Mammals

This dramatic shot of a raptor circling a tree in search of its next meal was captured by the motion-activated cameras of St. Louis Wildlife Project biologists.

St. Louis Wildlife Project

Many urban-adapted mammals live throughout St. Louis, including at the national park. Animals who do well in urban environments are sometimes referred to as synanthropes, or urban exploiters. Synanthropes are often found at greater densities in cities than in more "natural" locations. If you live in a city or town, chances are good that you've seen pigeons, Canada geese, feral cats, raccoons, white tailed deer, and rats sharing your neighborhood. All of these animals are synanthropes, and all have rising populations. In fact, there are now over 100x more deer in the USA than there were in 1900!

Here at the Gateway Arch, squirrels and rabbits are ubiquitous and frequently seen by tourists. However, with luck and patience, several more secretive mammals can also be found here.

St. Louis Wildlife Project

Since spring 2019, professional biologists who hold research permits from the National Park Service have been researching wildlife here at the park and at several other locations around St. Louis. For a few weeks four times a year, the biologists set up a motion-activated camera near a scented lure tablet. Later, human volunteers review the pictures and identify the pictured species. Below is their data for our park.

 

Species	Total Detections to Date (as of January 2023)
Squirrel	247
Coyote	36
Virginia opossum	30
Raccoon	8
Domestic cat (without human chaperone)	7
Eastern cottontail rabbit	6
Woodchuck	5

The St. Louis Wildlife Project can't estimate the population size of the photographed species. We can't know whether there are really 5 woodchucks, or the same woodchuck captured on camera five times. However, we do know there are at least two coyotes because they were seen on camera together (see photo below).

If you’re interested in volunteering for the St Louis Wildlife Project, you can contact them through their website.

 

Acoustic Bat Monitoring

The St. Louis Wildlife Project biologists also received a special use permit to set up acoustic monitors to identify bats that were calling within Gateway Arch National Park's boundaries. They detected calls from:

Common Bat Species
Big Brown Bat, Eptesicus fuscus
Eastern Red Bat, Lasiurus borealis
Evening Bat, Nycticeius humeralis
Gray Bat Myotis grisescens
Hoary Bat, Lasiurus cinereus
Silver Haired Bat, Lasionycteris noctivagans

Rare/Unvetted Bat Species
Little Brown Myotis, Myotis lucifugus
Tricolored Bat, Perimyotic subflavus

Species were identified using the bat analysis software Kaleidoscope Pro by Wildlife Acoustics. “Common” species were classified as having or more than 20 calls of that species detected per site, while “rare/unvetted” species have less than 20 calls per site in the time period of this report. These calls have not been verified by a third party bat expert and would need further vetting to confirm actual species presence.

 

An infrared image, taken at night, of two coyotes photographed by the motion-activated cameras set on the Arch Grounds as part of the St. Louis Wildlife Project

St Louis Wildlife Project

 

Virginia Opossums, like this one photographed near Luther Ely Smith Square, live in many urban environments throughout the United States. They tend to be most active in the early mornings or late evenings.

NPS Photo