Raphaël Nussbaumer

Raphaël Nussbaumer
Cornell University | CU · Laboratory of Ornithology

PhD
Postdoctoral Fellow at the Cornell Lab of Ornithology

About

49
Publications
9,560
Reads
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75
Citations
Introduction
Birds' ability to navigate and know their timing fascinates me. I'm currently working on modelling and quantifying nocturnal bird migration using weather radar data. I use geostatistical methods to study spatio-temporal patterns of bird migration. Drawing on my hydrology background, I explore ways to model mass bird migration as a fluid flow.
Additional affiliations
October 2020 - March 2021
Swiss Ornithological Institute
Position
  • PostDoc Position
January 2020 - present
A Rocha Kenya
Position
  • Research Associate
January 2019 - January 2020
Swiss Ornithological Institute
Position
  • PostDoc Position
Education
December 2014 - December 2018
University of Lausanne
Field of study
  • Earth Science
September 2013 - September 2014
Imperial College London
Field of study
  • Hydrology and Water Resource Management
September 2010 - June 2013
École Polytechnique Fédérale de Lausanne
Field of study
  • Science et Ingénierie de l'Environnement

Publications

Publications (49)
Article
Full-text available
Wind has a significant yet complex effect on bird migration speed. With prevailing south wind, overall migration is generally faster in spring than in autumn. However, studies on the difference in airspeed between seasons have shown contrasting results so far, in part due to their limited geographical or temporal coverage. Using the first full-year...
Presentation
Full-text available
Video: https://youtu.be/U7jAK9nZNQU Abstract: The recent development of miniaturized multi-sensor geolocators (<1.3g) offers new opportunities to better understand the movements of small birds. On the spatial scale, light and activity data are most commonly used to determine birds’ location and the inclusion of wind data has shown promise in reduc...
Presentation
Full-text available
Video: https://youtu.be/Pmeg0_DCv6o Abstract: Quantifying and characterising seasonal bird migration is critical to understand the influence of mass migration on habitats, ecosystems and human societies, especially in light of rapid population declines of common nocturnal migrants. Bird migration is notoriously difficult to measure, occurring conti...
Article
The phenology and routes of long-distance migrations of European Nightjars are well described for Western European individuals migrating within the East Atlantic and Mediterranean flyways, while little is known about populations from other parts of the Eurasian breeding range. We describe the route choice and timing of European Nightjars breeding i...
Preprint
Full-text available
Background In addition to light, the use of pressure and activity data recorded by multi-sensor geolocators has recently been shown to improve the estimation of a bird’s position. At the same time, modelling a bird’s trajectory with an MCMC sampler becomes more challenging when integrating this new information. Method In this work, we propose to mo...
Article
Full-text available
Do Ospreys prey on coral reef fish? In short, yes. We report for the first time in scientific literature with photographic proof that Ospreys eat coral reef fish and suggest, based on regular sightings of Osprey hunting over the Watamu Marine National Park lagoon and reef, that coral reef fish form a regular part of their diet while in Kenya.
Preprint
Full-text available
Background Knowing about the temporal and spatial use of habitats by wildlife is crucial to understand ecological relationships in nature. Tracking small birds and bats requires tags of less than 2g, such that light-weight geolocators are currently the most affordable and widespread option. Recent multi-sensor geolocators now capture accelerometer...
Preprint
Full-text available
Background Understanding the temporal and spatial use of habitats by wildlife is crucial to apprehend ecological relationships in nature. Tracking small birds and bats requires tags of less than 2g, therefore lightweight geolocators are currently the most affordable and widespread option. Recent multi-sensor geolocators now capture accelerometer an...
Article
Weather radar networks have great potential for continuous and long-term monitoring of aerial biodiversity of birds, bats, and insects. Biological data from weather radars can support ecological research, inform conservation policy development and implementation, and increase the public’s interest in natural phenomena such as migration. Weather rad...
Article
Full-text available
Thanks to their light weight and low cost relative to GPS trackers, light-level geolocators are uniquely positioned to uncover bird migration patterns across less well-financed and understudied regions of the world. A main drawback of geolocators is the need to recapture equipped birds to retrieve the data. Maximizing the recapture rate is therefor...
Article
Ocean currents have wide-ranging impacts on seabird movement and survival. By extension, the extreme oscillations they are subject to, such as extreme Indian Ocean Dipole (IOD) events, can also be expected to dramatically influence seabird populations. This study links the extreme IOD event that occurred in 2019-2020 to the unusually high number of...
Presentation
Full-text available
Link to video: https://www.youtube.com/watch?v=0JsYU_xfKN8 Abstract: The recent development of miniaturized multi-sensor geolocators (1.3g) offers new potential to refine our understanding of birds’ movement at a very fine temporal scale. On the spatial scale, light measurement is the most common variable used to determine birds’ location. Yet at...
Article
Full-text available
Several populations of Pied Avocet are understood to overlap in East Africa, yet the specific movements and size of each of them remains largely unclear. A review of current literature, combined with waterbird counts and recent citizen science data, suggests that potentially three populations occur in the region (Palaearctic, southern origin, and r...
Article
Full-text available
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 quantifi...
Article
Full-text available
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 mix...
Preprint
Full-text available
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...
Preprint
Full-text available
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 movem...
Article
Full-text available
Bayesian sequential simulation (BSS) is a geostastistical technique, which uses a secondary variable to guide the stochastic simulation of a primary variable. As such, BSS has proven significant promise for the integration of disparate hydrogeophysical data sets characterized by vastly differing spatial coverage and resolution of the primary and se...
Research Proposal
Full-text available
Within the current context of climate change particularly affecting Africa, it has become all the more urgent to study intra-African migratory birds, whose even general migration routes and timing are in most cases as yet largely unknown. In one of the first studies leveraging geolocators to uncover intra-African bird migration, we propose to inves...
Article
Full-text available
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...
Preprint
Full-text available
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 in...
Article
Full-text available
Deterministic geophysical inversion approaches yield tomographic images with strong imprints of the regularization terms required to solve otherwise ill-posed inverse problems. While such tomograms enable an adequate assessment of the larger-scale features of the probed subsurface, the finer-scale details tend to be unresolved. Yet, representing th...
Presentation
Full-text available
Video of the full presentation (1h26): youtu.be/sQD3sspBewM. Video of the introduction (2min20): youtu.be/u7dYTx2e8Ug
Thesis
Full-text available
Around the world, groundwater is vital for humankind, yet threatened by anthropogenicdeterioration. Sustainable groundwater management is thus crucial and relies on numericalmodels for adequately forecasting groundwater conditions. A key step in the construction ofsuchmodels is to determine hydrogeological parameters that describe the behaviour of...
Presentation
Full-text available
See the final paper: https://www.researchgate.net/publication/333825476_Simulation_of_fine-scale_electrical_conductivity_fields_using_resolution-limited_tomograms_and_area-to-point_kriging
Article
Full-text available
Sequential Gaussian Simulation (SGS) is a stochastic simulation technique commonly employed for generating realizations of Gaussian random fields. Arguably, the main limitation of this technique is the high computational cost associated with determining the kriging weights. This problem is compounded by the fact that often many realizations are req...
Article
Full-text available
Sequential Gaussian Simulation is a commonly used geostatistical method for populating a grid with a Gaussian random field. The theoretical foundation of this method implies that all previously simulated nodes, referred to as neighbors, should be included in the kriging system of each newly simulated node. This would, however, require solving a lar...
Presentation
Full-text available
Improving Bayesian Sequential Simulation with an Adaptative Log-linear Pooling
Presentation
Full-text available
Constant path in SGS: Consequences and benefits
Presentation
Full-text available
Sequential Simulation Path Biases and how to live with them?
Conference Paper
Full-text available
Bayesian sequential simulation (BSS) is a powerful geostatistical technique, which notably has shown significant potential for the assimilation of datasets that are diverse with regard to the spatial resolution and their relationship. However, these types of applications of BSS require a large number of realizations to adequately explore the soluti...
Poster
Full-text available
Bayesian sequential simulation (BSS) is a powerful geostatistical technique, which notably has shown significant potential for the assimilation of datasets that are diverse with regard to the spatial resolution and their relationship. However, these types of applications of BSS require a large number of realizations to adequately explore the soluti...
Poster
Full-text available
The geostatistical integration of geophysical and hydrological data has significant potential for adequately characterizing heterogeneous aquifers. Although progress has been made in this regard, the proposed methods were so far mostly limited to the local scale. Recently, Ruggeri et al. (2013) proposed a two-step Bayesian sequential simulation (BS...
Thesis
Full-text available
The Prairie Pothole Region (PPR) is a critical region in Canada because of its crucial role in agricultural production. The area is highly vulnerable to costly floods and droughts, and climate change impacts are likely to be highly damaging. The prairies are relatively flat, seasonally frozen, and semi-arid. The landscape is covered with ponds of v...

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Projects

Projects (7)
Project
Determine the position of a geolocator from atmospheric pressure measurements. see R package: https://raphaelnussbaumer.com/GeoPressureR
Project
Monitor the populations of waterbirds on the Kenyan coast with a particular focus on the north coast. Data collection consists mainly of (1) a January annual count covering a range of water bodies and (2) a monthly count at Sabaki River Mouth and Mida Creek. This is in collaboration with National Museums of Kenya, CWAC (http://cwac.birdmap.africa/) and Wetlands International (https://www.wetlands.org/).
Project
Discover destination, timing and drivers of the migration of Mangrove Kingfisher and Red-capped Robin Chat using geolocators.