OIL-SPILL/You've probably seen the disturbing images of pelicans so badly mired in leaking oil in the Gulf of Mexico that they can barely be distinguished as birds at all -- they look like part of the muck.

But nearly three months after the blowout at BP's Deepwater Horizon rig, there are other pelicans touched by the oil where the impact is far less apparent, though still real.

Take a look at some video I took during a boat trip on July 15 along West Pass, a long channel stretching out into the ocean from Louisiana's southern-most tip:

 

The video was taken aboard a small, bobbing boat with a light wind distorting sound, but it clearly shows a section of a rocky jetty stretching into the Gulf. There were hundreds of pelicans and gulls perched on the jetty; the video only shows a short section.

What's important to look for are the dark patches on the heads, beaks and wings of some of the pelicans; that is untreated black oil, according to Joao Talocchi of the environmental group Greenpeace. There was no black oil in the water nearby, or the reddish sludge of treated oil seen in the photo of the drenched pelican above, only a few isolated pea-sized beads of emulsified oil that appeared to have been treated with dispersant chemicals.