547 research outputs found

    Carnivoran Frugivory and its Effect on Seed Dispersal, Plant Community Composition, Migration, and Biotic Carbon Storage

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    Seed dispersal by animals is important for the ecology of plants. It is particularly important to understand which animals are involved and how they move seeds differently from one another. Some seed dispersers are understudied despite ample evidence they consume fruits and seeds. This includes animals commonly referred to as carnivores in the order Carnivora. The overall goal of my dissertation was to describe the extent and quality of seed dispersal by Carnivorans, estimate important aspects of seed dispersal for a specific Carnivoran, the coyote, and estimate how differences between a coyote and songbirds affect where plants will occur in the future and if that changes how much carbon plants store on the landscape. To achieve these goals, I first systematically reviewed existing research on frugivory and seed dispersal by Carnivorans. Then, I experimentally evaluated how long it takes for seeds to pass through a coyote, and if the consumption of seeds by coyotes negatively affects seed germination or viability. Finally, I modeled how differences in the distances that coyotes carry seeds vs. songbirds affect plant migrations. I found that Carnivoran frugivory and seed dispersal are common, involve many plant species, and occur worldwide across most ecosystems. Carnivorans also rarely damage seeds or hamper seed viability and germination when they consume and disperse seeds. Furthermore, I found that coyotes generally take between 4 and 24 hours to pass seeds from the fruits they consumed and deliver seeds to new landscapes without harming them. Given coyote travel speeds, these results suggest that coyotes regularly disperse seeds up to 5 km. This seed dispersal distance is substantially greater than songbirds and led to a 2.5 times larger expansion of where junipers grew in models extending 80 years into the future. Coyote seed dispersal would also result in 3.4 times greater conversion of grasslands and an increase total biotic carbon storage by 1.1 Pg. My findings show that understudied seed dispersers like Carnivorans can greatly impact plant ecology and ecosystem services and highlights the need for further studies on the impacts of Carnivora on seed dispersal

    Disk-Loss and Disk Renewal Phases in Classical Be Stars II. Detailed Analysis of Spectropolarimetric Data

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    In Wisniewski et al. 2010, paper I, we analyzed 15 years of spectroscopic and spectropolarimetric data from the Ritter and Pine Bluff Observatories of 2 Be stars, 60 Cygni and {\pi} Aquarii, when a transition from Be to B star occurred. Here we anaylize the intrinsic polarization, where we observe loop-like structures caused by the rise and fall of the polarization Balmer Jump and continuum V-band polarization being mismatched temporally with polarimetric outbursts. We also see polarization angle deviations from the mean, reported in paper I, which may be indicative of warps in the disk, blobs injected at an inclined orbit, or spiral density waves. We show our ongoing efforts to model time dependent behavior of the disk to constrain the phenomena, using 3D Monte Carlo radiative transfer codes.Comment: 2 pages, 6 figures, IAU Symposium 27

    Social Learning of Avoidance Behaviors: Trap Aversion in Captive Coyotes

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    Social learning can help animals gain knowledge rapidly and may enhance survival. In species that are subjected to capture in foothold traps and then lethally removed, such as the coyote (Canis latrans), learning to avoid traps is critical to survival. Here, we tested social learning of trap avoidance behavior in three experimental scenarios with captive coyotes. In the first experiment, coyotes observed an unfamiliar coyote get captured in a foothold trap (i.e., demonstrator) or did not observe a demonstrator and were therefore naïve to traps. The coyotes that observed a demonstrator showed similar latencies to approach the trap and be captured as coyotes without a demonstrator. In the second experiment, coyotes observed their trap-naïve mate get captured in a foothold trap while housed together. These coyotes had longer latencies to approach the trap and be captured than their mates. In the third experiment, demonstrator coyotes were housed separately in an enclosure adjacent to two other enclosures – one housing their mate and one housing an unfamiliar coyote. Here, unfamiliar coyotes had longer latencies to approach the trap and get captured than the mates of the demonstrator coyotes. These results suggest that coyotes have limited ability to socially learn avoidance behavior, with familiarity and proximity of the demonstrator influencing the ability of coyotes to use social learning. Thus, the different results emerging from this study may reflect behaviors related to territoriality and pair-bonds

    Spectral binning as an approach to post-acquisition processing of high resolution FIE-MS metabolome fingerprinting data

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    INTRODUCTION: Flow infusion electrospray high resolution mass spectrometry (FIE-HRMS) fingerprinting produces complex, high dimensional data sets which require specialist in-silico software tools to process the data prior to analysis. OBJECTIVES: Present spectral binning as a pragmatic approach to post-acquisition procession of FIE-HRMS metabolome fingerprinting data. METHODS: A spectral binning approach was developed that included the elimination of single scan m/z events, the binning of spectra and the averaging of spectra across the infusion profile. The modal accurate m/z was then extracted for each bin. This approach was assessed using four different biological matrices and a mix of 31 known chemical standards analysed by FIE-HRMS using an Exactive Orbitrap. Bin purity and centrality metrics were developed to objectively assess the distribution and position of accurate m/z within an individual bin respectively. RESULTS: The optimal spectral binning width was found to be 0.01 amu. 80.8% of the extracted accurate m/z matched to predicted ionisation products of the chemical standards mix were found to have an error of below 3 ppm. The open-source R package binneR was developed as a user friendly implementation of the approach. This was able to process 100 data files using 4 Central Processing Units (CPU) workers in only 55 seconds with a maximum memory usage of 1.36 GB. CONCLUSION: Spectral binning is a fast and robust method for the post-acquisition processing of FIE-HRMS data. The open-source R package binneR allows users to efficiently process data from FIE-HRMS experiments with the resources available on a standard desktop computer. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11306-022-01923-6

    Spatial Associations of Livestock Guardian Dogs and Domestic Sheep

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    Livestock guardian dogs (Canis lupus familiaris; LGDs) have been used for centuries to protect livestock, primarily domestic sheep (Ovis aries), from depredation by large carnivores. While previous studies have shown their efficacy, the mechanisms in which LGDs protect livestock have largely remained unstudied. Livestock guardian dogs are often considered to be effective only if they remain in spatial proximity to the livestock they are protecting. We determined space use of LGDs relative to domestic sheep on open-range grazing allotments used by working ranches in the Rocky Mountains area of the northwest United States between August 2012 and October 2016. We determined dynamic space use, measured as proximity of LGDs to domestic sheep, and evaluated if this metric differed by breed, sex, or age. The LGDs and sheep were fitted with global positioning system transmitters to obtain location data that were subsequently compared by the above traits using multiple mixed-effect linear models. We found no differences in proximity to sheep on open range among LGDs for any of the 3 traits. Overall, we did find a temporal effect in that all of the LGDs studied were closer to sheep in early morning hours when sheep moved the shortest distances and predators are most likely to be active. These results suggest any of the breeds tested, along with sex or age of these LGD breeds, will remain in proximity to sheep when properly bonded

    Mesopredator frugivory has no effect on seed viability and emergence under experimental conditions

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    Members of the order Carnivora are a unique and important seed disperser who consume and deposit undamaged seeds while providing regular long-distance seed dispersal opportunities. Some members of Carnivora, such as coyotes (Canis latrans), are undergoing range expansions which may help the plant species they consume colonize new locations or replace dispersal services provided by recently extirpated species. In this study, we evaluated aspects of the seed dispersal effectiveness of coyotes and gut passage time to determine the potential dispersal distances for three commonly consumed and commonly occurring plant species (Amelanchier alnifolia, Celtis ehrenbergiana, and Juniperus osteosperma). We also investigated the potential effects of secondary dispersal of seeds away from scats by comparing seedling emergence from whole scats to those where seeds were first removed from scats. We found that seeds generally took between 4 and 24 h to pass through the digestive tract of coyotes, which could result in regular seed dispersal up to 7 km. Gut passage through coyotes had no effect on seed viability or emergence for any of the three plant species, including that gut passage for A. alnifolia and J. osteosperma does not replace cold stratification for breaking physiological dormancy. By simulating secondary dispersal, we found that 22% (±8.2%) more C. ehrenbergiana seedlings emerged when seeds were removed from scats and those seedlings emerged 7 d earlier (±5 d) compared to seeds that remained in the coyote scat. Coyotes are effective seed dispersers, with the potential for regular long-distance dispersal services and for providing opportunities for secondary seed dispersal, which could aid in climate migration or serve to replace extirpated dispersal mutualists

    Frugivory and Seed Dispersal by Carnivorans

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    Seed dispersal is critical to the ecological performance of sexually reproducing plant species and the communities that they form. The Mammalian order Carnivora provide valuable and effective seed dispersal services but tend to be overlooked in much of the seed dispersal literature. Here we review the literature on the role of Carnivorans in seed dispersal, with a literature search in the Scopus reference database. Overall, we found that Carnivorans are prolific seed dispersers. Carnivorans’ diverse and plastic diets allow them to consume large volumes of over a hundred families of fruit and disperse large quantities of seeds across landscapes. Gut passage by these taxa generally has a neutral effect on seed viability. While the overall effect of Carnivorans on seed dispersal quality is complex, Carnivorans likely increase long-distance dispersal services that may aid the ability of some plant species to persist in the face of climate change

    Space Use and Movement of Urban Bobcats

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    Global urbanization is rapidly changing the landscape for wildlife species that must learn to persist in declining wild spacing, adapt, or risk extinction. Many mesopredators have successfully exploited urban niches, and research on these species in an urban setting offers insights into the traits that facilitate their success. In this study, we examined space use and activity patterns from GPS-collared bobcats (Lynx rufus) in the Dallas–Fort Worth metroplex, Texas, USA. We found that bobcats select for natural/agricultural features, creeks, and water ways and there is greater home-range overlap in these habitats. They avoid roads and are less likely to have home-range overlap in habitats with more roads. Home-range size is relatively small and overlap relatively high, with older animals showing both greater home-range size and overlap. Simultaneous locations suggest bobcats are neither avoiding nor attracted to one another, despite the high overlap across home ranges. Finally, bobcats are active at all times of day and night. These results suggest that access to natural features and behavioral plasticity may enable bobcats to live in highly developed landscapes

    Comparison of Multiple Hop Test Kinematics Between Force-Platforms and Video Footage – A Cross Sectional Study

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    Background: Multiple hop performances have been assessed using force-platforms and motion-capture cameras. However, the accessibility of these technologies might be a hindering factor for many performance coaches. Currently, tablet devices are being used as alternatives to measure jumping and hopping performances. Objective: This study aimed to compare multiple hop kinematics using the Kinovea application with force-platforms, the gold standard. Methods: Using an observational cross-sectional study design, male athletes (n=44; age 20.1 ± 1.4 years) completed triple hops (3-Hop) and quintuple hops (5-Hop) on force-platforms while being filmed using an iPad. Ground contact time, flight time and total time were analysed using Kinovea and compared with the force platform data. Results: Statistical analysis showed a high level of agreement across all variables of interest but significant differences (flight time; -2.14 to -5.96 %, ground contact time; 4.89 to 5.83 %, total time; -0.37 to -0.58%) were observed across all variables of interest. A systematic bias for flight and ground contact times were seen for 3-Hop and 5-Hop. Conclusion: The use of iPad and Kinovea application can be used as a valid alternative to measure multiple hop kinematics when performance coaches do not have access to expensive force-platforms or motion-capture cameras
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