extirpated species major causes of extinctions/extirpations –climate change (e.g., increased...

Extirpated Species

• Major causes of extinctions/extirpations

– Climate change (e.g., increased temperature during Holocene)

– Overharvesting (Pleistocene megafauna, modern game, furbearers)

– Habitat change/destruction (tallgrass prairie, wetland, forest)

Erithizon dorsatum(porcupine)

• Inhabited northeast Iowa hardwood forests

• Extirpated soon after Euroamerican invasion

• Still in southern Wisconsin

• Road kills in Clayton, Scott counties (1960s)

Canis lupus(gray wolf)

• Inhabited northern, western Iowa

• Last individual killed in Butler County (1885)

• Still in northern Minnesota

• Requires large forests or tundra, ungulates

Ursus americanus(black bear)

• Formerly statewide

• Extirpated by mid-1800s

• Still in Minnesota, Wisconsin

• At least 5 sightings since extirpation; 1997 in Allamakee County

Martes pennanti(fisher)

• Formerly rare in northern Iowa

• Extirpated by early 1800s

• Closest population in central Wisconsin

• Hunted for pelt; requires pine forests, porcupines

Gulo gulo(wolverine)• Formerly rare in

northeastern Iowa

• Extirpation date unknown

• Closest population

in northern Canada

• 1 in Tama County (1964)

Felis lynx(lynx)

• Formerly northern Iowa (coniferous forests); rare

• Extirpated in ?

• Still in northern Minnesota

• 1 in Shelby County (1963); avoids humans

Cervus canadensis(elk)• Formerly statewide

• Extirpated by 1871

• Reintroduced to Michigan, several other states

Alces alces(moose)

• First record in 1973 (not an extirpated species)

• Boreal species; unlikely to become established

• About 15 entered Iowa via Minnesota since 1973

Antilocapra americana

(pronghorn)• In western Iowa until

early 1800s

• In Nebraska, South Dakota, Minnesota

• Forbs (flowering, broadleaved herbs) essential in diet