Living with Bambi

US Route 20 originates in Kenmore Square, Boston, and proceeds westward over 2,300 miles to the east entrance of Yellowstone National Park. If you invest five days of driving, you can make the trip that took early explorers up to half a year.

The park, comprising nearly 3,500 square miles, is situated on the Yellowstone Caldera, the largest supervolcano in North America. As a result, it offers many geothermal features such as geysers (think Old Faithful), hot springs, fumaroles, and mudpots.

It is also home to 4,000 bison (American buffalo) and 20,000 elk, large herds which present huge pressure to the ecosystem. These ungulates (hooved animals) compete for grasses, bark, and leaves, and have actually changed the appearance of Yellowstone. This is largely due to the interventions of man as we, perhaps answering deep tribal fears, exterminated the only significant predator in the park – the grey wolf.

To hear the National Park Service tell it, “By the mid-1900s, wolves had been almost entirely eliminated from the 48 states.”

While farmers and ranchers and park game managers initially thought this a good thing, shockingly, we found that removing a natural predator cannot be done without effect.

As elk and bison stripped the river banks of shoots and leaves and grasses, the natural willow groves were decimated. Beaver populations plummeted and their dams disappeared. River banks collapsed during flood season and river courses straightened as the flow increased. Species of fish and songbirds declined as the biodiversity of the ecosystem became less robust. The ungulate herds became less healthy as starvation and disease ravaged their ranks.

Finally coming to their senses, park managers determined in the early 1990s to reintroduce the wolf population. Not without controversy (hunting outfitters and neighboring ranchers were staunchly opposed), a small number of Canadian wolves were captured and released into the park in 1994 and 1995. Initially numbering only 15-20 wolves, the several packs now total about 450.

In the nearly twenty years since this experiment commenced, what have we seen? First, the bison and elk herds have been trimmed and are, overall, much healthier. The wolves prey on the sick and the weak: only the strong survive. While this could be considered very tough love, the bison and elk are the better for it.

But more unexpectedly, the ecosystem itself has become healthier. The willow groves have rebounded and river banks solidified by trees and grasses and other plants. The rivers themselves have resumed their lazy, more curvaceous course. Beavers have returned with their dams creating pools, friendly conditions for fish and amphibians. Songbirds once again nest in the willows.

The park is, overall, much more balanced and healthy than it was twenty years ago. All due to the reintroduction of a feared predator.

What does this augur for our highly populated eastern regions? It is not likely that folks will be agitating for the return of wolves and cougars to Boston and Foxboro and the like. But we will pay the price.

Local homeowners are familiar with having their shrubbery stripped by deer during a hard winter. The deer herd itself suffers from malnutrition and disease. Anyone who has collided with a deer rues the damage to their car and mourns the poor animal they crippled or killed.

What’s the answer? Perhaps only to keep an open mind regarding human predation of the deer herd. Those few who choose to hunt are providing a service that we won’t allow wild predators to perform. We might consider the idea of harvesting deer and donating the venison to homeless shelters.

The lesson from Yellowstone is that predation, from wolves or otherwise, is necessary for a healthy ecosystem. Man’s intervention has been historically unwise. Let’s try to do better.

Attack of the Killer Coyotes

A hungry coyote.  Photo courtesy of USDA.

We are counting our blessings in New England.  This is the mildest winter we have seen in many years.  But while we walk and jog and even play golf, luxuriating in moderate temperatures and enjoying the lack of snow, there is a grim struggle for survival going on.

The number of coyote attacks reported this winter has been rapidly escalating.  Dogs injured and killed, cats missing without a trace, and even children bitten and terrorized.  What the heck is going on?  Have coyotes suddenly turned malevolent, possessed by evil spirits?

No, the answer is far simpler, and in two parts.  First, as we have become an urban nation,  coyotes have extended their range into our suburbs while at the same time we have stopped vigorously hunting them; they have lost their fear of man.  But this is a long term trend that has played out over many decades. Of more immediate portent, they are ravenous. Slowly starving, they are driven to attack pets and children and livestock and whatever else might keep them sustained for another day.

The question begs to be answered: why? The proximate cause is an extreme lack of acorns.  In a good year (called a high mast year), a single large oak tree can produce tens of thousands of acorns.  In a low mast year, perhaps half that.  But in the autumn of 2011, there were large tracts of New England without an acorn.  Nary a one.  And that is catastrophic for mice and chipmunks and squirrels and many other direct acorn-eaters including wild turkeys, quail, and deer.  Some ecologists have estimated that up to 90% of the current rodent population could die by spring.  This puts enormous pressure on coyotes and other predators, such as foxes and weasels and hawks and owls, who must compete for that rapidly dwindling food supply.

No wonder the coyotes are famished.

But where did the acorns go?  There are multiple theories; here are two that seem most likely, especially in tandem:

1. In the spring of 2010, we suffered extremely heavy rains and flooding.  This excessive moisture interfered with the pollination of oak flowers, the necessary precursor to acorns.
2. The intense winter moth infestation in the autumn of 2010 caused the trees to be nearly defoliated the following spring.  This greatly stressed the oaks.

Perhaps as result of two consecutive whammies, the 2011 acorn yield was a record near-zero.  It is most likely that we will soon return to normal mast production and a recovery of the rodent population will remove pressure from coyotes and other predators.  Hard spring rains are not typically intense enough to interfere with the blooming of oaks.  And there is a new tool for winter moth control.  Cyzenis albicans, a parasitic fly imported from Europe (where winter moths originated) is showing promise in controlling moth outbreaks.

So the problem remains, how to minimize the risk of coyote attacks?  Here is a short list of ideas from the Massachusetts Department of Fish and Game and the New York State Department of Environmental Conservation:

• Don't let coyotes intimidate you. Don't hesitate to scare or threaten coyotes with loud noises and bright lights. Don't hesitate to pick up small objects, such as a tennis ball, and throw them at the coyote. If a water hose is close at hand, spray the coyote with water in the face. Let the coyote know it is unwelcome in your area.
• Secure your garbage. Coyotes will raid open trash materials and compost piles. Secure your garbage in tough plastic containers with tight fitting lids and keep in secure buildings when possible. Take out trash on the morning pick up is scheduled, not the previous night. Keep compost in containers designed to contain but vent the material.
• Don't feed or try to pet coyotes. Keep wild things wild. Feeding, whether direct or indirect, can cause coyotes to act tame and over time may lead to bold behavior. Coyotes that rely on natural food items remain wild and wary of humans.
•  Keep your pets safe. Coyotes view cats and small dogs as potential food and larger dogs as competition. For the safety of your pets, keep them restrained at all times.   
• Eliminate availability of bird seed. Coyotes are attracted to the concentration of birds and rodents that come to feeders. If you do feed birds, clean up waste seed and spillage.
• Ask your neighbors to follow these same steps.

Some of these may seem cruel… poor squirrels, poor birds!  Why can’t we feed them?  But remember that you are trying to save Tabby and Rover and even Junior from becoming a coyote meal.  Mother nature will return to a balance – have faith.