35 research outputs found
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A study of differential tax assessment in selected areas of Washington County, Oregon
Farm Use Assessment used as a planning tool to preserve
farmland in Oregon has achieved mixed success. While some land enrolled
in the program (especially near urban areas) has been converted to nonfarm
use, the majority of land has not. However, this may be due to
lack of '1opportunity profits" for landowners rather than to incentives
designed into the program to prevent conversion. This paper examines
the Farm Use Assessment. program in certain areas of Washington County,
Oregon. Tax lot data for the time period since the program was
enacted was analyzed for those changes in land use which occurred on
land enrolled in the program. This research shows that although farmland
owners found the tax benefits of the program advantageous in
holding down farming cost, these same benefits were not great enough to
affect the profits to be gained from conversion of land to non-farm uses
Terrestrial locomotion imposes high metabolic requirements on bats
The evolution of powered flight involved major morphological changes in Chiroptera. Nevertheless, all bats are also capable of crawling on the ground and some are even skilled sprinters. We asked if a highly derived morphology adapted for flapping flight imposes high metabolic requirements on bats when moving on the ground. We measured the metabolic rate during terrestrial locomotion in mastiff bats, Molossus currentium, a species that is both a fast-flying aerial-hawking bat and an agile crawler on the ground. Metabolic rates of bats averaged 8.0±4.0 ml CO2 minâ1 during a 1-min period of sprinting at 1.3±0.6 km hâ1. With rising average speed, mean metabolic rates increased, reaching peak values that were similar to those of flying conspecifics. Metabolic rates of M. currentium were higher than those of similar-sized rodents that sprinted at similar velocities under steady-state conditions. When M. currentium sprinted at peak velocities, its aerobic metabolic rate was 3â5 times higher than those of rodent species running continuously in steady-state conditions. Costs of transport (J kgâ1 mâ1) were more than 10 times higher for running than for flying bats. We conclude that at the same speed bats experience higher metabolic rates during short sprints than quadruped mammals during steady-state terrestrial locomotion, yet running bats achieve higher maximal mass-specific aerobic metabolic rates than non-volant mammals such as rodents
Rain increases the energy cost of bat flight
Similar to insects, birds and pterosaurs, bats have evolved powered flight.
But in contrast to other flying taxa, only bats are furry. Here, we asked
whether flight is impaired when bat pelage and wing membranes get wet. We
studied the metabolism of short flights in Carollia sowelli, a bat that is
exposed to heavy and frequent rainfall in neotropical rainforests. We expected
bats to encounter higher thermoregulatory costs, or to suffer from lowered
aerodynamic properties when pelage and wing membranes catch moisture.
Therefore, we predicted that wet bats face higher flight costs than dry ones.
We quantified the flight metabolism in three treatments: dry bats, wet bats
and no rain, wet bats and rain. Dry bats showed metabolic rates predicted by
allometry. However, flight metabolism increased twofold when bats were wet, or
when they were additionally exposed to rain. We conclude that bats may not
avoid rain only because of sensory constraints imposed by raindrops on
echolocation, but also because of energetic constraints
Nathusiusâ bats, Pipistrellus nathusii, bypass mating opportunities of their own species, but respond to foraging heterospecifics on migratory transit flights
In late summer, migratory bats of the temperate zone face the challenge of accomplishing two energy-demanding tasks almost at the same time: migration and mating. Both require information and involve search efforts, such as localizing prey or finding potential mates. In non-migrating bat species, playback studies showed that listening to vocalizations of other bats, both con-and heterospecifics, may help a recipient bat to find foraging patches and mating sites. However, we are still unaware of the degree to which migrating bats depend on con-or heterospecific vocalizations for identifying potential feeding or mating opportunities during nightly transit flights. Here, we investigated the vocal responses of Nathusiusâ pipistrelle bats, Pipistrellus nathusii, to simulated feeding and courtship aggregations at a coastal migration corridor. We presented migrating bats either feeding buzzes or courtship calls of their own or a heterospecific migratory species, the common noctule, Nyctalus noctula. We expected that during migratory transit flights, simulated feeding opportunities would be particularly attractive to bats, as well as simulated mating opportunities which may indicate suitable roosts for a stopover. However, we found that when compared to the natural silence of both pre-and post-playback phases, bats called indifferently during the playback of conspecific feeding sounds, whereas P. nathusii echolocation call activity increased during simulated feeding of N. noctula. In contrast, the call activity of P. nathusii decreased during the playback of conspecific courtship calls, while no response could be detected when heterospecific call types were broadcasted. Our results suggest that while on migratory transits, P. nathusii circumnavigate conspecific mating aggregations, possibly to save time or to reduce the risks associated with social interactions where aggression due to territoriality might be expected. This avoidance behavior could be a result of optimization strategies by P. nathusii when performing long-distance migratory flights, and it could also explain the lack of a response to simulated conspecific feeding. However, the observed increase of activity in response to simulated feeding of N. noctula, suggests that P. nathusii individuals may be eavesdropping on other aerial hawking insectivorous species during migration, especially if these occupy a slightly different foraging niche
Unravelling the Stability of Nightingale Song Over Time and Space Using Open, Citizen Science and Shared Data
Open science approaches enable and facilitate the investigation of many scientific questions in bioacoustics, such as studies on the temporal and spatial evolution of song, as in vocal dialects. In contrast to previous dialect studies, which mostly focused on songbird species with a small repertoire, here we studied the common nightingale (Luscinia megarhynchos), a bird species with a complex and large repertoire. To study dialects on the population level in this species, we used recordings from four datasets: an open museum archive, a citizen science platform, a citizen science project, and shared recordings from academic researchers. We conducted the to date largest temporal and geographic dialect study of birdsong including recordings from 1930 to 2019 and from 13 European countries, with a geographical coverage of 2,652 km of linear distance. To examine temporal stability and spatial dialects, a catalog of 1,868 song types of common nightingales was created. Instead of dialects, we found a high degree of stability over time and space in both, the sub-categories of song and in the occurrence of song types. For example, the second most common song type in our datasets occurred over nine decades and across Europe. In our case study, open and citizen science data proved to be equivalent, and in some cases even better, than data shared by an academic research group. Based on our results, we conclude that the combination of diverse and open datasets was particularly useful to study the evolution of song in a bird species with a large repertoire
Metabolic costs of bat echolocation in a non-foraging context support a role in communication
The exploitation of information is a key adaptive behavior of social animals,
and many animals produce costly signals to communicate with conspecifics. In
contrast, bats produce ultrasound for auto-communication, i.e., they emit
ultrasound calls and behave in response to the received echo. However,
ultrasound echolocation calls produced by non-flying bats looking for food are
energetically costly. Thus, if they are produced in a non-foraging or
navigational context this indicates an energetic investment, which must be
motivated by something. We quantified the costs of the production of such
calls, in stationary, non-foraging lesser bulldog bats (Noctilio albiventris)
and found metabolic rates to increase by 0.021 ± 0.001 J/pulse (mean ±
standard error). From this, we estimated the metabolic rates of N. albiventris
when responding with ultrasound echolocation calls to playbacks of
echolocation calls from familiar and unfamiliar conspecific as well as
heterospecific bats. Lesser bulldog bats adjusted their energetic investment
to the social information contained in the presented playback. Our results are
consistent with the hypothesis that in addition to orientation and foraging,
ultrasound calls in bats may also have function for active communication
Community engagement and data quality: best practices and lessons learned from a citizen science project on birdsong
Citizen Science (CS) is a research approach that has become popular in recent years and offers innovative potential for dialect research in ornithology. As the scepticism about CS data is still widespread, we analysed the development of a 3-year CS project based on the song of the Common Nightingale (Luscinia megarhynchos) to share best practices and lessons learned. We focused on the data scope, individual engagement, spatial distribution and species misidentifications from recordings generated before (2018, 2019) and during the COVID-19 outbreak (2020) with a smartphone using the âNaturblickâ app. The number of nightingale song recordings and individual engagement increased steadily and peaked in the season during the pandemic. 13,991 nightingale song recordings were generated by anonymous (64%) and non-anonymous participants (36%). As the project developed, the spatial distribution of recordings expanded (from Berlin based to nationwide). The rates of species misidentifications were low, decreased in the course of the project (10â1%) and were mainly affected by vocal similarities with other bird species. This study further showed that community engagement and data quality were not directly affected by dissemination activities, but that the former was influenced by external factors and the latter benefited from the app. We conclude that CS projects using smartphone apps with an integrated pattern recognition algorithm are well suited to support bioacoustic research in ornithology. Based on our findings, we recommend setting up CS projects over the long term to build an engaged community which generates high data quality for robust scientific conclusions.Gesellschaftliches Engagement und DatenqualitĂ€t: BewĂ€hrte Praktiken und Erfahrungen aus einem bĂŒrgerwissenschaftlichen Projekt zum Vogelgesang
Citizen Science (CS) ist eine Forschungsmethode, die in den letzten Jahren an Bedeutung gewonnen hat und innovatives Potenzial fĂŒr die Dialektforschung in der Ornithologie bietet. Da die Vorbehalte gegenĂŒber CS-Daten immer noch weit verbreitet sind, haben wir die Entwicklung eines dreijĂ€hrigen CS-Projekts zum Gesang der Nachtigall (Luscinia megarhynchos) analysiert, um bewĂ€hrte Praktiken und gewonnene Erfahrungen darzustellen. Wir fokussierten uns auf den Datenumfang, das individuelle Engagement von Teilnehmenden, die rĂ€umliche Verteilung und die Fehlbestimmungen von Arten aus Aufnahmen, die vor (2018, 2019) und wĂ€hrend des COVID-19-Ausbruchs (2020) mit einem Smartphone unter Verwendung der "Naturblick" App erstellt wurden. Die Anzahl der Aufnahmen von NachtigallgesĂ€ngen und das individuelle Engagement stiegen stetig an und erreichten ihren Höhepunkt in der Saison wĂ€hrend der Pandemie. 13.991 Aufnahmen von NachtigallgesĂ€ngen wurden von anonymen (64%) und nicht-anonymen Teilnehmenden (36%) erstellt. Im Laufe des Projekts weitete sich die rĂ€umliche Verteilung der Aufnahmen aus (von Berlin auf bundesweit). Die Rate der Fehlbestimmungen war gering, ging im Laufe des Projekts zurĂŒck (von 10% auf 1%) und wurde hauptsĂ€chlich von gesanglichen Ăhnlichkeiten mit anderen Vogelarten beeinflusst. Unsere Studie zeigte auĂerdem, dass das gesellschaftliche Engagement und die DatenqualitĂ€t nicht direkt von den durchgefĂŒhrten DisseminationsaktivitĂ€ten beeinflusst wurden, sondern dass erstere von externen Faktoren abhingen und letztere von der App profitierte. Wir schlieĂen daraus, dass CS-Projekte, die Smartphone-Apps mit einem integrierten Mustererkennungsalgorithmus verwenden, gut geeignet sind, um die bioakustische Forschung in der Ornithologie zu unterstĂŒtzen. Auf der Grundlage unserer Ergebnisse empfehlen wir, CS-Projekte langfristig zu etablieren, um eine aktive Teilnehmergemeinschaft (Community) aufzubauen, die qualitativ hochwertige Daten fĂŒr fundierte wissenschaftliche Schlussfolgerungen generiert
Improving attitudes and knowledge in a citizen science project about urban bat ecology
In order to deal with the current, dramatic decline in biodiversity, the public at large needs to be aware of and participate in biodiversity research activities. One way to do this is citizen science projects, in which researchers collaborate with volunteering citizens in scientific research. However, it remains unclear whether engaging in such projects has an impact on the learning outcomes of volunteers. Previous research has so far presented mixed results on the improvement of citizensâ attitudes and knowledge, mostly because such research has focused only on single aspects of citizen science projects in case studies. To address these limitations, we investigated the impact of an urban bat ecology project on citizensâ attitudes and knowledge about bats, and on their engagement with citizen science. We also examined whether the degree of citizen participation (i.e., collecting data vs. collecting and analyzing data) had an influence on the outcomes. We conducted four field studies and used a survey-based, experimental, pre-/post-measurement design. To vary the degree of participation, we assessed the post measurement in one group directly after data collection, whereas, in a second group, we assessed it after data collection and analysis, at the end of the project. Across all studies, the results demonstrated that citizensâ content knowledge of urban bat ecology increased, and their attitudes toward bats and toward their engagement in citizen science improved during their participation. Citizensâ degrees of participation did not influence these outcomes. Thus, our research illustrates that citizen science can increase awareness of urban bat conservation, independently of citizensâ degree of participation. We discuss the implications of our findings for the citizen science community. © 2022 by the author(s)
Knowledge for Change: A Decade of Citizen Science (2020â2030) in Support of the SDGs
In October 2020, the Museum fĂŒr Naturkunde Berlin (MfN) with many partners, supported by the European Commission and the Federal Ministry of Education and Research (BMBF), held an international, hybrid conference in order to showcase, evaluate, and discuss the contribution of citizen science to frame and achieve the SDGs. The conference Knowledge for Change: A Decade of Citizen Science (2020-2030) in Support of the SDGs took place as an official event of Germanyâs 2020 EU Council presidency.
The SDGs are a scientifically based framework for the whole world to address hunger and malnutrition, health, environment as well as culture and justice, decided by the UN. Citizen Science, the contribution of lay people to scientific activities, may support the achievement of the SDGs â by providing data and insights, but also by adapting and prioritising research questions.
Aim
The conference presented, evaluated and discussed the exciting contributions that Citizen Science makes in framing and achieving sustainable development, specifically the UN SDGs. The conference brought together expertise from policy makers, institutional and citizen scientists, economists, NGOs and civil society to implement mechanisms and processes for the transition towards a more sustainable future.
The Declaration
A Declaration including policy recommendations resulted from the conference: "Our world â our goals: citizen science for the Sustainable Development Goals". The Declaration acts as a voluntary commitment by all partners to define the roles, competences and concrete potentials of Citizen Science to advance the SDGs. It was formulated in an open and participatory process.
The Declaration groups the various important contributions of citizen science to the SDGs in three central recommendations:
1) Harness the benefits of citizen science for the SDGs,
2) strengthen citizen science and its connections with other communities, and
3) strengthen future citizen science systems