I'm pretty sure I saw one at the I Beams once. 80 feet deep!
Do you think they do the Scyzoryk/Pocket knife?
This is actually a good question YellowEye ! Thank you !
I think in most cases birds dive transitioning from the flight in the air to dive / flight underwater. From what I have seen, this bird was actually using his wings for propulsion more than feet underwater.
You can also see it from the picture after zooming in to certain extent.
In this case velocity probably helps the bird to go effortlessly through some depth of positive buoyancy therefore I would call it a technique similar though alternative to Scyzoryk / pocket knife.
Wikipedia also refers to a "half-jump ?!" Another alternative ? See below.
If the critter wasn't born with relatively heavy lower part of the body, legs or tail it will find an alternative way to save energy and dive more effortlessly.Thank you Everyone for your feedback !
For now the consensus is that the bird was a Cormorant and that they do dive deep. I had no idea that they could free dive that deep ! I guess "You live and learn everyday".
Here is also a quote from Wikipedia. I will contact them and request update that at least some Cormorants are using more wings for propulsion underwater than feet from what I have seen and also some scientists agree with my observation in the following video referring to Cormorant pumping his wings underwater which results in his head bobbing up and down in the video.http://www.wcs.org/news-and-features-ma ... -dive.aspx
"... They dive from the surface, though many species make a characteristic half-jump as they dive, presumably to give themselves a more streamlined entry into the water. Under water they propel themselves with their feet. Some cormorant species have been found, using depth gauges, to dive to depths of as much as 45 metres. [147 feet !] ..."