by Merritt Clifton
Is “green building” better for wildlife?
Yes and no.
Before answering that question, we need to more precisely define the terms. First, what exactly do we mean by “green building”? Second, what exactly do we mean by “better”?
There are a variety of different and sometimes conflicting definitions of “green building” flying around the blogosphere. Rather than getting into the nuts and bolts of any of them, I’ll allow that “green building” is any type of construction that tries to take environmental health into account.
As regards wildlife, quite a lot that “green” builders do can be either “better” or worse, depending on what we believe “better” to be.
Before getting further into the definition of “better,” let me point out right from the outset of this discussion that part of the subject, inevitably, is whether either old buildings or undeveloped habitat are “better” for wildlife than habitat changed by new construction of any kind.
Further, we need to define what wildlife species we are talking about.
Give me a home where the buffalo roam and I’ll show you a house full of buffalo chips and confused buffalo trying to butt their way out. “Green” or any other color, that house is not long for the world.
Construction of any kind is not easily compatible (if at all) with the habits of large migratory species, from antelope to zebras. And no intelligent builder, whether “green” or otherwise, should try to construct homes or businesses in the migratory paths of bison, elephants, or any other species whose living habits are normally incompatible with those of humans.
Likewise, no intelligent builder should construct anything, including open roads and parking lots, that tends to lure wildlife into conflict with humans. Normal people don’t want three bears coming to breakfast, or elk competing for parking spaces––and the animals don’t want to be there either. Animals get into such situations when humans do dim-witted things, such as going for a walk with porridge on the table and the door open, or not figuring out that a parking lot where calcium chloride is used to prevent black ice from forming will soon be seen by ungulates––such as elk and deer––as a giant salt lick, if not protected by drainage ditches and fencing that limits access.
Most wildlife are compatible with humans
Fortunately, most wildlife––both in North America and abroad––are easily and often compatible with humans. If “better” means “more food, more water, more safe cover for sleeping and raising young, less predation, and more protection from the elements,” practically any human development is “better” for most familiar wildlife than practically any undeveloped habitat.
Indeed, this is precisely why such familiar wildlife are familiar, whether we are talking about deer and raccoons here in the U.S., or macaques and Indian house crows in Southeast Asia, or street dogs and feral cats practically anywhere in the world. We create their preferred habitat.
Hundreds of familiar species have co-evolved with human civilization, and have spread around the world with us, often practically unnoticed, because our conflicts with them are so few. Sparrows, for instance, spread from a small habitat niche following herd animals and picking insects from their dung to a global habitat niche, following our work animals and grazing farmed species.
We notice a few normally innocuous species such as mice, rats, crows, and pigeons because they do occasionally come into conflict with us; but relative to their abundance, the numbers of these species with whom we have conflict are miniscule––far fewer than the numbers of fellow humans with whom we have territorial arguments.
A person who traps half a dozen mice in his home per year may consider himself to have a bad mouse infestation, but that person has usually lived with mice for many years without noticing them, before something brought them into abnormal abundance and visibility, and may mutter at more than half a dozen other motorists every morning on his way to work.
Unfamiliar species are another matter. Unfamiliar species are typically rare, highly specialized, suited only to specific kinds of habitat, and are sometimes governmentally recognized as “threatened” or “endangered.” Practically every builder in the U.S., Europe, and many other parts of the world has either had experience with trying to cope with the specific legal requirements pertaining to “threatened” and “endangered” species, or has heard horror stories about associated bureaucratic entanglements.
But, because “threatened” and “endangered” species are by definition few, occurring only in specific places, most of the impact of construction on wildlife goes completely unnoticed, both by the builders and by the users of whatever is constructed. Often the first hints of wildlife/human conflict, if any develops, occur decades after the construction was finished.
Typically those first hints of wildlife/human conflict occur because of habitat change. Habitat change, like the passage of time itself, is inevitable and unavoidable. Yard vegetation grows and matures; the vegetation on surrounding properties may grow and mature, or be removed; construction on surrounding properties may alter the characteristics of the habitat in many different ways, for instance by changing the availability of surface water, the abundance of culverts and mature tree canopy, and the volume and speed of traffic in the neighborhood.
To be remembered is that short of applications of the Second Law of Thermodynamics, habitat is neither created nor destroyed. Habitat is, however, constantly changing, whether changed by humans or by natural forces such as weather and climate. The habitat that a builder bulldozes to make way for construction is lost, but even a construction site is habitat of a different sort, especially for foraging and scavenging animals, and more significantly, as the point of dispersal for countless mostly small species who arrive with building materials and workers. Every building site is an experiment in micro ecology, testing the viability of insects, plant seeds, and many other accidentally introduced species in a new location.
This is only the beginning. A newly constructed building, “green” or otherwise, may look sterile and ecologically vacant to a casual observer, but it is already interacting with wildlife in many ways, from the influences of the lighting and windows on bird migration to much less evident effects such as the accumulations of windblown pollen on rooftops and the attractions of backfill around foundations to burrowing insects, mollusks, and the mammals such as shrews, moles, and skunks who feed upon them.
The older the building, the better the habitat
Every year that a building exists, it attracts more wildlife, at least transiently, who test the habitat and take up residence if finding it congenial. Usually the numbers of species using the habitat increase with the age of the building. As the building deteriorates over time, it allows entry to animals who could not have gained access earlier, when shingles were tight, vent screens were all still in place, no one had drilled holes for additional telephone lines, etc.
In terms of accommodating biodiversity, both native and non-native, the older the building, the “better” the habitat. No new building, no matter how “green” and how sensitively built, will ever accommodate either resident or transient use by as many species as that same building will a decade or two or three decades later.
The same can be said of surrounding yards, and even of surrounding habitat that has been left intentionally undisturbed by the construction itself. Regardless of how pristine the builder tries of leave surrounding habitat, the new construction will attract an array of species who will test the surrounding habitat in various ways and sometimes opt to live there. The vegetation will age. Changes will occur, usually working toward net increases in biodiversity, though not necessarily “native” biodiversity.
Fires or other disasters may temporarily diminish biodiversity, but almost inevitably more species move into disturbed habitat than were there before.
Large charismatic megafauna
But, ecologically important as biodiversity is, encouraging biodiversity is in practical terms the least of the relevant considerations in determining whether habitat is “better” or worse for the wildlife whom humans normally think of, also known as “large charismatic megafauna.”
In biological terms, “large charismatic megafauna” are “any species big enough to see unaided and give a name.” Mice and elephants both are “large charismatic megafauna”; the fleas on mice and elephants are not, though the fleas (and the mites on the fleas) are part of the biodiversity.
The most useful and relevant things a builder can do to accommodate and encourage large charismatic megafauna are not actions to attract them, but rather actions to minimize conflict between the large charismatic megafauna who will come anyway, and the humans who reside or work in the new construction.
“Better” is “more considerate”
From this perspective, “better” is simply “more considerate.” By carefully considering other environmental aspects of construction, “green” builders have a good chance to build homes, businesses, and infrastructure such as roads and parking lots that are “better” for wildlife than conventional builders; but the real test of “better” will not be before-and-after biodiversity assays.
Rather, the real test of “better” will be how well the human users of the facilities manage to accommodate interactions with wildlife over time. If those humans feel compelled to fight wildlife incursions constantly with poisons, traps, and guns, the construction was not “better” even if X-percentage of the site was left undisturbed, biodiversity is high, and all building materials were ecologically friendly and conscientiously sourced.
Building with greater consideration for wildlife, both now and in the future, may include many aspects that most builders consider already. Maintaining views, privacy, ease of access, ecologically appropriate landscaping, and good drainage all can have critical importance to minimizing conflict between humans and animals.
In each respect, what is best for people is usually also best for most large charismatic megafauna. A short driveway, for instance, will result in fewer roadkills than a long driveway, if the habitat alongside the driveway is comparable and comparably maintained; but if the shorter driveway would have to go through a wetland, a copse of trees providing heavily used food sources for wildlife, or the most accessible habitat for burrowing species, then the longer driveway may be both more easily and inexpensively built, and more congenial to resident animals.
Big words for big concepts
“Conservation,” “preservation,” “mitigation,” “restoration,” “transformation” and “accommodation” are all tediously long Latinate words which nonetheless need to be remembered and thought about in considering how best to address wildlife issues on any building site.
None are necessarily the only or best approach to dealing with wildlife in a specific location, but mulling them over can lead to finding the solutions appropriate to your particular habitat.
“Conservation” refers usually to encouraging ecological processes. Intelligent conservation––and quite a lot isn’t––recognizes that habitat and the relative abundance of species will continually change if not continually managed. The idea behind wildlife conservation is to try to prevent catastrophic change through use of an array of approaches which may include hunting, trapping, poisoning, and burning off the habitat for “undesirable” species.
Conservationists are typically good at maintaining populations of “game” species, including deer and fur-bearing mammals, and typically try to maintain populations of endangered and threatened species by using the same toolbox, with varying success.
“Conservation” is by far the oldest approach to wildlife management. Though still the dominant approach in the western hemisphere, conservationism has significant drawbacks, especially for property owners who do not wish to invest time and money in unending active intervention to suppress “nuisance” wildlife.
“Preservation,” another ancient concept, is allied to conservationism, to the extent that many people who think of themselves as “conservationists” are actually “preservationists.” But preservationism differs in attempting to maintain indefinitely exactly the same set of conditions today and tomorrow that existed yesterday. Often a preservationist approach is mandated by the laws protecting threatened and endangered species, yet is foredoomed by the reality that habitat changes no matter what we do.
For example, the latitude at which snow falls and remains on the ground for months each winter has gradually moved about 200 miles northward just during my 45 years on animal and habitat-related news beats. Much habitat is now being “preserved” for rare animal and plant species who will never again be able to dwell there. At the same time some of those same species are trying to survive in habitat farther north where they sometimes have no protection at all.
A preservationist approach to wildlife and wildlife habitat may work for the typical homeowner for the duration of the time the typical homeowner will occupy the home, but will not succeed for as long as the home is likely to be occupied by someone.
“Mitigation” is more a legal concept than a practical approach to wildlife ecology. The idea behind mitigation is that if habitat for a particular species or array of species is lost as result of a construction project, perhaps the builder can replace it by setting aside habitat somewhere else. In reality, this may preserve some existing habitat for longer than it would be preserved against development pressure, but does little else.
Habitat set aside as a “mitigation” strategy is usually already occupied to the maximum appropriate density by the same species who have been displaced by construction, so has little value as an “island” refuge for displaced animals, who will not be able to sustain themselves within the “island” for as long as would be necessary to allow viable habitat to recover within the developed area. Most of the animals who are displaced by construction will have to find new habitat or die; and if they flee into “mitigation” habitat instead of dispersing more broadly, the net effect may be to overburden the “mitigation” habitat so severely that more animals die instead of fewer.
This tendency is particularly obvious with deer. A healthy local deer herd is on balance good for suburban developments, in part because deer consume understory which may otherwise die back and dry out from lack of sunlight as the tree canopy expands, and fuel wildfires. But too many deer will consume too much understory, too rapidly, depriving many bird species of nesting habitat and depriving small mammals such as varying hares of needed cover.
Contrary to common belief, urban and suburban deer seldom starve, even after eating their way through understory. Instead, they turn to eating bark, stripping trees, causing the trees to produce less foliage, which in turn allows more light to reach the ground and stimulates more growth of understory, after the deer have moved on. But stripping trees of bark also opens tree trunk habitat to insects, and can ultimately kill the trees.
Though this may be “good” for woodpeckers, owls, and other species for whom insect-infected dead trees are good habitat, none of it is what developers have in mind when they undertake “mitigation” measures that concentrate large numbers of deer in green spaces much smaller than the habitat the deer formerly occupied.
“Restoration” rather than “mitigation” has accordingly become a more popular concept among wildlife ecologists. The concept behind restoration is that while habitat for the species now occupying a particular area may be destroyed by construction, both the habitat and the species can be brought back to a semblance of what they were through appropriate landscaping.
“Restoration” very often works quite well, especially when the damage to the habitat during construction has been either territorially limited or of short duration, or preferably both. I have myself engaged in several successful experiments in “restoration ecology,” which exponentially increased biodiversity, especially native biodiversity, on severely damaged land. Each location, within just a few years, went from sustaining little large charismatic megafauna to sustaining residence or use by all of the large charismatic megafauna inhabiting the surrounding regions.
But “restoration” has limits. Restoring the tindery native plant ecology of chaparral country to windswept dry canyons where hundreds or even thousands of homes have been built is not a good idea, even if all of those homes should have been built elsewhere. Restoring an abundance of beech trees whose mast attracts bears is not a good idea in a residential suburb. Restoring tall grass to become infested with Lyme ticks in an area where Lyme disease is common is downright inhumane to wildlife as well as humans.
Often “transformation” is the more appropriate and ecologically considerate approach. Transformation is the art of adapting one sort of habitat to become another, that is at least equally able to thrive in the particular location, and is more congenial to the occupants.
Unfortunately, most planned habitat transformations are catastrophic failures, in part because the thought behind them is limited to consideration of human interests.
For example, golf courses typically transform former farm land into habitat which attracts some animals, but not the whole ecological suite of species that would maintain a comfortable balance for the human users. The combination of broad expanses of grass and watertraps creates ideal habitat for nonmigratory Canada geese, whose droppings sometimes provide more nitrogen to the soil than the turf can use, and become an unpleasant, often slippery hazard to the golfers.
This problem could be reduced, and could even be prevented, by planning golf courses to provide safe habitat for raccoons, coyotes, and foxes as well, all of whom are major nocturnal predators and nest predators of nonmigratory Canada geese.
Berkeley before & after
Raccoons, coyotes, and foxes would rarely be seen by golfers, who of course play mostly by daylight, even on lighted courses. Instead of welcoming and encouraging raccoons, coyotes, and foxes, however, most golf course managers try to keep them away––and meanwhile hire exterminators to kill geese.
Successful habitat transformations usually occur almost unnoticed, directed only by Mother Nature. A particularly successful and well-documented example is the transformation of the site of present-day Berkeley, California, from mudflats and chaparral when the first University of California was founded in 1866 into one of the richest, most biologically diverse urban forests in the world.
The ancient gnarled live oaks scattered along Codornices Creek and Strawberry Creek in pre-settlement times are still there, but have grown much taller, encouraged by much more abundant water. Water has become much more abundant because of the cumulative effects of increased biomass, holding and recycling precipitation.
Berkeley is receiving little if any more rain, fog, and occasional snow now than the region did in the mid-19th century, but instead of the water running off or evaporating almost immediately, it now irrigates the fruit trees brought to the hills north of the University of California by the orchardists for whom the settled neighborhood was originally called Nut Hill; the generations of shade trees planted around the fruit trees; and a variety of other trees, both introduced and “volunteer.”
A century and a half of falling leaves from those trees have replaced tall, dry, and often fire-swept grasslands with deep, rich humus, which in turn has encouraged some of the oldest and most successful urban gardening projects in the U.S., now serving as models for similar projects worldwide.
The bottom line in the Berkeley transformation, and in most other successful habitat transformations, is “accommodation,” a cultural norm which might be translated as “live and let live.” Accommodation means accepting, appreciating, and learning to live with whatever nature brings by way of either plants or wildlife. Viable accommodation begins with avoiding conflict.
This is where “green building” strategies can be most effective, even when accommodating wildlife is not the builder’s first concern. “Zero energy” approaches are particularly promising in this regard, because of the happy confluence of factors such as managing tree canopy in minimizing energy use and avoiding conflicts with animals. Green builders in general try to encourage tree canopy, but “zero energy” builders tend to be particularly attentive to where trees are because of the value of trees as windbreaks and in soaking up runoff, offset by the need to keep tall trees and tree debris from interfering with solar panels.
Tree canopy is at once the most used of urban and suburban wildlife habitat components, and often the most overlooked, since the animals living there tend to be mostly out of sight and out of mind.
Tree canopy harbors the migratory and resident birds whose guano deposits can be seasonally problematic, the visiting crows whose racket threatens to wake the dead, the squirrels and chipmunks who may use trees as ladders to enter attics, and raccoons, who on average tend to be more clever with their hands than the average homeowner. Certain tree species––beech, for example––can attract bears.
None of these animals are inherently problematic, at a comfortable distance from a house, where they can be observed and photographed, but none tend to be congenial guests.
At long last returning to the original question, “Is green building better for wildlife?”, the question really should be, “Does green building better accommodate wildlife, even if the builder and building occupants know little or nothing of animal behavior?”
The answer, in that case, is “Yes.” And if the green builder and building occupants take the time to study the local wildlife and assess what needs to be done to fulfill wildlife needs at the same time as meeting human requirements, so much the better.
12 Essential Steps to Zero Energy, reviewed at http://wp.me/p4pKmM-PB;
27 ways to avoid hitting animals that may save your life too!, http://wp.me/p4pKmM-OM;
Deerland: America’s Hunt for Ecological Balance & the Essence of Wilderness, by Al Cambronne, reviewed at http://wp.me/p4pKmM-ws;
Nature Wars: The Incredible Story of How Wildlife Comebacks Turned Backyards Into Battlegrounds, by Jim Sterba, reviewed at http://wp.me/p4pKmM-wm;
Witch hunts & wildlife, http://wp.me/p4pKmM-kV.
Please donate to support our work: http://www.animals24-7.org/donate/