View of The Rhodope Mountain Range, Smolyan Lakes, Bulgaria
Europe
In this section: Studies | Observations | Gallery
Located between the freezing polar North and the hot Mediterranean in the south, the European continent encompasses a diverse range of biomes: tundra, taiga, montane forest, temperate broadleaf forest, Mediterranean forest, temperate and dry steppe. This variety supports a rich array of wildlife, with thousands of plant and animal species adapted to different environments. Europe’s rivers, like the Danube River, and mountain ranges, like the Alps, contribute to its ecological richness and diversity.
The continent plays a significant role in the bird migration cycle, hosting over 900 bird species across its territory. Each year, millions of birds travel between Europe and Africa along major flyways, moving south to Africa to avoid the harsh European winters and returning back north to breed. Migration requires precise navigation, using the sun, stars, and Earth’s magnetic field, as well as significant energy reserves.
My master’s degree focused on the understanding of the dynamics in social birds and the evolution of cooperation, in long-tailed tits (Aegithalos caudatus). The long-tailed tits breed independently in spring, when they would only use a particular “home” range to collect building materials for their nests and for foraging. Later on towards the summer, in Jun-Jul, they form flocks in preparation to spend the winter. It has been shown that usually genetic relatives would flock together. “Failed” breeders, who have not managed to breed successfully during the mating season, become helpers-at-nests, and help out their first-order kin to gain indirect genetic benefits [1].
I tested whether the flocking formation and the social interactions in the post-breeding period of long-tailed tits, would be based on previous interactions the individuals would have, during the breeding season. Moreover, my second hypothesis was that the spatial distribution of the pairs during the breeding season would have an effect on the locations of the flocks after breeding [2].
The data collected was observational, from Rivelin Valley in The Peak District National Park, UK. I compared the social networks from the two seasons (breeding and post-breeding) and monitored all between-individual interactions (positive and negative), as well as the geospatial home ranges of breeding pairs and positioning of the flocks.
Results showed that previous interactions, during the breeding season of the long-tailed tits had no effect on how the individuals formed their flocks later on. Neither did the spatial home range overlaps affected in any way which individuals would then choose to flock together in the post-breeding season. What was certain, though, was that genetically related individuals had higher number of interactions after the breeding season, when forming their flocks [2].
update home ranges on ArcGIS (KDEs)
add a graph for the interactions before and after breeding (potentially would be cool if I can do them on the same graph, so that the ones during breeding are actually)?
add a graph for the range overlap during the breeding and post-breeding season
Studies
Additional Projects
Bulgaria is situated in the south-east of Europe, on the Balkan peninsula, having a coastline on the Black Sea. It is a cornerstone location for the seasonal migratory species, as along its coastline passes the second major migratory route between Europe and Africa - the Via Pontica. In addition, Bulgaria’s high mountains with jagged outlines, green valleys with Thracian and Byzantine sanctuaries, and coastline full of breath-taking scenery, sandy beaches, coastal lakes, marshes and lagoons, make it a remarkable hotspot for both resident and migratory species. Bulgaria is a home to more than 400 bird species.
A project that I have shifted my focus on recently, is the effect of space weather events on the migration routes of birds during their seasonal shifts between nesting and wintering grounds.
What is space weather?
This is the effect of the interaction between the natural activity of the Sun, the Earth’s magnetic field and atmosphere, and the Earth’s position in the Solar System. Different phenomena originate from this interaction and they can result in space weather storms, such as Solar Particle Events, Solar Flares, or Coronal Mass Ejections. In addition, there is a constant stream of radiation (charged particles), which is emitted from the Sun, that makes up the Solar wind.
Space weather events might have different effects on the Earth, such as Auroras, or they might disrupt radio signals, GPS, or power grids, depending on the intensity of the event. Their frequency depends on the 11-year Solar cycle and can occur continuously, but, usually, are expected to be most common during a Solar Maximum [3].
How do Space Weather events affect bird migration?
Many species on Earth depend on the geomagnetic field to navigate whilst making their way during long-distance seasonal migrations. Space weather events regularly cause disturbances in the Earth’s magnetic field, which can cause temporary disorientation to the animals that use it as a navigational instrument.
For instance, there are studies that have shown that geomagnetic disturbances affect the birds’ migration direction from their natal sites to their grounds for breeding. They also influence the migratory routes the birds use and increase bird vagrancy outside their normal ranges [4].
As most studies which link space weather events to bird migration are based on data collected in the USA, I am interested in looking into data from the European continent, with birds migrating towards Africa.
For this purpose, I am currently opened to funding and gathering a team for data collection. I would need assistance in collecting data on geomagnetic disturbances from observatories, bird identification and count at points along the migratory route in Eastern Europe - The Via Pontica.
Alonnisos, Greece
Etar, Bulgaria
Little owl (Athene noctua), LC, Borislavtsi, Bulgaria
Buzludja Monument, Bulgaria
Karlovo, Bulgaria
Mute swan (Cygnus olor), LC, Varna Lake, Bulgaria
Provadia, Bulgaria
Bibliography:
[1] Hatchwell BJ, Anderson C, Ross DJ, Fowlie MK, and Blackwell PG (2001) Social organisation of cooperatively breeding long-tailed tits: kinship and spatial dynamics. Journal of Animal Ecology. Vol. 70. P. 820-830.
[2] Preslavska C (2019). The effect of breeding interactions on the post-breeding social system of a cooperative bird. [Unpublished Master’s Thesis]. The University of Sheffield.
[3] NOAA, Space Weather Storms from the Sun. Available at: https://www.swpc.noaa.gov/sites/default/files/images/u33/swx_booklet.pdf
[4] Gulson-Castillo ER, Van Doren BM, Bui MX, and Winger BM (2023). Space weather disrupts nocturnal bird migration. PNAS. Vol. 120(42): e2306317120.
[5]
All image captions printed in the following format: Species’ Common Name (where applicable), (Scientific name), IUCN Red List Status, Location, Country