ParksidePollinators

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Category: Ecosystems

  • The Snake, the Hawk, and the Mouse

    The Snake, the Hawk, and the Mouse

    At work recently, I saw a garter snake, which gave a great excuse for a water break.  Then I did another task across the yard to give the snake time to clear out safely, thinking about what I’d just seen.

    On this day, it moved into cover so fast I didn’t have time to snap a picture but it looked as if all the yard’s twigs and fallen leaves met at Fashion Week in Paris and decided on a cubist motif for next year’s season.

    That’s not to say snakes have a sense of fashion. The removal, and shedding, of skin is a process of pure function. The pattern itself blends to allow for visual deception for all but the keenest hawk’s eye.

    In those cases, looking perched from a thread in the ecosystem’s web, we see the evolution of the relationship between predator and prey.

    If something wants to eat you but they have bad eyesight and often look your way from hundreds of yards up, you only need an approximation of forest detritus to effectively survive. As the predator’s eyes get sharper, the snake needs better camouflage to avoid being eaten, which is why there are no pink and green snakes, or bright blue.

    If they even ever existed, then as the predators eyesight evolves to see them: anything that stands out gets eaten first.

    Equilibrium arises as both sides work to defeat the others’ ecological advantage. Over time, the snakes will continue to develop better pattern avoidance just as the hawks continue to develop better pattern recognition.

    What does the garter snake eat? Mice, mostly. Insects. Grasshoppers.

    It’s not like I know that many farmers living deep in the city but for those I know, still haven’t met one yet that has a cruel thing to say about a snake that eats mice.

    And that’s the rub, not farmers and food security. Instead, if we’re only discussing healthy ecosystems we must first recognize the challenge of labeling any aspect of it with a human centric perspective.

    Snakes certainly don’t see mice as pests. Within a set of prescribed circumstances snakes are very happy to see mice alive; me? Not so much. After my third mouse hotel cleaning and demolition in the last five years I’m ok with snakes eating all the mice they can get.

    But what if I trapped, or poisoned, mice? If I put out the best, most effective traps would it hurt the snakes. The hawks? Coyotes and bobcats? Fewer mice means less food for creatures higher up the food chain, if the mice are living and mingling within the same ecosystem. It won’t matter if the mice are in the walls…but if you remove Virginia creeper does it reduce the snake’s hunting grounds?

    Yes, but…I need to deflect so I don’t feel guilty. To be clear, it would only be harmful to the extreme if we behave in a way that’s extreme. If we scrapped bare the ground leaving nothing behind. No place for mice to hide from snakes but no place for snakes to hide from hawks, either.

    If the ecosystems are disrupted, it’s harder for higher-level creatures to find enough food. From our perspective, the system works because all the pieces exist holistically, yet I’m sure the mice could find cause to disagree.

  • The Good. The Bad. The Virginia Creeper.

    The Good. The Bad. The Virginia Creeper.

    A native plant (or exotic, depending on who you ask), Virginia creeper, theoretically, provides food for birds in winter. It is also known to be, “overly vigorous,” when it receives excessive watering—or, it turns into a wet year.

    For that very reason, I must regrettably report that this summer the client asked me to remove a large patch of it that was choking out other locally native plants. It’s a tough decision but they made it because the balance no longer leaned towards species diversity.

    With Virginia creeper, the problem is its voraciousness. Or, the problem is us and houses, but you can’t tell that to the man who pays the bills…

    Especially in wet and rainy years, Virginia creeper will expand its solar footprint to excess, working its way up and through to outcompete other beneficial plants.

    Poisonous to humans and pets, but important to birds that eat berries, yet if we remove the Virginia creeper and leave behind the Apache plume, scrub oak, and (yes, even the) Russian sage, we remove a plant that will always try to take more than its fair share and take it first (as defined on any scale other than its own) and expands its solar footprint till it consumes all resources.

    Does Virginia creeper really act with such salacious selfishness? Not at all. Ironic to say, maybe, but only in the framework of everyone else’s needs should we consider it a selfish plant.

    Beyond birds, it offers habitat and home for additional populations of native insects. Which means even as it chokes out native plants and trees, it is providing space for some of our most threatened ecological niches to gain additional resiliency (insects—not mice).

    This is all, of course, speculation, educated guesswork,  and good ol’ fashioned field observation mixed with healthy doses of colonial privilege, anecdotal assumption, and reasonably serious research. Virginia creeper is actually a beneficial plant because it provides habitat for snakes and food for birds but is that statement true if we examine the vine’s impact on Apache plume and rabbit brush’s growth rate?

    We need to check this perspective and be clear it’s totally human centric. Even then, if we’re discussing perspectives in which we say randomly something like, “plants are altruistic,” or even, “plants are selfish,” it is often framed in context of evolutionary advantage.

    And if that’s the case then it’s not really altruism.

    Can plants actually be altruistic? Let’s say not, because the power exchange within the ecosystem is usually not self balancing…but if we look at the larger system as a whole, individual players within the ecology only behave in ways that are tangential to altruistic action. If they can’t be altruistic themselves can the larger system still transmute selfishness into a more common currency?

     

    A swallow-tail butterfly drinking nectar from a tiger lilly.
    It depends on their needs.

     

    This leads to questions: is it helpful to anthropomorphize intangibles like “ecosystem,” or even the broader concept of “nature”? Can the larger system work altruistically if the individual is always motivated by self interest?

    Maybe best if we never know…but, if you’re looking for answers, best ask the Virginia creeper, or my bank account.