28 Leaving Footprints, Changing Landscapes: Advances in Ichnological and Zoogeomorphological Research (Posters)

Monday, 21 March 2022
8:00 AM - 12:00 PM
Freedom Hall A

WHITE-TAILED DEER AS A ZOOGEOMORPHIC AGENT ON A POST-FLOOD STREAM TERRACE, BUCKS COUNTY, PENNSYLVANIA

Paper number: 28-10
Program: Theme Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

The population of white-tailed deer (Odocoileus virginianus) in southeast Pennsylvania has been increasing due to a lack of predators and decreasing hunting pressure. This study investigated the impact of the deer along a bedrock-controlled terrace of Neshaminy Creek (Northampton, Bucks County) following an intense storm event (Ida, 2021). The accompanying flood stripped ground vegetation and re-deposited patches of legacy mud along small feeder creeks draining from a sandstone outcrop. Trampling and individual hoofprints of O. virginianus were studied geo-located and measured (dimensions, travel azimuth) to assess their distribution and short-term impact. Adult and subadult/juvenile cervid tracks occurred on two types of substrate: silty mud (loading pressure ~0.28 kg/cm2) and sandy gravel (~0.19 kg/cm2). Individual hoofprints ranged from 4.0-9.0 cm in length, 2.0-4.0 cm in width, and 1.0-5.5 cm in depth. The deepest prints were due to edge-loading on mud-rich sloping sections. On average, an individual white-tailed deer was found to have displaced >200 cm3 of sediment per step (non-overlapping four-point contact), increasing substantially with sliding. In addition to slope erosion, increasing particle size reduces compaction and raises permeability upon impact. Our results suggest that ungulates travelling along and l streams (cervids, suids, etc.) must be considered as significant zoogeomorphic agents of erosion and redeposition, capable of initiating and sustaining geomorphic cascades in riparian watersheds.

Geological Society of America Abstracts with Programs. Vol. 54, No. 3

doi: 10.1130/abs/2022NE-373667

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