Mammals of Southeastern Pennsylvania

As I’m writing this blog post, rain and ice has been falling since yesterday. The cold temperatures, rain, and ice may make you want to stay inside, bundled nice and warm, but here at TLC, we believe “the warmth is in the walk!” Despite the 16-degree weather last Saturday, a room full of winter-ready, excited participants joined me and expert TLC Naturalist, Gary, to learn all about the Mammals of Southeastern Pennsylvania.

 

The program started out indoors at TLC’s Walnut Hill Headquarters, where Gary laid out fascinating pelts, skulls, and antlers of mammals from our area. Gary began the program by talking about what makes a mammal a mammal: being warm-blooded, having hair, birthing live babies (except for Platypuses, which lay eggs, of course), and having mammary glands. He touched on the apex predators which historically lived here, including the Eastern Timberwolf, the Bobcat, and the Black Bear, and how in their absence, the ecosystem has changed completely. Naturally, this brought us to a discussion about the White-tailed Deer, whose populations have exploded in recent years because of the lack of the apex predators. This explosion in Deer has given the invasive plants in our area an advantage; the White-tailed Deer have evolved to choose the native plants as their food source leaving invasives like Autumn-olive, Multiflora rose, and Mile-a-Minute completely untouched.

The photo on the left shows Gary holding the pelt of a Nutria, an invasive species in North America which is part of the rodent family. On the right, he is explaining how mammal's skulls have evolved to eat meat, vegetation, or both.

Then, we started to talk about other families of mammals: Canines (Coyotes, Eastern Gray Fox, and Red Fox), the Felines (Bobcats), the Weasels (Minks, Otters, Martins) and more.  Gary discussed the different senses these mammals use—how Canines with their long noses utilize their sense of smell, and Felines have short noses, but big eyes which allow them to hunt primarily by sight. He pulled out a Coyote skull, and showed us how these carnivores have teeth built for tearing and slicing meat as opposed to the teeth of herbivorous deer, which primarily have molars for grinding vegetation. As omnivores, human teeth fall somewhere in-between, with both incisors for tearing and molars for grinding.

 

At that point, we grabbed our Tracks & Scat field guides, bundled up, and headed outside to search for evidence of mammals in the area. Since we had already learned most mammals are nocturnal, we knew searching for evidence is the best way to understand what is living in our area. Just steps away, right beneath the Chandler Mill Bridge we were able to find a large amount of frozen tracks in the mud. We immediately spotted some tiny tracks leading up to the creek, which we keyed out to be a gray squirrel. We moved further along the creek, and found raccoon tracks, more squirrel tracks, domestic dog tracks, and what we believe were mink tracks!

The tracks on the left were left by a Raccoon, the photo on the right shows various different animal tracks.

TLC offers a host of outdoor education programs all year round at Bucktoe Creek Preserve. Up next we have Wildlife in Winter Part II: Adaptations with Naturalist Holly Merker. This program will be held on Saturday, February 20^th from 1:00-2:30. Learn how wildlife in our area survive the extreme winter weather by using different types of adaptations, such as camouflage. Check out all of our upcoming programs here.