How do migrating birds fly so far, so fast?

Blackpoll Warblers fly 1000s of miles over open ocean!

Our last newsletter explored how pigeons – and likely many other birds, use “infrasonic” sound and barometric pressure fluctuations as navigation cues. Barometric pressure changes are a key indicator of oncoming weather – well before any clouds show up in the sky.

For birds, rapid pressure fluctuations would indicate an unstable weather front, presaging variable oncoming winds which would buffet and torment their flight. But a constant decrease in barometric pressure would indicate a stable, oncoming weather front that would provide them with healthy tailwinds – assisting their monumental flights across long stretches of land and sea.

It is through their meteorological skills that blackpoll warblers can use 200mph (320kph) tailwinds to hurl their tiny little bodies 3.500 km (2,175 miles) over open ocean, and even smaller hummingbirds flying over 500 miles in a single day!

And these migration paths are seasonally timed to intersect with feeding, breeding, and nesting conditions that coincide with seasonal cycles of foliage, food sources, and breeding opportunities. Unlike humans, many birds don’t vacation with their seasonal spouses. This is good for the gene pool for critters that need to throw their lives to the mercy of the winds twice a year.

I bring this up because I find global migration fascinating, marvelous, and humbling: We inhabit a living planet that has collectively, and adaptively figured out these sorts of things.

I also bring this up because our human enterprises are on the verge of disrupting these fascinating and marvelous migrations.

I recently submitted a paper examining the potential biological impacts of offshore wind farms on avian and cetacean navigation cues. This is in response out pivot off of fossil fuel with the forced rush in developing a rash of wind farms along what ornithologists call “The Atlantic Flyway.”

It so happens that wind turbines generate a lot of ‘infrasonic” energy – to the extent that that it can be measured seismically. This energy will likely interfere with the bio-geological cues that migrating animals – in this case birds and whales, need to figure out where they are, and where they need to be.

The gist of my argument – like many of my assertions on other offshore industrial antics, is that we are disrupting marine habitats and transforming the relationships that pretty much all ocean critters have depended upon since the last serious biological disruption – some 65 million years ago.