Animals

Cottontails are frequently seen inside the fort.

NPS / LINDA GORDON ROKOSZ

Nature & Science
Animals

MAMMALS

The most common mammals at Fort Union include white-tailed deer, coyote, red fox, ground squirrels, beaver, muskrat, desert cottontail, raccoon, porcupine, and prairie vole.

BIRDS

The site's location along a major flyway results in the seasonal passage of an array of migratory and non-migratory birds, including Canada geese and white pelicans. In the winter golden and bald eagles lay over and prey in the scattered open river waters. Smaller species include American Goldfinch, Lazuli Bunting, Black-Headed Grossbeak, and Pine Siskin.

INSECTS

Numerous insect species are recorded along the Missouri of which mosquitoes are historically the most nettlesome. In 1806, Captain Clark was to wait for Lewis at the confluence of the Missouri and Yellowstone, but moved several miles downstream to escape the "mosquitors".

AMPHIBIANS

Chorus frog, Leopard Frog, and Spadefoot Plains Toad use the river bottoms as breeding and feeding grounds, and are occasionally seen within the fort.

REPTILES

Garter snakes may be seen sunning in open areas or darting out of sight. Bull snakes are rarely seen, camoflaged in the prairie by day and hunting in mammal burrows by night.

 

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Species Attribute Definitions

Definitions

Occurrence

Occurrence values are defined below. One or more Occurrence Tags may be associated with each Occurrence value.

Present: Species occurs in park; current, reliable evidence available.

Probably Present: High confidence species occurs in park but current, verified evidence needed.

Unconfirmed: Species is attributed to park but evidence is weak or absent.

Not In Park: Species is not known to occur in park.

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Occurrence Tags

Adjacent: Species is known to occur in areas near to or contiguous with park boundaries.

False Report: Species was reported to occur within the park, but current evidence indicates the report was based on misidentification, a taxonomic concept no longer accepted, or other similar problem of error or interpretation.

Historical: Species' historical occurrence in park is documented. Assigned based on judgment as opposed to determination based on age of the most recent evidence.

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Abundance

Abundant:

• Animals: May be seen daily, in suitable habitat and season, and counted in relatively large numbers.
• Plants: Large number of individuals; wide ecological amplitude or occurring in habitats covering a large portion of the park.

Common:

• Animals: May be seen daily, in suitable habitat and season, but not in large numbers.
• Plants: Large numbers of individuals predictably occurring in commonly encountered habitats but not those covering a large portion of the park.

Uncommon:

• Animals: Likely to be seen monthly in appropriate habitat and season. May be locally common.
• Plants: Few to moderate numbers of individuals; occurring either sporadically in commonly encountered habitats or in uncommon habitats.

Rare:

• Animals: Present, but usually seen only a few times each year.
• Plants: Few individuals, usually restricted to small areas of rare habitat.

Occasional:

• Animals: Occurs in the park at least once every few years, varying in numbers, but not necessarily every year.
• Plants: Abundance variable from year to year (e.g., desert plants).

Unknown: Abundance unknown

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Nativeness

Native: Species naturally occurs in park or region.

Non-native: Species occurs on park lands as a result of deliberate or accidental human activities.

Unknown: Nativeness status is unknown or ambiguous.

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List Differences

The Checklist contains only those species that are designated as "present" or "probably present" in the park.

The Full List includes all the checklist species in addition to species that are unconfirmed, historically detected, or incorrectly reported as being found in the park. The full list also contains species that are "in review" because their status in the park hasn't been fully determined. Additional details about the status of each species is included in the full list.

The checklist will almost always contain fewer species than the full list.

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Fort Union Trading Post National Historic Site

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Species attribute definitions

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