2 May – The great exchange

I’m searching the skies for the first few swifts,
even as the geese conclude their northward drifts.
Strange to think if I lived in Norway or Sweden
such different birds would herald my Spring season.
Stranger still to think about the whole great exchange
and how so many avian species know how to arrange
their jaw-dropping migrations around our vast planet –
to imagine myself inside the minds of cuckoos or gannets.
Migration is a marvel we are only starting to unravel
as we investigate the routes each different bird travels.
People used to believe swallows hibernated in dirt
before it was discovered just how far they traversed.
And still no one has charted where house martins go –
for now that is a mystery we must keep waiting to know.
We think that many birds can read magnetic forces
and orientate directions from the sun and stars’ courses.
We know some find their way without first being shown,
the route somehow understood before being known.
Millions race back home, hundreds of kilometres a day,
only pausing intermittently for short breaks on the way.
The distances they fly are astounding for their size –
a bi-annual Olympics played out before distracted eyes.
For all that we achieve with our advanced technology,
this great exchange holds an even greater awe for me.
I will never tire of learning about these brave explorers’ routes
and their in-built natural navigator system attributes.

1 May - The great exchange