Proposal for Barbara

The Migrants

Birds have been always been a great reference when discussing migration due to their complex travels and behaviours. Although it has been widely studied, many questions still exists on how birds accomplish such journeys. This work explores the migration process of 3 species of birds in relation to their use of sound to create infrasonic maps of the territory.

Different studies have shown that birds are able to generate mental maps of the ecosystems they get to know. These maps are generated by the sum of different sensorial cues, magnetic stimulus, skylight polarization at sunset, the stars as guides and the least studied: infrasounds generated by the Earth itself 1 Birds create infrasonic maps of the planet, translating frequencies from the earth into coordinates to locate themselves through their journeys, those frequencies - below 20 Hz - are capable of traveling for thousands of kilometers thanks to the amplitude of their wave2. This infrasounds are generated by superficial waves coming, constant movements between layers of earth, ocean waves, winds and the relationship between all of this, the mountains and the landscape.

Migrants and the ecosystems depend on each other, they are defined by their interactions and rely on a delicate balance between the local and the temporal populations. Migration is not only beneficial for the individuals who travel, it also brings new dynamics to the ecosystems that embrace them. For example, in the case of birds, migration is responsible for long distance dispersal of seeds, creating connections between forests that have been separated for years.

1. Ă…kesson, S., & HedenstrĂśm, A. (2007). How Migrants Get There: Migratory Performance and Orientation.

BioScience,57(2), 123-133. doi:10.1641/b570207 2.Hagstrum, J. T. (2013). Atmospheric propagation modeling indicates homing pigeons use loft-specific infrasonic map cues. Journal of Experimental Biology,216(4), 687-699. doi:10.1242/jeb.072934

The distance between the bird and the steepness of the mountain defines the infrasound map of the territory.

In the installation the steepness of the mountain is mapped and represented as an audible sound. The frequencies ranged between 20.000 and 15.000Hz which are the limit of human perception.

In april 2014 a storm hit the west coast of the United States, causing numerous human and material loses. However, a flock of Golden-winged Warblers (Vermivora chrysoptera) were able to escape the storm unharmed two days before we were able to sense it. Scientists claim that thanks to infrasounds, they were able to hear the storm´s rumbles and change the path they usually followed. The warblers were forced to alter their traditional route through the Caribbean to a new path from the United States through Mexico, - passing through all Central America- all the way down to Colombia in order to survive and overcome the difficulties this journey implied.

Streby, H., Kramer, G., Peterson, S., Lehman, J., Buehler, D., & Andersen, D. (2015). Tornadic Storm Avoidance Behavior in Breeding Songbirds. Current Biology,25(1), 98-102. doi:10.1016/j.cub.2014.10.079

Another impressive example is shown by the Montagu's harriers (Circus pygargus). These raptors nest in Europe but migrate during winter to the sub-Sahara using three different routes, one goes through Gibraltar and Spain, another route goes through Central Africa through Sicily and the third one goes through Eastern Africa, Argelia and Grece. Migrants usually have stable communities in their European nesting sites but the route they choose and the places where they choose to winter are not so stable, they interact with individuals coming from different breeding sites before going back home.

Trierweiler, C., Klaassen, R. H., Drent, R. H., Exo, K., Komdeur, J., Bairlein, F., & Koks, B. J. (2014). Migratory connectivity and population-specific migration routes in a long-distance migratory bird. Proceedings of the Royal Society B: Biological Sciences,281(1778), 20132897-20132897. doi:10.1098/rspb.2013.2897

The third remarkable example are the Green and Greenish Warblers (Phylloscopus trochiloides), where two different subspecies have created specific mental migratory maps through different routes to cross the Himalayas to the Tibet, each subspecies through the east or west to avoid the colder and higher areas. When the different subspecies intercross, hybrids fly through the center of the mountains and die.

Irwin, D.E., Irwin J.H. (2005). Siberian migratory divides: the role of seasonal migration in speciation. Birds of Two Worlds: The Ecology and Evolution of Migration. John Hopkins University Press. Pages 27-40

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The soil - geological stratum - shares information with the birds - we could imply, through these exchanges of information, the existence of a language. The birds speak the language of the earth, and it is through these exchanges that they constitute one of their maps of reality. The earth sketches a path through the infrasound and the bird, following its route, returns the seeds to germinate the soil.

There is no inert matter in the soil. When we say that the earth speaks with the birds, what exactly does it speak? the seemingly inert compounds of the earth have agency, the power to act on these migrants - they were guiding the birds - are they really inert compounds? If the earth moves, product of exchanges of energy between the tectonic layers of geology, it should be added that the earth is moved, is affected by the other actors that weave relations with it.

Migration is a relational space, a zone of exchange and encounters. In order for the golden warblers to escape the storm and manage to migrate, several layers of communication existed, the birds spoke with the wind and understood the information that the weather showed them because it rumbled on the ground. Then they had to communicate with each other, exchange information with their peers. And the flow of exchanges does not stop at that point, to find their way they needed to understand the gradients of the trees and mountains, which also expected from the birds the seeds that will reforest their lands, and achieve maintain energy balances among the inhabitants of the ecosystems they reach.

However, in the anthropic era, where man is a stratum of geology, we should also say that these maps of connections intertwine, and make up a network that is capable of redefining and transforming what it is made of. How is it transformed? What implications do these transformations have? Broadly speaking, human transformations have involved large changes in the topographies of the planet, and with them the network is adjusted again. To what extent? We know, thanks to numerous studies that

raspberry pi

The camera is moved by a motor that powers a cam system, which allows movements with 3 degrees of freedom (movements in the 3 axis)

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micro camera

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The camera also translates the steepness of the mountains into low frequencies allowing us to perceive an infrasound map, from the birds’ perspective.

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Sound produced by the installation goes between 20.000 HZ to 15.000 HZ

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4 axis- movement

50 cm - 19 inch

micro camera

Plexiglass box

50 cm - 19 inch

subwoofer

Subwoofer box

Movement Mechanism for the Z axis of the piece

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