Mapping the Post-Hurricane Maria Migration

Puerto Ricans, as U.S. citizens, are able to travel freely between Puerto Rico and the U.S. mainland. In the wake of Hurricane Maria, many of them sought refuge in Florida, New York and other parts of the U.S. Using anonymized cell phone location data for some 500,000 smart phones, data analysis firm Teralytics was able to map where Puerto Ricans moved from August 2017 to February 2018. CityLab has the maps and the story: “Between these months, nearly 6 percent of the Puerto Rican population left the island and is still living in the continental U.S. Another 6 percent left between October and September 2017 but returned to the island by February 2018.”

Birds Discover Longitude

Eurasian reed warblers don’t need no stinkin’ marine chronometers. A new study suggests that the migratory birds make use of magnetic declination to determine longitude, “at least under some circumstances under clear skies. Experienced migrants tested during autumn migration in Rybachy, Russia, were exposed to an 8.5° change in declination while all other cues remained unchanged. This corresponds to a virtual magnetic displacement to Scotland if and only if magnetic declination is a part of their map. The adult migrants responded by changing their heading by 151° from WSW to ESE, consistent with compensation for the virtual magnetic displacement.”

Not, it would seem, accurate enough for the species to earn a chunk of the Longitude Prize, and it’s not like John Harrison should have been messing about with birds instead of clocks, but interesting all the same. [GeoLounge]

Migrations in Motion

migrations-in-motion

Migrations in Motion models the average directions wildlife will need to move in order to survive the effects of climate change. As Canadian Geographic explains, “As climate change disrupts habitats, researchers believe wildlife will instinctively migrate to higher elevations and latitudes, but for many species, that will mean navigating around, over or through human settlements and infrastructure.” The map, the design of which is modeled on the hint.fm wind map, covers both North and South America and does not purport to model the path of individual species; rather it’s an average based on computer modelling.