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Olive-backed Euphonias

 

Soon after building Cecropia Camp, my thatch hut at Heliconia Haven, I found a nearly perfect oropendula nest (images at sides) that had fallen from a huge ceiba tree. I hung it under my roof.  Within two months, I noticed a pair of small birds building a nest within the original opening for the oropendula.  Silhouetted above are my friends, the pair of olive-backed euphonias that have now been nesting here for over four years. I have been fortunate enough to have seen 4-5 of the fledgling flights, as newly emerged chicks reluctantly left their nest.

The most fascinating aspect of these birds is their elaborate charades to deter predators.  Both parents participate in nest building and in feeding the young and they always seem to fly together.  As they approach the nest with building material or food, they stop 4 or 5 feet away
on a bush or house-pole.  For many seconds, they look fore and aft, searching everywhere for any potential predators.  Then, one at a time (usually the male first or solely), they begin making short feigning flights of 2-3 feet, always returning to the same spot.  Finally, when they feel safe, they both simultaneously fly up to the nest entrance but, only one goes in (usually the female first) while the other returns quickly to the original pole or bush.

The "pole sitter" continues feigning flights and searching for predators.  Then, when the
"nest bird" is ready to switch, signals are exchanged, and once again, they make a
simultaneous exchange
, swapping places so quickly, that
a predator would see little more
than a blur
.  How did they learn this behavior?   Amazing!

(see "My Recommended Books", A Neotropical Companion, John Kricher -
  an excellent resource for understanding symbiotic relationships in the tropics)
   

 

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