Deer Crossing UGR 2023-2024
Description
Individual observers (MSE, KRW, AGF, and undergraduate research assistants trained on our ethogram) with binoculars located a group of two or more mule deer foraging in proximity on the campus, recording the location, group size, sex ratio of group, and age composition of the group (see Table 1) on arrival. Deer were followed at >15 feet. If the deer were disrupted by observer's presence, the observer waited until the deer resumed normal foraging behavior. All observations took place on the campus of Fort Lewis College (see Fig. 1). Fort Lewis covers approximately 247 acres at an altitude of 6,872 feet. Observations took place approximately two hours before Astronomical Twilight to capture the crepuscular foraging activity of mule deer. Observations took place 2-3 nights per week from May 2023-November 2024. 33 instances of group road crossing behavior were recorded in this period. The first individual to cross a paved road section of the environment while oriented away from 75% of the group was labeled the initiator (sensu Stueckle and Zinner 2008). Crossing events were timed with cellular phone stopwatch apps. The initiator’s social phenotype (Table 1) and the cardinal direction of the initiator’s crossing were recorded. Each crossing was marked as a separate event. If an individual crossed an anthropogenic barrier but had no followers, that individual was listed as the initiator of the crossing. Crossings included those occurring immediately after external stimuli such as the arrival of a vehicle or a sudden noise as well as during “relaxed” foraging. For five minutes the observer recorded the social phenotype of each subsequent individual deer who, oriented towards the initiator, closed distance with the initiator across the terrain barrier within five minutes of the initiator’s crossing. Observation of each group lasted approximately one hour. Each new crossing event was recorded as a separate event.