58 research outputs found

    Terrestriske fuglearter som indikatorer for bærekraftig utvikling i Norge: tilstanden i ulike naturtyper og effekter av klimaendring

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    Det er behov for gode indikatorer for å følge tilstanden i norske økosystemer, blant annet for å kunne vurdere om vi har en utvikling som er bærekraftig. Fugl har mange egenskaper som gjør de godt egnet som indikator på økosystemets tilstand. Derfor er fugler inkludert blant indikatorer for bærekraftig utvikling både i EU, Norge og mange andre land. Det finnes mange ulike fuglearter med stor spredning i levesett, og ikke alle er like godt egnet som indikatorer. Hensikten med denne utredningen er å identifisere arter som er egnet som indikatorer for tilstand og utvikling i naturtypene fjell, skog, våtmark og vannkant, og kulturlandskapet, samt for effekter av klimaendring. Dette arbeidet er basert på en gjennomgang av relevant informasjon om hekkefugl i Norge.Direktoratet for Naturforvaltnin

    Censuses of breeding birds in a South Norwegian arctic-alpine habitat three decades apart show population declines in the most common species

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    Breeding bird censuses along line transects on the Hardangervidda plateau, southern Norway, were performed on open mountain heath at about1250 m elevation in 1980 and repeated in 2010 and 2011. Four passerine species and three species of waders constitute the commonest breeders. Significant decrease in numbers was found in the three commonest species, Meadow Pipit Anthus pratensis (down 40 %), Northern Wheatear Oenanthe oenanthe (down 65–67 %) and, in particular, Lapland Bunting Calcarius lapponicus (down 82–87 %). The decline in Lapland Bunting is discussed in relation to changes in the vegetation on the breeding grounds probably caused by reduced grazing and climatic changes, and in relation to possible negative factors in parts of the wintering area

    Chasing the bird: 3D acoustic tracking of aerial flight displays with a minimal planar microphone array

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    Tracking the flight patterns of birds and bats in three-dimensional space is central to key questions in evolutionary ecology but remains a difficult technical challenge. For example, complex aerial flight displays are common among birds breeding in open habitats, but information on flight performance is limited. Here, we demonstrate the feasibility of using a large ground-based 4-microphone planar array to track the aerial flight displays of the cryptic Jack Snipe Lymnocryptes minimus. The main element of male display flights resembles a galloping horse at a distance. Under conditions of sufficient signal-to-noise ratio and of vertical alignment with the microphone array, we successfully tracked male snipe in 3D space for up to 25 seconds with a total flight path of 280 m. The ’gallop’ phase of male snipe dropped from ca. 141 to 64 m above ground at an average velocity of 77 km/h and up to 92 km/h. Our project is one of the first applications of bioacoustics to measure 3D flight paths of birds under field conditions, and our results were consistent with our visual observations. Our microphone array and postprocessing workflow provides a standardised protocol that could be used to collect comparative data on birds with complex aerial flight displays. Acoustic display; animal flight; flight tracking; Jack Snipe; Lymnocryptes minimus; microphone arraypublishedVersio

    Species distributions models may predict accurately future distributions but poorly how distributions change : A critical perspective on model validation

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    Aim: Species distribution models (SDMs) are widely used to make predictions on how species distributions may change as a response to climatic change. To assess the reliability of those predictions, they need to be critically validated with respect to what they are used for. While ecologists are typically interested in how and where distributions will change, we argue that SDMs have seldom been evaluated in terms of their capacity to predict such change. Instead, typical retrospective validation methods estimate model's ability to predict to only one static time in future. Here, we apply two validation methods, one that predicts and evaluates a static pattern, while the other measures change and compare their estimates of predictive performance. Location: Fennoscandia.Methods: We applied a joint SDM to model the distributions of 120 bird species in four model validation settings. We trained models with a dataset from 1975 to 1999 and predicted species' future occurrence and abundance in two ways: for one static time period (2013- 2016, "static validation') and for a change between two time periods (difference between 1996- 1999 and 2013- 2016, "change validation'). We then measured predictive performance using correlation between predicted and observed values. We also related predictive performance to species traits. Results: Even though static validation method evaluated predictive performance as good, change method indicated very poor performance. Predictive performance was not strongly related to any trait.Main Conclusions: Static validation method might overestimate predictive performance by not revealing the model's inability to predict change events. If species' distributions remain mostly stable, then even an unfit model can predict the near future well due to temporal autocorrelation. We urge caution when working with forecasts of changes in spatial patterns of species occupancy or abundance, even for SDMs that are based on time series datasets unless they are critically validated for forecasting such change.Peer reviewe

    Covariation in population trends and demography reveals targets for conservation action

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    Wildlife conservation policies directed at common and widespread, but declining, species are difficult to design and implement effectively, as multiple environmental changes are likely to contribute to population declines. Conservation actions ultimately aim to influence demographic rates, but targeting actions towards feasible improvements in these is challenging in widespread species with ranges that encompass a wide range of environmental conditions. Across Europe, sharp declines in the abundance of migratory landbirds have driven international calls for action, but actions that could feasibly contribute to population recovery have yet to be identified. Targeted actions to improve conditions on poor-quality sites could be an effective approach, but only if local conditions consistently influence local demography and hence population trends. Using long-term measures of abundance and demography of breeding birds at survey sites across Europe, we show that co-occurring species with differing migration behaviours have similar directions of local population trends and magnitudes of productivity, but not survival rates. Targeted actions to boost local productivity within Europe, alongside large-scale (non-targeted) environmental protection across non-breeding ranges, could therefore help address the urgent need to halt migrant landbird declines. Such demographic routes to recovery are likely to be increasingly needed to address global wildlife declines.Peer reviewe

    Overvåking av langtransporterte forurensninger 2009. sammendragsrapport

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    Rapporten presenterer sammendrag av resultatene for 2009 fra tre overvåkingsprogrammer: “Overvåking av langtrans­portert forurenset luft og nedbør”, ”Overvåkingsprogram for skogskader” (OPS) og “Program for terrestrisk naturovervåking” (TOV). The report presents results for 2009 from three national monitoring programmes on long-range transboundary air pollution

    Temperature synchronizes temporal variation in laying dates across European hole-nesting passerines

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    Publisher Copyright: © 2022 The Authors. Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.Identifying the environmental drivers of variation in fitness-related traits is a central objective in ecology and evolutionary biology. Temporal fluctuations of these environmental drivers are often synchronized at large spatial scales. Yet, whether synchronous environmental conditions can generate spatial synchrony in fitness-related trait values (i.e., correlated temporal trait fluctuations across populations) is poorly understood. Using data from long-term monitored populations of blue tits (Cyanistes caeruleus, n = 31), great tits (Parus major, n = 35), and pied flycatchers (Ficedula hypoleuca, n = 20) across Europe, we assessed the influence of two local climatic variables (mean temperature and mean precipitation in February–May) on spatial synchrony in three fitness-related traits: laying date, clutch size, and fledgling number. We found a high degree of spatial synchrony in laying date but a lower degree in clutch size and fledgling number for each species. Temperature strongly influenced spatial synchrony in laying date for resident blue tits and great tits but not for migratory pied flycatchers. This is a relevant finding in the context of environmental impacts on populations because spatial synchrony in fitness-related trait values among populations may influence fluctuations in vital rates or population abundances. If environmentally induced spatial synchrony in fitness-related traits increases the spatial synchrony in vital rates or population abundances, this will ultimately increase the risk of extinction for populations and species. Assessing how environmental conditions influence spatiotemporal variation in trait values improves our mechanistic understanding of environmental impacts on populations.Peer reviewe

    Terrestriske fuglearter som indikatorer for bærekraftig utvikling i Norge: tilstanden i ulike naturtyper og effekter av klimaendring

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    Det er behov for gode indikatorer for å følge tilstanden i norske økosystemer, blant annet for å kunne vurdere om vi har en utvikling som er bærekraftig. Fugl har mange egenskaper som gjør de godt egnet som indikator på økosystemets tilstand. Derfor er fugler inkludert blant indikatorer for bærekraftig utvikling både i EU, Norge og mange andre land. Det finnes mange ulike fuglearter med stor spredning i levesett, og ikke alle er like godt egnet som indikatorer. Hensikten med denne utredningen er å identifisere arter som er egnet som indikatorer for tilstand og utvikling i naturtypene fjell, skog, våtmark og vannkant, og kulturlandskapet, samt for effekter av klimaendring. Dette arbeidet er basert på en gjennomgang av relevant informasjon om hekkefugl i Norge.Direktoratet for Naturforvaltnin
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