Project

Bird Migration Modelling (BMM)

Goal: Create a geostatistical model of bird density throughout Europe based on data from weather radar. see https://github.com/Rafnuss-PostDoc/BMM

Updates
0 new
11
Recommendations
0 new
4
Followers
0 new
38
Reads
0 new
443

Project log

Raphaël Nussbaumer
added a research item
To understand the influence of biomass flows on ecosystems, we need to characterize and quantify migrations at various spatial and temporal scales. Representing the movements of migrating birds as a fluid, we applied a flow model to bird density and velocity maps retrieved from the European weather radar network, covering almost a year. We quantified how many birds take-off, fly, and land across Western Europe to (1) track bird migration waves between nights, (2) cumulate the number of birds on the ground and (3) quantify the seasonal flow into and out of the study area through several regional transects. Our results identified several migration waves that crossed the study area in 4 days only and included up to 188 million (M) birds that took-off in a single night. In spring, we estimated that 494 M birds entered the study area, 251 M left it, and 243 M birds remained within the study area. In autumn, 314 M birds entered the study area while 858 M left it. In addition to identifying fundamental quantities, our study highlights the potential of combining interdisciplinary data and methods to elucidate the dynamics of avian migration from nightly to yearly time scales and from regional to continental spatial scales.
Raphaël Nussbaumer
added an update
In a recently published paper, we presented a novel method to distinguish birds and insects in single-polarimetric weather radar data.
Read the paper for more information:
Take a look at the video abstract to learn more:
 
Raphaël Nussbaumer
added a research item
Recent and archived data from weather radar networks are extensively used for the quantification of continent-wide bird migration patterns. While the process of discriminating birds from weather signals is well established, insect contamination is still a problem. We present a simple method combining two Doppler radar products within a Gaussian mixture model to estimate the proportions of birds and insects within a single measurement volume, as well as the density and speed of birds and insects. This method can be applied to any existing archives of vertical bird profiles, such as the European Network for the Radar surveillance of Animal Movement repository, with no need to recalculate the huge amount of original polar volume data, which often are not available.
Raphaël Nussbaumer
added a research item
Recent and archived data from weather radar networks are extensively used for quantification of continent-wide bird migration pattern. While discriminating birds from weather signals is well established, insect contamination is still a problem. We present a simple method combining two doppler radar products within a single Gaussian-mixture model to estimate the proportions of birds and insects within a single measurement, as well as the density and speed of birds and insects. The method can be applied to any existing archives of vertical bird profiles, such as the ENRAM repository (enram.eu) with no need to recalculate the huge amount of original polar volume data, which often are not available.
Raphaël Nussbaumer
added an update
Présentation "Détection du flux migratoire nocturne par les radars météorologique européens" lors colloque Migration 2020 (https://colloquemigration2020.weebly.com/) organisé par la LPO France:
Abstract
La migration des oiseaux est par essence un phénomène difficile à quantifier, lié au fait qu’elle a lieu principalement de nuit, s’étend à l'échelle continentale, et varie d’une nuit à l’autre. Au cours des dernières décennies, des progrès technologiques ont permis de décrire et d'expliquer les processus sous-jacents à la migration. Il reste cependant essentiel de pouvoir quantifier ce phénomène à sa juste grandeur – notamment dans un contexte de diminution des populations d'oiseaux au niveau global. Offrant des données standardisées à l'échelle continentale et à une résolution temporelle fine, les radars météorologiques constituent aujourd'hui une source de donnée prometteuse pour le suivi de la migration à l'échelle continentale. Nous présenterons les résultats des premières études couvrant le couloir de migration d'Europe de l'ouest, démontrant le potentiel de cette méthode et les challenges qui nous restent à affronter.
 
Raphaël Nussbaumer
added a research item
The movements of migratory birds constitute huge biomass flows that influence ecosystems and human economy, agriculture and health through the transport of energy, nutrients, seeds, and parasites. To better understand the influence on ecosystems and the corresponding services and disservices, we need to characterize and quantify the migratory movements at various spatial and temporal scales. Representing the flow of birds in the air as a fluid, we applied a flow model to interpolated maps of bird density and velocity retrieved from the European weather radar network, covering almost a full year. Using this model, we quantified how many birds take-off, fly, and land across Western Europe, (1) to track waves of bird migration between nights, (2) cumulate the number of bird on the ground and (3) quantify the seasonal flow into and out of the study area through several regional transects. Our results show that up to 188 million (M) birds take-off over a single night. Exemplarily, we tracked a migration wave in spring, in which birds crossed the study area in 4 days with nocturnal flights of approximately 300 km. Over the course of a season, we estimated that 494 million (M) birds entered through the southern transects and, at the same time, 251 M left in the northern transects, creating a surplus of 243 M birds within the study area. Similarly, in autumn, 544 M more birds departed than arrived: 314 M birds entered through the northern transects while 858 M left through the southern transects. Our study show-cases the potential of combining interdisciplinary data and methods to elucidate the dynamics of avian migration from nightly to seasonal and yearly time-scales and from regional to continental spatial scales.
Raphaël Nussbaumer
added an update
The raw vertical profile of bird density measured by weather radar can be quite tricky to visualize. Although bioRad ( https://github.com/adokter/bioRad ) does an exellent job if you're familiar with R.
To help us quickly view and explore vertical profile, we developed this webapp based on plotly:
 
Raphaël Nussbaumer
added an update
 
Raphaël Nussbaumer
added a research item
Quantifying nocturnal bird migration at high resolution is essential for (1) understanding the phenology of migration and its drivers, (2) identifying critical spatio-temporal protection zones for migratory birds, and (3) assessing the risk of collision with artificial structures. We propose a tailored geostatistical model to interpolate migration intensity monitored by a network of weather radars. The model is applied to data collected in autumn 2016 from 69 European weather radars. To validate the model, we performed a cross-validation and also compared our interpolation results with independent measurements of two bird radars. Our model estimated bird densities at high resolution (0.2 • latitude-longitude, 15 min) and assessed the associated uncertainty. Within the area covered by the radar network, we estimated that around 120 million birds were simultaneously in flight (10-90 quantiles: 107-134). Local estimations can be easily visualized and retrieved from a dedicated interactive website. This proof-of-concept study demonstrates that a network of weather radar is able to quantify bird migration at high resolution and accuracy. The model presented has the ability to monitor population of migratory birds at scales ranging from regional to continental in space and daily to yearly in time. Near-real-time estimation should soon be possible with an update of the infrastructure and processing software.
Raphaël Nussbaumer
added a research item
Quantifying nocturnal bird migration at high resolution is essential for (1) understanding the phenology of migration and its drivers, (2) identifying critical spatio-temporal protection zones for migratory birds, and (3) assessing the risk of collision with man-made structures. We propose a tailored geostatistical model to interpolate migration intensity monitored by a network of weather radars. The model is applied to data collected in autumn 2016 from 69 European weather radars. To cross-validate the model, we compared our results with independent measurements of two bird radars. Our model estimated bird densities at high resolution (0.2°latitude-longitude, 15min) and assessed the associated uncertainty. Within the area covered by the radar network, we estimated that around 120 million birds were simultaneously in flight [10-90 quantiles: 107-134]. Local estimations can be easily visualized and retrieved from a dedicated interactive website: birdmigrationmap.vogelwarte.ch . This proof-of-concept study demonstrates that a network of weather radar is able to quantify bird migration at high resolution and accuracy. The model presented has the ability to monitor population of migratory birds at scales ranging from regional to continental in space and daily to yearly in time. Near-real-time estimation should soon be possible with an update of the infrastructure and processing software.
Raphaël Nussbaumer
added an update
It is now possible to query the estimated number of bird for three variables:
  • Bird density [bird/km2]: Drawing a marker on the map, it will show you the timeserie at this location with the uncertainty.
  • Number of bird [bird]: Draw a polygon on the map, it will show you the timeserie of the total number of bird flying over this area.
  • Flux of bird (MTR) [bird/km/hr]: Draw a line (two points) on the map, it will show the timeserie of the average flux of bird perpendicular to this transect.
 
Raphaël Nussbaumer
added an update
Preliminary result of estimation and simulation map available on a map based web app: https://zoziologie.raphaelnussbaumer.com/bmm-map/
 
Raphaël Nussbaumer
added a project goal
Create a geostatistical model of bird density throughout Europe based on data from weather radar. see https://github.com/Rafnuss-PostDoc/BMM