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Southwest Region

Species and Description
(click for a detailed technical account)
(click to view literature citations and larger graph)
(current and historic range)
Utah prairie dog
Cynomys parvidens The Utah prairie dog declined due to habitat loss to livestock and agriculture, a deliberate poisoning campaign, sylvatic plague, and drought. The species has rebounded from just 3,300 individuals in 1972 to an estimated at 9,332 individuals by 1981.

UT(b) ---

Arctic peregrine falcon
Falco peregrinus tundrius
The use of DDT and other organochlorine pesticides resulted in reproductive failures in Arctic peregrines and caused their population to plummet. After DDT was banned, migration counts at the New Jersey Cape May Hawkwatch site saw the number of migrating Arctic peregrines increase from 103 in 1976, to 429 in 1992 (the species was delisted in 1994), to 1,017 in 2004.

AL(m), AK(b), AZ(m), AR(m), CA(m), CO(m), CT(m), DE(m), DC(m), FL(m), GA(m), ID(m), IL(m), IN(m), IA(m), KS(m), KY(m), LA(m), ME(m), MD(m), MA(m), MI(m), MN(m), MS(m), MO(m), MT(m), NE(m), NV(m), NH(m), NY(m), NM(m), NJ(m), NC(m), ND(m), OH(m), OK(m), OR(m), PA(m), RI(m), SC(m), SD(m), TN(m), TX(m), UT(m), VT(m), VA(m), WA(m), WV(m), WI(m), WY(m) ---

Whooping crane
Grus americana
The whooping crane declined precipitously in the late 1800's and early 1900's due to hunting and habitat loss. It rebounded from 54 birds (48 wild and 6 captive) when listed as an endangered species 1967 to 513 (368 wild and 145 captive) in 2006.

CO(m), FL(b), GA(m), IL(m), IN(m), KS(m), KY(m), MT(m), NE(m), ND(m), OK(m), SD(m), TN(m), TX(s), WI(b), WY(m) --- AL(x), AR(x), DE(x), DC(x), IA(x), LA(x), MD(x), MN(x), MS(x), MO(x), NJ(x), NC(x), OH(x), SC(x), UT(x), VA(x), WV(x)

American peregrine falcon
Falco peregrinus anatum
The use of DDT and other organochlorine pesticides resulted in reproductive failures in American peregrines and caused populations to plummet. After DDT was banned, the number of American peregrine pairs breeding in the U.S. increased from 324 in 1975 to 1,700 in 2000; the species was delisted in 1999.

AL(m), AK(b), AZ(b), AR(m), CA(b), CO(b), CT(b), DE(b), DC(m), GA(b), ID(b), IL(b), IN(b), IA(b), KS(m), KY(b), LA(m), ME(b), MD(b), MA(b), MI(b), MN(b), MS(m), MO(m), MT(b), NE(b), NV(b), NH(b), NY(b), NM(b), NJ(b), NC(b), ND(m), OH(b), OK(m), OR(b), PA(b), RI(b), SC(b), SD(b), TN(b), TX(b), UT(b), VT(b), VA(b), WA(b), WV(m), WI(b),

California condor
Gymnogyps californianus
The California condor had declined to just nine individuals in 1985 due to DDT, lead poisoning, and hunting. A successful captive breeding and reintroduction program has increased the 2005 wild population to 121 and the captive population to 158.

AZ(b), CA(b) --- NV(x), OR(x), UT(x), WA(x)

Black-footed ferret
Mustela nigripes
As many as 5.6 million black-footed ferrets once occurred throughout the grasslands and basins of interior North America, but were widely extirpated with the elimination of prairie dogs nationwide. The ferret was thought to be extinct in 1980, but reintroductions from a single population in Wyoming have led to 400 ferrets in the wild in 6 states, and 400 more in captive breeding facilities.

AZ(b), CO(b), MT(b), SD(b), UT(b), WY(b) --- KS(x), NE(x), NM(x), ND(x), OK(x), TX(x)

Apache trout
Oncorhynchus gilae apache
Overfishing, habitat degradation, and the stocking of nonnative salmonids reduced the Apache trout to fewer than 30 stream miles in 12 streams. Today, due to recovery efforts, the number of Apache trout in remaining habitat has increased and in 1999, 28 self-sustaining populations were reported nearing the goal of 30 outlined in the recovery plan.

Precise population data are not available. However, population numbers have increased dramatically. This species was downlisted to Threatened in 1975 and is under consideration for delisting. AZ(b) ---

Gila trout
Oncorhynchus gilae gilae
Habitat degradation and competition and hybridization with exotic fish species, most notably rainbow and brown trout, caused declines in Gila trout populations and numbers. A survey conducted in 1975 estimated the entire Gila trout population at less than 7,600, but today numbers have increased to around 37,000 and the number of Gila trout populations has increased from five to fourteen.

AZ(b), NM(b) ---

California brown pelican
Pelecanus occidentalis californicus
DDT pollution, eventually traced back to a Los Angeles area factory, resulted in declines in the California brown pelican population. The number of California brown pelican nests dropped to a low of 466 in 1974, began increasing in 1979, and by 1987 rose to 7,900 nests; since then populations have fluctuated around a mean of 5,000.

AZ(o), CA(b), OR(s), WA(s) ---

Gray wolf (Western DPS)
Canis lupus (Western DPS)
Hunting and persecution of gray wolves led to their extirpation in the western portion of the lower 48 states. Gray wolves began recolonizing the Rocky Mountain region in the early 1980s and currently 93 wolves are estimated to be in Montana, 294 in Greater Yellowstone, and 525 in Central Idaho.

ID(b), MT(b), OR(o), WA(o), WY(b) --- CA(x), CO(x), NV(x), UT(x)

Gray wolf (Southwest DPS)
Canis lupus (Southwest DPS)
Hunting and trapping resulted in the extirpation of Mexican gray wolves from the United States by 1970. Wolves captured in Mexico were used to establish a captive breeding program and as of 2005, there were 35-49 Mexican gray wolves in the wild making up eight packs.

AZ(b), NM(b) --- CO(x), OK(x), TX(x), UT(x)

Grizzly bear (Yellowstone DPS)
Ursus arctos horribilis (Yellowstone DPS)
The killing of grizzly bears and the destruction and fragmentation of their habitat caused drastic population declines in the lower 48 states; by 1975 only six populations remained. The number of grizzly bears in the greater Yellowstone population has increased from an estimated 224 bears in 1975 to over 500 bears in 2005.

ID(b), MT(b), WA(b), WY(b) --- AZ(x), CA(x), CO(x), KS(x), MN(x), NE(x), NV(x), NM(x), ND(x), OK(x), OR(x), SD(x), TX(x), UT(x)

Bald eagle (Continental U.S. DPS)
Haliaeetus leucocephalus (Continental U.S. DPS)
The bald eagle declined throughout the Lower 48 states due to habitat loss and DDT application. The banning of DDT, increased habitat protection, and aggressive captive breeding and translocation programs caused the number of bald eagle pairs in the Lower 48 to soar from 416 in 1963 to approximately 9,789 in the latest census between 2004-2006.

AL(b), AZ(b), AR(b), CA(b), CO(b), CT(b), DE(b), DC(b), FL(b), GA(b), ID(b), IL(b), IN(b), IA(b), KS(b), KY(b), LA(b), ME(b), MD(b), MA(b), MI(b), MN(b), MS(b), MO(b), MT(b), NE(b), NV(b), NH(b), NY(b), NM(b), NJ(b), NC(b), ND(b), OH(b), OK(b), OR(b), PA(b), RI(b), SC(b), SD(b), TN(b), TX(b), UT(b), VT(b), VA(b), WA(b), WV(b), WI(b), WY(b) ---

Socorro isopod
Thermosphaeroma thermophilum
The Socorro isopod was reduced to single spring due to water diversions. That spring is prone to catastrophic failure because of human presence and alteration. After the species was nearly driven to extinction by an accident in 1988, three new populations were established on site and in a research park. All populaiton are closely monitored and strictly protected.

NM(b) ---

(b) currently breeds, (s) seasonally present, (m) migration route, (o) occasionally present, (x) extirpated

Banner photo © Phillip Colla