I'm been sorting through old sound recordings I made, with the intent of uploading them to their corresponding eBird records, and it's a pretty fascinating process - especially with some of the soundscapes.

In this particular one I was trying to capture the insistent three note call of Green Shrike-vireo above the din of a troop of howler monkeys at dawn.  It's a common canopy bird here in Panama but one that you see once for every 99 times you hear it. It's 3 note call is often aptly transliterated as 'can't-see-me'!

But listening to it again now, it's the background species that really catch my ear:

After the first few listens I could also pick out;
  • the gentle rise and fall whistle of Rufous Mourner
  • the familiar (to me) Black-faced Ant-thrush
  • a Golden-fronted greenlet somewhere close to the mic
  • and a Fasciated Antshrike
But not until listening very carefully around 20 times could I filter out the howler monkeys and separate the other calls enough to hear;
  • Yellow-throated Toucan (or whatever it's being called post-split)
  • Northern Slaty-Antshrike 
  • Southern Bentbill
  • Bright-rumped Attila
And finally... not until an email exchange with a friend back in Panama, did I manage to pull out a single faint call note of Forest Elaenia.

Even though I'd consider myself someone who doesn't have a particularly good ear (or memory) for calls, it's amazing what the ear and brain can do if you allow them the time and space to learn.

Also revealing, is how the visualisation of sound helps. Run this same sequence through Audacity and the Forest Elaenia becomes more evident, as does the almost inaudible song of the Southern Bentbill.  When watching the spectrogram scroll by, the elaenia's call note seems fairly obvious, but in the barrage of sound it's almost impossible to hear. Kudos to Kent Livezey for hearing this!

It would take a special ear to hear (and count) this live.

In the middle of the sequence, the 4.0KHZ U-shaped rising call of a Forest Elaenia, visible just before the louder golden-fronted greenlet and over the lower pitched song of Green Shrike-vireo.

Now in the depths of an NY winter there isn't much to record of course, but I'm looking forward to setting up a binaural system to pick up some of these more expansive soundscapes, rather than just recording individual calls and songs, in the Spring.

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I work in NYC and own a wildlife and wilderness agency specializing in the southern cone of South America. I still do some guiding down there, especially looking for Fuegian and Patagonian avifauna. I'm particularly interested in the wintering ecology of neotropical migrants, and in avian biogeography in general. You can follow me at - @domhall And find me at - AventuraArgentina.com