Posts tagged: natural history

May 12, 2010

The possibility of naturalists

categories natural history | comments 2 Comments

John James Audubon
Creative Commons License photo credit: cliff1066™

Being a naturalist is something that I’ve been thinking about personally and academically for a while now. Now when I say naturalist, images such as this painting of John James Audubon may come to mind. Being a 19th century naturalist was one of collecting and cataloguing, attempting to create order out of the perceived chaos of the natural world. While this work did manage to order the natural world in a particular way, it was undertaken in places like North America by Europeans without regard for value of local knowledge. In this way, it was an extension of the colonial act of “settling” an empty land. As we can now acknowledge, North America was anything but empty.

Significantly, scientific knowledge left the practice of natural history behind as the official way of coming to know the more-than-human. And, if we look at Audubon with his rifle — his instrument of collection — perhaps that fine. Because when I speak of being a naturalist, I am not interested in reproducing this violent, romantic and gendered way of coming to know the more-than-human. But I do think that our personal, intimate and material understanding of our lives is impoverished. And I think that a certain practice of natural history can offer opportunities to discover the networks of material relations that we have between the many actors implicated in our lives. Today, being a naturalist means attempting to broach the divide between human and non-human.

Barry Lopez echoes this (or I echo Barry Lopez) in a 2001 article published in the autumn issue of Orion magazine. In short (and I encourage you to read the whole thing because he is saying many things), he sees naturalists who are attentive to the mystery of nature (and I acknowledge that this does have a bit of a romantic ring to it, so I would say attentive to the more-than-human and in firm grasp of the limitations of what and how we know ), as a new kind of political actor.

And this is key. Naturalists from every era, whether stated explicitly or not, have always acted politically in this world. In the case of 19th century white men coming to the new world, it was a particular kind of politics that they were rendering — it did not deviate much from the larger cultural script of ordering and expansion. Today, however, naturalists have the opportunity to enact a kind of politics that does deviate from the larger cultural script. As witnesses with understanding fostered by skills of observation and reflection, they can say meaningful things about our cultural relationship to the natural world. Words and actions that rough up the flat perspectives and shallow moral obligations that currently are the status quo. This is the naturalist re-cast.

January 22, 2010

How might a warmer climate affect hibernation?

categories Animals | comments 0 Comments

Inspired by Gregg McLachlan’s recent twitter conversation with Caroline Schultz1, allow me some reasoned conjecture answering what might happen to animals that hibernate in a warming climate.

First, some definitions: hibernation, colloquially-speaking, is the long, uninterrupted sleep that animals undertake to avoid the winter. More correctly, hibernation is one kind of dormancy along a continuum—kinds of deep rest that muddle across periods of time and kinds of organisms, including: torpor, estivation, brumation and diapause. But let’s focus on hibernation2. Two important things happen in hibernation that set it apart from the others I’ve just listed: it involves a lowered body temperature and a lowered heart rate. In turn, this means a lowered metabolism.

Now here in Southern Ontario, we have few animals that enter true hibernation. Bears (and in our case we’re talking Black Bears or Ursus americanus) do not enter true hibernation. But Groundhogs (Marmota monax, pictured below), Eastern Chimpunks (Tamias striatus) and Little Brown Bats (Myotis lucifugus) do.

groundhog day!
Creative Commons License photo credit: NapaneeGal

Now our enjoyment of, as a species of naked apes, the winter season may lead us to believe that other animals enter hibernation to avoid the same cold weather that (some of us) suffer though. The truth is somewhere else—these hibernators have depressed their metabolism so they can avoid having to find food. So, rather than an inability to deal with cold weather, it is the lack of food that has driven the evolution of entering a physiologically dormant state when food disappears.

We’ve (the naked apes in Souther Ontario) have been enjoying a warm period this January and its supposed to get as warm as 6 degrees Celsius on Sunday. Before we tackle the larger question of climate change, what might a warm period like we’ve been having do for those animals hibernating right now?

I’m turning to the great book Winter World: The Ingenuity Of Animal Survival by Bernd Heinrich to help me answer the question and I’m going to focus on the ground squirrels (the Chipmunk and the Groundhog) just to simplify things. Chipmunks and Groundhogs, though they both hibernate, show different strategies in preparation. Simplified: Chipmunks collect food and Groundhogs get fat.

In fact, Heinrich writes that a chipmunk’s “availability of stored food affects whether is remains active or enters [hibernation]” (p.99) meaning that in years with lots of available food, Chipmunks can be active the entire winter and don’t need to suppress their metabolism. This was the subject of an entire doctoral dissertation, so I can’t possibly give a nuanced answer, but being active in the cold seems to be associated more with lots of stored food rather than warmer temperatures. So, for Chipmunks, it will be some combination of the two factors (food & cold) that will predict the depth and length of their hibernation. In fact a Southern species, the California Chipmunk (Tamias obscurus) does not hibernate at all.

Groundhogs are different. They follow something called a circannual calendar—named, to continue our connection to Southern Ontario, by two researcher from the University of Toronto—which means they prepare for, enter and exit hibernation on an internal clock, independent of external conditions.

So, what do these intermittent warm periods do? For Groundhogs, nothing, as they’re busily following the ticking of their circannual clock, waiting for it to rouse them sometime in mid to late February. Like most things in the natural world, there is an exception to Groundhog’s circannual clock: in the U of T experiments, when the air temperature remained above 30 degrees Celsius, the Groundhogs did not enter hibernation. Chipmunks, on the other hand, are easy to rouse, even when in hibernation. Does this mean a longer period of warm weather would wake them up? Perhaps. Likely, those that are active are the Chipmunks with access to food in their cache, so being active, and the higher metabolism, isn’t as serious.

What would a warming climate do? This is where the guess work comes in. Over a long period of time, I would guess that the Eastern Chipmunk would come to resemble its southern cousin and not hibernate at all. For the Groundhog, it would seem that the climate would need to warm a great deal—above 30 degrees Celsius in the wintertime—for them not to hibernate. That’s not an immediate concern right now, and if ever Southern Ontario’s winter temperature ever got to 30 due to global climate change, I think the lack of hibernation would be the least of a Groundhog’s worries.

In the short term, it’s a bit more interesting to guess. Different populations of Groundhogs emerge at different times. This is evident in the fact that Groundhog day falls on February 2nd even though our Southern Ontario Groundhogs emerge later in February. February 2nd is the time of year the southern Groundhogs, specifically those in Punxsutawney, Pennsylvania, generally emerge. This shows some plasticity in the length of that circannual calendar. I would suspect with a warming climate that the clock would begin to change—Southern Ontario groundhogs entering their den later in the year and emerging earlier. Would these climatic changes occur faster than that the circannual calendar could change? I don’t know. For Chipmunks, it would be similar to the long-term changes. Eastern Chipmunks, I suspect, in combination with access to food, will be more active.

What all of this points to though, and what I haven’t really addressed in relation to global climate change, is that access to food continues to be the most important factor associated with hibernators. The question that then needs to be asked: how with global climate change, change the plant communities of Southern Ontario and what impact could that have on the mammals that currently live here?

Perhaps I’ll take a stab at that next time…

circannual calendar
  1. As aside, here’s why Twitter is awesome—before Twitter, how or where else do you get to have an informal chat with the executive director of Ontario Nature and the founder of environmentally-focused career site? [↩]
  2. If you want more in-depth, scientific information, I suggest this open learning source [↩]
November 21, 2009

Two minds meet in a parking lot

categories birds | comments 0 Comments

Haines Ferry Terminal, Haines, Alaska

I had just pulled the van into the ferry queue and stepped outside when they arrived: from the tree-tops of the nearby Pacific Northwest temperate rain forest, two Northwestern Crows (Corvus caurinus) glided and landed on the asphalt beside me. Hopping to a stop and quickly re-arranging their wings, they looked up at me and I looked down at them. In a moment, with our mutual glances, it was obvious that these two were here because of the growing line of cars, vans and campers that were parked, lining up to board the evening ferry to Skagway, Alaska. I decided to watch.

Earlier in the evening, I had glimpsed a pair of Northwestern Crows foraging by the ocean as I was driving along the coast of the Lutak Inlet to the ferry terminal. As the common corvid of the coast in this part of North America, it wasn’t a surprise to see them here. The tide was receding along a rocky beach, and as I passed, the crows appeared from the shoreline below. Their wings beating in the stiff on-shore breeze with the kind of tempo one expects when birds take flight, they both flew up into a sharp parabola. One of the pair had something in its bill—it looked like some sort of mollusc—and slowed down its wing beats, quickly decelerating. Reaching the apex of its flight, it dropped the object from its mouth onto the rocky shore below. Down the birds flew, on I drove.

This kind of behaviour isn’t unusual in the Northwestern Crow. They’re known to be foragers along the edge of the ocean, looking for aquatic organisms that become stranded as the tide ebbs. If it can be found between the exposed rockweed, it can be considered food and these crows find their protein in the fish, molluscs and crustaceans that live along the coast of the Northern Pacific. While they are foragers, and live commensally with humans, I experienced something unexpected along the line of vehicles.

Northwestern Crows

As I watched the crows standing at my feet, they hopped past me and my vehicle towards the van that had pulled up behind mine in the queue. With what I would describe as curiosity, the two crows began to inspect the grill of the camper van. It became clear what they were looking for: insects. Or, more correctly, they were searching out freshly-deceased insects that had stuck to the camper’s metal and chrome. And so the metal grill became the shore: up these birds flew, gleaning the remains. Because of the lack of a good perch, they looked more like oversized Ruby-Crowned Kinglets (Regulus calendula) feeding in this way, with their wings quickly flapping to give them the purchase they needed to get their food. This was challenging work for the crows. After the “easy” carcases were gone, it became a cooperative effort with each bird taking turns in one of two roles: one flying up to remove the insects and the other, after the insect hit the pavement, eating it up.

In the minutes before the ferry arrived they continued looking for more to eat, moving from car to van down the line of vehicles.