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Department of Fish, Wildlife, and Conservation Biology

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https://hdl.handle.net/10217/100423
These digital collections include theses, dissertations, faculty publications, student publications, and datasets from the Department of Fish, Wildlife, and Conservation Biology. Due to departmental name changes, materials from the following historical departments are also included here: Fishery; Fishery and Wildlife Biology; Wildlife Biology.

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Browsing Department of Fish, Wildlife, and Conservation Biology by Subject "acoustic monitoring"

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    Forest elephants modulate their behavior to adapt to sounds of danger
    (Colorado State University. Libraries, 2023) Verahrami, Anahita K., author; Bombaci, Sara, advisor; Blanchard, Nathaniel, committee member; Wittemyer, George, committee member
    The African forest elephant (Loxodonta cyclotis) plays a critical role in upholding the structure and function of the Congo Basin, the world's second largest tropical forest which crucially contributes to global carbon sequestration. Research has demonstrated an 86% decline in forest elephant population numbers between 1990-2021, largely because of hunting for ivory. Due to the species' cryptic nature in their dense rainforest habitat, little is known on how they respond to human disturbances such as gun hunting. The studies that have been completed reveal that forest elephants may respond to disturbance by demonstrating changes in their abundance, distribution, and nocturnal activity. Changes in forest elephant distribution and activity not only have ramifications for the species' activity budgets, which when affected, may influence their foraging and reproductive behaviors and success, but may also impact the species' interspecific interactions with vegetation in certain areas, affecting forest growth and function. However, little is known on how a key population of this critically endangered species in the northern Republic of Congo is responding to disturbance such as hunting in the region. Using acoustic detection models in combination with a landscape-scale acoustic monitoring effort in and around Nouabalé-Ndoki National Park, Republic of Congo, I assess how forest elephant vocal activity is being influenced by gun hunting. Using these data, I examine (1) how forest elephant vocal activity changes across an eight-day period and (2) if forest elephants are shifting to more nighttime vocal activity following a gun hunting event. Results show that, on average, forest elephants are present and vocal at sites without gun events 53% of the time, but at sites with gun events, this value drops to 43%. Results also indicate that this change in activity following a gun hunting event is sustained over the eight-day period examined and does not vary from day-to-day. Results from the analysis exploring how the proportion of nighttime calling activity changes in response to gun hunting show that number of gunshots is an important predictor of nighttime vocal activity. Specifically, as the number of gunshots increase, there is a dramatic increase in the proportion of nighttime calling activity. Understanding the degree at which forest elephants are affected by gun hunting provides a convincing argument to focus limited conservation resources on developing more effective strategies to reduce indirect impacts from hunting on this critically endangered and ecologically important species.
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    ItemOpen Access
    The use of on-animal acoustical recording devices for studying animal behavior
    (Colorado State University. Libraries, 2013-07) Lynch, Emma, author; Angeloni, Lisa, author; Fristrup, Kurt, author; Joyce, Damon, author; Wittemyer, George, author; John Wiley and Sons, publisher
    Audio recordings made from free-ranging animals can be used to investigate aspects of physiology, behavior, and ecology through acoustic signal processing. On-animal acoustical monitoring applications allow continuous remote data collection, and can serve to address questions across temporal and spatial scales. We report on the design of an inexpensive collar-mounted recording device and present data on the activity budget of wild mule deer (Odocoileus hemionus) derived from these devices applied for a 2-week period. Over 3300 h of acoustical recordings were collected from 10 deer on their winter range in a natural gas extraction field in northwestern Colorado. Analysis of a subset of the data indicated deer spent approximately 33.5% of their time browsing, 20.8% of their time processing food through mastication, and nearly 38.3% of their time digesting through rumination, with marked differences in diel patterning of these activities. Systematic auditory vigilance was a salient activity when masticating, and these data offer options for quantifying wildlife responses to varying listening conditions and predation risk. These results (validated using direct observation) demonstrate that acoustical monitoring is a viable and accurate method for characterizing individual time budgets and behaviors of ungulates, and may provide new insight into the ways external forces affect wildlife behavior.