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 here at Gateway Arch 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 fall 2022)
Eastern gray squirrel	227
Bird (unknown species)	119
Tree Squirrel (unknown species)	54
Coyote	32
Virginia opossum	30
Unknown	19
Domestic cat	7
Eastern cottontail rabbit	6
Raccoon	5
Woodchuck	5

The St. Louis Wildlife Project can't estimate the population size of the photographed species. We can't know whether there are 3 woodchucks, or the same woodchuck captured on camera three times. However, we 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.

 

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

 

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. In the summer of 2021 and spring of 2022 they detected calls from:

Big Brown Bat, Eptesicus fuscus
Red Bat,, Lasiurus borealis
Tricolored Bat, Perimyotic subflavus
Evening Bat, Nycticeius humeralis
Hoary Bat, Lasiurus cinereus
Silver Haired Bat, Lasionycteris noctivagans