66 research outputs found

    Fireflies

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    Introduction: Fireflies may be expected to have inappropriate, innate responses to foreign light, similar to those that occur in other organisms. (Excerpted from: Ecological Consequences of Artificial Night Lighting, edited by Catherine Rich and Travis Longcore, published by Island Press, 2005.

    Studying the Earth at Night from CubeSats

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    This paper presents examples of the latest imaging data of the Earth at night from multiple CubeSat platforms. Beginning in 2012, with AeroCube-4, The Aerospace Corporation has launched multiple CubeSat platforms in different orbits equipped with a common suite of CMOS sensors. Originally designed as utility cameras to assist with attitude control system studies and star sensor development, we have been using these simple camera sensors to image the Earth at night since 2014. Our initial work focused on observing nighttime urban lights and global gas flare signals at higher resolution than is possible with the VIIRS sensor. To achieve optimum sensitivity and resolution, orbital motion is compensated for via the use of on-board reaction wheels to perform point-and-stare experiments, often with multiple frame exposures as the sensor moves in orbit. Ground sample distances for these systems range from approximately 100 to 130 meters for the narrow-field-of-view cameras, to 500 meters for the medium-field-of-view cameras. In our initial work, we demonstrated that CMOS sensors flown on AeroCube satellites can achieve a nighttime light detection sensitivity on the order of 20 nW-cm-2 -sr-1 . This resolution and sensitivity allows for detection of urban lighting, road networks, major infrastructure illumination, natural gas flares, and other phenomena of interest. For wide-area surveys, we can also program our cameras to observe regions of interest and co-add pixels to reduce the data bandwidth. This allows for a greater number of frames to be collected and downloaded. These results may then be used to task later satellite passes. Here, we present new examples of our nighttime Earth observation studies using CubeSats. These include: 1) detecting urban growth and change via repeat imaging, 2) investigating the utility of color observations, 3) spotting major sources of light pollution, 4) studying urban-wildland interface regions where lighting may be important to understanding wildlife corridors, 5) imaging lightning and cloud cover at night using wide-area imaging, 6) observations of the very bright lights of fishing boats, and 7) observing other interesting natural phenomenon, including airglow emissions, and the streaking caused by proton strikes in the South Atlantic Anomaly. Our ongoing work includes utilizing a diversity in overpass times from multiple satellites to observe nighttime scenes, imaging high-latitude cities not optimally accessed by the international space station’s cameras, and building a catalogue of observations of rapidly developing megacities and global infrastructure nodes. Data from CMOS sensors flown in common on 5 different AeroCubes in 4 different orbits have been collected. Our results show that enhanced CubeSat sensors can improve mapping of the human footprint in targeted regions via nighttime lights and contribute to better monitoring of: urban growth, light pollution, energy usage, the urban-wildland interface, the improvement of electrical power grids in developing countries, light-induced fisheries, and oil industry flare activity. Future CubeSat sensors should be able to contribute to nightlights monitoring efforts by organizations such as NOAA, NASA, ESA, the World Bank and others, and offer low-cost options for nighttime studies

    Wildlife Underpass Use and Environmental Impact Assessment: A Southern California Case Study

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    Environmental planners often rely on transportation structures (i.e., underpasses, bridges) to provide connectivity for animals across developed landscapes. Environmental assessments of predicted environmental impacts from proposed developments often rely on literature reviews or other indirect measures to establish the importance of wildlife crossings. Literature-based evaluations of wildlife crossings may not be accurate, and result in under-estimation of impacts or establishment of inappropriate mitigation measures. To investigate the adequacy of literature-based evaluations, we monitored wildlife use of a freeway underpass that had been identified as critically important to wildlife connectivity, and which was evaluated in an environmental review document. Photographs were obtained from a network of trail cameras over 3 years. Six mid- to large-sized native mammal species used the underpass and two other mammal species were photographed near the underpass but not using it. American badger (Taxidea taxus) was photographed at a higher rate in the underpass than in the surrounding area. Gray fox (Urocyon cinereoargenteus) was rarely detected in the underpass relative to surrounding habitats, whereas the absence of mule deer (Odocoileus hemionus) in the underpass was unexpected, given relatively frequent detection in adjacent habitats. These results differed from the environmental assessment in that American badger was listed as potentially present while mule deer were expected to use the underpass. Results underscore importance of gathering data to document wildlife use of corridors, because some species do not or rarely take advantage of apparently suitable corridors, while others may be present when assumed to be absent

    Use of Anticoagulant Rodenticides in Single-Family Neighborhoods Along an Urban-Wildland Interface in California

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    Urbanization poses many threats for many wildlife species. In addition to habitat loss and fragmentation, non-target wildlife species are vulnerable to poisoning by rodenticides, especially acutely toxic second generation anticoagulant rodenticides (SGARs). Although such poisonings are well documented for birds and mammals worldwide, the pathways by which these widely available compounds reach non-target wildlife have not been adequately studied, particularly in urban landscapes. Long-term studies of wild carnivores in and around Santa Monica Mountains National Recreation Area, a national park north of Los Angeles, have documented \u3e85% exposure to anticoagulant rodenticides among bobcats, coyotes, and mountain lions. To investigate potential mechanisms of transfer of chemicals from residential users of rodenticides to non-target wildlife in the Santa Monica Mountains in Los Angeles County, California, we distributed surveys to residents in two study areas on the north (San Fernando Valley) and south (Bel Air-Hollywood Hills) slopes of these mountains. We assessed knowledge of residents about the environmental effects of rodenticides, and for information about individual application of chemicals. We asked for the same information from pest control operators (PCOs) in both study areas. Forty residents completed the survey in the San Fernando Valley area, and 20 residents completed the survey in Bel Air-Hollywood Hills. Despite the small number of total responses, we documented a number of important findings. Homeowners (as opposed to gardeners or PCOs) were the primary applicators of rodenticides, predominantly SGARs, and awareness of the hazards of secondary poisoning to wildlife was not consistent. Some residents reported improperly applying rodenticides (e.g., exceeding prescribed distances from structures), and in one instance a respondent reported observing dead animals outside after placing poison inside a structure. Improper application of SGARs that ignores label guidelines occurs in neighborhoods along the urban–wildland interface, thereby providing a transmission pathway for chemical rodenticides to reach native wildlife. Moreover, the responses suggest that even on-label use (e.g. placing poisons inside) can create risk for non-target wildlife

    The One Health Approach to Toxoplasmosis: Epidemiology, Control, and Prevention Strategies

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    One Health is a collaborative, interdisciplinary effort that seeks optimal health for people, animals, plants, and the environment. Toxoplasmosis, caused by Toxoplasma gondii, is an intracellular protozoan infection distributed worldwide, with a heteroxenous life cycle that practically affects all homeotherms and in which felines act as definitive reservoirs. Herein, we review the natural history of T. gondii, its transmission and impacts in humans, domestic animals, wildlife both terrestrial and aquatic, and ecosystems. The epidemiology, prevention, and control strategies are reviewed, with the objective of facilitating awareness of this disease and promoting transdisciplinary collaborations, integrative research, and capacity building among universities, government agencies, NGOs, policy makers, practicing physicians, veterinarians, and the general public

    Improving Light and Soundscapes for Wildlife Use of Highway Crossing Structures

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    UC-ITS-2020-03Transportation and other agencies and organizations are increasingly planning and building under- and over-crossing structures for wildlife to traverse busy highways. However, if wildlife do not use these structures due to noise, light, and other factors, then the structures may have a low benefit to cost ratio. Several criteria are key for their success\u2014 sufficient safety and/or conservation need, cost, location, and anticipated use by wildlife. There is limited information in wildlife-crossing guidance on how wildlife biologists should advise designers, engineers, and architects on the use of structural and vegetation elements that could reduce noise and light disturbances. To address this problem, this study used field measurements and modeling of light and noise from traffic to inform and test the designs of two wildlife overcrossings. Wildlife-responsive designs were developed and tested for two crossings being considered or planned by California Department of Transportation in California. For the planned crossing of US 101 near the city of Agoura Hills (the Wallis-Annenberg crossing), the three designs consisted of noise/glare barriers; noise/glare barriers + berm; and noise/glare barriers + multiple berms. For the potential crossing of Interstate 15 south of Temecula, one design used noise/glare barriers of 3 different heights and the other had no barriers. Key limitations and opportunities for each design approach were identified. Creating \u201cdark and quiet paths\u201d using a combination of berms and noise/glare barriers could decrease disturbance in the crossing structure approach zones and increase the wildlife-responsiveness of the designs

    A Science-Based Policy for Managing Free-Roaming Cats

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    Free-roaming domestic cats (i.e., cats that are owned or unowned and are considered ‘at large’) are globally distributed non-native species that have marked impacts on biodiversity and human health. Despite clear scientific evidence of these impacts, free-roaming cats are either unmanaged or managed using scientifically unsupported and ineffective approaches (e.g., trap-neuter-release [TNR]) in many jurisdictions around the world. A critical first initiative for effective, science-driven management of cats must be broader political and legislative recognition of free-roaming cats as a non-native, invasive species. Designating cats as invasive is important for developing and implementing science-based management plans, which should include efforts to prevent cats from becoming free-roaming, policies focused on responsible pet ownership and banning outdoor cat feeding, and better enforcement of existing laws. Using a science-based approach is necessary for responding effectively to the politically charged and increasingly urgent issue of managing free-roaming cat populations

    An Estimate of Avian Mortality at Communication Towers in the United States and Canada

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    Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action
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