to collect data on how natural predators respond to flagging However, deer aren’t the only animals to use an ‘I see you’ signal when they’ve spotted a predator.

Many ungulates, like Thomson’s gazelles, pronghorn, and springbok will leap from all four feet, straight up into the air, in a behaviour called stotting, when they spot an approaching predator. Like flagging, this jump signals to the predator that its been seen, then takes it one step further by also communicating that they are more than capable of outrunning the threat.  It seems to work. Studies in Africa have found that cheetahs will abandon hunts more frequently when their target stots and if they still choose to initiate a chase, they’re less likely to win.

Like with most animals, these relatively simple signals are just a small part of a whole array of behaviours that make up a complex web of communication between predator and prey. So, take the time to be observant. With patience and intuition, you can learn the language and open your eyes to a whole new level of understanding of the world around you.

Dust From a Distant Sun

Aurora Borealis by Heather HinamAutumn has flown by, marked by brilliant leaves and skies filled with birds winging their way to warmer climes. The bustle of the season swept me up with back to school (I haven’t taught a fall course in over 7 years) and my regular work as a naturalist/guide/illustrator, leaving this blog sitting on the shelf for a while.

However, now, as the nights turn truly cold and the days become darker, I finally have a chance to settle and get back to sharing those things that fascinate me the most. I thank you for sticking with me.

The colder temperatures remind me of the many reasons I love living in the more northerly reaches of the planet. Not the least of those is the chance we get, now and then, to witness one of the most amazing natural phenomena on earth: the auroras. Here, in the northern hemisphere, they are the aurora borealis or northern lights. They’re not actually more common in the colder months; but many tend to associate them with winter, probably because the longer nights give us more opportunity to see them.  The picture above was actually taken in August.

For people who have never seen them, aurora are kind of hard to describe. They appear with no warning, beginning usually with a barely noticeable glow just above the horizon. You stare, transfixed, wondering if you’re seeing things. Suddenly, the silent flames grow, licking out across the sky, a rippling curtain of light that is ceaseless in its movements. The shifting colours hold you in their thrall until, just as quickly as they had appeared, the lights dissolve into the ether, leaving you feeling a little bereft for their loss.

Just what are these silent, shimmering waves of light? Though they are best seen on the darkest of nights, aurora are a product of the sun. Being a giant ball of hot plasma (ionized gas particles), the sun is a tempestuous place to be. Protons and electrons are being flung about the atmosphere, creating ‘solar winds’, which are streams of plasma that escape the star’s gravity and sail across the universe at truly mind-boggling speeds of millions of kilometres per hour. On occasion, fountains of particles will spew out of the sun’s atmosphere in a coronal mass ejection, sending a wave of protons and electrons on a collision course for earth.

When they reach our magnetic field, most are deflected, riding the field lines to the poles, where they start to swirl around, like atomic tornadoes, in the ionosphere (the height at which the International Space Station orbits). Whirling faster and faster, the ions become unstable, colliding with nearby gas atoms, releasing so much energy that they glow. The colour of the light depends on the gas they interact with and how far above the earth they are. The green and yellow we are most familiar with is created by an interaction with oxygen, while blue and violet are caused by nitrogen.

So, what you’re seeing is millions of chemical reactions playing out several hundred kilometres above the earth. The unearthly flame is concentrated in a halo around each pole, an auroral ring that shifts ever so slowly with the movement of our magnetic poles.

For the layperson, the appearance of these ghostly fire dances are impossible to predict. However, scientists in Canada have spent over a hundred years studying the phenomenon and have teased out some trends. Some years are better than others. It turns out that solar activity (solar flares, mass ejections and other radiation) goes through a relatively predictable 11 year cycle that should be hitting its peak sometime over the next few months.  Besides being a treat for aurora watchers, this intensified light show will be invaluable for researchers looking for ways to protect our satellite and communications networks from this increased radiation. While they may be beautiful, the ions spiralling through space can, and have, wreaked havoc on our electrical grids.

This year’s maximum has turned out to be the weakest in over a century, but there are still lights to be seen.  So, look up, look waaay up and hopefully you will have the chance to experience a true natural wonder.

P.S. to find out when and where your best chances for aurora spotting are, visit: www.gi.alaska.edu/AuroraForecast

Flight of Dragons

Dragonfly portrait by Heather HinamAlthough growing up, I was very much a tomboy, climbing trees and mucking around in the bush and ditches near my house, my relationship with insects was more typical of most city girls. I didn’t like them.  I thought nothing of swatting a house fly and I’m sad to say that I’ve run, screaming, away from a pursuing horsefly or the longhorn beetles that show up around August at the cottage.

However, as I’ve aged, my impression of insects has evolved quite a bit.  As I’ve grown to appreciate the amazing beauty and complexity of our natural world, I find myself drawn more often to those things that used to frighten or disgust me to re-examine them with my new perspective on life. I’m pleased to report that I’ve developed a new appreciation for longhorn beetles.

However, the one group of insects has always fascinated me, even as a child, is the dragonflies. I have a vivid memory of canoeing with my father down the La Salle River, south of Winnipeg, when a dragonfly landed on my knee.  I was rapt as I carefully held my lower half as still as I could while paddling to ensure my visitor a smooth ride, wanting to keep it with me as long as possible.

I’m not the only one with this fascination. There’s just something about these bejewelled predators that captures the imagination. I see representations of dragonflies everywhere, on t-shirts, in wind chimes and other household decorations, on jewellery and even fridge magnets. I think most people simply find them attractive, with their iridescent colours and delicate wings. They’re also ‘benevolent bugs’ from the human standpoint, voraciously devouring our ‘undesirables’ like mosquitoes and black flies.

Even with all of this goodwill, I don’t think the average person really knows all that much about them.  Dragonflies, and damselflies belong to the order Odonata (toothed ones), which contains some of the most ancient and largest insects ever known. There are over 5,900 living species, with nearly 100 of them found in Manitoba.

They’ve been around a long time, with the earliest fossil Protodonata (pre-dragonflies) dating to around 325 million years ago.  They were also a lot larger then, with wingspans reaching nearly a metre. I’m not sure we would’ve been so fond of them if they were still that size. When these insects first took to the air, they were the monarchs of the skies, feeding on whatever flew into their path. Vertebrates were only just crawling out of the water and so dragonflies had little competition and few predators. The benefits of being big, however, only lasted until dinosaurs started coming into their own.

Although they’ve become much smaller over time, the overall structure of a dragonfly hasn’t really changed all that much in 250 million years. These bugs are built to hunt on the wing. Their compound eyes are enormous relative to the size of their body and over 80% of their brain function is devoted to analyzing the visual input from the up to 30,000 ommatidia (facets) that make up each eye.  Having eyes made up of independent facets results in an incredible ability to detect movement because they can see in just about all directions at once.

This hyped-up visual centre can also detect parts of the colour spectrum that we can’t. Human eyes have three types of opsins, light-sensitive proteins that detect red, green and blue light. Diurnal dragonflies have four or five types of opsins arranged very specifically throughout each compound eye, with blue and UV receptors pointed up and longer wavelength receptors pointed down, likely to maximize their efficiency.

With amazing visual acuity, the ability to focus on one prey item at the expense of all else, almost all of their limbs facing towards the head and prehensile labia (mouthparts), they can snatch their prey out of the air with about a 95% success rate.

The last part of this deadly equation is their stunning aerial ability. We’ve all seen them dive and weave, hover and back-up, all while reaching speeds of nearly 50 km/h.  Dragonfly flight is actually very complicated, probably the most complex process of all flying organisms.  With four wings that can move independently of each other and dynamic airfoils that can flex around several angles, things can get complicated and scientists are still trying to sort it all out with the help of high-speed film.

They can make use of the classical lift that keeps planes in the air and a back and forth figure-eight stroke much like hummingbirds as well as take advantage of the vortices they create.  Some can turn 360 degrees around the axis of their bodies with the wings on one side stroking forward and the other side stroking back in one coordinated movement.  All of it is driven by a circuit of 16 neurons hard-wiring the brain to the highly developed motor muscles in the thorax.

So, the next time you catch the flash of a dragonfly as it zips along, take a moment to marvel at these truly ancient wonders of the natural world.

A Thing With Feathers

Feather by Heather HinamEven if you can somehow go through your entire life without ever seeing a bird, chances are very good that you will still have some experience with feathers. Whether displayed in a  hatband, stuffed into a pillow or quilt or tied together at the end of a duster, feathers are a fairly ubiquitous part of the world around us and certainly the defining characteristic of the group of flying vertebrates we know today as birds.

But, have you ever given much thought to where they came from?

As it turns out, feathers have been around a lot longer than most people realize. As paleontologists find more fossils every year to slot into the puzzle that is the evolution of life on this planet, the picture becomes clearer and stories start to make sense.

When it comes to the story of the evolution of feathers, the first thing you have to remember is that birds are modern dinosaurs, having evolved from the lineage known as Theropods, whose ranks include those Jurassic Park villains Velociraptor and Tyrannosaurus rex.  However, what didn’t make it into the movies was the fact that, at the very least, Velociraptor was not only ferocious, but fluffy. At first, this detail was inferred from the discovery that many of its ancestors were feathered and some, like the bizarre, bi-plane like creature Microraptor gui, could fly. Then, a discovery of quill nobs, a trait seen in modern birds, on the forearm bones of one specimen confirmed it. Now an accurate representation of Velociraptor is something like a sleek, predatory ostrich.

Even more recent discoveries have put the assumption of a scaly hide in Tyrannosaurus rex into doubt. While they haven’t found specimens of this iconic dinosaur with feathers yet, a cousin from about 125 million years old China, named Yutyrannus most definitely was feathered. About the size of a bus, these are the largest feathered dinosaurs known to date.

So how far back do feathers go? In time, we can trace their existence at least 160 million years to chicken-like dinosaurs called Anchiornis, but these critters already had the highly complex barbed feathers we see in modern birds today.  Most evolutionary biologists agree that feathers likely started out as single, hollow,  hair-like filaments that became branched and barbed as needed over time. These have been found in many species, most notably, Sciurumimus, a dinosaur found very near the base of the Theropod branch. Described for the first time just last year, this species shows a spectacularly preserved coat of dense, filamentous plumes. Finding feathers like these near the base of the branch suggests that maybe more advanced Theropods, including T-rex had some kind of plumage. Still, we don’t know just how far back down the tree they go.

The point of origin keeps getting pushed closer and closer to the root of at least the dinosaur’s evolutionary tree thanks to feather filaments being found in some Ornisthischian dinosaurs, like the Triceratops cousin, Psittacosaurus, who are about as far removed from Theropods and modern birds as a dinosaur can be. Actually, they’re starting to find feathers all over the dinosaur family tree, leaving us to wonder if they predate the group altogether. In fact, the genes responsible for taking an undifferentiated plate of keratin and turning it into a feather has been found in crocodilians, who although they are birds’ closest living relatives, branched off from the group well over 250 million years ago.

So what did these prehistoric feathers look like? Structurally, early feathers started out as simple, hollow strands, growing out from a plate of keratin embedded in the skin. More advanced feathers split into barbs, looking like fluffy ostrich plumes. Eventually, those barbs developed tiny barbules that allowed their wearers to ‘zip them up’, turning them into strong, but flexible sheets that eventually were co-opted into airfoils. This same evolutionary progression can be seen today in the growth of every bird embryo.

Most fascinating, however is the fact that paleontologists now know what colour some of these plumes were. Recent work with Anchiornis turned up microscopic pockets of pigment called melanozomes. By comparing these ancient structures to those known today, they managed to work out that not only was Anchiornis about the size of a chicken, it actually kind of looked like one, a bright tableau of shiny black and white spangles with a flash of red on a crest. Who knows, maybe in time, we’ll see our very own field guide to dinosaur plumage. Either way, you can’t help but marvel at these remarkable, ancient, ingenious  and unarguably beautiful innovations of evolution.

Writing in the Snow

Qali Growing up, I would hear people quote this statistic: “Eskimos have more than a hundred words for snow.” Actually, I still hear people rattle off this little ‘fact’, especially in winter.  However, there are a lot of problems with this statement, not even including the fact that the indigenous people of North America’s tundra and Arctic regions are known as Inuit, not Eskimo. No, what really grates on me about this blanket statement is the implication that it’s somehow weird to have so many words to describe one thing.

When it’s something that makes up a very large part of your daily life during a significant portion of the year, why wouldn’t you take the time to describe it as accurately as possible? The English language has several words for rain: showers, downpour, drizzle, sheets, so why not snow, especially in light of the fact that it sticks around a lot longer than its warm weather counterpart.  Actually, as a Canadian, I’m surprised that we, as a population, haven’t developed more words beyond flurries, blizzard and slush to describe this white stuff that blankets much of the country for four to six months out of the year.

To do that, we have to turn to other cultures and languages. While the true count is well under one hundred, many Inuit dialects have several useful words to describe the incredible variety of snow that we can encounter throughout the course of the winter.  For those of us who live in forested areas, one handy word to know is qali. It refers to the snow that builds up on the branches of trees, glazing limbs in white and making it look like someone attacked the woods with a decorator’s bag full of royal icing.

I was lucky to have learned several Inuit terms for snow as part of some of my undergraduate university courses and like many people who study winter ecology, they’ve been part of my lexicon ever since. So, it took a bit of digging to figure out where the word qali comes from. According to William Wonders, who wrote the book Canada’s Changing North (2003), the word originates from the Kobuk Valley Inuit of northwestern Alaska, along the edge of the treeline.

Qali can range in thickness from a light dusting that could almost be mistaken for hoar frost to heavy globs of wet snow that drag beleaguered limbs to the ground under its unrelenting weight. All along that spectrum, it has a significant impact on the ecological community.

Many winter residents are affected by qali. Spruce grouse and squirrels that regularly feed on cones often find themselves driven down to the ground by a particularly heavy layer of qali. The snow-covered branches can be hard to navigate, forcing these species to search elsewhere for food. On the other hand, qali can make some food more accessible. With particularly heavy wet snows, the qali that builds up on young birches, willow and aspen pulls the flexible branches down, bringing the young, tender tips within reach of hungry cottontails and snowshoe hare. These contorted trees may also provide shelter for a whole host of wildlife.

You might not have ever realized it, but if you live in an area that experiences snow, qali has likely affected you at some point and I don’t mean that moment when you accidentally brush up against a laden branch and send an unwanted shock of snow pouring down the collar of your coat. I’m talking about more significant impacts. Qali can be very heavy and often trees buckle under the weight taking down whatever else is nearby, which is some cases are power lines. I know I’ve spent the odd cold, snowy night in the dark, waiting for hydro to be restored.  These qali-broken trees also open up the forest floor to new growth, creating pockets of mini forest succession and driving the forest cycle on a smaller scale.

Snow is an amazing thing and qali is only one small facet in a dizzying array of diversity, which thanks to northern cultures, we’re able to describe in accurate and imaginative ways. So, next time you take a winter walk surrounded by white, take a moment and discover that variety for yourself and maybe even create your own words to describe it.