Wednesday, April 12, 2017

Spear fishing by white egrets

This morning, I watched a group of white egrets fishing for breakfast.  There seemed to be two modes of fishing using their beak: 1) capturing the fish in their mouth and 2) thrusting their beak to spear the fish.   One episode recorded below shows the egret speared the fish at their gill - is this an accident or a skill?  Later I'll annotate the photos below  - for now you can look and make your own interpretation.

Wing assisted propelling the beak into the water

Another variant of wing assisted spearing

Wing assisted plunging the beak into the water.

Caught something with her beak

And flies away for post processing

Flying away with a mouth full of "stuff"

Holding a small fish in her mouth

Prepare to swallow

Catching a fish:  Thrusting her beak forward with neck power

Thrusting the beak using neck power

The result of the thrust

Plant material and a speared fish (in contrast to catching between the upper and lower parts of the beak - as shown above)

Step 2

Step 3:  speared fish

Step 4: spearing through the fish gill

Step 5:  Reposition fish

Step 6: Reposition again

Step 7:  Reposition again

Step 8: Move fish to the end of beak

Step 9: Quickly release and reacquire

Step 10: stabilize holding the fish with minimal plant debris

Step 11: Move fish closer to the swallowing position

Step 12: release extraneous plant material

Step 13: Reposition fish to the swallowing position

Step 14: rotate fish

Step 15: swallow fish only (avoid plant debris)

Step 16: reposition plant material 

Step 17: consolidate plant material

Step 18: Discharge plant material

Step 19: Savor the flavor

Juvenile Little Blue Heron

Tricolor Heron

Little Blue Heron

Black Crowned Night Heron

Hungry Great blue heron chick

NIctitating Membrane covering the eye

NIctitating Membrane withdrawn

Green heron

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