The Animals Of Iowa

Section 01

The Most Altered Landscape In America

Iowa has been transformed more completely than any other state. Roughly 85 percent of its land is now in agricultural production, and the figures for what was lost are stark: about 99.9 percent of its tallgrass prairie is gone, along with roughly 95 percent of its wetlands and nearly all of its original forest along the rivers.

The reason is the same as in Illinois but more extreme. Iowa sits on some of the deepest, most productive topsoil on the planet, built by thousands of years of prairie growth and glacial deposition. Once the steel plough and tile drainage arrived, converting it was almost inevitable.

The consequences for wildlife were severe and specific. Bison, elk, wolves, cougars, black bears, and passenger pigeons were gone by the late 1800s. Prairie chickens, once so numerous they were shipped to eastern markets by the barrel, were extirpated as a breeding bird. Iowa lost more of its original habitat than any other state and consequently has one of the smallest remaining sets of intact natural communities.

What survives is concentrated in three places. The Loess Hills along the Missouri River in the west are wind-deposited silt bluffs up to 200 feet deep, a formation of that scale found in only one other place on Earth, in China, and they hold dry prairie remnants with western species. The Driftless Area in the northeast escaped the last glaciation and retains cold spring-fed streams, limestone bluffs, and algific talus slopes that hold ice year-round and shelter Ice Age relict species. And the Missouri and Mississippi river corridors on either border remain major flyway routes.

Section 02

Iowa's Official State Animals

If Iowa were choosing a state mammal today the obvious candidate would be a species it has actually recovered. The state's most striking wildlife success is the trumpeter swan, North America's largest waterfowl, which was extirpated from Iowa by 1883 and reintroduced beginning in 1993. Iowa now has a self-sustaining breeding population, rebuilt from captive stock over three decades.

Section 03

Habitats By Region, And Who Lives In Each

1. Loess Hills, western border

Steep wind-deposited silt bluffs along the Missouri River, holding Iowa's best dry prairie. Because they are too steep to plough, the hills preserve species that vanished elsewhere: plains spadefoot toad, great plains skink, prairie rattlesnake at the northeast edge of its range, ornate box turtle, and western species like the western meadowlark. Bison and elk have been returned to Broken Kettle Grasslands as management animals.

2. Prairie pothole region, north-central Iowa

The southern tip of the vast North American pothole country, where retreating glaciers left thousands of shallow depressions. Most were drained, but the remaining and restored wetlands are disproportionately valuable: they are among the continent's most productive duck breeding habitat. Blue-winged teal, mallard, northern shoveler, black tern, Wilson's phalarope, and yellow-headed blackbird all breed here.

3. Des Moines Lobe and central farmland

The flattest and most intensively farmed part of the state, a young glacial landscape drained by an extensive tile network. Wildlife survives in road ditches, grassed waterways, terraces, and conservation reserve fields. Ring-necked pheasant, white-tailed deer, coyote, and red fox are the common large animals.

4. Driftless Area, northeast Iowa

Unglaciated bluff country with cold, spring-fed trout streams, limestone cliffs, and algific talus slopes where cold air vents from ice-filled fractures year-round. Those slopes hold the Iowa Pleistocene snail, a species that survived the Ice Age in place and lives nowhere else, plus the northern monkshood plant. Also present: timber rattlesnake, bobcat, brook trout in a few headwaters, and cliff-nesting peregrine falcons.

5. River corridors and southern hills

The Mississippi and Missouri floodplains hold backwater lakes, sloughs, and bottomland forest, with bald eagles wintering below the locks and dams in large numbers, plus American white pelicans, wood ducks, and river otters. Southern Iowa's rolling hills carry more pasture and oak-hickory woodland than the rest of the state, which is where most of the recovering bobcat population lives.

Section 04

Mammals Of Iowa

Iowa has around 60 mammal species. As in Illinois and Indiana, the story is total loss of large animals followed by recovery of mid-sized ones.

• White-tailed deer: extirpated by about 1898 and restocked in the 20th century. Now several hundred thousand, and the leading wildlife management issue in the state.
• Bobcat: effectively gone by 1900 and considered extirpated for much of the century. Natural recolonisation from Missouri rebuilt the population through the 1990s and 2000s, and a regulated season now exists in southern counties.
• River otter: extirpated, then reintroduced between 1985 and 2003 with animals from Louisiana. Otters are now present in every county and were removed from the state list.
• Beaver: trapped out by the mid-1800s, now common in nearly every watershed.
• Coyote, red and gray fox, mink, long-tailed weasel, badger, striped and spotted skunk, raccoon, opossum, woodchuck, fox and gray squirrel, thirteen-lined ground squirrel, muskrat, eastern cottontail, jackrabbit: all present. The spotted skunk has declined severely and is a state endangered species.
• Prairie dogs: historically present in the far west and now absent as a wild colony, existing only where reintroduced.
• Bats: nine species, with Indiana bat and northern long-eared bat federally listed and white-nose syndrome causing sharp declines.
• Bison and elk: only as conservation herds, notably at Broken Kettle Grasslands and Neal Smith National Wildlife Refuge, where their grazing helps restore prairie structure. Related: why bison vanished.

Absent as breeding populations: gray wolf, cougar, and black bear. All three now appear as occasional dispersers, and Iowa confirms cougars and the occasional bear moving through from western or northern populations.

Section 05

Birds Of Iowa

More than 425 species have been recorded. Iowa sits squarely in the Mississippi Flyway, and its two border rivers do most of the work.

• Waterfowl and waterbirds: prairie pothole wetlands breed large numbers of dabbling ducks, and the river corridors stage snow geese, canvasback, lesser scaup, and tundra swans. American white pelicans have become abundant migrants within recent decades.
• Trumpeter swan: the flagship recovery. Extirpated by 1883, reintroduced from 1993, and now breeding across the state after a thirty-year effort.
• Bald eagle: reduced to no known nests in the mid-20th century, now nesting in most counties, with major winter concentrations at Mississippi lock and dam sites.
• Grassland birds: the group that suffered most. Greater prairie-chicken was extirpated as a breeder and reintroduction attempts in southern Iowa have struggled. Henslow's sparrow, bobolink, dickcissel, upland sandpiper, and grasshopper sparrow all depend on the small grassland base and on conservation reserve fields, which fluctuate with farm policy.
• Sandhill cranes: absent as breeders for a century, they returned to nest in Iowa in 1992 and have expanded since, a quiet success story.
• Others: eastern goldfinch (the state bird), ring-necked pheasant, wild turkey restored to all counties, peregrine falcons on Driftless cliffs and city buildings, and red-shouldered hawk in bottomland forest.

Iowa's grassland bird decline is worth understanding as policy rather than nature. Most of the state's remaining grassland is enrolled in the federal Conservation Reserve Program, which pays farmers to keep marginal land out of crops. When commodity prices rise, enrolment falls and fields return to row crop, and bird populations follow within a season or two. Henslow's sparrow and bobolink numbers in Iowa therefore track farm economics more closely than they track weather or predators, which makes them among the few American birds whose abundance is set largely in Washington.

Section 06

Reptiles, Amphibians, And Fish

Iowa has around 45 reptile and 20 amphibian species. Four snakes are venomous, all rare.

Snakes: about 27 species. The venomous four are timber rattlesnake and eastern massasauga (both state endangered or threatened and confined to small areas), prairie rattlesnake in the Loess Hills, and copperhead in a few southeastern counties. Bites in Iowa are extremely rare.

Turtles: Blanding's turtle, ornate box turtle, wood turtle, yellow mud turtle, and smooth softshell are all species of concern, alongside common painted, map, and snapping turtles. Iowa's turtles have declined from habitat loss, road mortality, and commercial harvest, which the state has moved to restrict.

Amphibians: tiger salamander, mudpuppy, central newt, plus crawfish frog, plains spadefoot, Blanchard's cricket frog (declining sharply), and around a dozen other frogs and toads.

Fish and mussels: roughly 150 species. The Driftless streams hold brook, brown, and rainbow trout, and the border rivers hold paddlefish, lake sturgeon, shovelnose sturgeon, and a significant mussel fauna including the federally endangered Higgins eye pearlymussel in the Mississippi. Silver and bighead carp are established in both border rivers.

The Iowa Pleistocene snail deserves separate mention: a tiny land snail that survived the last Ice Age on algific talus slopes in the Driftless Area, living in the cold air venting from underground ice. It exists in a few dozen sites in Iowa and adjacent states and nowhere else on Earth.

Section 07

Dangerous Animals In Iowa

• White-tailed deer: overwhelmingly the most dangerous animal in Iowa, causing thousands of vehicle collisions annually with regular fatalities.
• Venomous snakes: four species, all rare and localised. Two are themselves protected as state endangered or threatened.
• Ticks and mosquitoes: Lyme disease is expanding in eastern Iowa, and West Nile virus is established statewide.
• Brown recluse and black widow spiders: both present in the south, both reclusive.
• Livestock: worth naming honestly in an agricultural state. Cattle and hogs cause more serious human injuries in Iowa than all wild animals combined.
• Rabies: bats and skunks are the main vectors.

Section 08

Endangered And Protected Species

Iowa is the clearest illustration in the country that habitat conversion, not persecution or pollution, is the primary driver of wildlife loss. With 99.9 percent of prairie and 95 percent of wetlands gone, conservation here is almost entirely restoration rather than preservation. Neal Smith National Wildlife Refuge, which is rebuilding tallgrass prairie and oak savanna from cropland on a landscape scale, is the flagship attempt.

Section 09

Where To See Wildlife In Iowa

• Neal Smith National Wildlife Refuge: bison and elk on restored tallgrass prairie near Des Moines, plus grassland birds.
• Loess Hills and Broken Kettle Grasslands: the state's best prairie, with bison, prairie rattlesnakes, and western species.
• Effigy Mounds and the Driftless bluffs: timber rattlesnakes, peregrines, and Ice Age relict habitats.
• Union Slough and Prairie Pothole wetlands: breeding ducks, terns, and marsh birds in spring.
• Mississippi River locks at Guttenberg and Dubuque: wintering bald eagles in large numbers.
• DeSoto and Boyer Chute National Wildlife Refuges: Missouri River bottomland, snow geese, and pelicans.
• Yellow River State Forest and Iowa's trout streams: cold-water species and Driftless forest birds.