Archive for June 2nd, 2011

A marine ornithologist's two best friends. The seclusion of a blind, and an accurate spotting scope.

One of our early season priorities while working on Metinic is re-sighting banded Arctic Terns.  Tern banding is one of our responsibilities late in the breeding season, but banding efforts continue in their overwintering sites and everywhere in between.    US Federal bands come in two varieties, the first being Federal ID bands which have 9 digits xxxx-xxxxx.  These bands act much like a social security code for the bird, as no other individual will have a band with the same number.  This number repeats once around the band and is very difficult to read, even with a spotting scope.

Even with a spotting scope, BBL bands can be extremely difficult to read.

Because of this, species of interest like our state-threatened Arctic Terns and federally endangered Roseate Terns also have a field readable band.  Normally these consist of two letters over two numbers.  These bands are larger and the code repeats twice around the band for easy reading.

Field readable bands make identifying individuals easier, but can still be time consuming if the bird is moving or far away.

So why do I get so excited when an Arctic Tern shifts just enough for me to get the last two digits of his field readable?  All of our banding and re-sighting information gets entered into a database called Sterna Finder.  This database can tell us not only where the bird was born and how old it is, but everywhere it has been seen since being banded.  This information is used for a meta-population study, tracking breeding tern movements across the refuge islands.  Does one colony’s chicks become another islands breeders?  That’s what we’re trying to find out.  Plus it’s pretty cool to find out the bird you were watching was banded in Brazil and is older than you.

Respecting our feathered elders,

Metinic Crew (Charlie Walsh, Jennie Wiacek, and special guests Courtney Viall, and Adrienne Leppold)


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