Impact of habitat destruction on wildlife


Last updated: January 3, 2018

We humans can adjust to changes in our environment rapidly. If we should be forced out of our lodging or off our land most of us could move to another place that suits us. We’d immediately have some idea of what possibilities lay in the next neighborhood over or across town. Even in another state. We know where grocery stores can be found, full of food and beverages. And, because of automobiles, we can get there fast. Under ordinary circumstances, we can quickly locate retailers of everything we need for survival, even in an unfamiliar city.

But, what of wildlife?

When the habitat wildlife are adapted to disappears, where can they go? Except for birds and other flying animals, imagine the challenge of relocating to suitable habitat when your visual vantage point is only three feet above the ground, like that of a fox. Or just a few inches, like that of a chipmunk. Which direction should they go? Can they find food before they starve? Or a safe place to rest? And water — where’s water? The familiar place they were forced from was utterly familiar: The best hiding spot is under the old log behind the bushes. The creek is just around the bend to the left. Food is on the ground under the fruit trees that stand behind the small forest of pine trees on the other side of the hill.

Some animals manage to find suitable new locations. Others adapt to a new way of life, as the Northern Raccoon and Virginia Opossum have done so very well within cities. But, some animals never find their way to safety and sustenance. Others can’t adjust, their instincts and needs are so unalterable, they can’t substitute, say, a forest of pines for a forest of deciduous trees. Some bird species won’t breed except in a specific habitat — when their perfect habitat is destroyed, one-by-one they just die off.

What are the causes of habitat loss? Urbanization and development, timber cutting, agriculture, and fragmentation by roads and reservoirs. Native ecosystems, which developed their delicate balance over eons are disappearing at an estimated 6,000¹ acres per day in the U.S., as they’re dredged, drained, cleared, paved over, built upon or otherwise made uninhabitable for much of its historical wildlife.

Regarding the international impact of habitat loss, Wired.com² makes this strong statement: “…humans are Earth’s great omnivore, and our omnivorous nature can only be understood at global scales. Scientists estimate that 83 percent of the terrestrial biosphere is under direct human influence. Crops cover some 12 percent of Earth’s land surface and account for more than one-third of terrestrial biomass. One-third of all available fresh water is diverted to human use.

“Altogether, roughly 20 percent of Earth’s net terrestrial primary production, the sheer volume of life produced on land on this planet every year, is harvested for human purposes — and, to return to the comparative factoids, it’s all for a species that accounts for .00018 percent of Earth’s non-marine biomass.”

Aerial view of cookie-cutter neighborhood

Urban growth leaves wildlife homeless. (© Brad Driver / iStock)

Threatened and endangered species in the United States 
The U.S. Fish and Wildlife Service (USFWS), has a stated mission to help “conserve, protect and enhance fish, wildlife and plants and their habitats” and maintains a list of Threatened and Endangered² U.S. species. As of January 3, 2018, it lists 1,661 animal and plant species and subspecies as threatened or endangered. The list includes 102 birds, including species of warbler, tern, thrush, vireo, quail, the Whooping Crane, the Bald Eagle and the California Condor. Ninety-five mammals are on the list, including wolves, squirrels, rabbits, pumas, deer, caribou, foxes, jaguars, the Florida Panther, and whales. Forty-five reptiles are on the list, too, along with 272 invertebrates, which includes butterflies, snails, insects, and others. The tally for plants is 947, with 903 of those being flowering plants. 

A states-eye view
Here’s a quick look at some state statistics: California has 112 threatened or endangered animal species, Florida has 131, and Texas has 67. Kansas has 57; New York has 14, Oregon has 36 and Arizona has 44. You can find a list of the endangered species in your state or county here

Some endangered species and their stories

ATTWATER’S PRAIRIE CHICKENTympanuchus cupido attwateri, a ground-dwelling grouse, is nearly extinct due to the conversion of its coastal tallgrass prairie environment into farmland. Less than a hundred years ago, one million of these birds inhabited six million acres in Texas and Louisiana. Their habitat was destroyed acre-by-acre until, eventually, it was almost gone. The Attwater’s was extinct in Louisiana by 1919. By 1937 their population was down to 8,700 individuals in Texas.

Attwater's Prairie Chicken

Attwater’s Prairie Chicken. (George Lavendowski, USFWS; PD)

There now remains less than one percent of the original habitat. In 2016 there were 32 left in the wild, and the USFWS had 29 in a captive breeding program. Then, along came Hurricane Harvey in 2016, which wiped out all but five of the birds. Soon after, two more went missing. The only bit of good news to be had is that a few zoos have small populations of their own in ongoing captive breeding programs.

The OCELOT (Leopardus pardalis) is a spotted and striped wildcat native to the Southwest, Mexico and regions farther south. It’s endangered in the U.S. because of the loss of sub-tropical woodlands it calls home. What was once three million acres of coastal prairies and chaparral thickets has been reduced by 95 percent. An estimated 50 Ocelots are all that remain in the wild. Most of them live on the 45,000-acre Laguna Atascosa National Wildlife Refuge near Bayview, Texas.


Ocelot. (© matte6969 / iStock)

Territorial animals, young Ocelots go in search of a suitable territory of their own when they leave their mothers at about one year of age. Unfortunately, every year several of them are hit by cars as they cross roads within the refuge. The Ocelot requires a very wild, naturalized environment to survive and most of the area around the refuge has been stripped of vegetation. There’s no place else for them to go.

The WHOOPING CRANE (Grus americana) story is another tale of a large population that fell precipitously because of human activity — in their case, habitat destruction, along with over-hunting. Fossil evidence shows that the Whooping Crane dates back several million years and lived across the entire eastern half of the U.S., north into Canada and south into Mexico. 

However, by the 1890s most Whooping Cranes had been killed or driven away. The last nesting pair in the U.S. was seen in 1939, and by 1941 there were only 16 birds left in the flock. By 1950 the Whooping Crane was gone from within our borders.

Whooping Crane

Whooping Crane. (Eileenmak / Flickr; cc by 2.0)

Experimental captive-breeding programs were started by USFWS and a new flock was successfully re-introduced in 2001, bringing the number of flocks to two. The breeding program raises and releases more birds each year and the wild population is growing. As of 2015, USFWS counted 308 in the wild. Whooping Cranes summer in Canada and winter in Texas, migrating 2,500 miles each way every year. Their long-term survival is still not assured. During migration, which takes several weeks each way, they face weather hardships, illegal shooting, power lines, cell phone towers, predators, disease, and the continuing destruction and pollution of their winter refuge

The BLACK-FOOTED FERRET (Mustela nigripes), North America’s only native ferret species, is one of our most endangered mammals. Considered globally extinct in 1987, a group of seven was discovered in Wyoming in 1991. Since then, a USFWS captive breeding program, along with efforts by numerous groups, such as local agencies, Native American tribes, conservation groups and others has given Black-footed Ferrets a second chance for survival.

Black-footed ferret.

Black-footed ferret. (USDA; cc by 2.0)

They still remain fragile, however. Their primary prey, Black-tailed Prairie Dogs, have been eradicated by landowners and government-sponsored poisoning programs to near extinction themselves, with only two percent of their original abundance remaining. Additionally, less than two percent of the ferret’s prairie habitat remains, and it’s highly fragmented. This has resulted in a wide dispersal of the prairie dog towns, making it difficult for the ferrets to find them.

RED WOLVESCanis rufus, beautiful carnivores once common throughout the southeastern U.S., were down to 17 individuals by the 1980s due to habitat loss and comprehensive predator eradication programs. USFWS captured those remaining wolves and began a captive breeding program.

Captive Red Wolf.

Captive Red Wolf. (pdza_rw5 : Flickr; cc by 2.0)

There are now 50 to 75 wolves back in the wild, inhabiting five North Carolina counties, many of them in refuges and other protected areas. Another 200 are held in 38 captive breeding facilities across the U.S. Without these safeguards, Red Wolves living in the wild will become history. In 2017 the North Carolina Wildlife Resources Commission, at the request of private landowners, asked the USFWS to remove all Red Wolves that are on private land in their state. If that happens, the wolf population will drop once again.

The GRAY BAT (Myotis grisescens), a cave dweller, could possibly be affected by human encroachment. Unlikely as it seems, the bat is endangered throughout its range — Missouri, Kentucky, Tennessee, and nine other states. 

Small cluster of Gray Bats.

A cluster of Gray Bats. (Larisa Bishop-Boros / Wiki; CC BY-SA 3.0)

There are about one million Gray Bats, but 90 percent of them hibernate in only eight caves. So, a disturbance, even if only in one cave, affects a huge number of them at once. The opening of many of the bats’ caves to the public, leading to excessive harassment and loss of their young, disturbances from cave exploration, the flooding of caves through dam-building, and disturbing them during hibernation have been their main challenges. The Gray Bat population had declined by an estimated 50 percent by the year 2000, most of the loss occurring during the last part of the twentieth century

Other wildlife, too
In the U.S., there are 165 species of threatened and endangered fish. They haven’t suffered so much from the loss of habitat as from its misuse: pollution, climate change, blockage of migration, negative consequences of water management and, in some cases, non-native species that have been introduced and are decimating native fish populations.

Coho Salmon, Oncorhynchus kisutch

Coho Salmon, Oncorhynchus kisutch, endangered because of deterioration of their freshwater habitat caused by humans (BLM; cc by 2.0)

On a worldwide basis, an estimated 90 percent of all large ocean fishes are now gone, the result of habitat loss and overfishing. A 10-year study by Dalhousie University in Halifax, Nova Scotia reveals there’s no part of the ocean that hasn’t been over-fished. Nations have moved to curb the decline through fishing restrictions, but considerable illegal fishing goes on and it appears to be an uphill fight.

Around the world, there are 207 species of turtles and tortoises. The highly regarded International Union for Conservation of Nature (IUCN) lists 129 of them as vulnerable, endangered, or critically endangered.

Red-bellied Cooter turtle

Northern Red-bellied Cooter, Pseudemys rubriventrisan, endangered because of habitat loss and fragmentation caused by human development. (cuatrok77 / Flickr; cc by-sa 2.0)

Also deserving mention are 592 species of reptiles, amphibians, insects, spiders, clams, crustaceans, snails and corals.

Karner Blue Butterfly, Lycaeides melissa samuelis

Karner Blue Butterfly, Lycaeides melissa samuelis, endangered because Wild Blue Lupine, a plant it depends on is now endangered. (Joel Trick, USFWS; cc by 2.0

Scientists warn us that the complete loss of too many species, or even a drastic reduction in their populations, may have an unforeseen disastrous effect on humans later. Earth has had numerous extinction events, both large and small, during the hundreds of millions of years since life first appeared. But, always before there has been intervening time for it to recover its biodiversity. On a moral level, there’s also the issue of whether it’s right to wipe out other species because they inconvenience us, or for sport.

Plants are crying out, too
Plants don’t take on the tragic aura of animals, especially when they’re milkweeds, clover and a remote orchid, as shown below. But, there are many more than that. Globally, 14 percent of rose species, 32 percent of lilies, 32 percent of irises, 14 percent of cherry species and 29 percent palms are among the plants most at risk. The United States has more species of plants threatened with extinction than any other country — 947.

How did this happen? In much the same way humans have impacted animals — the conversion of wilderness to agricultural land, development, logging, and the unwise introduction of alien species that crowd out native species.

Think about how vital plant life is to humans. Some 3,000 species of plants have been used for food. Of the top 150 medicines today, 87 are based on plants. Experts believe that genes from even more plants may lead to the medicines of tomorrow, but only if they’re still around. Plants, also, have industrial importance — they provide fibers for clothing, wood for building and burning, and fuel, such as corn ethanol and soy diesel.

Plants provide oxygen through photosynthesis. Their foliage traps dust and pollutants, and they intake carbon dioxide, which helps lessen the greenhouse effect. They control erosion. And, of course, they provide food, hiding and nesting places for wildlife. Water plants provide cover and habitat for spawning fish, as well as help to filter sediments and keep water clean.

Their aesthetic value would be a loss, too: Who hasn’t been awed by the beauty of a field of wildflowers, of tropical foliage nestled under a canopy of majestic trees draped with moss, of grasses waving in a soft breeze, or even a precisely symmetrical formal garden?

The DWARF BEAR-POPPY inhabits small areas in Utah, including cities. It’s endangered because of habitat loss.

Dwarf Bear-poppy, Arctomecon humilis, endangered species

Dwarf Bear-poppy, Arctomecon humilis, endangered. (Stan Shebs – Wiki; cc by-sa 3.0)

The WESTERN PRAIRIE FRINGED ORCHID inhabits a range extending from southeastern Manitoba, Canada to Kansas. It’s a tall native of tallgrass prairies that prefers an alkaline and stony but slightly moist soil. It’s threatened by conversion, overgrazing, intensive mowing, water drainage, competition from introduced species and herbicides.

White Prairie Fringed Orchid, Platanthera praeclara, endangered.

White Prairie Fringed Orchid, Platanthera praeclara, threatened. (Justin Meissen / Flickr; cc by-sa 3.0)

MEAD’S MILKWEED is a host plant for Monarch Butterflies. It’s either endangered or threatened throughout its range. An herb characterized by a drooping stem, it has large, greenish-cream flowers tinged with purple. It grows on dry prairies and chert-lime glades.

Mead's Milkweed, Asclepias meadii, threatened species

Mead’s Milkweed, Asclepias meadii, threatened. (Jay Sturner / Flickr; cc by 2.0)

Around the world today there are 19,817 species threatened with extinction, according to the latest IUCN Red List of Threatened Species (2012). Two out of every five known species on earth faces extinction in the foreseeable future. This includes one in eight birds, one in four mammals and one in three amphibians. All total, 784 species have become extinct since record-keeping began. Just since 1975, 19 species of birds have become extinct, bringing the total of extinct birds to 80 since 1900. The most recent is the Po’ouli, a Hawaiian bird, in 2004.

We can ensure that plants and animals stop disappearing as a result of human actions, through communal, concerted effort. Many expert groups around the world are trying. We can personally help slow the extinction rate by doing what we can, where we can: Donate time and money to conservation groups; contact political leaders and influential businesspeople; and create backyard wildlife habitats, where, under our own stewardship, wildlife and native plants will be safe.


Passenger Pigeon
No extinction has been more dramatic than that of the Passenger Pigeon (Ectopistes migratorius). When Europeans first arrived in North America an estimated three-to-five billion Passenger Pigeons blanketed the continent. They darkened the skies. 

Martha, the last Passenger Pigeon,

Martha, the last Passenger Pigeon, died in 1914. (PD)

John James Audubon, the famous naturalist, wrote of watching a flock in 1813 that passed overhead for three full days.

It seems inconceivable that such an enormous population could go extinct, but the forests they depended on for nuts and berries were turned into farmland, and the pigeons were killed for food and their feathers. And, particularly for sport — hunters would fill wagonloads of pigeons during organized shoots.

The last wild one was shot in Ohio in 1900 and the last captive pigeon, named “Martha,” died in 1914. She was named after President George Washington’s wife.

Ivory-billed Woodpecker
The Ivory-billed woodpecker (Campephilus principalis) had been considered extinct for 60 years due to the destruction of most of the forests it lived in, until April 2004, when one — just one — was reportedly seen in a deeply forested area of Arkansas.

Ivory-billed Woodpecker photo taken in 1935 by Arthur A. Allen

Ivory-billed Woodpecker photo taken in 1935 by Arthur A. Allen. (Colorized by Jerry A. Payne, USDA Forestry Service; cc by 3.0)

Extensive organized searches in the area since then have turned up nothing and the sighting is now considered by most to have been a misidentification of a similar woodpecker. 

Dusky Seaside Sparrow
The saga of the Dusky Seaside Sparrow (Ammodramus maritimus nigrescens) is another illustration of the effect of thoughtless human actions on a species. The Dusky was a black-and-white shorebird that lived exclusively on the central Atlantic coast of Florida and on Merritt Island, which is situated just off the coast, between Cocoa and Cocoa Beach, Florida. The Dusky depended on cordgrass (Spartina bakerii) habitat for nesting. The cordgrass required a very specific habitat in order to grow — wet, but not too wet.

The last Dusky Seaside Sparrow

The last Dusky Seaside Sparrow, Ammodramus maritimus nigrescens, was called Orange Band. When he died on June 17, 1987 his species became extinct. (USFWS; CC)

In 1963 nearby Kennedy Space Center attempted to control a mosquito-breeding problem by flooding the sparrows’ marsh, without trying to preserve habitat for any of the species that depended on it. This action, along with the use of the insecticide DDT, effectively destroyed the population of Dusky Seaside Sparrows.

But then, seemingly good news! Another population of the sparrows was discovered in a different marsh that had cordgrass. This time, concerned parties convinced the USFWS to purchase the land and protect it as a nature reserve. Regardless of this, the Florida Department of Transportation was allowed to build a highway through the reserve as a connection from Disney World to the Kennedy Space Center and, ultimately, the last of the marsh was drained for real estate purposes.

The Dusky had no place left to go. A belated effort was made in the mid-70s to turn part of the area back into a marsh, but it proved to be too late for the little sparrows. In 1979 and 1980 the few remaining Dusky Seaside sparrows were captured, five of them, all male, and introduced into a crossbreeding program with a similar species. The program eventually failed and through the years, one by one, the birds died. The last Dusky, called “Orange Band,” died in 1987.
Listen to a Dusky’s call 
More about the Dusky 
Robert James Waller’s essay on Orange Band

What will our world be as time goes by and we have more extinctions and fewer species? Ecologists suggest that the more you simplify systems of living organisms the less stable they become. That means you’re more likely to have massive die-offs, starvations, loss of additional species, increase of pests, all kinds of things. So the greater diversity, usually the more stable…to sustain human life that’s what we want, a stable system. — Robert Glotzhober curator natural history, Ohio Historical Society

¹U.S. Fish & Wildlife Service
²‘s source for this data comes from The Encyclopedia of Earth.

* Some states maintain their own list of threatened or endangered species, which may include species not federally listed.