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Creators/Authors contains: "Francis, Xavier"

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  1. Human-wildlife interactions continue to increase due to anthropogenic disturbances, with some interactions resulting in conflict. Leveraging a taxa’s bias for a particular sensory cue is a promising management avenue for reducing the potential and realized negative consequences of human-wildlife conflict. For instance, many avian species heavily depend on acoustic communication, and acoustic cues can provide opportunities to reduce conflict with various avian species. The monk parakeet (Myiopsitta monachus) is a gregarious parrot native to South America that has established populations worldwide and is considered an urban and agricultural pest in parts of its native and introduced ranges. We conducted playback experiments with a captive population of monk parakeets to evaluate auditory cues that may be useful for designing management protocols. Our experiment evaluated the efficacy of two stimuli: predator vocalizations as potential repulsion and conspecific vocalizations as potential attraction stimuli for parakeets. We measured two responses: (1) categorical group-level behavioral responses and (2) time to cease vigilance and return to behavior prior to playback. In the repulsion playbacks, monk parakeets were repelled by predator vocalizations in 80% of trials and took longer to cease vigilance and return to baseline behavior compared to attraction playbacks. In the attraction playbacks, monk parakeets exhibited vigilant behavior and weak or no attraction to the stimulus, with attraction only being observed in 10% of trials. Our results demonstrate that predator playbacks may be particularly useful for completing management objectives, such as temporary removal from a location. 
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  2. Abstract Proxy reconstructions from the mid‐Holocene (MH: 6,000 years ago) indicate an intensification of the West African Monsoon and a weakening of the South American Monsoon, primarily resulting from orbitally‐driven insolation changes. However, model studies that account for MH orbital configurations and greenhouse gas concentrations can only partially reproduce these changes. Most model studies do not account for the remarkable vegetation changes that occurred during the MH, in particular over the Sahara, precluding realistic simulations of the period. Here, we study precipitation changes over northern Africa and South America using four fully coupled global climate models by accounting for the Saharan greening. Incorporating the Green Sahara amplifies orbitally‐driven changes over both regions, and leads to an improvement in proxy‐model agreement. Our work highlights the local and remote impacts of vegetation and the importance of considering vegetation changes in the Sahara when studying and modeling global climate. 
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