The Natural Georgia Series: Atlanta's Urban Wildlife
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The Natural Georgia Series: Atlanta's Urban Wildlife |
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The
Natural History of AtlantaPerhaps no city in the United States can rival Atlanta for its trees and diversity of habitats. Atlanta is reported to have more trees than any other major city in the United States, yet we are also reported to clear and develop more land than any other major city in the United States. At some point Atlanta will lose its status as the "City of Trees" unless something changes.
As Atlanta nears the next century, what has happened, and what is going to happen to the city's natural history? Will unplanned development continue to erode away Atlanta's natural diversity? Will our remaining unspoiled landscapes turn into nothing but isolated islands, unconnected forest fragments of habitats that previously existed? Atlanta has kept many of its original natural characteristics, some plants and animals are adapted for coinhabiting habitats with humans. Other species are slowly being crowded out.
Atlanta is situated in the regional landscape called the Piedmont or foothills of the Appalachian Mountains. The Piedmont is characterized by hilly topography and a variety of ecosystems, from the exposed rock surfaces and rocky, shallow soils of the granite outcrops to the few relic mature oak-hickory-poplar hardwood forests. The Piedmont extends almost 1,000 miles from New York to Alabama. The elevation ranges from about 500 feet above sea level to about 1,000 feet. The Atlanta area ranges in elevation from about 850 feet to 1,100 feet with a few mountains that are 300 to 800 feet higher. The rocks of the Piedmont are mainly metamorphic with complex structures. Most of the rocks are classified as gneiss and schist with some pockets of marble and quartzite. There are many mineralogical varieties of these rocks, but it is these metamorphic rocks that make up the original or country rock.
About 20 percent of the Piedmont province is comprised of granite. The granite features are the result of igneous intrusions (magma cooling beneath the land's surface and then being exposed as the result of millions of years of erosion of the less-resistant overlaying metamorphic rocks). Stone, Panola, and Arabia mountains were all formed independently in this basic manner. (Arabia Mountain consists also of remelted gneiss called migmatite.)
The Piedmont is known for its old, highly weathered, fairly nutrient-poor soils. Past farming practices have accentuated this problem, as much of the organically formed topsoil has been eroded away during the past two centuries.
Vegetation in Atlanta is predominantly pine with mixed hardwood species. The climax forest, or final stage in ecological succession, of this region is a deciduous hardwood forest. This habitat, however, includes a wide diversity of forests.
Much of the landscape is dominated by pine forests, primarily Loblolly Pine (Pinus taeda), but in more xeric ridges and poorer soils, Shortleaf Pine (Pinus echinata) is common. In the extreme northern sections of metro Atlanta, a few Virginia Pines are also present. Roadsides feature diverse vegetation, from wild plums, ash, mimosa, and black locust to old field grasses to planted dogwoods, crepe myrtles, and redbud trees.
The history of this region is one of constant and substantial human disturbance including periods of extensive agriculture (1820–1930), forestry, and most recently, urban development (1960–present). The area that later would become Atlanta has had a long history of human inhabitation. When the first European explorers reached the upper Piedmont of Georgia, it was already inhabited by Creek Indians, also known as the Muskogee. This inhabitation extended into the early 1800s. The Decatur area, for instance, was treatied over from the Creeks in 1820. Many people assume that Native Americans left the forests virtually untouched; however, this is not true. Native Americans cleared, farmed, and burned the landscape of Georgia, in some areas greatly impacting and changing the natural landscape. In the Atlanta area, indigenous populations apparently never attained sizable numbers. Therefore, their influence on the present Atlanta landscape probably was minimal.
The 1830s to the 1930s was the time of great expansion of agriculture in the Georgia Piedmont. Cotton was king, and virtually any place flat enough to plow was under agriculture. Large patches of forests were cleared, and where fields were not flat they were terraced. Opening up these great expanses of fields exposed soils to erosion and leaching of soil nutrients. In only a hundred years, most of the original topsoils, reported to be several feet thick, washed down into streams.
Finally, in the 1930s the soils played out. The Atlanta area farms ran dry, soils were poor, and farming shifted elsewhere. The small farms went bankrupt, and many fields were abandoned. Pines quickly reclaimed most fields, and forestry became the agriculture of the Piedmont. Pines could survive in the poor soils, and the Piedmont gradually reforested.
From 1930 to 1960, Atlanta slowly grew from a primarily suburban and rural city to a large urban city. The real exponential growth took place from 1965 to present. This period of time saw tremendous residential, industrial, and transportation growth. Atlanta became the great international city that it is today. This expansion eliminated many of our trees, changed drainage patterns, increased impermeable surfaces, and fragmented and isolated habitat patches. Much of Atlanta's growth has been unplanned and continues to give little regard to the environmental outcomes. Only recently, with news stories of Chattahoochee sewage spills and poor air quality, have Atlantans slowed down enough to consider the consequences of our rapid, unplanned population growth.
The area of greater Atlanta represents a mosaic of habitats. Many small forest fragments are separated by areas of residential and intensive industrial development. Some development retains much of the integrity of the past forest while other areas have greatly altered the terrain.
All of the terrestrial ecosystems of Atlanta fall under the landscape of pine to deciduous forests. The dominant vegetation in areas that have been undisturbed is the oak-hickory-poplar forest. What we see, however, is many areas in various stages of recovery from past disturbances. Recently disturbed areas start recovery with a grass stage first dominated by the pioneer species, crabgrass. This is a very short-lived stage of forest recovery or succession. We often see examples of this stage in cleared land that is abandoned and along roadsides where periodic mowing helps to maintain this stage. If left undisturbed, the grass stage progresses to the grass shrub stage dominated by blackberry (Rubus sp.) and broomsedge (Andropogon sp.). If the habitat is large enough, Eastern Cottontail Rabbits, box turtles, Hispid Cotton Rats, doves, and quail can be found.
The first trees that dominate a disturbed area are pines. Why? The pines are tolerant of dry conditions and full sunlight. Their needlelike leaves with a thick, waxy covering allow them to tolerate desiccation. Pines dominate for many years, but after they form a closed canopy, hardwoods are able to colonize the understory. As seedlings and saplings, these broadleafed trees need the shelter of a canopy; therefore, they are shade tolerant. As pines finally succumb to ice storms, windfall, pine bark beetles, or old age, the understory hardwoods replace them, first forming a mixed forest, then a hardwood forest. Forests around Atlanta with large oaks and hickories must have been relatively undisturbed for over 100 to 150 years.
Atlanta consists of a variety of habitats. What habitat exists in any land area is dependent upon many factors: past land use, human disturbance, and microhabitat factors such as soil depth, soil moisture, available nutrients, shade, and canopy coverage. The areas of Atlanta form a patchwork of habitats, some very natural looking, others dominated by human architecture. Following are descriptions of some of the more common habitats found in the Atlanta metropolitan area.
Downtown habitat: Downtown Peachtree Street, at first glance, looks like a concrete jungle devoid of all flora and fauna except an occasional planted oak or dogwood, many humans, and an occasional dog. A closer inspection reveals pigeons, English or House Sparrows, grassy parks, and lawns. Yes, life is greatly altered, but some species have adapted. In fact, most urban species are dependent on humans. The pigeon (Rock Pigeon) and House Sparrow pick up or beg for our food scraps. Starlings and grackles do the same. At night, hidden in the alleys, storerooms, and attics are mice and rats. These generalist animals have learned to exist in cities by taking advantage of humans for food and shelter. All of the above mentioned animals are nonnative species that have invaded cities throughout most of the world. Pigeons, Starlings, and House Sparrows rarely nest in trees, but instead choose billboards, signs, and the eaves of buildings and houses.
Exotic species are introduced in urban areas, both intentionally and unintentionally, for a variety of reasons. The English or House Sparrow, Passer domesticus, was intentionally introduced into Brooklyn, New York, from Europe in 1853 in an attempt to control an outbreak of Snow-linden Moths (Ennomos subsignarius) that were defoliating trees. Starlings were introduced in the 1890s in Central Park, New York, by an eccentric Shakespearean scholar, Eugene Schieffelin, in an attempt to introduce all the birds mentioned in the works of Shakespeare.
Other animals wander into the urban habitat. The old trees of historic landmarks and established neighborhoods afford habitat for squirrels, flying squirrels, woodpeckers, and bats. Several years ago, a large branch fell from one of the large oaks at the Capitol building. Within the hollow of the branch was a sleeping Hoary Bat. This uncommon bat had apparently decided to overwinter in downtown Atlanta.
We have to think small, not large, when dealing with restricted, highly visible habitats. Mowed grass lawns and parks harbor hordes of microarthropods. Small millipedes, centipedes, beetles, springtails, and mites abound in this habitat. These small animals can then fall prey to spiders. The abundant House Spider inhabits these habitats, but additionally, the dangerous Black Window and Brown Recluse spiders are common in and around buildings.
Granite outcrops: Atlanta is home to some of the most unique and specialized habitats in the southeastern United States. "Granite" outcrops include various igneous and metamorphic rock formations where rock is exposed to the surface, not covered by soil. Some outcrops are simply exposed, flat rock surfaces (e.g. the Rock Chapel area and others in the Lithonia area) whereas others are impressive domes or monadnocks that rise 500 to 800 feet above the surrounding countryside (e.g. Stone, Panola, Kennesaw, and Arabia mountains). These habitats are characterized by shallow soils with low moisture-holding capacity and rapid runoff following rain. Limited growing substrate and soil nutrients, water extremes, and extremes in temperatures present plants and animals with a habitat much like a desert.
Plants and animals of the outcrop are often very specialized to the outcrop's stressful environment. Plants cope with these environmental limiting factors with several strategies: 1) Many plants are annual species, growing during favorable weather conditions, reproducing, and dying after the next generation is left in seed or spore to survive until the next year. 2) Some plants and lichens grow slowly, are long-lived, and are able to survive long periods of drought stress. 3) Another strategy involves specialized adaptations for water storage and protection. These include cacti that store water in their stems and have leaves modified into spines. The common cactus at the outcrops is the Prickly Pear (Opuntia sp.). Other plants store water in thickened leaves. A great example is the small, red sedum species, Diamorpha. Diamorpha (Sedum smalli) also synthesizes anthocyanins, giving it a bright red color that aids in protecting it against damaging radiation from the sun. The Woolly Ragwort (Senecio tomentosus) has fussy leaves that usually point upward, thus reducing solar heating and desiccation. Additionally, this plant contains dangerous cyanide compounds that protect it from insect herbivores which could cause great damage to a slow-growing outcrop plant species.
The granite outcrops really consist of three distinct habitats: 1) the primary successional communities associated with the bare rock weathering pits, 2) the ecotone area bordering the surrounding pine-hardwood forests, and 3) the shallow pool communities associated with a select few of the outcrops.
The stable plant communities exist as islands surrounded by exposed rock surfaces. Several plant communities have been described. Stages of primary succession follow a progression of plant development from the bare rock to a pine-hardwood stage. Most of the outcrops are in the bare rock-lichen stage, meaning they feature exposed rock surfaces covered to varying degrees by lichens (Xanthoparmelia conspersa) and a pioneer moss (Grimmia laevigata). Lichen is not a single organism but instead two, living in a symbiotic relationship. Lichen consists of a fungus species together with a cyanobacteria or an algae species. Lichens are photosynthetic, but they grow extremely slow. It has been estimated that some of the lichens on outcrops may grow only 1 to 2 square centimeters per 60 years.
Three endemic invertebrates are found on exposed rock: the Lichen Colored Grasshopper (Trimerotropis saxatilis), the Lichen Colored Spider (Pardosa lapidicina), and the omnivorous Orange And Green Beetle (Collops georgianus). If a soil depression forms (2 to 9 centimeters deep), the first colonizers form a stage called the Diamorpha stage. The dominant plant is a small annual species called Diamorpha (Sedum smalli). It begins growing in late fall or early winter and blooms in March, and by April only its dead stalks and seeds remain to grow again the next year.
The next stage is the lichen-annual herb stage. Soil in this stage is deeper (9 to 18 centimeters). Living plants are present all year. This stage is characterized by moss and reindeer lichen along with Confederate Daisies (Viguiera porteri). Following this stage there is the annual-perennial stage. This stage is characterized by many perennials such as broomsedge, spiderwort, Confederate Daisy, Carolina Jassamine, and greenbriar. The next stage is the herb-shrub stage. At this stage, the outcrop features most of the species from the previous stage with some shrubs, including Sparkleberry and Fringetree (Chionanthus virginica), and small trees, principally Loblolly Pine. The final stage, which also includes much of the surrounding edges or ecotones, is the pine-hardwood stage. This stage is dominated by Loblolly Pine but includes the diminutive Georgia Oak (Quercus georgiana), Sumac, Fringetree, Water Oak, Chestnut Oak, Red Cedar, and Optunia Cactus.
Several of the Atlanta outcrops (Arabia Mountain and Stone Mountain) support shallow vernal pools usually situated at the top. Growing in these pools are several of the rarest plants in the Southeast. Two are the endangered, fern allies, the Black Spore Quillwort (Isoetes melanospora) and Mat-forming Quilwort (Isoetes tegetiformans). Another is the delicate, threatened Snorkelweed or Little Amphianthus (Amphianthus pusillus).
Animals found in and around the outcrops are varied. Deer are seen with regularity especially early in the morning before humans venture out on the exposed surfaces. Secretive Bobcats, Gray Foxes, and Coyotes are regular visitors to the outcrops of DeKalb, Rockdale, and Gwinnett counties. In and around the outcrops, Fence Lizards are common, along with Black Racers and Coachwhip Snakes, their main predators. The Fowler's Toad is abundant, and occasionally its predator the Hognose Snake can be observed. This snake is a specialized toad eater with an unusual defensive behavior. When the little, nonvenomous Hognose encounters danger, it will first flare out its neck and act like a cobra. If this proves unsuccessful, it will turn over on its back and play dead. This two-act play usually so confuses a potential predator that the snake escapes unharmed.
Mixed pine-hardwood: Most of Atlanta falls into the habitat best described as a mixed pine-hardwood habitat. In most mesic habitats, the dominant trees are Loblolly Pines (Pinus taeda) being replaced by Shortleaf Pines (Pinus echinata) on drier, shallower soils of ridges. Older land parcels that have not been harvested or recently farmed often contain varying percentages of deciduous hardwoods such as Tulip Poplar, Sweetgum, hickories, and oaks. Many areas of Atlanta have maintained a nice canopy of tree species, but often the trees are thinned out and the native understory trees (save dogwoods) and shrubs removed. Residents like to plant nonnative azaleas, hollies, and evergreen shrubbery complemented by nonnative grass lawns. The grass lawns are usually maintained with lime, fertilizers, and pesticides. The trees maintain habitats for many of the bird and arboreal species, but many of the shrub- and ground-dwelling animals and native plants lose. Around houses and power lines, dead trees (snags) are removed and fallen leaves and branches picked up. These snags, if left, provide nesting, feeding, and living habitats for many species (e.g. woodpeckers and flying squirrels). When fallen leaves and logs are removed, the microhabitats for many small invertebrates and vertebrates, such as salamanders, are destroyed.
Atlanta is home to numerous amphibian species, but their habitats are shrinking and numbers are on a decline. Northern Georgia, especially the mountains, has the greatest biodiversity of salamanders in the world. Common species in Atlanta and surrounding areas are the Northern Slimy Salamander (Plethodon glutinosus), Red Salamander (Pseudotriton ruber), Spotted Salamander (Ambystoma maculatum), Northern Dusky Salamander (Desmognathus fuscus), Southern Redback Salamander (Plethodon serratus), Two-lined Salamander (Eurycea cirrigea), and Three-lined Salamander (Eurycea l. guttolineata). Some salamanders that are less common are the Eastern Newt (Notopthalmus viridescens), Mud Salamander (Pseudotriton montanus), Four-toed Salamander (Hemidactylium scutatum), the endangered Webster's Salamander (Plethodon websteri) (known in the Atlanta area only from a restricted area in Cobb County), and Seal Salamander (Desmognathus monticola) (a species common in the mountains but in Atlanta known only from Fernbank Creek).
Pine-hardwood habitats are home to many bird species, Opossums, rabbits, squirrels, flying squirrels, Raccoons, shrews, moles, voles, and mice. Even large birds such as Pileated Woodpeckers, Red-tailed Hawks, and Great Horned Owls share some pine-hardwood habitats with us. People have increased some species' chances of survival by feeding and providing bird houses and other unintentional nesting sites such as attics, hanging baskets, and shrubbery. Bird feeders have benefited birds such as Northern Cardinals, Blue Jays, finches, chickadees, Tufted Titmice, and nuthatches, as well as greatly helped Gray Squirrels, mice, rats, and Opossums. Our holly bushes and other ornamental shrubs have supported large populations of bird species such as Cedar Waxwings and Northern Mockingbirds.
Pine-hardwood forests left relatively undisturbed are home to many species of native wildflowers and other plants. Large concentrations of Yellow Lady Slippers still exist in Cobb, southern Fulton, and Douglas counties. Wild azaleas are common in and around creeks in this habitat. In small pockets of habitat, there are unusual plant species usually associated with the mountains such as the Silky Camellia (Stewartia sp.) in Gwinnett County and Carolina Silverbell (Halesia carolina) in DeKalb and Fulton counties.
Mesic hardwoods: In metro Atlanta, there are still several intact hardwood enclaves where no logging or farming have occurred. These have deep, rich, organic soils with a canopy comprised mostly of oak species (Northern Red, Southern Red, White, Black, and, to a lesser extent, Water, Scarlet, and Post), hickory species (Caryea sp.), and Tulip Poplar (Lireodendron tulipifera). Beech, Green Ash, Sourwood, Blackgum, and Musclewood (Carpinus caroliniana) are mixed with a rare Shortleaf Pine or Loblolly Pine. Shrubs in these mesic habitats include dwarf Pawpaw, Heart's-a-bustin' (Euonymus americanus), and Spicebush (Lindera benzoin).
An example of one of these relic old-growth forests is the Fernbank Forest reserve in Decatur. Within this forest, wildflowers such as Bloodroot, trillium, and Jack-in-the-pulpit and ferns such as Broad Beech Fern, Lady Fern, and Northern Maidenhair Fern are present. Secretive animals have a safe haven from the encroaching development. Mink have been seen in the last year, and flying squirrels, Raccoons, Shorttail Shrews, and Opossums are also common. This is one of the few spots where many neotropical migrant bird species still are afforded temporary stopover spots or summer nesting habitat. Birds such as the Gray-cheeked Thrush, Hermit Thrush, Scarlet Tanager, Summer Tanager, and Red-eyed Vireo can still be seen and/or heard. Other residents are Screech Owls, Barred Owls, and Great Horned Owls. Cooper's Hawks, Red-tailed Hawks, and kingfishers are seen on occasion. The thick leaf litter is home to countless insects, daddy-long-legs, spiders, centipedes, millipedes, salamanders, and fungus species. The cryptically colored, venomous Copperhead is relatively common in this habitat.
Old-growth forests are a snapshot of what the Piedmont habitat looked like before European settlers greatly used and abused this landscape. Many of the species are reminiscent of present mountain habitats. Other species have a more Coastal Plain flavor. With the exception of some of the outcrop species, the Piedmont harbors very few endemic species.
Moist ravines and bluffs: Bordering the Chattahoochee River, Sweetwater Creek, and other larger rivers in the Atlanta area are steep mesic slope forests. The rocky, steep terrain has allowed portions of this area to avoid agriculture and development. Much of this habitat looks like typical mountain habitat with Mountain Laurel (Kalmia latifolia), Partridgeberry, Galax, and Trout Lilies. These mesic slopes are home to northern tree species such as beech, Chalk and Sugar maple, and a few relic American Chestnut root sprouts. The ground often supports dense growth of ferns, in particular the Christmas Fern (Polystichum acrostieoides).
These habitats support the Gray Squirrel (Sciurus carolinensis), the Whitefooted Mouse (Peromyscus sp.), the Striped Skunk (Mephitis mephitis), the Eastern Chipmunk, and the rarely seen Long-tailed Weasel (Mustela frenata). White-tailed Deer frequent these habitats, if adjacent forested land provides more open browse habitat.
A prime example of this habitat is the forested slopes of Sweetwater Creek State Park in Douglas County and the national park scenic river areas along the Chattahoochee River in Fulton and Cobb counties. This represents some of the largest intact forested area in the Atlanta area.
Open water habitats: The Atlanta area has many creeks, streams, and rivers draining its multitude of watersheds. We have small creeks supporting small minnows, an array of aquatic insects, salamanders, and other wildlife. Most of these are our typical backyard creeks. Some are fairly pristine while others suffer from severe runoff erosion problems, sewage infiltration, and nonpoint-source pollution.
Our larger rivers suffer the same problems only on a larger scale. The Chattahoochee River north of Atlanta is a beautiful, fairly pristine river, in sections. Farther out of Atlanta is the Alcovy River with its large tupelo trees, Birdvoiced Treefrogs, and River Otters. These animals are more typically found in the Coastal Plain, with some species having their northern distributional limit in this portion of the Piedmont. The Alcovy supports a variety of aquatic insects, small fish, trout, and salamanders. Along its banks roam Raccoons, Mink, Muskrats, and Beavers.
Associated with these habitats are areas of freshwater marshes, such as are seen at and near the Chattahoochee Nature Center in Roswell. These backwater marshes serve as valuable waterfowl habitat and stopovers. Additionally, these marshes harbor many rare plant and animal species; act as buffers, holding excess waters and thus preventing flooding; and help to filter runoff before it enters the river. The marsh's prime wildlife habitat provides a home for many ducks and geese (Mallard Ducks and Canada Geese in particular but also Wood Ducks, and Blue-winged Teal), wading birds (Great Blue Herons, Egrets, and Green Herons), and Belted Kingfishers.
In the marsh, the dominant vegetation is emergent plant species including cattails, rushes, and sedge species. The bordering plants include alder, River Birch, Swamp Ash, buttonbush, and Jewelweed. One popular jogging trail near Powers Ferry Landing even supports a nice population of Poison-sumac!
Beavers have created many small isolated pockets of wetlands throughout the area. They dam up small streams, creating a flooded woodland that will soon progress into an open marsh. These isolated wetlands are incredible pockets of wildlife habitat. Some Beaver-created wetlands are small, isolated patches while others are quite extensive. South of the Atlanta airport, in the upper reaches of the Flint River, are some of the most extensive Beaver-modified wetlands in the state. I visited a small Beaver pond off North Druid Hills Road recently and saw almost 100 basking turtles (Yellowbelly Sliders and Painted Turtles), chorus frogs (Pseudacris crucifer and P. triserata), Southern Leopard Frogs with eggs (Rana utricularia), a pair of Mallards, and a pair of Canada Geese. All of this was observed as the rush hour traffic sat bumper-to-bumper on North Druid Hills Road.
Atlanta has an abundance of small ponds, lakes, and even several large reservoirs. These standing water habitats provide a different open water habitat. Many contain native fish, while others have been stocked with larger game fish. This mosaic of water habitats provides many stopover and feeding opportunities for waterfowl species. I have seen numerous Ring-necked Ducks, Buffleheads, Mallards, and Pied-billed Grebe taking advantage of Atlanta's numerous lakes during the winter months. Recently, I observed a male Northern Shoveler swimming about with a small group of Mallards in a little 2-acre pond off of Hairston Road near Stone Mountain. Canada Geese used to be uncommon migrants through Atlanta. A successful introduction project has firmly established a nonmigratory resident population at a level that has actually become a nuisance along Lake Lanier and many lakefront communities and golf courses. Canada Geese sure can produce large quantities of slippery excrement!
Probably the wetland habitat in greatest jeopardy in the Piedmont is the bottomland hardwoods. Bottomland hardwoods are usually associated with the large rivers of the Coastal Plain. Most of these habitats around Atlanta have been cleared and drained for shopping centers, residential housing, car dealerships, and other development. In Atlanta, these habitats are often characterized by Sweetgum, Red Maple, Tulip Poplar, and occasionally Sycamore. Barred Owls, hawks, Golden Mice, Mink, and watersnakes characterize this habitat. The best examples left of this habitat are associated with the great tupelo swamps of the Alcovy River.
Wetlands are not restricted to large natural or even intentionally constructed areas. Sometimes roads block or dam up water, creating seasonal wetlands or roadside ditches. These too are wildlife sanctuaries. Spring Peepers and Chorus Frogs abound in some of these habitats. Mosquitos, dragonflies, juncuses, and cattails can quickly become established in small habitats.
Xeric forests: Atlanta contains some rather xeric habitats or scrub growth in shallow soils or in drastically altered areas. Examples of this habitat can be seen in Gwinnett, DeKalb, Rockdale, and Henry counties. These well-drained or shallow soils are often associated with ridges that have adjacent mesic slopes which are covered with mesic hardwood species. In this habitat, scrubby vegetation such as Post Oak, Blackjack Oak, Southern Red Oak, Persimmon, and Blackgum are frequently observed. Drought-tolerant species such as Fence Lizards and Crowned Snakes (Tantilla coronata) can be encountered. The bird species often include Chuck-will's-widow and Whip-poor-will whose whistles can be heard at night. Dry environs with abundant surface cover are excellent habitat for spiders and scorpions.
Backyard habitats, schoolyards, and parks: We often overlook our own yards, schools, playgrounds, and golf courses as wildlife habitat. Much of Atlanta is now contained within this broad category of habitat. Virtually everyone has seen birds, squirrels, bats, and the occasional Raccoon or Opossum roaming their neighborhood. Are there things we can do to enhance our own yards and recreational areas to enhance their value for wildlife? Of course!
When building or developing areas, we need to retain as many trees and natural land features as possible. With a little additional planning, houses can be built fitting into natural landscapes. All too often the mode of construction is clear, grade the land flat, and come back later and spend large amounts of money planting trees to revegetate the area. Homeowners should carefully select plant species that are wildlife attractors–ones that provide cover, flowers, fruit, and seeds. Native plant species such as Beautybush and Fringetree are beautiful species that are very underutilized in landscaping. Native plants often resist drought and insects better than nonnatives, thus requiring less water, fertilizers, and pesticides. Provide feeding stations, houses, and, just as important, water features such as birdbaths and small ponds. Encourage schools and golf courses to incorporate wildlife habitats. A compromise is possible between wildlife and some of our recreational activities.
The greatest problem facing wildlife, in any habitat, is loss of suitable habitat. Diminishing habitat causes not only a reduction in species numbers but also a loss of biological diversity of species. Only so many individuals can live on a selected area of land.
Development changes habitat in a variety of ways. Cutting and clearing of trees removes a sheltering canopy and exposes the ground to more sunlight and drier conditions. Sometimes trees are left but understory is removed. This exposes animals to predators and removes food sources, nesting habitat, and shelter.
Cities create a myriad of other problems for native wildlife and flora. Wildlife must cope with the hazards of roads. Countless numbers of animals die each day trying to maneuver the blacktop hazards put in the path of their normal daily movements. Other obstacles such as tall buildings, communication towers, guide wires, and power lines take a tremendous toll on birds, especially during fall and spring migrations.
One of the most threatening problems facing our native species is the introduction of exotic or nonnative species. Nonnative plants such as English Ivy, Kudzu, Chinese Privet, Japanese Honeysuckle, Wisteria, Bamboo, and many less-visible species outcompete native species. Many of these species are bird dispersed. Birds will eat the fruit and later discard the undigested seeds miles from the seed source. Recent studies in Fernbank Forest have shown that English Ivy causes a loss of native wildflowers by shading and producing allelopathic chemicals that act as a pre-emergent and retard seedling growth. Kudzu is disrupting natural successional patterns on countless roadsides and disturbed sites around the Southeast.
Introduced animals are also greatly impacting native species. Birds such as Starlings and House Sparrows compete for food and habitat with native species. Norway and Black rats take over the habitat of several native rodents.
Some of the greatest damage to native wildlife is done by our beloved house cats. Pet cats and feral cats kill countless native mice, shrews, birds, lizards, snakes, chipmunks, and squirrels. Some studies indicate that these little furry loved ones kill and impact more wildlife than do automobiles!
As Atlanta continues its tremendous growth spurt into the next century, we need to focus on controlled, planned, sustainable growth. Simple adjustments in current development can be environmentally friendly. Incorporation of green space, retention of natural land contours, protection of habitat corridors along streams and rivers, and establishment of forest corridors connecting intact forests can all reduce the fragmentation of Atlanta's prized habitats. Paramount to all efforts is public education, for people only protect what they understand and love. If we raise a generation that does not treasure the outdoors and understand the value of protecting these precious habitats, we all lose.
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