A threatened species is any species which is vulnerable to extinction in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of critical depensation, a mathematical measure of biomass related to population growth rate. This quantitative metric is one method of evaluating the degree of endangerment without direct reference to human activity.
Euchloe ausonides insulanus, the island marble butterfly, is a subspecies of the Euchloe ausonides and is found in the San Juan Islands in Washington in the northwestern United States. The butterfly was thought to be extinct and was last observed on Gabriola Island, British Columbia in 1908. The species was rediscovered during a prairie butterfly survey in San Juan Island National Historical Park in 1998. After this rediscovery, surveys were conducted throughout the presumed range and found a few populations on San Juan Island and Lopez Island, but no remaining populations in Canada.
Euchloe ausonides, the large marble or creamy marblewing, is a species of butterfly that occurs in western North America. It lays eggs on the terminal flower buds of a variety of plants in the mustard family, including introduced Eurasian species, and the larvae feed on the buds, flowers and fruit of these plants. In California, it has witnessed population declines since the 1980s, especially in the Central Valley and the Bay Area. In Washington, subspecies the island marble butterfly was listed as an endangered species under the Endangered Species Act in 2020.
The arroyo toad is a species of true toads in the family Bufonidae, endemic to California, U.S. and Baja California state, Mexico. It is currently classified as an Endangered species on the IUCN Red List of Threatened Species because of habitat destruction. The arroyo toad is at the intersection of ecological significance and conservation concern.
Sprague's pipit is a small songbird (passerine) in the family Motacillidae that breeds in the short- and mixed-grass prairies of North America. Migratory, it spends the winters in the southwestern United States and northern Mexico. Sprague's pipits are unusual among songbirds in that they sing high in the sky, somewhat like a goldfinch or skylark. It is more often identified by its distinctive descending song heard from above than by being seen on the ground. Males and females are cryptically coloured and similar in appearance; they are a buffy brown with darker streaking, slender bills and pinkish to yellow legs. Sprague's pipit summer habitat is primarily native grasslands in the north central prairies of the United States and Canada. The species was named after the botanical illustrator Isaac Sprague.
The Utah prairie dog is the smallest species of prairie dog endemic to the south-central steppes of the American state of Utah.
Fender's blue butterfly is a subspecies of Boisduval's blue endemic to the Willamette Valley of northwestern Oregon, United States. The potential range of the butterfly extends from south and west of Portland, OR to south of Eugene, OR. The butterfly is host-specific on the Kincaid's lupine, which it relies on for reproduction and growth. The male and female can be identified by their difference in wing color. The Fender's Blue Butterfly was added to the endangered species list in January 2000, but as of February of 2023, has been reclassified as "threatened". The Fender's blue butterfly population has increased over the past 20 years and projected to increase more through conservation efforts. In Willamette Valley, Oregon, there are currently 90 sites filled with Fender's blue.
The Mission blue is a blue or lycaenid butterfly subspecies native to the San Francisco Bay Area of the United States. The butterfly has been declared as endangered by the US federal government. It is a subspecies of Boisduval's blue.
The Chipola slabshell is a part of the phylum Mollusca and the class Bivalvia. This species has suffered a large decrease with upwards of 75% of habitat lost. It is now confined to only a few remnant sites in small drainages within the Chipola River. The federal Endangered Species Act protects it as a designated threatened species by Florida's Endangered and Threatened Species Rule.
The callippe silverspot butterfly is a federal endangered subspecies in the brush-footed butterfly family Nymphalidae. This is a subspecies. It is a member of the Heliconiinae, the subfamily known as longwings. The adult has a wingspan of just over two inches. The wings are eyecatching with a brown, tan, and black scalloped pattern on their surfaces and orange-brown with characteristic silver spots on the undersides. The wings and abdomen are hairy. The larvae are spiny, dark-colored caterpillars.
Myrtle's silverspot is a medium-sized butterfly in the brush foot family (Nymphalidae), an endangered subspecies of the zerene fritillary. It is endemic to California, where it is known from only about four locations just north of the San Francisco Bay Area, including two at Point Reyes National Seashore. Its wingspan is approximately 2.2 inches (56 mm). The upper surfaces of the wings are golden brown with numerous black spots and lines. The undersides are brown, orange and tan with black lines and silver and black spots. Larvae are dark colored with many sharp branching spines on their backs. Myrtle's silverspot is larger and paler than the closely related Behrens' silverspot, which is now limited to the vicinity of Point Arena in Mendocino County. Myrtle's silverspot is also closely related to the Oregon silverspot.
The midvalley fairy shrimp, Branchinecta mesovallensis, is a small freshwater crustacean in the Branchinectidae family endemic to shallow ephemeral pools near the middle of California's Central Valley. These vernal pool ecosystems are home to other unique organisms adapted to the ephemeral nature of the water cycle in the pools in California's mediterranean climate.
The Zayante band-winged grasshopper is a species of insect in the family Acrididae. It is endemic to a small portion of the Santa Cruz Mountains in California.
Papilio aristodemus, the Schaus' swallowtail or island swallowtail, is a species of American butterfly in the family Papilionidae. It is found in southern Florida in the United States and throughout the West Indies. It is named in honor of William Schaus.
The Manitoba Tall Grass Prairie Preserve is located in southeastern Manitoba near Gardenton and Vita, this is about 50 kilometres (31 mi) south of Steinbach, Manitoba. It is one of the last remaining stands of tallgrass prairie in Manitoba and is part of the Tallgrass Aspen Parkland conservation area in Manitoba and Minnesota. Several groups and organizations help in land preservation in the Manitoba Tall Grass Prairie such as the Nature Conservancy of Canada, Nature Manitoba, Environment Canada, Manitoba Conservation and the Manitoba Habitat Heritage Corporation.
The crystal skipper is a species of butterfly in the family Hesperiidae that is found only along a 30-mile (50 km) stretch of barrier islands in North Carolina. The skipper was first discovered in 1978 and the paper describing it as a full species was published in 2015.
Polites mardon, the Mardon skipper, is a butterfly native to the United States northwest coast.
Hesperia ottoe, the Ottoe skipper, is a butterfly of the family Hesperiidae.
Hesperia pahaska, the Pahaska skipper, is a butterfly of the family Hesperiidae.
Oarisma poweshiek, the Poweshiek skipperling, is a North American butterfly in the family Hesperiidae (skippers), subfamily Hesperiinae. The range of this species in Canada is restricted to southeastern Manitoba, and in the United States it historically ranged from the Dakotas to the southern Lower Peninsula of Michigan.
